File: | src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/CodeGen/SelectionDAGNodes.h |
Warning: | line 1114, column 10 Called C++ object pointer is null |
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1 | //===- DAGCombiner.cpp - Implement a DAG node combiner --------------------===// | |||
2 | // | |||
3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. | |||
4 | // See https://llvm.org/LICENSE.txt for license information. | |||
5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception | |||
6 | // | |||
7 | //===----------------------------------------------------------------------===// | |||
8 | // | |||
9 | // This pass combines dag nodes to form fewer, simpler DAG nodes. It can be run | |||
10 | // both before and after the DAG is legalized. | |||
11 | // | |||
12 | // This pass is not a substitute for the LLVM IR instcombine pass. This pass is | |||
13 | // primarily intended to handle simplification opportunities that are implicit | |||
14 | // in the LLVM IR and exposed by the various codegen lowering phases. | |||
15 | // | |||
16 | //===----------------------------------------------------------------------===// | |||
17 | ||||
18 | #include "llvm/ADT/APFloat.h" | |||
19 | #include "llvm/ADT/APInt.h" | |||
20 | #include "llvm/ADT/ArrayRef.h" | |||
21 | #include "llvm/ADT/DenseMap.h" | |||
22 | #include "llvm/ADT/IntervalMap.h" | |||
23 | #include "llvm/ADT/None.h" | |||
24 | #include "llvm/ADT/Optional.h" | |||
25 | #include "llvm/ADT/STLExtras.h" | |||
26 | #include "llvm/ADT/SetVector.h" | |||
27 | #include "llvm/ADT/SmallBitVector.h" | |||
28 | #include "llvm/ADT/SmallPtrSet.h" | |||
29 | #include "llvm/ADT/SmallSet.h" | |||
30 | #include "llvm/ADT/SmallVector.h" | |||
31 | #include "llvm/ADT/Statistic.h" | |||
32 | #include "llvm/Analysis/AliasAnalysis.h" | |||
33 | #include "llvm/Analysis/MemoryLocation.h" | |||
34 | #include "llvm/Analysis/TargetLibraryInfo.h" | |||
35 | #include "llvm/Analysis/VectorUtils.h" | |||
36 | #include "llvm/CodeGen/DAGCombine.h" | |||
37 | #include "llvm/CodeGen/ISDOpcodes.h" | |||
38 | #include "llvm/CodeGen/MachineFrameInfo.h" | |||
39 | #include "llvm/CodeGen/MachineFunction.h" | |||
40 | #include "llvm/CodeGen/MachineMemOperand.h" | |||
41 | #include "llvm/CodeGen/RuntimeLibcalls.h" | |||
42 | #include "llvm/CodeGen/SelectionDAG.h" | |||
43 | #include "llvm/CodeGen/SelectionDAGAddressAnalysis.h" | |||
44 | #include "llvm/CodeGen/SelectionDAGNodes.h" | |||
45 | #include "llvm/CodeGen/SelectionDAGTargetInfo.h" | |||
46 | #include "llvm/CodeGen/TargetLowering.h" | |||
47 | #include "llvm/CodeGen/TargetRegisterInfo.h" | |||
48 | #include "llvm/CodeGen/TargetSubtargetInfo.h" | |||
49 | #include "llvm/CodeGen/ValueTypes.h" | |||
50 | #include "llvm/IR/Attributes.h" | |||
51 | #include "llvm/IR/Constant.h" | |||
52 | #include "llvm/IR/DataLayout.h" | |||
53 | #include "llvm/IR/DerivedTypes.h" | |||
54 | #include "llvm/IR/Function.h" | |||
55 | #include "llvm/IR/LLVMContext.h" | |||
56 | #include "llvm/IR/Metadata.h" | |||
57 | #include "llvm/Support/Casting.h" | |||
58 | #include "llvm/Support/CodeGen.h" | |||
59 | #include "llvm/Support/CommandLine.h" | |||
60 | #include "llvm/Support/Compiler.h" | |||
61 | #include "llvm/Support/Debug.h" | |||
62 | #include "llvm/Support/ErrorHandling.h" | |||
63 | #include "llvm/Support/KnownBits.h" | |||
64 | #include "llvm/Support/MachineValueType.h" | |||
65 | #include "llvm/Support/MathExtras.h" | |||
66 | #include "llvm/Support/raw_ostream.h" | |||
67 | #include "llvm/Target/TargetMachine.h" | |||
68 | #include "llvm/Target/TargetOptions.h" | |||
69 | #include <algorithm> | |||
70 | #include <cassert> | |||
71 | #include <cstdint> | |||
72 | #include <functional> | |||
73 | #include <iterator> | |||
74 | #include <string> | |||
75 | #include <tuple> | |||
76 | #include <utility> | |||
77 | ||||
78 | using namespace llvm; | |||
79 | ||||
80 | #define DEBUG_TYPE"dagcombine" "dagcombine" | |||
81 | ||||
82 | STATISTIC(NodesCombined , "Number of dag nodes combined")static llvm::Statistic NodesCombined = {"dagcombine", "NodesCombined" , "Number of dag nodes combined"}; | |||
83 | STATISTIC(PreIndexedNodes , "Number of pre-indexed nodes created")static llvm::Statistic PreIndexedNodes = {"dagcombine", "PreIndexedNodes" , "Number of pre-indexed nodes created"}; | |||
84 | STATISTIC(PostIndexedNodes, "Number of post-indexed nodes created")static llvm::Statistic PostIndexedNodes = {"dagcombine", "PostIndexedNodes" , "Number of post-indexed nodes created"}; | |||
85 | STATISTIC(OpsNarrowed , "Number of load/op/store narrowed")static llvm::Statistic OpsNarrowed = {"dagcombine", "OpsNarrowed" , "Number of load/op/store narrowed"}; | |||
86 | STATISTIC(LdStFP2Int , "Number of fp load/store pairs transformed to int")static llvm::Statistic LdStFP2Int = {"dagcombine", "LdStFP2Int" , "Number of fp load/store pairs transformed to int"}; | |||
87 | STATISTIC(SlicedLoads, "Number of load sliced")static llvm::Statistic SlicedLoads = {"dagcombine", "SlicedLoads" , "Number of load sliced"}; | |||
88 | STATISTIC(NumFPLogicOpsConv, "Number of logic ops converted to fp ops")static llvm::Statistic NumFPLogicOpsConv = {"dagcombine", "NumFPLogicOpsConv" , "Number of logic ops converted to fp ops"}; | |||
89 | ||||
90 | static cl::opt<bool> | |||
91 | CombinerGlobalAA("combiner-global-alias-analysis", cl::Hidden, | |||
92 | cl::desc("Enable DAG combiner's use of IR alias analysis")); | |||
93 | ||||
94 | static cl::opt<bool> | |||
95 | UseTBAA("combiner-use-tbaa", cl::Hidden, cl::init(true), | |||
96 | cl::desc("Enable DAG combiner's use of TBAA")); | |||
97 | ||||
98 | #ifndef NDEBUG1 | |||
99 | static cl::opt<std::string> | |||
100 | CombinerAAOnlyFunc("combiner-aa-only-func", cl::Hidden, | |||
101 | cl::desc("Only use DAG-combiner alias analysis in this" | |||
102 | " function")); | |||
103 | #endif | |||
104 | ||||
105 | /// Hidden option to stress test load slicing, i.e., when this option | |||
106 | /// is enabled, load slicing bypasses most of its profitability guards. | |||
107 | static cl::opt<bool> | |||
108 | StressLoadSlicing("combiner-stress-load-slicing", cl::Hidden, | |||
109 | cl::desc("Bypass the profitability model of load slicing"), | |||
110 | cl::init(false)); | |||
111 | ||||
112 | static cl::opt<bool> | |||
113 | MaySplitLoadIndex("combiner-split-load-index", cl::Hidden, cl::init(true), | |||
114 | cl::desc("DAG combiner may split indexing from loads")); | |||
115 | ||||
116 | static cl::opt<bool> | |||
117 | EnableStoreMerging("combiner-store-merging", cl::Hidden, cl::init(true), | |||
118 | cl::desc("DAG combiner enable merging multiple stores " | |||
119 | "into a wider store")); | |||
120 | ||||
121 | static cl::opt<unsigned> TokenFactorInlineLimit( | |||
122 | "combiner-tokenfactor-inline-limit", cl::Hidden, cl::init(2048), | |||
123 | cl::desc("Limit the number of operands to inline for Token Factors")); | |||
124 | ||||
125 | static cl::opt<unsigned> StoreMergeDependenceLimit( | |||
126 | "combiner-store-merge-dependence-limit", cl::Hidden, cl::init(10), | |||
127 | cl::desc("Limit the number of times for the same StoreNode and RootNode " | |||
128 | "to bail out in store merging dependence check")); | |||
129 | ||||
130 | static cl::opt<bool> EnableReduceLoadOpStoreWidth( | |||
131 | "combiner-reduce-load-op-store-width", cl::Hidden, cl::init(true), | |||
132 | cl::desc("DAG cominber enable reducing the width of load/op/store " | |||
133 | "sequence")); | |||
134 | ||||
135 | static cl::opt<bool> EnableShrinkLoadReplaceStoreWithStore( | |||
136 | "combiner-shrink-load-replace-store-with-store", cl::Hidden, cl::init(true), | |||
137 | cl::desc("DAG cominber enable load/<replace bytes>/store with " | |||
138 | "a narrower store")); | |||
139 | ||||
140 | namespace { | |||
141 | ||||
142 | class DAGCombiner { | |||
143 | SelectionDAG &DAG; | |||
144 | const TargetLowering &TLI; | |||
145 | const SelectionDAGTargetInfo *STI; | |||
146 | CombineLevel Level; | |||
147 | CodeGenOpt::Level OptLevel; | |||
148 | bool LegalDAG = false; | |||
149 | bool LegalOperations = false; | |||
150 | bool LegalTypes = false; | |||
151 | bool ForCodeSize; | |||
152 | bool DisableGenericCombines; | |||
153 | ||||
154 | /// Worklist of all of the nodes that need to be simplified. | |||
155 | /// | |||
156 | /// This must behave as a stack -- new nodes to process are pushed onto the | |||
157 | /// back and when processing we pop off of the back. | |||
158 | /// | |||
159 | /// The worklist will not contain duplicates but may contain null entries | |||
160 | /// due to nodes being deleted from the underlying DAG. | |||
161 | SmallVector<SDNode *, 64> Worklist; | |||
162 | ||||
163 | /// Mapping from an SDNode to its position on the worklist. | |||
164 | /// | |||
165 | /// This is used to find and remove nodes from the worklist (by nulling | |||
166 | /// them) when they are deleted from the underlying DAG. It relies on | |||
167 | /// stable indices of nodes within the worklist. | |||
168 | DenseMap<SDNode *, unsigned> WorklistMap; | |||
169 | /// This records all nodes attempted to add to the worklist since we | |||
170 | /// considered a new worklist entry. As we keep do not add duplicate nodes | |||
171 | /// in the worklist, this is different from the tail of the worklist. | |||
172 | SmallSetVector<SDNode *, 32> PruningList; | |||
173 | ||||
174 | /// Set of nodes which have been combined (at least once). | |||
175 | /// | |||
176 | /// This is used to allow us to reliably add any operands of a DAG node | |||
177 | /// which have not yet been combined to the worklist. | |||
178 | SmallPtrSet<SDNode *, 32> CombinedNodes; | |||
179 | ||||
180 | /// Map from candidate StoreNode to the pair of RootNode and count. | |||
181 | /// The count is used to track how many times we have seen the StoreNode | |||
182 | /// with the same RootNode bail out in dependence check. If we have seen | |||
183 | /// the bail out for the same pair many times over a limit, we won't | |||
184 | /// consider the StoreNode with the same RootNode as store merging | |||
185 | /// candidate again. | |||
186 | DenseMap<SDNode *, std::pair<SDNode *, unsigned>> StoreRootCountMap; | |||
187 | ||||
188 | // AA - Used for DAG load/store alias analysis. | |||
189 | AliasAnalysis *AA; | |||
190 | ||||
191 | /// When an instruction is simplified, add all users of the instruction to | |||
192 | /// the work lists because they might get more simplified now. | |||
193 | void AddUsersToWorklist(SDNode *N) { | |||
194 | for (SDNode *Node : N->uses()) | |||
195 | AddToWorklist(Node); | |||
196 | } | |||
197 | ||||
198 | /// Convenient shorthand to add a node and all of its user to the worklist. | |||
199 | void AddToWorklistWithUsers(SDNode *N) { | |||
200 | AddUsersToWorklist(N); | |||
201 | AddToWorklist(N); | |||
202 | } | |||
203 | ||||
204 | // Prune potentially dangling nodes. This is called after | |||
205 | // any visit to a node, but should also be called during a visit after any | |||
206 | // failed combine which may have created a DAG node. | |||
207 | void clearAddedDanglingWorklistEntries() { | |||
208 | // Check any nodes added to the worklist to see if they are prunable. | |||
209 | while (!PruningList.empty()) { | |||
210 | auto *N = PruningList.pop_back_val(); | |||
211 | if (N->use_empty()) | |||
212 | recursivelyDeleteUnusedNodes(N); | |||
213 | } | |||
214 | } | |||
215 | ||||
216 | SDNode *getNextWorklistEntry() { | |||
217 | // Before we do any work, remove nodes that are not in use. | |||
218 | clearAddedDanglingWorklistEntries(); | |||
219 | SDNode *N = nullptr; | |||
220 | // The Worklist holds the SDNodes in order, but it may contain null | |||
221 | // entries. | |||
222 | while (!N && !Worklist.empty()) { | |||
223 | N = Worklist.pop_back_val(); | |||
224 | } | |||
225 | ||||
226 | if (N) { | |||
227 | bool GoodWorklistEntry = WorklistMap.erase(N); | |||
228 | (void)GoodWorklistEntry; | |||
229 | assert(GoodWorklistEntry &&((void)0) | |||
230 | "Found a worklist entry without a corresponding map entry!")((void)0); | |||
231 | } | |||
232 | return N; | |||
233 | } | |||
234 | ||||
235 | /// Call the node-specific routine that folds each particular type of node. | |||
236 | SDValue visit(SDNode *N); | |||
237 | ||||
238 | public: | |||
239 | DAGCombiner(SelectionDAG &D, AliasAnalysis *AA, CodeGenOpt::Level OL) | |||
240 | : DAG(D), TLI(D.getTargetLoweringInfo()), | |||
241 | STI(D.getSubtarget().getSelectionDAGInfo()), | |||
242 | Level(BeforeLegalizeTypes), OptLevel(OL), AA(AA) { | |||
243 | ForCodeSize = DAG.shouldOptForSize(); | |||
244 | DisableGenericCombines = STI && STI->disableGenericCombines(OptLevel); | |||
245 | ||||
246 | MaximumLegalStoreInBits = 0; | |||
247 | // We use the minimum store size here, since that's all we can guarantee | |||
248 | // for the scalable vector types. | |||
249 | for (MVT VT : MVT::all_valuetypes()) | |||
250 | if (EVT(VT).isSimple() && VT != MVT::Other && | |||
251 | TLI.isTypeLegal(EVT(VT)) && | |||
252 | VT.getSizeInBits().getKnownMinSize() >= MaximumLegalStoreInBits) | |||
253 | MaximumLegalStoreInBits = VT.getSizeInBits().getKnownMinSize(); | |||
254 | } | |||
255 | ||||
256 | void ConsiderForPruning(SDNode *N) { | |||
257 | // Mark this for potential pruning. | |||
258 | PruningList.insert(N); | |||
259 | } | |||
260 | ||||
261 | /// Add to the worklist making sure its instance is at the back (next to be | |||
262 | /// processed.) | |||
263 | void AddToWorklist(SDNode *N) { | |||
264 | assert(N->getOpcode() != ISD::DELETED_NODE &&((void)0) | |||
265 | "Deleted Node added to Worklist")((void)0); | |||
266 | ||||
267 | // Skip handle nodes as they can't usefully be combined and confuse the | |||
268 | // zero-use deletion strategy. | |||
269 | if (N->getOpcode() == ISD::HANDLENODE) | |||
270 | return; | |||
271 | ||||
272 | ConsiderForPruning(N); | |||
273 | ||||
274 | if (WorklistMap.insert(std::make_pair(N, Worklist.size())).second) | |||
275 | Worklist.push_back(N); | |||
276 | } | |||
277 | ||||
278 | /// Remove all instances of N from the worklist. | |||
279 | void removeFromWorklist(SDNode *N) { | |||
280 | CombinedNodes.erase(N); | |||
281 | PruningList.remove(N); | |||
282 | StoreRootCountMap.erase(N); | |||
283 | ||||
284 | auto It = WorklistMap.find(N); | |||
285 | if (It == WorklistMap.end()) | |||
286 | return; // Not in the worklist. | |||
287 | ||||
288 | // Null out the entry rather than erasing it to avoid a linear operation. | |||
289 | Worklist[It->second] = nullptr; | |||
290 | WorklistMap.erase(It); | |||
291 | } | |||
292 | ||||
293 | void deleteAndRecombine(SDNode *N); | |||
294 | bool recursivelyDeleteUnusedNodes(SDNode *N); | |||
295 | ||||
296 | /// Replaces all uses of the results of one DAG node with new values. | |||
297 | SDValue CombineTo(SDNode *N, const SDValue *To, unsigned NumTo, | |||
298 | bool AddTo = true); | |||
299 | ||||
300 | /// Replaces all uses of the results of one DAG node with new values. | |||
301 | SDValue CombineTo(SDNode *N, SDValue Res, bool AddTo = true) { | |||
302 | return CombineTo(N, &Res, 1, AddTo); | |||
303 | } | |||
304 | ||||
305 | /// Replaces all uses of the results of one DAG node with new values. | |||
306 | SDValue CombineTo(SDNode *N, SDValue Res0, SDValue Res1, | |||
307 | bool AddTo = true) { | |||
308 | SDValue To[] = { Res0, Res1 }; | |||
309 | return CombineTo(N, To, 2, AddTo); | |||
310 | } | |||
311 | ||||
312 | void CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO); | |||
313 | ||||
314 | private: | |||
315 | unsigned MaximumLegalStoreInBits; | |||
316 | ||||
317 | /// Check the specified integer node value to see if it can be simplified or | |||
318 | /// if things it uses can be simplified by bit propagation. | |||
319 | /// If so, return true. | |||
320 | bool SimplifyDemandedBits(SDValue Op) { | |||
321 | unsigned BitWidth = Op.getScalarValueSizeInBits(); | |||
322 | APInt DemandedBits = APInt::getAllOnesValue(BitWidth); | |||
323 | return SimplifyDemandedBits(Op, DemandedBits); | |||
324 | } | |||
325 | ||||
326 | bool SimplifyDemandedBits(SDValue Op, const APInt &DemandedBits) { | |||
327 | TargetLowering::TargetLoweringOpt TLO(DAG, LegalTypes, LegalOperations); | |||
328 | KnownBits Known; | |||
329 | if (!TLI.SimplifyDemandedBits(Op, DemandedBits, Known, TLO, 0, false)) | |||
330 | return false; | |||
331 | ||||
332 | // Revisit the node. | |||
333 | AddToWorklist(Op.getNode()); | |||
334 | ||||
335 | CommitTargetLoweringOpt(TLO); | |||
336 | return true; | |||
337 | } | |||
338 | ||||
339 | /// Check the specified vector node value to see if it can be simplified or | |||
340 | /// if things it uses can be simplified as it only uses some of the | |||
341 | /// elements. If so, return true. | |||
342 | bool SimplifyDemandedVectorElts(SDValue Op) { | |||
343 | // TODO: For now just pretend it cannot be simplified. | |||
344 | if (Op.getValueType().isScalableVector()) | |||
345 | return false; | |||
346 | ||||
347 | unsigned NumElts = Op.getValueType().getVectorNumElements(); | |||
348 | APInt DemandedElts = APInt::getAllOnesValue(NumElts); | |||
349 | return SimplifyDemandedVectorElts(Op, DemandedElts); | |||
350 | } | |||
351 | ||||
352 | bool SimplifyDemandedBits(SDValue Op, const APInt &DemandedBits, | |||
353 | const APInt &DemandedElts, | |||
354 | bool AssumeSingleUse = false); | |||
355 | bool SimplifyDemandedVectorElts(SDValue Op, const APInt &DemandedElts, | |||
356 | bool AssumeSingleUse = false); | |||
357 | ||||
358 | bool CombineToPreIndexedLoadStore(SDNode *N); | |||
359 | bool CombineToPostIndexedLoadStore(SDNode *N); | |||
360 | SDValue SplitIndexingFromLoad(LoadSDNode *LD); | |||
361 | bool SliceUpLoad(SDNode *N); | |||
362 | ||||
363 | // Scalars have size 0 to distinguish from singleton vectors. | |||
364 | SDValue ForwardStoreValueToDirectLoad(LoadSDNode *LD); | |||
365 | bool getTruncatedStoreValue(StoreSDNode *ST, SDValue &Val); | |||
366 | bool extendLoadedValueToExtension(LoadSDNode *LD, SDValue &Val); | |||
367 | ||||
368 | /// Replace an ISD::EXTRACT_VECTOR_ELT of a load with a narrowed | |||
369 | /// load. | |||
370 | /// | |||
371 | /// \param EVE ISD::EXTRACT_VECTOR_ELT to be replaced. | |||
372 | /// \param InVecVT type of the input vector to EVE with bitcasts resolved. | |||
373 | /// \param EltNo index of the vector element to load. | |||
374 | /// \param OriginalLoad load that EVE came from to be replaced. | |||
375 | /// \returns EVE on success SDValue() on failure. | |||
376 | SDValue scalarizeExtractedVectorLoad(SDNode *EVE, EVT InVecVT, | |||
377 | SDValue EltNo, | |||
378 | LoadSDNode *OriginalLoad); | |||
379 | void ReplaceLoadWithPromotedLoad(SDNode *Load, SDNode *ExtLoad); | |||
380 | SDValue PromoteOperand(SDValue Op, EVT PVT, bool &Replace); | |||
381 | SDValue SExtPromoteOperand(SDValue Op, EVT PVT); | |||
382 | SDValue ZExtPromoteOperand(SDValue Op, EVT PVT); | |||
383 | SDValue PromoteIntBinOp(SDValue Op); | |||
384 | SDValue PromoteIntShiftOp(SDValue Op); | |||
385 | SDValue PromoteExtend(SDValue Op); | |||
386 | bool PromoteLoad(SDValue Op); | |||
387 | ||||
388 | /// Call the node-specific routine that knows how to fold each | |||
389 | /// particular type of node. If that doesn't do anything, try the | |||
390 | /// target-specific DAG combines. | |||
391 | SDValue combine(SDNode *N); | |||
392 | ||||
393 | // Visitation implementation - Implement dag node combining for different | |||
394 | // node types. The semantics are as follows: | |||
395 | // Return Value: | |||
396 | // SDValue.getNode() == 0 - No change was made | |||
397 | // SDValue.getNode() == N - N was replaced, is dead and has been handled. | |||
398 | // otherwise - N should be replaced by the returned Operand. | |||
399 | // | |||
400 | SDValue visitTokenFactor(SDNode *N); | |||
401 | SDValue visitMERGE_VALUES(SDNode *N); | |||
402 | SDValue visitADD(SDNode *N); | |||
403 | SDValue visitADDLike(SDNode *N); | |||
404 | SDValue visitADDLikeCommutative(SDValue N0, SDValue N1, SDNode *LocReference); | |||
405 | SDValue visitSUB(SDNode *N); | |||
406 | SDValue visitADDSAT(SDNode *N); | |||
407 | SDValue visitSUBSAT(SDNode *N); | |||
408 | SDValue visitADDC(SDNode *N); | |||
409 | SDValue visitADDO(SDNode *N); | |||
410 | SDValue visitUADDOLike(SDValue N0, SDValue N1, SDNode *N); | |||
411 | SDValue visitSUBC(SDNode *N); | |||
412 | SDValue visitSUBO(SDNode *N); | |||
413 | SDValue visitADDE(SDNode *N); | |||
414 | SDValue visitADDCARRY(SDNode *N); | |||
415 | SDValue visitSADDO_CARRY(SDNode *N); | |||
416 | SDValue visitADDCARRYLike(SDValue N0, SDValue N1, SDValue CarryIn, SDNode *N); | |||
417 | SDValue visitSUBE(SDNode *N); | |||
418 | SDValue visitSUBCARRY(SDNode *N); | |||
419 | SDValue visitSSUBO_CARRY(SDNode *N); | |||
420 | SDValue visitMUL(SDNode *N); | |||
421 | SDValue visitMULFIX(SDNode *N); | |||
422 | SDValue useDivRem(SDNode *N); | |||
423 | SDValue visitSDIV(SDNode *N); | |||
424 | SDValue visitSDIVLike(SDValue N0, SDValue N1, SDNode *N); | |||
425 | SDValue visitUDIV(SDNode *N); | |||
426 | SDValue visitUDIVLike(SDValue N0, SDValue N1, SDNode *N); | |||
427 | SDValue visitREM(SDNode *N); | |||
428 | SDValue visitMULHU(SDNode *N); | |||
429 | SDValue visitMULHS(SDNode *N); | |||
430 | SDValue visitSMUL_LOHI(SDNode *N); | |||
431 | SDValue visitUMUL_LOHI(SDNode *N); | |||
432 | SDValue visitMULO(SDNode *N); | |||
433 | SDValue visitIMINMAX(SDNode *N); | |||
434 | SDValue visitAND(SDNode *N); | |||
435 | SDValue visitANDLike(SDValue N0, SDValue N1, SDNode *N); | |||
436 | SDValue visitOR(SDNode *N); | |||
437 | SDValue visitORLike(SDValue N0, SDValue N1, SDNode *N); | |||
438 | SDValue visitXOR(SDNode *N); | |||
439 | SDValue SimplifyVBinOp(SDNode *N); | |||
440 | SDValue visitSHL(SDNode *N); | |||
441 | SDValue visitSRA(SDNode *N); | |||
442 | SDValue visitSRL(SDNode *N); | |||
443 | SDValue visitFunnelShift(SDNode *N); | |||
444 | SDValue visitRotate(SDNode *N); | |||
445 | SDValue visitABS(SDNode *N); | |||
446 | SDValue visitBSWAP(SDNode *N); | |||
447 | SDValue visitBITREVERSE(SDNode *N); | |||
448 | SDValue visitCTLZ(SDNode *N); | |||
449 | SDValue visitCTLZ_ZERO_UNDEF(SDNode *N); | |||
450 | SDValue visitCTTZ(SDNode *N); | |||
451 | SDValue visitCTTZ_ZERO_UNDEF(SDNode *N); | |||
452 | SDValue visitCTPOP(SDNode *N); | |||
453 | SDValue visitSELECT(SDNode *N); | |||
454 | SDValue visitVSELECT(SDNode *N); | |||
455 | SDValue visitSELECT_CC(SDNode *N); | |||
456 | SDValue visitSETCC(SDNode *N); | |||
457 | SDValue visitSETCCCARRY(SDNode *N); | |||
458 | SDValue visitSIGN_EXTEND(SDNode *N); | |||
459 | SDValue visitZERO_EXTEND(SDNode *N); | |||
460 | SDValue visitANY_EXTEND(SDNode *N); | |||
461 | SDValue visitAssertExt(SDNode *N); | |||
462 | SDValue visitAssertAlign(SDNode *N); | |||
463 | SDValue visitSIGN_EXTEND_INREG(SDNode *N); | |||
464 | SDValue visitEXTEND_VECTOR_INREG(SDNode *N); | |||
465 | SDValue visitTRUNCATE(SDNode *N); | |||
466 | SDValue visitBITCAST(SDNode *N); | |||
467 | SDValue visitFREEZE(SDNode *N); | |||
468 | SDValue visitBUILD_PAIR(SDNode *N); | |||
469 | SDValue visitFADD(SDNode *N); | |||
470 | SDValue visitSTRICT_FADD(SDNode *N); | |||
471 | SDValue visitFSUB(SDNode *N); | |||
472 | SDValue visitFMUL(SDNode *N); | |||
473 | SDValue visitFMA(SDNode *N); | |||
474 | SDValue visitFDIV(SDNode *N); | |||
475 | SDValue visitFREM(SDNode *N); | |||
476 | SDValue visitFSQRT(SDNode *N); | |||
477 | SDValue visitFCOPYSIGN(SDNode *N); | |||
478 | SDValue visitFPOW(SDNode *N); | |||
479 | SDValue visitSINT_TO_FP(SDNode *N); | |||
480 | SDValue visitUINT_TO_FP(SDNode *N); | |||
481 | SDValue visitFP_TO_SINT(SDNode *N); | |||
482 | SDValue visitFP_TO_UINT(SDNode *N); | |||
483 | SDValue visitFP_ROUND(SDNode *N); | |||
484 | SDValue visitFP_EXTEND(SDNode *N); | |||
485 | SDValue visitFNEG(SDNode *N); | |||
486 | SDValue visitFABS(SDNode *N); | |||
487 | SDValue visitFCEIL(SDNode *N); | |||
488 | SDValue visitFTRUNC(SDNode *N); | |||
489 | SDValue visitFFLOOR(SDNode *N); | |||
490 | SDValue visitFMINNUM(SDNode *N); | |||
491 | SDValue visitFMAXNUM(SDNode *N); | |||
492 | SDValue visitFMINIMUM(SDNode *N); | |||
493 | SDValue visitFMAXIMUM(SDNode *N); | |||
494 | SDValue visitBRCOND(SDNode *N); | |||
495 | SDValue visitBR_CC(SDNode *N); | |||
496 | SDValue visitLOAD(SDNode *N); | |||
497 | ||||
498 | SDValue replaceStoreChain(StoreSDNode *ST, SDValue BetterChain); | |||
499 | SDValue replaceStoreOfFPConstant(StoreSDNode *ST); | |||
500 | ||||
501 | SDValue visitSTORE(SDNode *N); | |||
502 | SDValue visitLIFETIME_END(SDNode *N); | |||
503 | SDValue visitINSERT_VECTOR_ELT(SDNode *N); | |||
504 | SDValue visitEXTRACT_VECTOR_ELT(SDNode *N); | |||
505 | SDValue visitBUILD_VECTOR(SDNode *N); | |||
506 | SDValue visitCONCAT_VECTORS(SDNode *N); | |||
507 | SDValue visitEXTRACT_SUBVECTOR(SDNode *N); | |||
508 | SDValue visitVECTOR_SHUFFLE(SDNode *N); | |||
509 | SDValue visitSCALAR_TO_VECTOR(SDNode *N); | |||
510 | SDValue visitINSERT_SUBVECTOR(SDNode *N); | |||
511 | SDValue visitMLOAD(SDNode *N); | |||
512 | SDValue visitMSTORE(SDNode *N); | |||
513 | SDValue visitMGATHER(SDNode *N); | |||
514 | SDValue visitMSCATTER(SDNode *N); | |||
515 | SDValue visitFP_TO_FP16(SDNode *N); | |||
516 | SDValue visitFP16_TO_FP(SDNode *N); | |||
517 | SDValue visitVECREDUCE(SDNode *N); | |||
518 | ||||
519 | SDValue visitFADDForFMACombine(SDNode *N); | |||
520 | SDValue visitFSUBForFMACombine(SDNode *N); | |||
521 | SDValue visitFMULForFMADistributiveCombine(SDNode *N); | |||
522 | ||||
523 | SDValue XformToShuffleWithZero(SDNode *N); | |||
524 | bool reassociationCanBreakAddressingModePattern(unsigned Opc, | |||
525 | const SDLoc &DL, SDValue N0, | |||
526 | SDValue N1); | |||
527 | SDValue reassociateOpsCommutative(unsigned Opc, const SDLoc &DL, SDValue N0, | |||
528 | SDValue N1); | |||
529 | SDValue reassociateOps(unsigned Opc, const SDLoc &DL, SDValue N0, | |||
530 | SDValue N1, SDNodeFlags Flags); | |||
531 | ||||
532 | SDValue visitShiftByConstant(SDNode *N); | |||
533 | ||||
534 | SDValue foldSelectOfConstants(SDNode *N); | |||
535 | SDValue foldVSelectOfConstants(SDNode *N); | |||
536 | SDValue foldBinOpIntoSelect(SDNode *BO); | |||
537 | bool SimplifySelectOps(SDNode *SELECT, SDValue LHS, SDValue RHS); | |||
538 | SDValue hoistLogicOpWithSameOpcodeHands(SDNode *N); | |||
539 | SDValue SimplifySelect(const SDLoc &DL, SDValue N0, SDValue N1, SDValue N2); | |||
540 | SDValue SimplifySelectCC(const SDLoc &DL, SDValue N0, SDValue N1, | |||
541 | SDValue N2, SDValue N3, ISD::CondCode CC, | |||
542 | bool NotExtCompare = false); | |||
543 | SDValue convertSelectOfFPConstantsToLoadOffset( | |||
544 | const SDLoc &DL, SDValue N0, SDValue N1, SDValue N2, SDValue N3, | |||
545 | ISD::CondCode CC); | |||
546 | SDValue foldSignChangeInBitcast(SDNode *N); | |||
547 | SDValue foldSelectCCToShiftAnd(const SDLoc &DL, SDValue N0, SDValue N1, | |||
548 | SDValue N2, SDValue N3, ISD::CondCode CC); | |||
549 | SDValue foldSelectOfBinops(SDNode *N); | |||
550 | SDValue foldSextSetcc(SDNode *N); | |||
551 | SDValue foldLogicOfSetCCs(bool IsAnd, SDValue N0, SDValue N1, | |||
552 | const SDLoc &DL); | |||
553 | SDValue foldSubToUSubSat(EVT DstVT, SDNode *N); | |||
554 | SDValue unfoldMaskedMerge(SDNode *N); | |||
555 | SDValue unfoldExtremeBitClearingToShifts(SDNode *N); | |||
556 | SDValue SimplifySetCC(EVT VT, SDValue N0, SDValue N1, ISD::CondCode Cond, | |||
557 | const SDLoc &DL, bool foldBooleans); | |||
558 | SDValue rebuildSetCC(SDValue N); | |||
559 | ||||
560 | bool isSetCCEquivalent(SDValue N, SDValue &LHS, SDValue &RHS, | |||
561 | SDValue &CC, bool MatchStrict = false) const; | |||
562 | bool isOneUseSetCC(SDValue N) const; | |||
563 | ||||
564 | SDValue SimplifyNodeWithTwoResults(SDNode *N, unsigned LoOp, | |||
565 | unsigned HiOp); | |||
566 | SDValue CombineConsecutiveLoads(SDNode *N, EVT VT); | |||
567 | SDValue CombineExtLoad(SDNode *N); | |||
568 | SDValue CombineZExtLogicopShiftLoad(SDNode *N); | |||
569 | SDValue combineRepeatedFPDivisors(SDNode *N); | |||
570 | SDValue combineInsertEltToShuffle(SDNode *N, unsigned InsIndex); | |||
571 | SDValue ConstantFoldBITCASTofBUILD_VECTOR(SDNode *, EVT); | |||
572 | SDValue BuildSDIV(SDNode *N); | |||
573 | SDValue BuildSDIVPow2(SDNode *N); | |||
574 | SDValue BuildUDIV(SDNode *N); | |||
575 | SDValue BuildLogBase2(SDValue V, const SDLoc &DL); | |||
576 | SDValue BuildDivEstimate(SDValue N, SDValue Op, SDNodeFlags Flags); | |||
577 | SDValue buildRsqrtEstimate(SDValue Op, SDNodeFlags Flags); | |||
578 | SDValue buildSqrtEstimate(SDValue Op, SDNodeFlags Flags); | |||
579 | SDValue buildSqrtEstimateImpl(SDValue Op, SDNodeFlags Flags, bool Recip); | |||
580 | SDValue buildSqrtNROneConst(SDValue Arg, SDValue Est, unsigned Iterations, | |||
581 | SDNodeFlags Flags, bool Reciprocal); | |||
582 | SDValue buildSqrtNRTwoConst(SDValue Arg, SDValue Est, unsigned Iterations, | |||
583 | SDNodeFlags Flags, bool Reciprocal); | |||
584 | SDValue MatchBSwapHWordLow(SDNode *N, SDValue N0, SDValue N1, | |||
585 | bool DemandHighBits = true); | |||
586 | SDValue MatchBSwapHWord(SDNode *N, SDValue N0, SDValue N1); | |||
587 | SDValue MatchRotatePosNeg(SDValue Shifted, SDValue Pos, SDValue Neg, | |||
588 | SDValue InnerPos, SDValue InnerNeg, | |||
589 | unsigned PosOpcode, unsigned NegOpcode, | |||
590 | const SDLoc &DL); | |||
591 | SDValue MatchFunnelPosNeg(SDValue N0, SDValue N1, SDValue Pos, SDValue Neg, | |||
592 | SDValue InnerPos, SDValue InnerNeg, | |||
593 | unsigned PosOpcode, unsigned NegOpcode, | |||
594 | const SDLoc &DL); | |||
595 | SDValue MatchRotate(SDValue LHS, SDValue RHS, const SDLoc &DL); | |||
596 | SDValue MatchLoadCombine(SDNode *N); | |||
597 | SDValue mergeTruncStores(StoreSDNode *N); | |||
598 | SDValue ReduceLoadWidth(SDNode *N); | |||
599 | SDValue ReduceLoadOpStoreWidth(SDNode *N); | |||
600 | SDValue splitMergedValStore(StoreSDNode *ST); | |||
601 | SDValue TransformFPLoadStorePair(SDNode *N); | |||
602 | SDValue convertBuildVecZextToZext(SDNode *N); | |||
603 | SDValue reduceBuildVecExtToExtBuildVec(SDNode *N); | |||
604 | SDValue reduceBuildVecTruncToBitCast(SDNode *N); | |||
605 | SDValue reduceBuildVecToShuffle(SDNode *N); | |||
606 | SDValue createBuildVecShuffle(const SDLoc &DL, SDNode *N, | |||
607 | ArrayRef<int> VectorMask, SDValue VecIn1, | |||
608 | SDValue VecIn2, unsigned LeftIdx, | |||
609 | bool DidSplitVec); | |||
610 | SDValue matchVSelectOpSizesWithSetCC(SDNode *Cast); | |||
611 | ||||
612 | /// Walk up chain skipping non-aliasing memory nodes, | |||
613 | /// looking for aliasing nodes and adding them to the Aliases vector. | |||
614 | void GatherAllAliases(SDNode *N, SDValue OriginalChain, | |||
615 | SmallVectorImpl<SDValue> &Aliases); | |||
616 | ||||
617 | /// Return true if there is any possibility that the two addresses overlap. | |||
618 | bool isAlias(SDNode *Op0, SDNode *Op1) const; | |||
619 | ||||
620 | /// Walk up chain skipping non-aliasing memory nodes, looking for a better | |||
621 | /// chain (aliasing node.) | |||
622 | SDValue FindBetterChain(SDNode *N, SDValue Chain); | |||
623 | ||||
624 | /// Try to replace a store and any possibly adjacent stores on | |||
625 | /// consecutive chains with better chains. Return true only if St is | |||
626 | /// replaced. | |||
627 | /// | |||
628 | /// Notice that other chains may still be replaced even if the function | |||
629 | /// returns false. | |||
630 | bool findBetterNeighborChains(StoreSDNode *St); | |||
631 | ||||
632 | // Helper for findBetterNeighborChains. Walk up store chain add additional | |||
633 | // chained stores that do not overlap and can be parallelized. | |||
634 | bool parallelizeChainedStores(StoreSDNode *St); | |||
635 | ||||
636 | /// Holds a pointer to an LSBaseSDNode as well as information on where it | |||
637 | /// is located in a sequence of memory operations connected by a chain. | |||
638 | struct MemOpLink { | |||
639 | // Ptr to the mem node. | |||
640 | LSBaseSDNode *MemNode; | |||
641 | ||||
642 | // Offset from the base ptr. | |||
643 | int64_t OffsetFromBase; | |||
644 | ||||
645 | MemOpLink(LSBaseSDNode *N, int64_t Offset) | |||
646 | : MemNode(N), OffsetFromBase(Offset) {} | |||
647 | }; | |||
648 | ||||
649 | // Classify the origin of a stored value. | |||
650 | enum class StoreSource { Unknown, Constant, Extract, Load }; | |||
651 | StoreSource getStoreSource(SDValue StoreVal) { | |||
652 | switch (StoreVal.getOpcode()) { | |||
653 | case ISD::Constant: | |||
654 | case ISD::ConstantFP: | |||
655 | return StoreSource::Constant; | |||
656 | case ISD::EXTRACT_VECTOR_ELT: | |||
657 | case ISD::EXTRACT_SUBVECTOR: | |||
658 | return StoreSource::Extract; | |||
659 | case ISD::LOAD: | |||
660 | return StoreSource::Load; | |||
661 | default: | |||
662 | return StoreSource::Unknown; | |||
663 | } | |||
664 | } | |||
665 | ||||
666 | /// This is a helper function for visitMUL to check the profitability | |||
667 | /// of folding (mul (add x, c1), c2) -> (add (mul x, c2), c1*c2). | |||
668 | /// MulNode is the original multiply, AddNode is (add x, c1), | |||
669 | /// and ConstNode is c2. | |||
670 | bool isMulAddWithConstProfitable(SDNode *MulNode, | |||
671 | SDValue &AddNode, | |||
672 | SDValue &ConstNode); | |||
673 | ||||
674 | /// This is a helper function for visitAND and visitZERO_EXTEND. Returns | |||
675 | /// true if the (and (load x) c) pattern matches an extload. ExtVT returns | |||
676 | /// the type of the loaded value to be extended. | |||
677 | bool isAndLoadExtLoad(ConstantSDNode *AndC, LoadSDNode *LoadN, | |||
678 | EVT LoadResultTy, EVT &ExtVT); | |||
679 | ||||
680 | /// Helper function to calculate whether the given Load/Store can have its | |||
681 | /// width reduced to ExtVT. | |||
682 | bool isLegalNarrowLdSt(LSBaseSDNode *LDSTN, ISD::LoadExtType ExtType, | |||
683 | EVT &MemVT, unsigned ShAmt = 0); | |||
684 | ||||
685 | /// Used by BackwardsPropagateMask to find suitable loads. | |||
686 | bool SearchForAndLoads(SDNode *N, SmallVectorImpl<LoadSDNode*> &Loads, | |||
687 | SmallPtrSetImpl<SDNode*> &NodesWithConsts, | |||
688 | ConstantSDNode *Mask, SDNode *&NodeToMask); | |||
689 | /// Attempt to propagate a given AND node back to load leaves so that they | |||
690 | /// can be combined into narrow loads. | |||
691 | bool BackwardsPropagateMask(SDNode *N); | |||
692 | ||||
693 | /// Helper function for mergeConsecutiveStores which merges the component | |||
694 | /// store chains. | |||
695 | SDValue getMergeStoreChains(SmallVectorImpl<MemOpLink> &StoreNodes, | |||
696 | unsigned NumStores); | |||
697 | ||||
698 | /// This is a helper function for mergeConsecutiveStores. When the source | |||
699 | /// elements of the consecutive stores are all constants or all extracted | |||
700 | /// vector elements, try to merge them into one larger store introducing | |||
701 | /// bitcasts if necessary. \return True if a merged store was created. | |||
702 | bool mergeStoresOfConstantsOrVecElts(SmallVectorImpl<MemOpLink> &StoreNodes, | |||
703 | EVT MemVT, unsigned NumStores, | |||
704 | bool IsConstantSrc, bool UseVector, | |||
705 | bool UseTrunc); | |||
706 | ||||
707 | /// This is a helper function for mergeConsecutiveStores. Stores that | |||
708 | /// potentially may be merged with St are placed in StoreNodes. RootNode is | |||
709 | /// a chain predecessor to all store candidates. | |||
710 | void getStoreMergeCandidates(StoreSDNode *St, | |||
711 | SmallVectorImpl<MemOpLink> &StoreNodes, | |||
712 | SDNode *&Root); | |||
713 | ||||
714 | /// Helper function for mergeConsecutiveStores. Checks if candidate stores | |||
715 | /// have indirect dependency through their operands. RootNode is the | |||
716 | /// predecessor to all stores calculated by getStoreMergeCandidates and is | |||
717 | /// used to prune the dependency check. \return True if safe to merge. | |||
718 | bool checkMergeStoreCandidatesForDependencies( | |||
719 | SmallVectorImpl<MemOpLink> &StoreNodes, unsigned NumStores, | |||
720 | SDNode *RootNode); | |||
721 | ||||
722 | /// This is a helper function for mergeConsecutiveStores. Given a list of | |||
723 | /// store candidates, find the first N that are consecutive in memory. | |||
724 | /// Returns 0 if there are not at least 2 consecutive stores to try merging. | |||
725 | unsigned getConsecutiveStores(SmallVectorImpl<MemOpLink> &StoreNodes, | |||
726 | int64_t ElementSizeBytes) const; | |||
727 | ||||
728 | /// This is a helper function for mergeConsecutiveStores. It is used for | |||
729 | /// store chains that are composed entirely of constant values. | |||
730 | bool tryStoreMergeOfConstants(SmallVectorImpl<MemOpLink> &StoreNodes, | |||
731 | unsigned NumConsecutiveStores, | |||
732 | EVT MemVT, SDNode *Root, bool AllowVectors); | |||
733 | ||||
734 | /// This is a helper function for mergeConsecutiveStores. It is used for | |||
735 | /// store chains that are composed entirely of extracted vector elements. | |||
736 | /// When extracting multiple vector elements, try to store them in one | |||
737 | /// vector store rather than a sequence of scalar stores. | |||
738 | bool tryStoreMergeOfExtracts(SmallVectorImpl<MemOpLink> &StoreNodes, | |||
739 | unsigned NumConsecutiveStores, EVT MemVT, | |||
740 | SDNode *Root); | |||
741 | ||||
742 | /// This is a helper function for mergeConsecutiveStores. It is used for | |||
743 | /// store chains that are composed entirely of loaded values. | |||
744 | bool tryStoreMergeOfLoads(SmallVectorImpl<MemOpLink> &StoreNodes, | |||
745 | unsigned NumConsecutiveStores, EVT MemVT, | |||
746 | SDNode *Root, bool AllowVectors, | |||
747 | bool IsNonTemporalStore, bool IsNonTemporalLoad); | |||
748 | ||||
749 | /// Merge consecutive store operations into a wide store. | |||
750 | /// This optimization uses wide integers or vectors when possible. | |||
751 | /// \return true if stores were merged. | |||
752 | bool mergeConsecutiveStores(StoreSDNode *St); | |||
753 | ||||
754 | /// Try to transform a truncation where C is a constant: | |||
755 | /// (trunc (and X, C)) -> (and (trunc X), (trunc C)) | |||
756 | /// | |||
757 | /// \p N needs to be a truncation and its first operand an AND. Other | |||
758 | /// requirements are checked by the function (e.g. that trunc is | |||
759 | /// single-use) and if missed an empty SDValue is returned. | |||
760 | SDValue distributeTruncateThroughAnd(SDNode *N); | |||
761 | ||||
762 | /// Helper function to determine whether the target supports operation | |||
763 | /// given by \p Opcode for type \p VT, that is, whether the operation | |||
764 | /// is legal or custom before legalizing operations, and whether is | |||
765 | /// legal (but not custom) after legalization. | |||
766 | bool hasOperation(unsigned Opcode, EVT VT) { | |||
767 | return TLI.isOperationLegalOrCustom(Opcode, VT, LegalOperations); | |||
768 | } | |||
769 | ||||
770 | public: | |||
771 | /// Runs the dag combiner on all nodes in the work list | |||
772 | void Run(CombineLevel AtLevel); | |||
773 | ||||
774 | SelectionDAG &getDAG() const { return DAG; } | |||
775 | ||||
776 | /// Returns a type large enough to hold any valid shift amount - before type | |||
777 | /// legalization these can be huge. | |||
778 | EVT getShiftAmountTy(EVT LHSTy) { | |||
779 | assert(LHSTy.isInteger() && "Shift amount is not an integer type!")((void)0); | |||
780 | return TLI.getShiftAmountTy(LHSTy, DAG.getDataLayout(), LegalTypes); | |||
781 | } | |||
782 | ||||
783 | /// This method returns true if we are running before type legalization or | |||
784 | /// if the specified VT is legal. | |||
785 | bool isTypeLegal(const EVT &VT) { | |||
786 | if (!LegalTypes) return true; | |||
787 | return TLI.isTypeLegal(VT); | |||
788 | } | |||
789 | ||||
790 | /// Convenience wrapper around TargetLowering::getSetCCResultType | |||
791 | EVT getSetCCResultType(EVT VT) const { | |||
792 | return TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT); | |||
793 | } | |||
794 | ||||
795 | void ExtendSetCCUses(const SmallVectorImpl<SDNode *> &SetCCs, | |||
796 | SDValue OrigLoad, SDValue ExtLoad, | |||
797 | ISD::NodeType ExtType); | |||
798 | }; | |||
799 | ||||
800 | /// This class is a DAGUpdateListener that removes any deleted | |||
801 | /// nodes from the worklist. | |||
802 | class WorklistRemover : public SelectionDAG::DAGUpdateListener { | |||
803 | DAGCombiner &DC; | |||
804 | ||||
805 | public: | |||
806 | explicit WorklistRemover(DAGCombiner &dc) | |||
807 | : SelectionDAG::DAGUpdateListener(dc.getDAG()), DC(dc) {} | |||
808 | ||||
809 | void NodeDeleted(SDNode *N, SDNode *E) override { | |||
810 | DC.removeFromWorklist(N); | |||
811 | } | |||
812 | }; | |||
813 | ||||
814 | class WorklistInserter : public SelectionDAG::DAGUpdateListener { | |||
815 | DAGCombiner &DC; | |||
816 | ||||
817 | public: | |||
818 | explicit WorklistInserter(DAGCombiner &dc) | |||
819 | : SelectionDAG::DAGUpdateListener(dc.getDAG()), DC(dc) {} | |||
820 | ||||
821 | // FIXME: Ideally we could add N to the worklist, but this causes exponential | |||
822 | // compile time costs in large DAGs, e.g. Halide. | |||
823 | void NodeInserted(SDNode *N) override { DC.ConsiderForPruning(N); } | |||
824 | }; | |||
825 | ||||
826 | } // end anonymous namespace | |||
827 | ||||
828 | //===----------------------------------------------------------------------===// | |||
829 | // TargetLowering::DAGCombinerInfo implementation | |||
830 | //===----------------------------------------------------------------------===// | |||
831 | ||||
832 | void TargetLowering::DAGCombinerInfo::AddToWorklist(SDNode *N) { | |||
833 | ((DAGCombiner*)DC)->AddToWorklist(N); | |||
834 | } | |||
835 | ||||
836 | SDValue TargetLowering::DAGCombinerInfo:: | |||
837 | CombineTo(SDNode *N, ArrayRef<SDValue> To, bool AddTo) { | |||
838 | return ((DAGCombiner*)DC)->CombineTo(N, &To[0], To.size(), AddTo); | |||
839 | } | |||
840 | ||||
841 | SDValue TargetLowering::DAGCombinerInfo:: | |||
842 | CombineTo(SDNode *N, SDValue Res, bool AddTo) { | |||
843 | return ((DAGCombiner*)DC)->CombineTo(N, Res, AddTo); | |||
844 | } | |||
845 | ||||
846 | SDValue TargetLowering::DAGCombinerInfo:: | |||
847 | CombineTo(SDNode *N, SDValue Res0, SDValue Res1, bool AddTo) { | |||
848 | return ((DAGCombiner*)DC)->CombineTo(N, Res0, Res1, AddTo); | |||
849 | } | |||
850 | ||||
851 | bool TargetLowering::DAGCombinerInfo:: | |||
852 | recursivelyDeleteUnusedNodes(SDNode *N) { | |||
853 | return ((DAGCombiner*)DC)->recursivelyDeleteUnusedNodes(N); | |||
854 | } | |||
855 | ||||
856 | void TargetLowering::DAGCombinerInfo:: | |||
857 | CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO) { | |||
858 | return ((DAGCombiner*)DC)->CommitTargetLoweringOpt(TLO); | |||
859 | } | |||
860 | ||||
861 | //===----------------------------------------------------------------------===// | |||
862 | // Helper Functions | |||
863 | //===----------------------------------------------------------------------===// | |||
864 | ||||
865 | void DAGCombiner::deleteAndRecombine(SDNode *N) { | |||
866 | removeFromWorklist(N); | |||
867 | ||||
868 | // If the operands of this node are only used by the node, they will now be | |||
869 | // dead. Make sure to re-visit them and recursively delete dead nodes. | |||
870 | for (const SDValue &Op : N->ops()) | |||
871 | // For an operand generating multiple values, one of the values may | |||
872 | // become dead allowing further simplification (e.g. split index | |||
873 | // arithmetic from an indexed load). | |||
874 | if (Op->hasOneUse() || Op->getNumValues() > 1) | |||
875 | AddToWorklist(Op.getNode()); | |||
876 | ||||
877 | DAG.DeleteNode(N); | |||
878 | } | |||
879 | ||||
880 | // APInts must be the same size for most operations, this helper | |||
881 | // function zero extends the shorter of the pair so that they match. | |||
882 | // We provide an Offset so that we can create bitwidths that won't overflow. | |||
883 | static void zeroExtendToMatch(APInt &LHS, APInt &RHS, unsigned Offset = 0) { | |||
884 | unsigned Bits = Offset + std::max(LHS.getBitWidth(), RHS.getBitWidth()); | |||
885 | LHS = LHS.zextOrSelf(Bits); | |||
886 | RHS = RHS.zextOrSelf(Bits); | |||
887 | } | |||
888 | ||||
889 | // Return true if this node is a setcc, or is a select_cc | |||
890 | // that selects between the target values used for true and false, making it | |||
891 | // equivalent to a setcc. Also, set the incoming LHS, RHS, and CC references to | |||
892 | // the appropriate nodes based on the type of node we are checking. This | |||
893 | // simplifies life a bit for the callers. | |||
894 | bool DAGCombiner::isSetCCEquivalent(SDValue N, SDValue &LHS, SDValue &RHS, | |||
895 | SDValue &CC, bool MatchStrict) const { | |||
896 | if (N.getOpcode() == ISD::SETCC) { | |||
897 | LHS = N.getOperand(0); | |||
898 | RHS = N.getOperand(1); | |||
899 | CC = N.getOperand(2); | |||
900 | return true; | |||
901 | } | |||
902 | ||||
903 | if (MatchStrict && | |||
904 | (N.getOpcode() == ISD::STRICT_FSETCC || | |||
905 | N.getOpcode() == ISD::STRICT_FSETCCS)) { | |||
906 | LHS = N.getOperand(1); | |||
907 | RHS = N.getOperand(2); | |||
908 | CC = N.getOperand(3); | |||
909 | return true; | |||
910 | } | |||
911 | ||||
912 | if (N.getOpcode() != ISD::SELECT_CC || | |||
913 | !TLI.isConstTrueVal(N.getOperand(2).getNode()) || | |||
914 | !TLI.isConstFalseVal(N.getOperand(3).getNode())) | |||
915 | return false; | |||
916 | ||||
917 | if (TLI.getBooleanContents(N.getValueType()) == | |||
918 | TargetLowering::UndefinedBooleanContent) | |||
919 | return false; | |||
920 | ||||
921 | LHS = N.getOperand(0); | |||
922 | RHS = N.getOperand(1); | |||
923 | CC = N.getOperand(4); | |||
924 | return true; | |||
925 | } | |||
926 | ||||
927 | /// Return true if this is a SetCC-equivalent operation with only one use. | |||
928 | /// If this is true, it allows the users to invert the operation for free when | |||
929 | /// it is profitable to do so. | |||
930 | bool DAGCombiner::isOneUseSetCC(SDValue N) const { | |||
931 | SDValue N0, N1, N2; | |||
932 | if (isSetCCEquivalent(N, N0, N1, N2) && N.getNode()->hasOneUse()) | |||
933 | return true; | |||
934 | return false; | |||
935 | } | |||
936 | ||||
937 | static bool isConstantSplatVectorMaskForType(SDNode *N, EVT ScalarTy) { | |||
938 | if (!ScalarTy.isSimple()) | |||
939 | return false; | |||
940 | ||||
941 | uint64_t MaskForTy = 0ULL; | |||
942 | switch (ScalarTy.getSimpleVT().SimpleTy) { | |||
943 | case MVT::i8: | |||
944 | MaskForTy = 0xFFULL; | |||
945 | break; | |||
946 | case MVT::i16: | |||
947 | MaskForTy = 0xFFFFULL; | |||
948 | break; | |||
949 | case MVT::i32: | |||
950 | MaskForTy = 0xFFFFFFFFULL; | |||
951 | break; | |||
952 | default: | |||
953 | return false; | |||
954 | break; | |||
955 | } | |||
956 | ||||
957 | APInt Val; | |||
958 | if (ISD::isConstantSplatVector(N, Val)) | |||
959 | return Val.getLimitedValue() == MaskForTy; | |||
960 | ||||
961 | return false; | |||
962 | } | |||
963 | ||||
964 | // Determines if it is a constant integer or a splat/build vector of constant | |||
965 | // integers (and undefs). | |||
966 | // Do not permit build vector implicit truncation. | |||
967 | static bool isConstantOrConstantVector(SDValue N, bool NoOpaques = false) { | |||
968 | if (ConstantSDNode *Const = dyn_cast<ConstantSDNode>(N)) | |||
969 | return !(Const->isOpaque() && NoOpaques); | |||
970 | if (N.getOpcode() != ISD::BUILD_VECTOR && N.getOpcode() != ISD::SPLAT_VECTOR) | |||
971 | return false; | |||
972 | unsigned BitWidth = N.getScalarValueSizeInBits(); | |||
973 | for (const SDValue &Op : N->op_values()) { | |||
974 | if (Op.isUndef()) | |||
975 | continue; | |||
976 | ConstantSDNode *Const = dyn_cast<ConstantSDNode>(Op); | |||
977 | if (!Const || Const->getAPIntValue().getBitWidth() != BitWidth || | |||
978 | (Const->isOpaque() && NoOpaques)) | |||
979 | return false; | |||
980 | } | |||
981 | return true; | |||
982 | } | |||
983 | ||||
984 | // Determines if a BUILD_VECTOR is composed of all-constants possibly mixed with | |||
985 | // undef's. | |||
986 | static bool isAnyConstantBuildVector(SDValue V, bool NoOpaques = false) { | |||
987 | if (V.getOpcode() != ISD::BUILD_VECTOR) | |||
988 | return false; | |||
989 | return isConstantOrConstantVector(V, NoOpaques) || | |||
990 | ISD::isBuildVectorOfConstantFPSDNodes(V.getNode()); | |||
991 | } | |||
992 | ||||
993 | // Determine if this an indexed load with an opaque target constant index. | |||
994 | static bool canSplitIdx(LoadSDNode *LD) { | |||
995 | return MaySplitLoadIndex && | |||
996 | (LD->getOperand(2).getOpcode() != ISD::TargetConstant || | |||
997 | !cast<ConstantSDNode>(LD->getOperand(2))->isOpaque()); | |||
998 | } | |||
999 | ||||
1000 | bool DAGCombiner::reassociationCanBreakAddressingModePattern(unsigned Opc, | |||
1001 | const SDLoc &DL, | |||
1002 | SDValue N0, | |||
1003 | SDValue N1) { | |||
1004 | // Currently this only tries to ensure we don't undo the GEP splits done by | |||
1005 | // CodeGenPrepare when shouldConsiderGEPOffsetSplit is true. To ensure this, | |||
1006 | // we check if the following transformation would be problematic: | |||
1007 | // (load/store (add, (add, x, offset1), offset2)) -> | |||
1008 | // (load/store (add, x, offset1+offset2)). | |||
1009 | ||||
1010 | if (Opc != ISD::ADD || N0.getOpcode() != ISD::ADD) | |||
1011 | return false; | |||
1012 | ||||
1013 | if (N0.hasOneUse()) | |||
1014 | return false; | |||
1015 | ||||
1016 | auto *C1 = dyn_cast<ConstantSDNode>(N0.getOperand(1)); | |||
1017 | auto *C2 = dyn_cast<ConstantSDNode>(N1); | |||
1018 | if (!C1 || !C2) | |||
1019 | return false; | |||
1020 | ||||
1021 | const APInt &C1APIntVal = C1->getAPIntValue(); | |||
1022 | const APInt &C2APIntVal = C2->getAPIntValue(); | |||
1023 | if (C1APIntVal.getBitWidth() > 64 || C2APIntVal.getBitWidth() > 64) | |||
1024 | return false; | |||
1025 | ||||
1026 | const APInt CombinedValueIntVal = C1APIntVal + C2APIntVal; | |||
1027 | if (CombinedValueIntVal.getBitWidth() > 64) | |||
1028 | return false; | |||
1029 | const int64_t CombinedValue = CombinedValueIntVal.getSExtValue(); | |||
1030 | ||||
1031 | for (SDNode *Node : N0->uses()) { | |||
1032 | auto LoadStore = dyn_cast<MemSDNode>(Node); | |||
1033 | if (LoadStore) { | |||
1034 | // Is x[offset2] already not a legal addressing mode? If so then | |||
1035 | // reassociating the constants breaks nothing (we test offset2 because | |||
1036 | // that's the one we hope to fold into the load or store). | |||
1037 | TargetLoweringBase::AddrMode AM; | |||
1038 | AM.HasBaseReg = true; | |||
1039 | AM.BaseOffs = C2APIntVal.getSExtValue(); | |||
1040 | EVT VT = LoadStore->getMemoryVT(); | |||
1041 | unsigned AS = LoadStore->getAddressSpace(); | |||
1042 | Type *AccessTy = VT.getTypeForEVT(*DAG.getContext()); | |||
1043 | if (!TLI.isLegalAddressingMode(DAG.getDataLayout(), AM, AccessTy, AS)) | |||
1044 | continue; | |||
1045 | ||||
1046 | // Would x[offset1+offset2] still be a legal addressing mode? | |||
1047 | AM.BaseOffs = CombinedValue; | |||
1048 | if (!TLI.isLegalAddressingMode(DAG.getDataLayout(), AM, AccessTy, AS)) | |||
1049 | return true; | |||
1050 | } | |||
1051 | } | |||
1052 | ||||
1053 | return false; | |||
1054 | } | |||
1055 | ||||
1056 | // Helper for DAGCombiner::reassociateOps. Try to reassociate an expression | |||
1057 | // such as (Opc N0, N1), if \p N0 is the same kind of operation as \p Opc. | |||
1058 | SDValue DAGCombiner::reassociateOpsCommutative(unsigned Opc, const SDLoc &DL, | |||
1059 | SDValue N0, SDValue N1) { | |||
1060 | EVT VT = N0.getValueType(); | |||
1061 | ||||
1062 | if (N0.getOpcode() != Opc) | |||
1063 | return SDValue(); | |||
1064 | ||||
1065 | if (DAG.isConstantIntBuildVectorOrConstantInt(N0.getOperand(1))) { | |||
1066 | if (DAG.isConstantIntBuildVectorOrConstantInt(N1)) { | |||
1067 | // Reassociate: (op (op x, c1), c2) -> (op x, (op c1, c2)) | |||
1068 | if (SDValue OpNode = | |||
1069 | DAG.FoldConstantArithmetic(Opc, DL, VT, {N0.getOperand(1), N1})) | |||
1070 | return DAG.getNode(Opc, DL, VT, N0.getOperand(0), OpNode); | |||
1071 | return SDValue(); | |||
1072 | } | |||
1073 | if (N0.hasOneUse()) { | |||
1074 | // Reassociate: (op (op x, c1), y) -> (op (op x, y), c1) | |||
1075 | // iff (op x, c1) has one use | |||
1076 | SDValue OpNode = DAG.getNode(Opc, SDLoc(N0), VT, N0.getOperand(0), N1); | |||
1077 | if (!OpNode.getNode()) | |||
1078 | return SDValue(); | |||
1079 | return DAG.getNode(Opc, DL, VT, OpNode, N0.getOperand(1)); | |||
1080 | } | |||
1081 | } | |||
1082 | return SDValue(); | |||
1083 | } | |||
1084 | ||||
1085 | // Try to reassociate commutative binops. | |||
1086 | SDValue DAGCombiner::reassociateOps(unsigned Opc, const SDLoc &DL, SDValue N0, | |||
1087 | SDValue N1, SDNodeFlags Flags) { | |||
1088 | assert(TLI.isCommutativeBinOp(Opc) && "Operation not commutative.")((void)0); | |||
1089 | ||||
1090 | // Floating-point reassociation is not allowed without loose FP math. | |||
1091 | if (N0.getValueType().isFloatingPoint() || | |||
1092 | N1.getValueType().isFloatingPoint()) | |||
1093 | if (!Flags.hasAllowReassociation() || !Flags.hasNoSignedZeros()) | |||
1094 | return SDValue(); | |||
1095 | ||||
1096 | if (SDValue Combined = reassociateOpsCommutative(Opc, DL, N0, N1)) | |||
1097 | return Combined; | |||
1098 | if (SDValue Combined = reassociateOpsCommutative(Opc, DL, N1, N0)) | |||
1099 | return Combined; | |||
1100 | return SDValue(); | |||
1101 | } | |||
1102 | ||||
1103 | SDValue DAGCombiner::CombineTo(SDNode *N, const SDValue *To, unsigned NumTo, | |||
1104 | bool AddTo) { | |||
1105 | assert(N->getNumValues() == NumTo && "Broken CombineTo call!")((void)0); | |||
1106 | ++NodesCombined; | |||
1107 | LLVM_DEBUG(dbgs() << "\nReplacing.1 "; N->dump(&DAG); dbgs() << "\nWith: ";do { } while (false) | |||
1108 | To[0].getNode()->dump(&DAG);do { } while (false) | |||
1109 | dbgs() << " and " << NumTo - 1 << " other values\n")do { } while (false); | |||
1110 | for (unsigned i = 0, e = NumTo; i != e; ++i) | |||
1111 | assert((!To[i].getNode() ||((void)0) | |||
1112 | N->getValueType(i) == To[i].getValueType()) &&((void)0) | |||
1113 | "Cannot combine value to value of different type!")((void)0); | |||
1114 | ||||
1115 | WorklistRemover DeadNodes(*this); | |||
1116 | DAG.ReplaceAllUsesWith(N, To); | |||
1117 | if (AddTo) { | |||
1118 | // Push the new nodes and any users onto the worklist | |||
1119 | for (unsigned i = 0, e = NumTo; i != e; ++i) { | |||
1120 | if (To[i].getNode()) { | |||
1121 | AddToWorklist(To[i].getNode()); | |||
1122 | AddUsersToWorklist(To[i].getNode()); | |||
1123 | } | |||
1124 | } | |||
1125 | } | |||
1126 | ||||
1127 | // Finally, if the node is now dead, remove it from the graph. The node | |||
1128 | // may not be dead if the replacement process recursively simplified to | |||
1129 | // something else needing this node. | |||
1130 | if (N->use_empty()) | |||
1131 | deleteAndRecombine(N); | |||
1132 | return SDValue(N, 0); | |||
1133 | } | |||
1134 | ||||
1135 | void DAGCombiner:: | |||
1136 | CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO) { | |||
1137 | // Replace the old value with the new one. | |||
1138 | ++NodesCombined; | |||
1139 | LLVM_DEBUG(dbgs() << "\nReplacing.2 "; TLO.Old.getNode()->dump(&DAG);do { } while (false) | |||
1140 | dbgs() << "\nWith: "; TLO.New.getNode()->dump(&DAG);do { } while (false) | |||
1141 | dbgs() << '\n')do { } while (false); | |||
1142 | ||||
1143 | // Replace all uses. If any nodes become isomorphic to other nodes and | |||
1144 | // are deleted, make sure to remove them from our worklist. | |||
1145 | WorklistRemover DeadNodes(*this); | |||
1146 | DAG.ReplaceAllUsesOfValueWith(TLO.Old, TLO.New); | |||
1147 | ||||
1148 | // Push the new node and any (possibly new) users onto the worklist. | |||
1149 | AddToWorklistWithUsers(TLO.New.getNode()); | |||
1150 | ||||
1151 | // Finally, if the node is now dead, remove it from the graph. The node | |||
1152 | // may not be dead if the replacement process recursively simplified to | |||
1153 | // something else needing this node. | |||
1154 | if (TLO.Old.getNode()->use_empty()) | |||
1155 | deleteAndRecombine(TLO.Old.getNode()); | |||
1156 | } | |||
1157 | ||||
1158 | /// Check the specified integer node value to see if it can be simplified or if | |||
1159 | /// things it uses can be simplified by bit propagation. If so, return true. | |||
1160 | bool DAGCombiner::SimplifyDemandedBits(SDValue Op, const APInt &DemandedBits, | |||
1161 | const APInt &DemandedElts, | |||
1162 | bool AssumeSingleUse) { | |||
1163 | TargetLowering::TargetLoweringOpt TLO(DAG, LegalTypes, LegalOperations); | |||
1164 | KnownBits Known; | |||
1165 | if (!TLI.SimplifyDemandedBits(Op, DemandedBits, DemandedElts, Known, TLO, 0, | |||
1166 | AssumeSingleUse)) | |||
1167 | return false; | |||
1168 | ||||
1169 | // Revisit the node. | |||
1170 | AddToWorklist(Op.getNode()); | |||
1171 | ||||
1172 | CommitTargetLoweringOpt(TLO); | |||
1173 | return true; | |||
1174 | } | |||
1175 | ||||
1176 | /// Check the specified vector node value to see if it can be simplified or | |||
1177 | /// if things it uses can be simplified as it only uses some of the elements. | |||
1178 | /// If so, return true. | |||
1179 | bool DAGCombiner::SimplifyDemandedVectorElts(SDValue Op, | |||
1180 | const APInt &DemandedElts, | |||
1181 | bool AssumeSingleUse) { | |||
1182 | TargetLowering::TargetLoweringOpt TLO(DAG, LegalTypes, LegalOperations); | |||
1183 | APInt KnownUndef, KnownZero; | |||
1184 | if (!TLI.SimplifyDemandedVectorElts(Op, DemandedElts, KnownUndef, KnownZero, | |||
1185 | TLO, 0, AssumeSingleUse)) | |||
1186 | return false; | |||
1187 | ||||
1188 | // Revisit the node. | |||
1189 | AddToWorklist(Op.getNode()); | |||
1190 | ||||
1191 | CommitTargetLoweringOpt(TLO); | |||
1192 | return true; | |||
1193 | } | |||
1194 | ||||
1195 | void DAGCombiner::ReplaceLoadWithPromotedLoad(SDNode *Load, SDNode *ExtLoad) { | |||
1196 | SDLoc DL(Load); | |||
1197 | EVT VT = Load->getValueType(0); | |||
1198 | SDValue Trunc = DAG.getNode(ISD::TRUNCATE, DL, VT, SDValue(ExtLoad, 0)); | |||
1199 | ||||
1200 | LLVM_DEBUG(dbgs() << "\nReplacing.9 "; Load->dump(&DAG); dbgs() << "\nWith: ";do { } while (false) | |||
1201 | Trunc.getNode()->dump(&DAG); dbgs() << '\n')do { } while (false); | |||
1202 | WorklistRemover DeadNodes(*this); | |||
1203 | DAG.ReplaceAllUsesOfValueWith(SDValue(Load, 0), Trunc); | |||
1204 | DAG.ReplaceAllUsesOfValueWith(SDValue(Load, 1), SDValue(ExtLoad, 1)); | |||
1205 | deleteAndRecombine(Load); | |||
1206 | AddToWorklist(Trunc.getNode()); | |||
1207 | } | |||
1208 | ||||
1209 | SDValue DAGCombiner::PromoteOperand(SDValue Op, EVT PVT, bool &Replace) { | |||
1210 | Replace = false; | |||
1211 | SDLoc DL(Op); | |||
1212 | if (ISD::isUNINDEXEDLoad(Op.getNode())) { | |||
1213 | LoadSDNode *LD = cast<LoadSDNode>(Op); | |||
1214 | EVT MemVT = LD->getMemoryVT(); | |||
1215 | ISD::LoadExtType ExtType = ISD::isNON_EXTLoad(LD) ? ISD::EXTLOAD | |||
1216 | : LD->getExtensionType(); | |||
1217 | Replace = true; | |||
1218 | return DAG.getExtLoad(ExtType, DL, PVT, | |||
1219 | LD->getChain(), LD->getBasePtr(), | |||
1220 | MemVT, LD->getMemOperand()); | |||
1221 | } | |||
1222 | ||||
1223 | unsigned Opc = Op.getOpcode(); | |||
1224 | switch (Opc) { | |||
1225 | default: break; | |||
1226 | case ISD::AssertSext: | |||
1227 | if (SDValue Op0 = SExtPromoteOperand(Op.getOperand(0), PVT)) | |||
1228 | return DAG.getNode(ISD::AssertSext, DL, PVT, Op0, Op.getOperand(1)); | |||
1229 | break; | |||
1230 | case ISD::AssertZext: | |||
1231 | if (SDValue Op0 = ZExtPromoteOperand(Op.getOperand(0), PVT)) | |||
1232 | return DAG.getNode(ISD::AssertZext, DL, PVT, Op0, Op.getOperand(1)); | |||
1233 | break; | |||
1234 | case ISD::Constant: { | |||
1235 | unsigned ExtOpc = | |||
1236 | Op.getValueType().isByteSized() ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND; | |||
1237 | return DAG.getNode(ExtOpc, DL, PVT, Op); | |||
1238 | } | |||
1239 | } | |||
1240 | ||||
1241 | if (!TLI.isOperationLegal(ISD::ANY_EXTEND, PVT)) | |||
1242 | return SDValue(); | |||
1243 | return DAG.getNode(ISD::ANY_EXTEND, DL, PVT, Op); | |||
1244 | } | |||
1245 | ||||
1246 | SDValue DAGCombiner::SExtPromoteOperand(SDValue Op, EVT PVT) { | |||
1247 | if (!TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG, PVT)) | |||
1248 | return SDValue(); | |||
1249 | EVT OldVT = Op.getValueType(); | |||
1250 | SDLoc DL(Op); | |||
1251 | bool Replace = false; | |||
1252 | SDValue NewOp = PromoteOperand(Op, PVT, Replace); | |||
1253 | if (!NewOp.getNode()) | |||
1254 | return SDValue(); | |||
1255 | AddToWorklist(NewOp.getNode()); | |||
1256 | ||||
1257 | if (Replace) | |||
1258 | ReplaceLoadWithPromotedLoad(Op.getNode(), NewOp.getNode()); | |||
1259 | return DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, NewOp.getValueType(), NewOp, | |||
1260 | DAG.getValueType(OldVT)); | |||
1261 | } | |||
1262 | ||||
1263 | SDValue DAGCombiner::ZExtPromoteOperand(SDValue Op, EVT PVT) { | |||
1264 | EVT OldVT = Op.getValueType(); | |||
1265 | SDLoc DL(Op); | |||
1266 | bool Replace = false; | |||
1267 | SDValue NewOp = PromoteOperand(Op, PVT, Replace); | |||
1268 | if (!NewOp.getNode()) | |||
1269 | return SDValue(); | |||
1270 | AddToWorklist(NewOp.getNode()); | |||
1271 | ||||
1272 | if (Replace) | |||
1273 | ReplaceLoadWithPromotedLoad(Op.getNode(), NewOp.getNode()); | |||
1274 | return DAG.getZeroExtendInReg(NewOp, DL, OldVT); | |||
1275 | } | |||
1276 | ||||
1277 | /// Promote the specified integer binary operation if the target indicates it is | |||
1278 | /// beneficial. e.g. On x86, it's usually better to promote i16 operations to | |||
1279 | /// i32 since i16 instructions are longer. | |||
1280 | SDValue DAGCombiner::PromoteIntBinOp(SDValue Op) { | |||
1281 | if (!LegalOperations) | |||
1282 | return SDValue(); | |||
1283 | ||||
1284 | EVT VT = Op.getValueType(); | |||
1285 | if (VT.isVector() || !VT.isInteger()) | |||
1286 | return SDValue(); | |||
1287 | ||||
1288 | // If operation type is 'undesirable', e.g. i16 on x86, consider | |||
1289 | // promoting it. | |||
1290 | unsigned Opc = Op.getOpcode(); | |||
1291 | if (TLI.isTypeDesirableForOp(Opc, VT)) | |||
1292 | return SDValue(); | |||
1293 | ||||
1294 | EVT PVT = VT; | |||
1295 | // Consult target whether it is a good idea to promote this operation and | |||
1296 | // what's the right type to promote it to. | |||
1297 | if (TLI.IsDesirableToPromoteOp(Op, PVT)) { | |||
1298 | assert(PVT != VT && "Don't know what type to promote to!")((void)0); | |||
1299 | ||||
1300 | LLVM_DEBUG(dbgs() << "\nPromoting "; Op.getNode()->dump(&DAG))do { } while (false); | |||
1301 | ||||
1302 | bool Replace0 = false; | |||
1303 | SDValue N0 = Op.getOperand(0); | |||
1304 | SDValue NN0 = PromoteOperand(N0, PVT, Replace0); | |||
1305 | ||||
1306 | bool Replace1 = false; | |||
1307 | SDValue N1 = Op.getOperand(1); | |||
1308 | SDValue NN1 = PromoteOperand(N1, PVT, Replace1); | |||
1309 | SDLoc DL(Op); | |||
1310 | ||||
1311 | SDValue RV = | |||
1312 | DAG.getNode(ISD::TRUNCATE, DL, VT, DAG.getNode(Opc, DL, PVT, NN0, NN1)); | |||
1313 | ||||
1314 | // We are always replacing N0/N1's use in N and only need additional | |||
1315 | // replacements if there are additional uses. | |||
1316 | // Note: We are checking uses of the *nodes* (SDNode) rather than values | |||
1317 | // (SDValue) here because the node may reference multiple values | |||
1318 | // (for example, the chain value of a load node). | |||
1319 | Replace0 &= !N0->hasOneUse(); | |||
1320 | Replace1 &= (N0 != N1) && !N1->hasOneUse(); | |||
1321 | ||||
1322 | // Combine Op here so it is preserved past replacements. | |||
1323 | CombineTo(Op.getNode(), RV); | |||
1324 | ||||
1325 | // If operands have a use ordering, make sure we deal with | |||
1326 | // predecessor first. | |||
1327 | if (Replace0 && Replace1 && N0.getNode()->isPredecessorOf(N1.getNode())) { | |||
1328 | std::swap(N0, N1); | |||
1329 | std::swap(NN0, NN1); | |||
1330 | } | |||
1331 | ||||
1332 | if (Replace0) { | |||
1333 | AddToWorklist(NN0.getNode()); | |||
1334 | ReplaceLoadWithPromotedLoad(N0.getNode(), NN0.getNode()); | |||
1335 | } | |||
1336 | if (Replace1) { | |||
1337 | AddToWorklist(NN1.getNode()); | |||
1338 | ReplaceLoadWithPromotedLoad(N1.getNode(), NN1.getNode()); | |||
1339 | } | |||
1340 | return Op; | |||
1341 | } | |||
1342 | return SDValue(); | |||
1343 | } | |||
1344 | ||||
1345 | /// Promote the specified integer shift operation if the target indicates it is | |||
1346 | /// beneficial. e.g. On x86, it's usually better to promote i16 operations to | |||
1347 | /// i32 since i16 instructions are longer. | |||
1348 | SDValue DAGCombiner::PromoteIntShiftOp(SDValue Op) { | |||
1349 | if (!LegalOperations) | |||
1350 | return SDValue(); | |||
1351 | ||||
1352 | EVT VT = Op.getValueType(); | |||
1353 | if (VT.isVector() || !VT.isInteger()) | |||
1354 | return SDValue(); | |||
1355 | ||||
1356 | // If operation type is 'undesirable', e.g. i16 on x86, consider | |||
1357 | // promoting it. | |||
1358 | unsigned Opc = Op.getOpcode(); | |||
1359 | if (TLI.isTypeDesirableForOp(Opc, VT)) | |||
1360 | return SDValue(); | |||
1361 | ||||
1362 | EVT PVT = VT; | |||
1363 | // Consult target whether it is a good idea to promote this operation and | |||
1364 | // what's the right type to promote it to. | |||
1365 | if (TLI.IsDesirableToPromoteOp(Op, PVT)) { | |||
1366 | assert(PVT != VT && "Don't know what type to promote to!")((void)0); | |||
1367 | ||||
1368 | LLVM_DEBUG(dbgs() << "\nPromoting "; Op.getNode()->dump(&DAG))do { } while (false); | |||
1369 | ||||
1370 | bool Replace = false; | |||
1371 | SDValue N0 = Op.getOperand(0); | |||
1372 | SDValue N1 = Op.getOperand(1); | |||
1373 | if (Opc == ISD::SRA) | |||
1374 | N0 = SExtPromoteOperand(N0, PVT); | |||
1375 | else if (Opc == ISD::SRL) | |||
1376 | N0 = ZExtPromoteOperand(N0, PVT); | |||
1377 | else | |||
1378 | N0 = PromoteOperand(N0, PVT, Replace); | |||
1379 | ||||
1380 | if (!N0.getNode()) | |||
1381 | return SDValue(); | |||
1382 | ||||
1383 | SDLoc DL(Op); | |||
1384 | SDValue RV = | |||
1385 | DAG.getNode(ISD::TRUNCATE, DL, VT, DAG.getNode(Opc, DL, PVT, N0, N1)); | |||
1386 | ||||
1387 | if (Replace) | |||
1388 | ReplaceLoadWithPromotedLoad(Op.getOperand(0).getNode(), N0.getNode()); | |||
1389 | ||||
1390 | // Deal with Op being deleted. | |||
1391 | if (Op && Op.getOpcode() != ISD::DELETED_NODE) | |||
1392 | return RV; | |||
1393 | } | |||
1394 | return SDValue(); | |||
1395 | } | |||
1396 | ||||
1397 | SDValue DAGCombiner::PromoteExtend(SDValue Op) { | |||
1398 | if (!LegalOperations) | |||
1399 | return SDValue(); | |||
1400 | ||||
1401 | EVT VT = Op.getValueType(); | |||
1402 | if (VT.isVector() || !VT.isInteger()) | |||
1403 | return SDValue(); | |||
1404 | ||||
1405 | // If operation type is 'undesirable', e.g. i16 on x86, consider | |||
1406 | // promoting it. | |||
1407 | unsigned Opc = Op.getOpcode(); | |||
1408 | if (TLI.isTypeDesirableForOp(Opc, VT)) | |||
1409 | return SDValue(); | |||
1410 | ||||
1411 | EVT PVT = VT; | |||
1412 | // Consult target whether it is a good idea to promote this operation and | |||
1413 | // what's the right type to promote it to. | |||
1414 | if (TLI.IsDesirableToPromoteOp(Op, PVT)) { | |||
1415 | assert(PVT != VT && "Don't know what type to promote to!")((void)0); | |||
1416 | // fold (aext (aext x)) -> (aext x) | |||
1417 | // fold (aext (zext x)) -> (zext x) | |||
1418 | // fold (aext (sext x)) -> (sext x) | |||
1419 | LLVM_DEBUG(dbgs() << "\nPromoting "; Op.getNode()->dump(&DAG))do { } while (false); | |||
1420 | return DAG.getNode(Op.getOpcode(), SDLoc(Op), VT, Op.getOperand(0)); | |||
1421 | } | |||
1422 | return SDValue(); | |||
1423 | } | |||
1424 | ||||
1425 | bool DAGCombiner::PromoteLoad(SDValue Op) { | |||
1426 | if (!LegalOperations) | |||
1427 | return false; | |||
1428 | ||||
1429 | if (!ISD::isUNINDEXEDLoad(Op.getNode())) | |||
1430 | return false; | |||
1431 | ||||
1432 | EVT VT = Op.getValueType(); | |||
1433 | if (VT.isVector() || !VT.isInteger()) | |||
1434 | return false; | |||
1435 | ||||
1436 | // If operation type is 'undesirable', e.g. i16 on x86, consider | |||
1437 | // promoting it. | |||
1438 | unsigned Opc = Op.getOpcode(); | |||
1439 | if (TLI.isTypeDesirableForOp(Opc, VT)) | |||
1440 | return false; | |||
1441 | ||||
1442 | EVT PVT = VT; | |||
1443 | // Consult target whether it is a good idea to promote this operation and | |||
1444 | // what's the right type to promote it to. | |||
1445 | if (TLI.IsDesirableToPromoteOp(Op, PVT)) { | |||
1446 | assert(PVT != VT && "Don't know what type to promote to!")((void)0); | |||
1447 | ||||
1448 | SDLoc DL(Op); | |||
1449 | SDNode *N = Op.getNode(); | |||
1450 | LoadSDNode *LD = cast<LoadSDNode>(N); | |||
1451 | EVT MemVT = LD->getMemoryVT(); | |||
1452 | ISD::LoadExtType ExtType = ISD::isNON_EXTLoad(LD) ? ISD::EXTLOAD | |||
1453 | : LD->getExtensionType(); | |||
1454 | SDValue NewLD = DAG.getExtLoad(ExtType, DL, PVT, | |||
1455 | LD->getChain(), LD->getBasePtr(), | |||
1456 | MemVT, LD->getMemOperand()); | |||
1457 | SDValue Result = DAG.getNode(ISD::TRUNCATE, DL, VT, NewLD); | |||
1458 | ||||
1459 | LLVM_DEBUG(dbgs() << "\nPromoting "; N->dump(&DAG); dbgs() << "\nTo: ";do { } while (false) | |||
1460 | Result.getNode()->dump(&DAG); dbgs() << '\n')do { } while (false); | |||
1461 | WorklistRemover DeadNodes(*this); | |||
1462 | DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result); | |||
1463 | DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), NewLD.getValue(1)); | |||
1464 | deleteAndRecombine(N); | |||
1465 | AddToWorklist(Result.getNode()); | |||
1466 | return true; | |||
1467 | } | |||
1468 | return false; | |||
1469 | } | |||
1470 | ||||
1471 | /// Recursively delete a node which has no uses and any operands for | |||
1472 | /// which it is the only use. | |||
1473 | /// | |||
1474 | /// Note that this both deletes the nodes and removes them from the worklist. | |||
1475 | /// It also adds any nodes who have had a user deleted to the worklist as they | |||
1476 | /// may now have only one use and subject to other combines. | |||
1477 | bool DAGCombiner::recursivelyDeleteUnusedNodes(SDNode *N) { | |||
1478 | if (!N->use_empty()) | |||
1479 | return false; | |||
1480 | ||||
1481 | SmallSetVector<SDNode *, 16> Nodes; | |||
1482 | Nodes.insert(N); | |||
1483 | do { | |||
1484 | N = Nodes.pop_back_val(); | |||
1485 | if (!N) | |||
1486 | continue; | |||
1487 | ||||
1488 | if (N->use_empty()) { | |||
1489 | for (const SDValue &ChildN : N->op_values()) | |||
1490 | Nodes.insert(ChildN.getNode()); | |||
1491 | ||||
1492 | removeFromWorklist(N); | |||
1493 | DAG.DeleteNode(N); | |||
1494 | } else { | |||
1495 | AddToWorklist(N); | |||
1496 | } | |||
1497 | } while (!Nodes.empty()); | |||
1498 | return true; | |||
1499 | } | |||
1500 | ||||
1501 | //===----------------------------------------------------------------------===// | |||
1502 | // Main DAG Combiner implementation | |||
1503 | //===----------------------------------------------------------------------===// | |||
1504 | ||||
1505 | void DAGCombiner::Run(CombineLevel AtLevel) { | |||
1506 | // set the instance variables, so that the various visit routines may use it. | |||
1507 | Level = AtLevel; | |||
1508 | LegalDAG = Level >= AfterLegalizeDAG; | |||
1509 | LegalOperations = Level >= AfterLegalizeVectorOps; | |||
1510 | LegalTypes = Level >= AfterLegalizeTypes; | |||
1511 | ||||
1512 | WorklistInserter AddNodes(*this); | |||
1513 | ||||
1514 | // Add all the dag nodes to the worklist. | |||
1515 | for (SDNode &Node : DAG.allnodes()) | |||
1516 | AddToWorklist(&Node); | |||
1517 | ||||
1518 | // Create a dummy node (which is not added to allnodes), that adds a reference | |||
1519 | // to the root node, preventing it from being deleted, and tracking any | |||
1520 | // changes of the root. | |||
1521 | HandleSDNode Dummy(DAG.getRoot()); | |||
1522 | ||||
1523 | // While we have a valid worklist entry node, try to combine it. | |||
1524 | while (SDNode *N = getNextWorklistEntry()) { | |||
1525 | // If N has no uses, it is dead. Make sure to revisit all N's operands once | |||
1526 | // N is deleted from the DAG, since they too may now be dead or may have a | |||
1527 | // reduced number of uses, allowing other xforms. | |||
1528 | if (recursivelyDeleteUnusedNodes(N)) | |||
1529 | continue; | |||
1530 | ||||
1531 | WorklistRemover DeadNodes(*this); | |||
1532 | ||||
1533 | // If this combine is running after legalizing the DAG, re-legalize any | |||
1534 | // nodes pulled off the worklist. | |||
1535 | if (LegalDAG) { | |||
1536 | SmallSetVector<SDNode *, 16> UpdatedNodes; | |||
1537 | bool NIsValid = DAG.LegalizeOp(N, UpdatedNodes); | |||
1538 | ||||
1539 | for (SDNode *LN : UpdatedNodes) | |||
1540 | AddToWorklistWithUsers(LN); | |||
1541 | ||||
1542 | if (!NIsValid) | |||
1543 | continue; | |||
1544 | } | |||
1545 | ||||
1546 | LLVM_DEBUG(dbgs() << "\nCombining: "; N->dump(&DAG))do { } while (false); | |||
1547 | ||||
1548 | // Add any operands of the new node which have not yet been combined to the | |||
1549 | // worklist as well. Because the worklist uniques things already, this | |||
1550 | // won't repeatedly process the same operand. | |||
1551 | CombinedNodes.insert(N); | |||
1552 | for (const SDValue &ChildN : N->op_values()) | |||
1553 | if (!CombinedNodes.count(ChildN.getNode())) | |||
1554 | AddToWorklist(ChildN.getNode()); | |||
1555 | ||||
1556 | SDValue RV = combine(N); | |||
1557 | ||||
1558 | if (!RV.getNode()) | |||
1559 | continue; | |||
1560 | ||||
1561 | ++NodesCombined; | |||
1562 | ||||
1563 | // If we get back the same node we passed in, rather than a new node or | |||
1564 | // zero, we know that the node must have defined multiple values and | |||
1565 | // CombineTo was used. Since CombineTo takes care of the worklist | |||
1566 | // mechanics for us, we have no work to do in this case. | |||
1567 | if (RV.getNode() == N) | |||
1568 | continue; | |||
1569 | ||||
1570 | assert(N->getOpcode() != ISD::DELETED_NODE &&((void)0) | |||
1571 | RV.getOpcode() != ISD::DELETED_NODE &&((void)0) | |||
1572 | "Node was deleted but visit returned new node!")((void)0); | |||
1573 | ||||
1574 | LLVM_DEBUG(dbgs() << " ... into: "; RV.getNode()->dump(&DAG))do { } while (false); | |||
1575 | ||||
1576 | if (N->getNumValues() == RV.getNode()->getNumValues()) | |||
1577 | DAG.ReplaceAllUsesWith(N, RV.getNode()); | |||
1578 | else { | |||
1579 | assert(N->getValueType(0) == RV.getValueType() &&((void)0) | |||
1580 | N->getNumValues() == 1 && "Type mismatch")((void)0); | |||
1581 | DAG.ReplaceAllUsesWith(N, &RV); | |||
1582 | } | |||
1583 | ||||
1584 | // Push the new node and any users onto the worklist. Omit this if the | |||
1585 | // new node is the EntryToken (e.g. if a store managed to get optimized | |||
1586 | // out), because re-visiting the EntryToken and its users will not uncover | |||
1587 | // any additional opportunities, but there may be a large number of such | |||
1588 | // users, potentially causing compile time explosion. | |||
1589 | if (RV.getOpcode() != ISD::EntryToken) { | |||
1590 | AddToWorklist(RV.getNode()); | |||
1591 | AddUsersToWorklist(RV.getNode()); | |||
1592 | } | |||
1593 | ||||
1594 | // Finally, if the node is now dead, remove it from the graph. The node | |||
1595 | // may not be dead if the replacement process recursively simplified to | |||
1596 | // something else needing this node. This will also take care of adding any | |||
1597 | // operands which have lost a user to the worklist. | |||
1598 | recursivelyDeleteUnusedNodes(N); | |||
1599 | } | |||
1600 | ||||
1601 | // If the root changed (e.g. it was a dead load, update the root). | |||
1602 | DAG.setRoot(Dummy.getValue()); | |||
1603 | DAG.RemoveDeadNodes(); | |||
1604 | } | |||
1605 | ||||
1606 | SDValue DAGCombiner::visit(SDNode *N) { | |||
1607 | switch (N->getOpcode()) { | |||
1608 | default: break; | |||
1609 | case ISD::TokenFactor: return visitTokenFactor(N); | |||
1610 | case ISD::MERGE_VALUES: return visitMERGE_VALUES(N); | |||
1611 | case ISD::ADD: return visitADD(N); | |||
1612 | case ISD::SUB: return visitSUB(N); | |||
1613 | case ISD::SADDSAT: | |||
1614 | case ISD::UADDSAT: return visitADDSAT(N); | |||
1615 | case ISD::SSUBSAT: | |||
1616 | case ISD::USUBSAT: return visitSUBSAT(N); | |||
1617 | case ISD::ADDC: return visitADDC(N); | |||
1618 | case ISD::SADDO: | |||
1619 | case ISD::UADDO: return visitADDO(N); | |||
1620 | case ISD::SUBC: return visitSUBC(N); | |||
1621 | case ISD::SSUBO: | |||
1622 | case ISD::USUBO: return visitSUBO(N); | |||
1623 | case ISD::ADDE: return visitADDE(N); | |||
1624 | case ISD::ADDCARRY: return visitADDCARRY(N); | |||
1625 | case ISD::SADDO_CARRY: return visitSADDO_CARRY(N); | |||
1626 | case ISD::SUBE: return visitSUBE(N); | |||
1627 | case ISD::SUBCARRY: return visitSUBCARRY(N); | |||
1628 | case ISD::SSUBO_CARRY: return visitSSUBO_CARRY(N); | |||
1629 | case ISD::SMULFIX: | |||
1630 | case ISD::SMULFIXSAT: | |||
1631 | case ISD::UMULFIX: | |||
1632 | case ISD::UMULFIXSAT: return visitMULFIX(N); | |||
1633 | case ISD::MUL: return visitMUL(N); | |||
1634 | case ISD::SDIV: return visitSDIV(N); | |||
1635 | case ISD::UDIV: return visitUDIV(N); | |||
1636 | case ISD::SREM: | |||
1637 | case ISD::UREM: return visitREM(N); | |||
1638 | case ISD::MULHU: return visitMULHU(N); | |||
1639 | case ISD::MULHS: return visitMULHS(N); | |||
1640 | case ISD::SMUL_LOHI: return visitSMUL_LOHI(N); | |||
1641 | case ISD::UMUL_LOHI: return visitUMUL_LOHI(N); | |||
1642 | case ISD::SMULO: | |||
1643 | case ISD::UMULO: return visitMULO(N); | |||
1644 | case ISD::SMIN: | |||
1645 | case ISD::SMAX: | |||
1646 | case ISD::UMIN: | |||
1647 | case ISD::UMAX: return visitIMINMAX(N); | |||
1648 | case ISD::AND: return visitAND(N); | |||
1649 | case ISD::OR: return visitOR(N); | |||
1650 | case ISD::XOR: return visitXOR(N); | |||
1651 | case ISD::SHL: return visitSHL(N); | |||
1652 | case ISD::SRA: return visitSRA(N); | |||
1653 | case ISD::SRL: return visitSRL(N); | |||
1654 | case ISD::ROTR: | |||
1655 | case ISD::ROTL: return visitRotate(N); | |||
1656 | case ISD::FSHL: | |||
1657 | case ISD::FSHR: return visitFunnelShift(N); | |||
1658 | case ISD::ABS: return visitABS(N); | |||
1659 | case ISD::BSWAP: return visitBSWAP(N); | |||
1660 | case ISD::BITREVERSE: return visitBITREVERSE(N); | |||
1661 | case ISD::CTLZ: return visitCTLZ(N); | |||
1662 | case ISD::CTLZ_ZERO_UNDEF: return visitCTLZ_ZERO_UNDEF(N); | |||
1663 | case ISD::CTTZ: return visitCTTZ(N); | |||
1664 | case ISD::CTTZ_ZERO_UNDEF: return visitCTTZ_ZERO_UNDEF(N); | |||
1665 | case ISD::CTPOP: return visitCTPOP(N); | |||
1666 | case ISD::SELECT: return visitSELECT(N); | |||
1667 | case ISD::VSELECT: return visitVSELECT(N); | |||
1668 | case ISD::SELECT_CC: return visitSELECT_CC(N); | |||
1669 | case ISD::SETCC: return visitSETCC(N); | |||
1670 | case ISD::SETCCCARRY: return visitSETCCCARRY(N); | |||
1671 | case ISD::SIGN_EXTEND: return visitSIGN_EXTEND(N); | |||
1672 | case ISD::ZERO_EXTEND: return visitZERO_EXTEND(N); | |||
1673 | case ISD::ANY_EXTEND: return visitANY_EXTEND(N); | |||
1674 | case ISD::AssertSext: | |||
1675 | case ISD::AssertZext: return visitAssertExt(N); | |||
1676 | case ISD::AssertAlign: return visitAssertAlign(N); | |||
1677 | case ISD::SIGN_EXTEND_INREG: return visitSIGN_EXTEND_INREG(N); | |||
1678 | case ISD::SIGN_EXTEND_VECTOR_INREG: | |||
1679 | case ISD::ZERO_EXTEND_VECTOR_INREG: return visitEXTEND_VECTOR_INREG(N); | |||
1680 | case ISD::TRUNCATE: return visitTRUNCATE(N); | |||
1681 | case ISD::BITCAST: return visitBITCAST(N); | |||
1682 | case ISD::BUILD_PAIR: return visitBUILD_PAIR(N); | |||
1683 | case ISD::FADD: return visitFADD(N); | |||
1684 | case ISD::STRICT_FADD: return visitSTRICT_FADD(N); | |||
1685 | case ISD::FSUB: return visitFSUB(N); | |||
1686 | case ISD::FMUL: return visitFMUL(N); | |||
1687 | case ISD::FMA: return visitFMA(N); | |||
1688 | case ISD::FDIV: return visitFDIV(N); | |||
1689 | case ISD::FREM: return visitFREM(N); | |||
1690 | case ISD::FSQRT: return visitFSQRT(N); | |||
1691 | case ISD::FCOPYSIGN: return visitFCOPYSIGN(N); | |||
1692 | case ISD::FPOW: return visitFPOW(N); | |||
1693 | case ISD::SINT_TO_FP: return visitSINT_TO_FP(N); | |||
1694 | case ISD::UINT_TO_FP: return visitUINT_TO_FP(N); | |||
1695 | case ISD::FP_TO_SINT: return visitFP_TO_SINT(N); | |||
1696 | case ISD::FP_TO_UINT: return visitFP_TO_UINT(N); | |||
1697 | case ISD::FP_ROUND: return visitFP_ROUND(N); | |||
1698 | case ISD::FP_EXTEND: return visitFP_EXTEND(N); | |||
1699 | case ISD::FNEG: return visitFNEG(N); | |||
1700 | case ISD::FABS: return visitFABS(N); | |||
1701 | case ISD::FFLOOR: return visitFFLOOR(N); | |||
1702 | case ISD::FMINNUM: return visitFMINNUM(N); | |||
1703 | case ISD::FMAXNUM: return visitFMAXNUM(N); | |||
1704 | case ISD::FMINIMUM: return visitFMINIMUM(N); | |||
1705 | case ISD::FMAXIMUM: return visitFMAXIMUM(N); | |||
1706 | case ISD::FCEIL: return visitFCEIL(N); | |||
1707 | case ISD::FTRUNC: return visitFTRUNC(N); | |||
1708 | case ISD::BRCOND: return visitBRCOND(N); | |||
1709 | case ISD::BR_CC: return visitBR_CC(N); | |||
1710 | case ISD::LOAD: return visitLOAD(N); | |||
1711 | case ISD::STORE: return visitSTORE(N); | |||
1712 | case ISD::INSERT_VECTOR_ELT: return visitINSERT_VECTOR_ELT(N); | |||
1713 | case ISD::EXTRACT_VECTOR_ELT: return visitEXTRACT_VECTOR_ELT(N); | |||
1714 | case ISD::BUILD_VECTOR: return visitBUILD_VECTOR(N); | |||
1715 | case ISD::CONCAT_VECTORS: return visitCONCAT_VECTORS(N); | |||
1716 | case ISD::EXTRACT_SUBVECTOR: return visitEXTRACT_SUBVECTOR(N); | |||
1717 | case ISD::VECTOR_SHUFFLE: return visitVECTOR_SHUFFLE(N); | |||
1718 | case ISD::SCALAR_TO_VECTOR: return visitSCALAR_TO_VECTOR(N); | |||
1719 | case ISD::INSERT_SUBVECTOR: return visitINSERT_SUBVECTOR(N); | |||
1720 | case ISD::MGATHER: return visitMGATHER(N); | |||
1721 | case ISD::MLOAD: return visitMLOAD(N); | |||
1722 | case ISD::MSCATTER: return visitMSCATTER(N); | |||
1723 | case ISD::MSTORE: return visitMSTORE(N); | |||
1724 | case ISD::LIFETIME_END: return visitLIFETIME_END(N); | |||
1725 | case ISD::FP_TO_FP16: return visitFP_TO_FP16(N); | |||
1726 | case ISD::FP16_TO_FP: return visitFP16_TO_FP(N); | |||
1727 | case ISD::FREEZE: return visitFREEZE(N); | |||
1728 | case ISD::VECREDUCE_FADD: | |||
1729 | case ISD::VECREDUCE_FMUL: | |||
1730 | case ISD::VECREDUCE_ADD: | |||
1731 | case ISD::VECREDUCE_MUL: | |||
1732 | case ISD::VECREDUCE_AND: | |||
1733 | case ISD::VECREDUCE_OR: | |||
1734 | case ISD::VECREDUCE_XOR: | |||
1735 | case ISD::VECREDUCE_SMAX: | |||
1736 | case ISD::VECREDUCE_SMIN: | |||
1737 | case ISD::VECREDUCE_UMAX: | |||
1738 | case ISD::VECREDUCE_UMIN: | |||
1739 | case ISD::VECREDUCE_FMAX: | |||
1740 | case ISD::VECREDUCE_FMIN: return visitVECREDUCE(N); | |||
1741 | } | |||
1742 | return SDValue(); | |||
1743 | } | |||
1744 | ||||
1745 | SDValue DAGCombiner::combine(SDNode *N) { | |||
1746 | SDValue RV; | |||
1747 | if (!DisableGenericCombines) | |||
1748 | RV = visit(N); | |||
1749 | ||||
1750 | // If nothing happened, try a target-specific DAG combine. | |||
1751 | if (!RV.getNode()) { | |||
1752 | assert(N->getOpcode() != ISD::DELETED_NODE &&((void)0) | |||
1753 | "Node was deleted but visit returned NULL!")((void)0); | |||
1754 | ||||
1755 | if (N->getOpcode() >= ISD::BUILTIN_OP_END || | |||
1756 | TLI.hasTargetDAGCombine((ISD::NodeType)N->getOpcode())) { | |||
1757 | ||||
1758 | // Expose the DAG combiner to the target combiner impls. | |||
1759 | TargetLowering::DAGCombinerInfo | |||
1760 | DagCombineInfo(DAG, Level, false, this); | |||
1761 | ||||
1762 | RV = TLI.PerformDAGCombine(N, DagCombineInfo); | |||
1763 | } | |||
1764 | } | |||
1765 | ||||
1766 | // If nothing happened still, try promoting the operation. | |||
1767 | if (!RV.getNode()) { | |||
1768 | switch (N->getOpcode()) { | |||
1769 | default: break; | |||
1770 | case ISD::ADD: | |||
1771 | case ISD::SUB: | |||
1772 | case ISD::MUL: | |||
1773 | case ISD::AND: | |||
1774 | case ISD::OR: | |||
1775 | case ISD::XOR: | |||
1776 | RV = PromoteIntBinOp(SDValue(N, 0)); | |||
1777 | break; | |||
1778 | case ISD::SHL: | |||
1779 | case ISD::SRA: | |||
1780 | case ISD::SRL: | |||
1781 | RV = PromoteIntShiftOp(SDValue(N, 0)); | |||
1782 | break; | |||
1783 | case ISD::SIGN_EXTEND: | |||
1784 | case ISD::ZERO_EXTEND: | |||
1785 | case ISD::ANY_EXTEND: | |||
1786 | RV = PromoteExtend(SDValue(N, 0)); | |||
1787 | break; | |||
1788 | case ISD::LOAD: | |||
1789 | if (PromoteLoad(SDValue(N, 0))) | |||
1790 | RV = SDValue(N, 0); | |||
1791 | break; | |||
1792 | } | |||
1793 | } | |||
1794 | ||||
1795 | // If N is a commutative binary node, try to eliminate it if the commuted | |||
1796 | // version is already present in the DAG. | |||
1797 | if (!RV.getNode() && TLI.isCommutativeBinOp(N->getOpcode()) && | |||
1798 | N->getNumValues() == 1) { | |||
1799 | SDValue N0 = N->getOperand(0); | |||
1800 | SDValue N1 = N->getOperand(1); | |||
1801 | ||||
1802 | // Constant operands are canonicalized to RHS. | |||
1803 | if (N0 != N1 && (isa<ConstantSDNode>(N0) || !isa<ConstantSDNode>(N1))) { | |||
1804 | SDValue Ops[] = {N1, N0}; | |||
1805 | SDNode *CSENode = DAG.getNodeIfExists(N->getOpcode(), N->getVTList(), Ops, | |||
1806 | N->getFlags()); | |||
1807 | if (CSENode) | |||
1808 | return SDValue(CSENode, 0); | |||
1809 | } | |||
1810 | } | |||
1811 | ||||
1812 | return RV; | |||
1813 | } | |||
1814 | ||||
1815 | /// Given a node, return its input chain if it has one, otherwise return a null | |||
1816 | /// sd operand. | |||
1817 | static SDValue getInputChainForNode(SDNode *N) { | |||
1818 | if (unsigned NumOps = N->getNumOperands()) { | |||
1819 | if (N->getOperand(0).getValueType() == MVT::Other) | |||
1820 | return N->getOperand(0); | |||
1821 | if (N->getOperand(NumOps-1).getValueType() == MVT::Other) | |||
1822 | return N->getOperand(NumOps-1); | |||
1823 | for (unsigned i = 1; i < NumOps-1; ++i) | |||
1824 | if (N->getOperand(i).getValueType() == MVT::Other) | |||
1825 | return N->getOperand(i); | |||
1826 | } | |||
1827 | return SDValue(); | |||
1828 | } | |||
1829 | ||||
1830 | SDValue DAGCombiner::visitTokenFactor(SDNode *N) { | |||
1831 | // If N has two operands, where one has an input chain equal to the other, | |||
1832 | // the 'other' chain is redundant. | |||
1833 | if (N->getNumOperands() == 2) { | |||
1834 | if (getInputChainForNode(N->getOperand(0).getNode()) == N->getOperand(1)) | |||
1835 | return N->getOperand(0); | |||
1836 | if (getInputChainForNode(N->getOperand(1).getNode()) == N->getOperand(0)) | |||
1837 | return N->getOperand(1); | |||
1838 | } | |||
1839 | ||||
1840 | // Don't simplify token factors if optnone. | |||
1841 | if (OptLevel == CodeGenOpt::None) | |||
1842 | return SDValue(); | |||
1843 | ||||
1844 | // Don't simplify the token factor if the node itself has too many operands. | |||
1845 | if (N->getNumOperands() > TokenFactorInlineLimit) | |||
1846 | return SDValue(); | |||
1847 | ||||
1848 | // If the sole user is a token factor, we should make sure we have a | |||
1849 | // chance to merge them together. This prevents TF chains from inhibiting | |||
1850 | // optimizations. | |||
1851 | if (N->hasOneUse() && N->use_begin()->getOpcode() == ISD::TokenFactor) | |||
1852 | AddToWorklist(*(N->use_begin())); | |||
1853 | ||||
1854 | SmallVector<SDNode *, 8> TFs; // List of token factors to visit. | |||
1855 | SmallVector<SDValue, 8> Ops; // Ops for replacing token factor. | |||
1856 | SmallPtrSet<SDNode*, 16> SeenOps; | |||
1857 | bool Changed = false; // If we should replace this token factor. | |||
1858 | ||||
1859 | // Start out with this token factor. | |||
1860 | TFs.push_back(N); | |||
1861 | ||||
1862 | // Iterate through token factors. The TFs grows when new token factors are | |||
1863 | // encountered. | |||
1864 | for (unsigned i = 0; i < TFs.size(); ++i) { | |||
1865 | // Limit number of nodes to inline, to avoid quadratic compile times. | |||
1866 | // We have to add the outstanding Token Factors to Ops, otherwise we might | |||
1867 | // drop Ops from the resulting Token Factors. | |||
1868 | if (Ops.size() > TokenFactorInlineLimit) { | |||
1869 | for (unsigned j = i; j < TFs.size(); j++) | |||
1870 | Ops.emplace_back(TFs[j], 0); | |||
1871 | // Drop unprocessed Token Factors from TFs, so we do not add them to the | |||
1872 | // combiner worklist later. | |||
1873 | TFs.resize(i); | |||
1874 | break; | |||
1875 | } | |||
1876 | ||||
1877 | SDNode *TF = TFs[i]; | |||
1878 | // Check each of the operands. | |||
1879 | for (const SDValue &Op : TF->op_values()) { | |||
1880 | switch (Op.getOpcode()) { | |||
1881 | case ISD::EntryToken: | |||
1882 | // Entry tokens don't need to be added to the list. They are | |||
1883 | // redundant. | |||
1884 | Changed = true; | |||
1885 | break; | |||
1886 | ||||
1887 | case ISD::TokenFactor: | |||
1888 | if (Op.hasOneUse() && !is_contained(TFs, Op.getNode())) { | |||
1889 | // Queue up for processing. | |||
1890 | TFs.push_back(Op.getNode()); | |||
1891 | Changed = true; | |||
1892 | break; | |||
1893 | } | |||
1894 | LLVM_FALLTHROUGH[[gnu::fallthrough]]; | |||
1895 | ||||
1896 | default: | |||
1897 | // Only add if it isn't already in the list. | |||
1898 | if (SeenOps.insert(Op.getNode()).second) | |||
1899 | Ops.push_back(Op); | |||
1900 | else | |||
1901 | Changed = true; | |||
1902 | break; | |||
1903 | } | |||
1904 | } | |||
1905 | } | |||
1906 | ||||
1907 | // Re-visit inlined Token Factors, to clean them up in case they have been | |||
1908 | // removed. Skip the first Token Factor, as this is the current node. | |||
1909 | for (unsigned i = 1, e = TFs.size(); i < e; i++) | |||
1910 | AddToWorklist(TFs[i]); | |||
1911 | ||||
1912 | // Remove Nodes that are chained to another node in the list. Do so | |||
1913 | // by walking up chains breath-first stopping when we've seen | |||
1914 | // another operand. In general we must climb to the EntryNode, but we can exit | |||
1915 | // early if we find all remaining work is associated with just one operand as | |||
1916 | // no further pruning is possible. | |||
1917 | ||||
1918 | // List of nodes to search through and original Ops from which they originate. | |||
1919 | SmallVector<std::pair<SDNode *, unsigned>, 8> Worklist; | |||
1920 | SmallVector<unsigned, 8> OpWorkCount; // Count of work for each Op. | |||
1921 | SmallPtrSet<SDNode *, 16> SeenChains; | |||
1922 | bool DidPruneOps = false; | |||
1923 | ||||
1924 | unsigned NumLeftToConsider = 0; | |||
1925 | for (const SDValue &Op : Ops) { | |||
1926 | Worklist.push_back(std::make_pair(Op.getNode(), NumLeftToConsider++)); | |||
1927 | OpWorkCount.push_back(1); | |||
1928 | } | |||
1929 | ||||
1930 | auto AddToWorklist = [&](unsigned CurIdx, SDNode *Op, unsigned OpNumber) { | |||
1931 | // If this is an Op, we can remove the op from the list. Remark any | |||
1932 | // search associated with it as from the current OpNumber. | |||
1933 | if (SeenOps.contains(Op)) { | |||
1934 | Changed = true; | |||
1935 | DidPruneOps = true; | |||
1936 | unsigned OrigOpNumber = 0; | |||
1937 | while (OrigOpNumber < Ops.size() && Ops[OrigOpNumber].getNode() != Op) | |||
1938 | OrigOpNumber++; | |||
1939 | assert((OrigOpNumber != Ops.size()) &&((void)0) | |||
1940 | "expected to find TokenFactor Operand")((void)0); | |||
1941 | // Re-mark worklist from OrigOpNumber to OpNumber | |||
1942 | for (unsigned i = CurIdx + 1; i < Worklist.size(); ++i) { | |||
1943 | if (Worklist[i].second == OrigOpNumber) { | |||
1944 | Worklist[i].second = OpNumber; | |||
1945 | } | |||
1946 | } | |||
1947 | OpWorkCount[OpNumber] += OpWorkCount[OrigOpNumber]; | |||
1948 | OpWorkCount[OrigOpNumber] = 0; | |||
1949 | NumLeftToConsider--; | |||
1950 | } | |||
1951 | // Add if it's a new chain | |||
1952 | if (SeenChains.insert(Op).second) { | |||
1953 | OpWorkCount[OpNumber]++; | |||
1954 | Worklist.push_back(std::make_pair(Op, OpNumber)); | |||
1955 | } | |||
1956 | }; | |||
1957 | ||||
1958 | for (unsigned i = 0; i < Worklist.size() && i < 1024; ++i) { | |||
1959 | // We need at least be consider at least 2 Ops to prune. | |||
1960 | if (NumLeftToConsider <= 1) | |||
1961 | break; | |||
1962 | auto CurNode = Worklist[i].first; | |||
1963 | auto CurOpNumber = Worklist[i].second; | |||
1964 | assert((OpWorkCount[CurOpNumber] > 0) &&((void)0) | |||
1965 | "Node should not appear in worklist")((void)0); | |||
1966 | switch (CurNode->getOpcode()) { | |||
1967 | case ISD::EntryToken: | |||
1968 | // Hitting EntryToken is the only way for the search to terminate without | |||
1969 | // hitting | |||
1970 | // another operand's search. Prevent us from marking this operand | |||
1971 | // considered. | |||
1972 | NumLeftToConsider++; | |||
1973 | break; | |||
1974 | case ISD::TokenFactor: | |||
1975 | for (const SDValue &Op : CurNode->op_values()) | |||
1976 | AddToWorklist(i, Op.getNode(), CurOpNumber); | |||
1977 | break; | |||
1978 | case ISD::LIFETIME_START: | |||
1979 | case ISD::LIFETIME_END: | |||
1980 | case ISD::CopyFromReg: | |||
1981 | case ISD::CopyToReg: | |||
1982 | AddToWorklist(i, CurNode->getOperand(0).getNode(), CurOpNumber); | |||
1983 | break; | |||
1984 | default: | |||
1985 | if (auto *MemNode = dyn_cast<MemSDNode>(CurNode)) | |||
1986 | AddToWorklist(i, MemNode->getChain().getNode(), CurOpNumber); | |||
1987 | break; | |||
1988 | } | |||
1989 | OpWorkCount[CurOpNumber]--; | |||
1990 | if (OpWorkCount[CurOpNumber] == 0) | |||
1991 | NumLeftToConsider--; | |||
1992 | } | |||
1993 | ||||
1994 | // If we've changed things around then replace token factor. | |||
1995 | if (Changed) { | |||
1996 | SDValue Result; | |||
1997 | if (Ops.empty()) { | |||
1998 | // The entry token is the only possible outcome. | |||
1999 | Result = DAG.getEntryNode(); | |||
2000 | } else { | |||
2001 | if (DidPruneOps) { | |||
2002 | SmallVector<SDValue, 8> PrunedOps; | |||
2003 | // | |||
2004 | for (const SDValue &Op : Ops) { | |||
2005 | if (SeenChains.count(Op.getNode()) == 0) | |||
2006 | PrunedOps.push_back(Op); | |||
2007 | } | |||
2008 | Result = DAG.getTokenFactor(SDLoc(N), PrunedOps); | |||
2009 | } else { | |||
2010 | Result = DAG.getTokenFactor(SDLoc(N), Ops); | |||
2011 | } | |||
2012 | } | |||
2013 | return Result; | |||
2014 | } | |||
2015 | return SDValue(); | |||
2016 | } | |||
2017 | ||||
2018 | /// MERGE_VALUES can always be eliminated. | |||
2019 | SDValue DAGCombiner::visitMERGE_VALUES(SDNode *N) { | |||
2020 | WorklistRemover DeadNodes(*this); | |||
2021 | // Replacing results may cause a different MERGE_VALUES to suddenly | |||
2022 | // be CSE'd with N, and carry its uses with it. Iterate until no | |||
2023 | // uses remain, to ensure that the node can be safely deleted. | |||
2024 | // First add the users of this node to the work list so that they | |||
2025 | // can be tried again once they have new operands. | |||
2026 | AddUsersToWorklist(N); | |||
2027 | do { | |||
2028 | // Do as a single replacement to avoid rewalking use lists. | |||
2029 | SmallVector<SDValue, 8> Ops; | |||
2030 | for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) | |||
2031 | Ops.push_back(N->getOperand(i)); | |||
2032 | DAG.ReplaceAllUsesWith(N, Ops.data()); | |||
2033 | } while (!N->use_empty()); | |||
2034 | deleteAndRecombine(N); | |||
2035 | return SDValue(N, 0); // Return N so it doesn't get rechecked! | |||
2036 | } | |||
2037 | ||||
2038 | /// If \p N is a ConstantSDNode with isOpaque() == false return it casted to a | |||
2039 | /// ConstantSDNode pointer else nullptr. | |||
2040 | static ConstantSDNode *getAsNonOpaqueConstant(SDValue N) { | |||
2041 | ConstantSDNode *Const = dyn_cast<ConstantSDNode>(N); | |||
2042 | return Const != nullptr && !Const->isOpaque() ? Const : nullptr; | |||
2043 | } | |||
2044 | ||||
2045 | /// Return true if 'Use' is a load or a store that uses N as its base pointer | |||
2046 | /// and that N may be folded in the load / store addressing mode. | |||
2047 | static bool canFoldInAddressingMode(SDNode *N, SDNode *Use, SelectionDAG &DAG, | |||
2048 | const TargetLowering &TLI) { | |||
2049 | EVT VT; | |||
2050 | unsigned AS; | |||
2051 | ||||
2052 | if (LoadSDNode *LD = dyn_cast<LoadSDNode>(Use)) { | |||
2053 | if (LD->isIndexed() || LD->getBasePtr().getNode() != N) | |||
2054 | return false; | |||
2055 | VT = LD->getMemoryVT(); | |||
2056 | AS = LD->getAddressSpace(); | |||
2057 | } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(Use)) { | |||
2058 | if (ST->isIndexed() || ST->getBasePtr().getNode() != N) | |||
2059 | return false; | |||
2060 | VT = ST->getMemoryVT(); | |||
2061 | AS = ST->getAddressSpace(); | |||
2062 | } else if (MaskedLoadSDNode *LD = dyn_cast<MaskedLoadSDNode>(Use)) { | |||
2063 | if (LD->isIndexed() || LD->getBasePtr().getNode() != N) | |||
2064 | return false; | |||
2065 | VT = LD->getMemoryVT(); | |||
2066 | AS = LD->getAddressSpace(); | |||
2067 | } else if (MaskedStoreSDNode *ST = dyn_cast<MaskedStoreSDNode>(Use)) { | |||
2068 | if (ST->isIndexed() || ST->getBasePtr().getNode() != N) | |||
2069 | return false; | |||
2070 | VT = ST->getMemoryVT(); | |||
2071 | AS = ST->getAddressSpace(); | |||
2072 | } else | |||
2073 | return false; | |||
2074 | ||||
2075 | TargetLowering::AddrMode AM; | |||
2076 | if (N->getOpcode() == ISD::ADD) { | |||
2077 | AM.HasBaseReg = true; | |||
2078 | ConstantSDNode *Offset = dyn_cast<ConstantSDNode>(N->getOperand(1)); | |||
2079 | if (Offset) | |||
2080 | // [reg +/- imm] | |||
2081 | AM.BaseOffs = Offset->getSExtValue(); | |||
2082 | else | |||
2083 | // [reg +/- reg] | |||
2084 | AM.Scale = 1; | |||
2085 | } else if (N->getOpcode() == ISD::SUB) { | |||
2086 | AM.HasBaseReg = true; | |||
2087 | ConstantSDNode *Offset = dyn_cast<ConstantSDNode>(N->getOperand(1)); | |||
2088 | if (Offset) | |||
2089 | // [reg +/- imm] | |||
2090 | AM.BaseOffs = -Offset->getSExtValue(); | |||
2091 | else | |||
2092 | // [reg +/- reg] | |||
2093 | AM.Scale = 1; | |||
2094 | } else | |||
2095 | return false; | |||
2096 | ||||
2097 | return TLI.isLegalAddressingMode(DAG.getDataLayout(), AM, | |||
2098 | VT.getTypeForEVT(*DAG.getContext()), AS); | |||
2099 | } | |||
2100 | ||||
2101 | SDValue DAGCombiner::foldBinOpIntoSelect(SDNode *BO) { | |||
2102 | assert(TLI.isBinOp(BO->getOpcode()) && BO->getNumValues() == 1 &&((void)0) | |||
2103 | "Unexpected binary operator")((void)0); | |||
2104 | ||||
2105 | // Don't do this unless the old select is going away. We want to eliminate the | |||
2106 | // binary operator, not replace a binop with a select. | |||
2107 | // TODO: Handle ISD::SELECT_CC. | |||
2108 | unsigned SelOpNo = 0; | |||
2109 | SDValue Sel = BO->getOperand(0); | |||
2110 | if (Sel.getOpcode() != ISD::SELECT || !Sel.hasOneUse()) { | |||
2111 | SelOpNo = 1; | |||
2112 | Sel = BO->getOperand(1); | |||
2113 | } | |||
2114 | ||||
2115 | if (Sel.getOpcode() != ISD::SELECT || !Sel.hasOneUse()) | |||
2116 | return SDValue(); | |||
2117 | ||||
2118 | SDValue CT = Sel.getOperand(1); | |||
2119 | if (!isConstantOrConstantVector(CT, true) && | |||
2120 | !DAG.isConstantFPBuildVectorOrConstantFP(CT)) | |||
2121 | return SDValue(); | |||
2122 | ||||
2123 | SDValue CF = Sel.getOperand(2); | |||
2124 | if (!isConstantOrConstantVector(CF, true) && | |||
2125 | !DAG.isConstantFPBuildVectorOrConstantFP(CF)) | |||
2126 | return SDValue(); | |||
2127 | ||||
2128 | // Bail out if any constants are opaque because we can't constant fold those. | |||
2129 | // The exception is "and" and "or" with either 0 or -1 in which case we can | |||
2130 | // propagate non constant operands into select. I.e.: | |||
2131 | // and (select Cond, 0, -1), X --> select Cond, 0, X | |||
2132 | // or X, (select Cond, -1, 0) --> select Cond, -1, X | |||
2133 | auto BinOpcode = BO->getOpcode(); | |||
2134 | bool CanFoldNonConst = | |||
2135 | (BinOpcode == ISD::AND || BinOpcode == ISD::OR) && | |||
2136 | (isNullOrNullSplat(CT) || isAllOnesOrAllOnesSplat(CT)) && | |||
2137 | (isNullOrNullSplat(CF) || isAllOnesOrAllOnesSplat(CF)); | |||
2138 | ||||
2139 | SDValue CBO = BO->getOperand(SelOpNo ^ 1); | |||
2140 | if (!CanFoldNonConst && | |||
2141 | !isConstantOrConstantVector(CBO, true) && | |||
2142 | !DAG.isConstantFPBuildVectorOrConstantFP(CBO)) | |||
2143 | return SDValue(); | |||
2144 | ||||
2145 | EVT VT = BO->getValueType(0); | |||
2146 | ||||
2147 | // We have a select-of-constants followed by a binary operator with a | |||
2148 | // constant. Eliminate the binop by pulling the constant math into the select. | |||
2149 | // Example: add (select Cond, CT, CF), CBO --> select Cond, CT + CBO, CF + CBO | |||
2150 | SDLoc DL(Sel); | |||
2151 | SDValue NewCT = SelOpNo ? DAG.getNode(BinOpcode, DL, VT, CBO, CT) | |||
2152 | : DAG.getNode(BinOpcode, DL, VT, CT, CBO); | |||
2153 | if (!CanFoldNonConst && !NewCT.isUndef() && | |||
2154 | !isConstantOrConstantVector(NewCT, true) && | |||
2155 | !DAG.isConstantFPBuildVectorOrConstantFP(NewCT)) | |||
2156 | return SDValue(); | |||
2157 | ||||
2158 | SDValue NewCF = SelOpNo ? DAG.getNode(BinOpcode, DL, VT, CBO, CF) | |||
2159 | : DAG.getNode(BinOpcode, DL, VT, CF, CBO); | |||
2160 | if (!CanFoldNonConst && !NewCF.isUndef() && | |||
2161 | !isConstantOrConstantVector(NewCF, true) && | |||
2162 | !DAG.isConstantFPBuildVectorOrConstantFP(NewCF)) | |||
2163 | return SDValue(); | |||
2164 | ||||
2165 | SDValue SelectOp = DAG.getSelect(DL, VT, Sel.getOperand(0), NewCT, NewCF); | |||
2166 | SelectOp->setFlags(BO->getFlags()); | |||
2167 | return SelectOp; | |||
2168 | } | |||
2169 | ||||
2170 | static SDValue foldAddSubBoolOfMaskedVal(SDNode *N, SelectionDAG &DAG) { | |||
2171 | assert((N->getOpcode() == ISD::ADD || N->getOpcode() == ISD::SUB) &&((void)0) | |||
2172 | "Expecting add or sub")((void)0); | |||
2173 | ||||
2174 | // Match a constant operand and a zext operand for the math instruction: | |||
2175 | // add Z, C | |||
2176 | // sub C, Z | |||
2177 | bool IsAdd = N->getOpcode() == ISD::ADD; | |||
2178 | SDValue C = IsAdd ? N->getOperand(1) : N->getOperand(0); | |||
2179 | SDValue Z = IsAdd ? N->getOperand(0) : N->getOperand(1); | |||
2180 | auto *CN = dyn_cast<ConstantSDNode>(C); | |||
2181 | if (!CN || Z.getOpcode() != ISD::ZERO_EXTEND) | |||
2182 | return SDValue(); | |||
2183 | ||||
2184 | // Match the zext operand as a setcc of a boolean. | |||
2185 | if (Z.getOperand(0).getOpcode() != ISD::SETCC || | |||
2186 | Z.getOperand(0).getValueType() != MVT::i1) | |||
2187 | return SDValue(); | |||
2188 | ||||
2189 | // Match the compare as: setcc (X & 1), 0, eq. | |||
2190 | SDValue SetCC = Z.getOperand(0); | |||
2191 | ISD::CondCode CC = cast<CondCodeSDNode>(SetCC->getOperand(2))->get(); | |||
2192 | if (CC != ISD::SETEQ || !isNullConstant(SetCC.getOperand(1)) || | |||
2193 | SetCC.getOperand(0).getOpcode() != ISD::AND || | |||
2194 | !isOneConstant(SetCC.getOperand(0).getOperand(1))) | |||
2195 | return SDValue(); | |||
2196 | ||||
2197 | // We are adding/subtracting a constant and an inverted low bit. Turn that | |||
2198 | // into a subtract/add of the low bit with incremented/decremented constant: | |||
2199 | // add (zext i1 (seteq (X & 1), 0)), C --> sub C+1, (zext (X & 1)) | |||
2200 | // sub C, (zext i1 (seteq (X & 1), 0)) --> add C-1, (zext (X & 1)) | |||
2201 | EVT VT = C.getValueType(); | |||
2202 | SDLoc DL(N); | |||
2203 | SDValue LowBit = DAG.getZExtOrTrunc(SetCC.getOperand(0), DL, VT); | |||
2204 | SDValue C1 = IsAdd ? DAG.getConstant(CN->getAPIntValue() + 1, DL, VT) : | |||
2205 | DAG.getConstant(CN->getAPIntValue() - 1, DL, VT); | |||
2206 | return DAG.getNode(IsAdd ? ISD::SUB : ISD::ADD, DL, VT, C1, LowBit); | |||
2207 | } | |||
2208 | ||||
2209 | /// Try to fold a 'not' shifted sign-bit with add/sub with constant operand into | |||
2210 | /// a shift and add with a different constant. | |||
2211 | static SDValue foldAddSubOfSignBit(SDNode *N, SelectionDAG &DAG) { | |||
2212 | assert((N->getOpcode() == ISD::ADD || N->getOpcode() == ISD::SUB) &&((void)0) | |||
2213 | "Expecting add or sub")((void)0); | |||
2214 | ||||
2215 | // We need a constant operand for the add/sub, and the other operand is a | |||
2216 | // logical shift right: add (srl), C or sub C, (srl). | |||
2217 | bool IsAdd = N->getOpcode() == ISD::ADD; | |||
2218 | SDValue ConstantOp = IsAdd ? N->getOperand(1) : N->getOperand(0); | |||
2219 | SDValue ShiftOp = IsAdd ? N->getOperand(0) : N->getOperand(1); | |||
2220 | if (!DAG.isConstantIntBuildVectorOrConstantInt(ConstantOp) || | |||
2221 | ShiftOp.getOpcode() != ISD::SRL) | |||
2222 | return SDValue(); | |||
2223 | ||||
2224 | // The shift must be of a 'not' value. | |||
2225 | SDValue Not = ShiftOp.getOperand(0); | |||
2226 | if (!Not.hasOneUse() || !isBitwiseNot(Not)) | |||
2227 | return SDValue(); | |||
2228 | ||||
2229 | // The shift must be moving the sign bit to the least-significant-bit. | |||
2230 | EVT VT = ShiftOp.getValueType(); | |||
2231 | SDValue ShAmt = ShiftOp.getOperand(1); | |||
2232 | ConstantSDNode *ShAmtC = isConstOrConstSplat(ShAmt); | |||
2233 | if (!ShAmtC || ShAmtC->getAPIntValue() != (VT.getScalarSizeInBits() - 1)) | |||
2234 | return SDValue(); | |||
2235 | ||||
2236 | // Eliminate the 'not' by adjusting the shift and add/sub constant: | |||
2237 | // add (srl (not X), 31), C --> add (sra X, 31), (C + 1) | |||
2238 | // sub C, (srl (not X), 31) --> add (srl X, 31), (C - 1) | |||
2239 | SDLoc DL(N); | |||
2240 | auto ShOpcode = IsAdd ? ISD::SRA : ISD::SRL; | |||
2241 | SDValue NewShift = DAG.getNode(ShOpcode, DL, VT, Not.getOperand(0), ShAmt); | |||
2242 | if (SDValue NewC = | |||
2243 | DAG.FoldConstantArithmetic(IsAdd ? ISD::ADD : ISD::SUB, DL, VT, | |||
2244 | {ConstantOp, DAG.getConstant(1, DL, VT)})) | |||
2245 | return DAG.getNode(ISD::ADD, DL, VT, NewShift, NewC); | |||
2246 | return SDValue(); | |||
2247 | } | |||
2248 | ||||
2249 | /// Try to fold a node that behaves like an ADD (note that N isn't necessarily | |||
2250 | /// an ISD::ADD here, it could for example be an ISD::OR if we know that there | |||
2251 | /// are no common bits set in the operands). | |||
2252 | SDValue DAGCombiner::visitADDLike(SDNode *N) { | |||
2253 | SDValue N0 = N->getOperand(0); | |||
2254 | SDValue N1 = N->getOperand(1); | |||
2255 | EVT VT = N0.getValueType(); | |||
2256 | SDLoc DL(N); | |||
2257 | ||||
2258 | // fold vector ops | |||
2259 | if (VT.isVector()) { | |||
2260 | if (SDValue FoldedVOp = SimplifyVBinOp(N)) | |||
2261 | return FoldedVOp; | |||
2262 | ||||
2263 | // fold (add x, 0) -> x, vector edition | |||
2264 | if (ISD::isConstantSplatVectorAllZeros(N1.getNode())) | |||
2265 | return N0; | |||
2266 | if (ISD::isConstantSplatVectorAllZeros(N0.getNode())) | |||
2267 | return N1; | |||
2268 | } | |||
2269 | ||||
2270 | // fold (add x, undef) -> undef | |||
2271 | if (N0.isUndef()) | |||
2272 | return N0; | |||
2273 | ||||
2274 | if (N1.isUndef()) | |||
2275 | return N1; | |||
2276 | ||||
2277 | if (DAG.isConstantIntBuildVectorOrConstantInt(N0)) { | |||
2278 | // canonicalize constant to RHS | |||
2279 | if (!DAG.isConstantIntBuildVectorOrConstantInt(N1)) | |||
2280 | return DAG.getNode(ISD::ADD, DL, VT, N1, N0); | |||
2281 | // fold (add c1, c2) -> c1+c2 | |||
2282 | return DAG.FoldConstantArithmetic(ISD::ADD, DL, VT, {N0, N1}); | |||
2283 | } | |||
2284 | ||||
2285 | // fold (add x, 0) -> x | |||
2286 | if (isNullConstant(N1)) | |||
2287 | return N0; | |||
2288 | ||||
2289 | if (isConstantOrConstantVector(N1, /* NoOpaque */ true)) { | |||
2290 | // fold ((A-c1)+c2) -> (A+(c2-c1)) | |||
2291 | if (N0.getOpcode() == ISD::SUB && | |||
2292 | isConstantOrConstantVector(N0.getOperand(1), /* NoOpaque */ true)) { | |||
2293 | SDValue Sub = | |||
2294 | DAG.FoldConstantArithmetic(ISD::SUB, DL, VT, {N1, N0.getOperand(1)}); | |||
2295 | assert(Sub && "Constant folding failed")((void)0); | |||
2296 | return DAG.getNode(ISD::ADD, DL, VT, N0.getOperand(0), Sub); | |||
2297 | } | |||
2298 | ||||
2299 | // fold ((c1-A)+c2) -> (c1+c2)-A | |||
2300 | if (N0.getOpcode() == ISD::SUB && | |||
2301 | isConstantOrConstantVector(N0.getOperand(0), /* NoOpaque */ true)) { | |||
2302 | SDValue Add = | |||
2303 | DAG.FoldConstantArithmetic(ISD::ADD, DL, VT, {N1, N0.getOperand(0)}); | |||
2304 | assert(Add && "Constant folding failed")((void)0); | |||
2305 | return DAG.getNode(ISD::SUB, DL, VT, Add, N0.getOperand(1)); | |||
2306 | } | |||
2307 | ||||
2308 | // add (sext i1 X), 1 -> zext (not i1 X) | |||
2309 | // We don't transform this pattern: | |||
2310 | // add (zext i1 X), -1 -> sext (not i1 X) | |||
2311 | // because most (?) targets generate better code for the zext form. | |||
2312 | if (N0.getOpcode() == ISD::SIGN_EXTEND && N0.hasOneUse() && | |||
2313 | isOneOrOneSplat(N1)) { | |||
2314 | SDValue X = N0.getOperand(0); | |||
2315 | if ((!LegalOperations || | |||
2316 | (TLI.isOperationLegal(ISD::XOR, X.getValueType()) && | |||
2317 | TLI.isOperationLegal(ISD::ZERO_EXTEND, VT))) && | |||
2318 | X.getScalarValueSizeInBits() == 1) { | |||
2319 | SDValue Not = DAG.getNOT(DL, X, X.getValueType()); | |||
2320 | return DAG.getNode(ISD::ZERO_EXTEND, DL, VT, Not); | |||
2321 | } | |||
2322 | } | |||
2323 | ||||
2324 | // Fold (add (or x, c0), c1) -> (add x, (c0 + c1)) if (or x, c0) is | |||
2325 | // equivalent to (add x, c0). | |||
2326 | if (N0.getOpcode() == ISD::OR && | |||
2327 | isConstantOrConstantVector(N0.getOperand(1), /* NoOpaque */ true) && | |||
2328 | DAG.haveNoCommonBitsSet(N0.getOperand(0), N0.getOperand(1))) { | |||
2329 | if (SDValue Add0 = DAG.FoldConstantArithmetic(ISD::ADD, DL, VT, | |||
2330 | {N1, N0.getOperand(1)})) | |||
2331 | return DAG.getNode(ISD::ADD, DL, VT, N0.getOperand(0), Add0); | |||
2332 | } | |||
2333 | } | |||
2334 | ||||
2335 | if (SDValue NewSel = foldBinOpIntoSelect(N)) | |||
2336 | return NewSel; | |||
2337 | ||||
2338 | // reassociate add | |||
2339 | if (!reassociationCanBreakAddressingModePattern(ISD::ADD, DL, N0, N1)) { | |||
2340 | if (SDValue RADD = reassociateOps(ISD::ADD, DL, N0, N1, N->getFlags())) | |||
2341 | return RADD; | |||
2342 | ||||
2343 | // Reassociate (add (or x, c), y) -> (add add(x, y), c)) if (or x, c) is | |||
2344 | // equivalent to (add x, c). | |||
2345 | auto ReassociateAddOr = [&](SDValue N0, SDValue N1) { | |||
2346 | if (N0.getOpcode() == ISD::OR && N0.hasOneUse() && | |||
2347 | isConstantOrConstantVector(N0.getOperand(1), /* NoOpaque */ true) && | |||
2348 | DAG.haveNoCommonBitsSet(N0.getOperand(0), N0.getOperand(1))) { | |||
2349 | return DAG.getNode(ISD::ADD, DL, VT, | |||
2350 | DAG.getNode(ISD::ADD, DL, VT, N1, N0.getOperand(0)), | |||
2351 | N0.getOperand(1)); | |||
2352 | } | |||
2353 | return SDValue(); | |||
2354 | }; | |||
2355 | if (SDValue Add = ReassociateAddOr(N0, N1)) | |||
2356 | return Add; | |||
2357 | if (SDValue Add = ReassociateAddOr(N1, N0)) | |||
2358 | return Add; | |||
2359 | } | |||
2360 | // fold ((0-A) + B) -> B-A | |||
2361 | if (N0.getOpcode() == ISD::SUB && isNullOrNullSplat(N0.getOperand(0))) | |||
2362 | return DAG.getNode(ISD::SUB, DL, VT, N1, N0.getOperand(1)); | |||
2363 | ||||
2364 | // fold (A + (0-B)) -> A-B | |||
2365 | if (N1.getOpcode() == ISD::SUB && isNullOrNullSplat(N1.getOperand(0))) | |||
2366 | return DAG.getNode(ISD::SUB, DL, VT, N0, N1.getOperand(1)); | |||
2367 | ||||
2368 | // fold (A+(B-A)) -> B | |||
2369 | if (N1.getOpcode() == ISD::SUB && N0 == N1.getOperand(1)) | |||
2370 | return N1.getOperand(0); | |||
2371 | ||||
2372 | // fold ((B-A)+A) -> B | |||
2373 | if (N0.getOpcode() == ISD::SUB && N1 == N0.getOperand(1)) | |||
2374 | return N0.getOperand(0); | |||
2375 | ||||
2376 | // fold ((A-B)+(C-A)) -> (C-B) | |||
2377 | if (N0.getOpcode() == ISD::SUB && N1.getOpcode() == ISD::SUB && | |||
2378 | N0.getOperand(0) == N1.getOperand(1)) | |||
2379 | return DAG.getNode(ISD::SUB, DL, VT, N1.getOperand(0), | |||
2380 | N0.getOperand(1)); | |||
2381 | ||||
2382 | // fold ((A-B)+(B-C)) -> (A-C) | |||
2383 | if (N0.getOpcode() == ISD::SUB && N1.getOpcode() == ISD::SUB && | |||
2384 | N0.getOperand(1) == N1.getOperand(0)) | |||
2385 | return DAG.getNode(ISD::SUB, DL, VT, N0.getOperand(0), | |||
2386 | N1.getOperand(1)); | |||
2387 | ||||
2388 | // fold (A+(B-(A+C))) to (B-C) | |||
2389 | if (N1.getOpcode() == ISD::SUB && N1.getOperand(1).getOpcode() == ISD::ADD && | |||
2390 | N0 == N1.getOperand(1).getOperand(0)) | |||
2391 | return DAG.getNode(ISD::SUB, DL, VT, N1.getOperand(0), | |||
2392 | N1.getOperand(1).getOperand(1)); | |||
2393 | ||||
2394 | // fold (A+(B-(C+A))) to (B-C) | |||
2395 | if (N1.getOpcode() == ISD::SUB && N1.getOperand(1).getOpcode() == ISD::ADD && | |||
2396 | N0 == N1.getOperand(1).getOperand(1)) | |||
2397 | return DAG.getNode(ISD::SUB, DL, VT, N1.getOperand(0), | |||
2398 | N1.getOperand(1).getOperand(0)); | |||
2399 | ||||
2400 | // fold (A+((B-A)+or-C)) to (B+or-C) | |||
2401 | if ((N1.getOpcode() == ISD::SUB || N1.getOpcode() == ISD::ADD) && | |||
2402 | N1.getOperand(0).getOpcode() == ISD::SUB && | |||
2403 | N0 == N1.getOperand(0).getOperand(1)) | |||
2404 | return DAG.getNode(N1.getOpcode(), DL, VT, N1.getOperand(0).getOperand(0), | |||
2405 | N1.getOperand(1)); | |||
2406 | ||||
2407 | // fold (A-B)+(C-D) to (A+C)-(B+D) when A or C is constant | |||
2408 | if (N0.getOpcode() == ISD::SUB && N1.getOpcode() == ISD::SUB) { | |||
2409 | SDValue N00 = N0.getOperand(0); | |||
2410 | SDValue N01 = N0.getOperand(1); | |||
2411 | SDValue N10 = N1.getOperand(0); | |||
2412 | SDValue N11 = N1.getOperand(1); | |||
2413 | ||||
2414 | if (isConstantOrConstantVector(N00) || isConstantOrConstantVector(N10)) | |||
2415 | return DAG.getNode(ISD::SUB, DL, VT, | |||
2416 | DAG.getNode(ISD::ADD, SDLoc(N0), VT, N00, N10), | |||
2417 | DAG.getNode(ISD::ADD, SDLoc(N1), VT, N01, N11)); | |||
2418 | } | |||
2419 | ||||
2420 | // fold (add (umax X, C), -C) --> (usubsat X, C) | |||
2421 | if (N0.getOpcode() == ISD::UMAX && hasOperation(ISD::USUBSAT, VT)) { | |||
2422 | auto MatchUSUBSAT = [](ConstantSDNode *Max, ConstantSDNode *Op) { | |||
2423 | return (!Max && !Op) || | |||
2424 | (Max && Op && Max->getAPIntValue() == (-Op->getAPIntValue())); | |||
2425 | }; | |||
2426 | if (ISD::matchBinaryPredicate(N0.getOperand(1), N1, MatchUSUBSAT, | |||
2427 | /*AllowUndefs*/ true)) | |||
2428 | return DAG.getNode(ISD::USUBSAT, DL, VT, N0.getOperand(0), | |||
2429 | N0.getOperand(1)); | |||
2430 | } | |||
2431 | ||||
2432 | if (SimplifyDemandedBits(SDValue(N, 0))) | |||
2433 | return SDValue(N, 0); | |||
2434 | ||||
2435 | if (isOneOrOneSplat(N1)) { | |||
2436 | // fold (add (xor a, -1), 1) -> (sub 0, a) | |||
2437 | if (isBitwiseNot(N0)) | |||
2438 | return DAG.getNode(ISD::SUB, DL, VT, DAG.getConstant(0, DL, VT), | |||
2439 | N0.getOperand(0)); | |||
2440 | ||||
2441 | // fold (add (add (xor a, -1), b), 1) -> (sub b, a) | |||
2442 | if (N0.getOpcode() == ISD::ADD) { | |||
2443 | SDValue A, Xor; | |||
2444 | ||||
2445 | if (isBitwiseNot(N0.getOperand(0))) { | |||
2446 | A = N0.getOperand(1); | |||
2447 | Xor = N0.getOperand(0); | |||
2448 | } else if (isBitwiseNot(N0.getOperand(1))) { | |||
2449 | A = N0.getOperand(0); | |||
2450 | Xor = N0.getOperand(1); | |||
2451 | } | |||
2452 | ||||
2453 | if (Xor) | |||
2454 | return DAG.getNode(ISD::SUB, DL, VT, A, Xor.getOperand(0)); | |||
2455 | } | |||
2456 | ||||
2457 | // Look for: | |||
2458 | // add (add x, y), 1 | |||
2459 | // And if the target does not like this form then turn into: | |||
2460 | // sub y, (xor x, -1) | |||
2461 | if (!TLI.preferIncOfAddToSubOfNot(VT) && N0.hasOneUse() && | |||
2462 | N0.getOpcode() == ISD::ADD) { | |||
2463 | SDValue Not = DAG.getNode(ISD::XOR, DL, VT, N0.getOperand(0), | |||
2464 | DAG.getAllOnesConstant(DL, VT)); | |||
2465 | return DAG.getNode(ISD::SUB, DL, VT, N0.getOperand(1), Not); | |||
2466 | } | |||
2467 | } | |||
2468 | ||||
2469 | // (x - y) + -1 -> add (xor y, -1), x | |||
2470 | if (N0.hasOneUse() && N0.getOpcode() == ISD::SUB && | |||
2471 | isAllOnesOrAllOnesSplat(N1)) { | |||
2472 | SDValue Xor = DAG.getNode(ISD::XOR, DL, VT, N0.getOperand(1), N1); | |||
2473 | return DAG.getNode(ISD::ADD, DL, VT, Xor, N0.getOperand(0)); | |||
2474 | } | |||
2475 | ||||
2476 | if (SDValue Combined = visitADDLikeCommutative(N0, N1, N)) | |||
2477 | return Combined; | |||
2478 | ||||
2479 | if (SDValue Combined = visitADDLikeCommutative(N1, N0, N)) | |||
2480 | return Combined; | |||
2481 | ||||
2482 | return SDValue(); | |||
2483 | } | |||
2484 | ||||
2485 | SDValue DAGCombiner::visitADD(SDNode *N) { | |||
2486 | SDValue N0 = N->getOperand(0); | |||
2487 | SDValue N1 = N->getOperand(1); | |||
2488 | EVT VT = N0.getValueType(); | |||
2489 | SDLoc DL(N); | |||
2490 | ||||
2491 | if (SDValue Combined = visitADDLike(N)) | |||
2492 | return Combined; | |||
2493 | ||||
2494 | if (SDValue V = foldAddSubBoolOfMaskedVal(N, DAG)) | |||
2495 | return V; | |||
2496 | ||||
2497 | if (SDValue V = foldAddSubOfSignBit(N, DAG)) | |||
2498 | return V; | |||
2499 | ||||
2500 | // fold (a+b) -> (a|b) iff a and b share no bits. | |||
2501 | if ((!LegalOperations || TLI.isOperationLegal(ISD::OR, VT)) && | |||
2502 | DAG.haveNoCommonBitsSet(N0, N1)) | |||
2503 | return DAG.getNode(ISD::OR, DL, VT, N0, N1); | |||
2504 | ||||
2505 | // Fold (add (vscale * C0), (vscale * C1)) to (vscale * (C0 + C1)). | |||
2506 | if (N0.getOpcode() == ISD::VSCALE && N1.getOpcode() == ISD::VSCALE) { | |||
2507 | const APInt &C0 = N0->getConstantOperandAPInt(0); | |||
2508 | const APInt &C1 = N1->getConstantOperandAPInt(0); | |||
2509 | return DAG.getVScale(DL, VT, C0 + C1); | |||
2510 | } | |||
2511 | ||||
2512 | // fold a+vscale(c1)+vscale(c2) -> a+vscale(c1+c2) | |||
2513 | if ((N0.getOpcode() == ISD::ADD) && | |||
2514 | (N0.getOperand(1).getOpcode() == ISD::VSCALE) && | |||
2515 | (N1.getOpcode() == ISD::VSCALE)) { | |||
2516 | const APInt &VS0 = N0.getOperand(1)->getConstantOperandAPInt(0); | |||
2517 | const APInt &VS1 = N1->getConstantOperandAPInt(0); | |||
2518 | SDValue VS = DAG.getVScale(DL, VT, VS0 + VS1); | |||
2519 | return DAG.getNode(ISD::ADD, DL, VT, N0.getOperand(0), VS); | |||
2520 | } | |||
2521 | ||||
2522 | // Fold (add step_vector(c1), step_vector(c2) to step_vector(c1+c2)) | |||
2523 | if (N0.getOpcode() == ISD::STEP_VECTOR && | |||
2524 | N1.getOpcode() == ISD::STEP_VECTOR) { | |||
2525 | const APInt &C0 = N0->getConstantOperandAPInt(0); | |||
2526 | const APInt &C1 = N1->getConstantOperandAPInt(0); | |||
2527 | APInt NewStep = C0 + C1; | |||
2528 | return DAG.getStepVector(DL, VT, NewStep); | |||
2529 | } | |||
2530 | ||||
2531 | // Fold a + step_vector(c1) + step_vector(c2) to a + step_vector(c1+c2) | |||
2532 | if ((N0.getOpcode() == ISD::ADD) && | |||
2533 | (N0.getOperand(1).getOpcode() == ISD::STEP_VECTOR) && | |||
2534 | (N1.getOpcode() == ISD::STEP_VECTOR)) { | |||
2535 | const APInt &SV0 = N0.getOperand(1)->getConstantOperandAPInt(0); | |||
2536 | const APInt &SV1 = N1->getConstantOperandAPInt(0); | |||
2537 | APInt NewStep = SV0 + SV1; | |||
2538 | SDValue SV = DAG.getStepVector(DL, VT, NewStep); | |||
2539 | return DAG.getNode(ISD::ADD, DL, VT, N0.getOperand(0), SV); | |||
2540 | } | |||
2541 | ||||
2542 | return SDValue(); | |||
2543 | } | |||
2544 | ||||
2545 | SDValue DAGCombiner::visitADDSAT(SDNode *N) { | |||
2546 | unsigned Opcode = N->getOpcode(); | |||
2547 | SDValue N0 = N->getOperand(0); | |||
2548 | SDValue N1 = N->getOperand(1); | |||
2549 | EVT VT = N0.getValueType(); | |||
2550 | SDLoc DL(N); | |||
2551 | ||||
2552 | // fold vector ops | |||
2553 | if (VT.isVector()) { | |||
2554 | // TODO SimplifyVBinOp | |||
2555 | ||||
2556 | // fold (add_sat x, 0) -> x, vector edition | |||
2557 | if (ISD::isConstantSplatVectorAllZeros(N1.getNode())) | |||
2558 | return N0; | |||
2559 | if (ISD::isConstantSplatVectorAllZeros(N0.getNode())) | |||
2560 | return N1; | |||
2561 | } | |||
2562 | ||||
2563 | // fold (add_sat x, undef) -> -1 | |||
2564 | if (N0.isUndef() || N1.isUndef()) | |||
2565 | return DAG.getAllOnesConstant(DL, VT); | |||
2566 | ||||
2567 | if (DAG.isConstantIntBuildVectorOrConstantInt(N0)) { | |||
2568 | // canonicalize constant to RHS | |||
2569 | if (!DAG.isConstantIntBuildVectorOrConstantInt(N1)) | |||
2570 | return DAG.getNode(Opcode, DL, VT, N1, N0); | |||
2571 | // fold (add_sat c1, c2) -> c3 | |||
2572 | return DAG.FoldConstantArithmetic(Opcode, DL, VT, {N0, N1}); | |||
2573 | } | |||
2574 | ||||
2575 | // fold (add_sat x, 0) -> x | |||
2576 | if (isNullConstant(N1)) | |||
2577 | return N0; | |||
2578 | ||||
2579 | // If it cannot overflow, transform into an add. | |||
2580 | if (Opcode == ISD::UADDSAT) | |||
2581 | if (DAG.computeOverflowKind(N0, N1) == SelectionDAG::OFK_Never) | |||
2582 | return DAG.getNode(ISD::ADD, DL, VT, N0, N1); | |||
2583 | ||||
2584 | return SDValue(); | |||
2585 | } | |||
2586 | ||||
2587 | static SDValue getAsCarry(const TargetLowering &TLI, SDValue V) { | |||
2588 | bool Masked = false; | |||
2589 | ||||
2590 | // First, peel away TRUNCATE/ZERO_EXTEND/AND nodes due to legalization. | |||
2591 | while (true) { | |||
2592 | if (V.getOpcode() == ISD::TRUNCATE || V.getOpcode() == ISD::ZERO_EXTEND) { | |||
2593 | V = V.getOperand(0); | |||
2594 | continue; | |||
2595 | } | |||
2596 | ||||
2597 | if (V.getOpcode() == ISD::AND && isOneConstant(V.getOperand(1))) { | |||
2598 | Masked = true; | |||
2599 | V = V.getOperand(0); | |||
2600 | continue; | |||
2601 | } | |||
2602 | ||||
2603 | break; | |||
2604 | } | |||
2605 | ||||
2606 | // If this is not a carry, return. | |||
2607 | if (V.getResNo() != 1) | |||
2608 | return SDValue(); | |||
2609 | ||||
2610 | if (V.getOpcode() != ISD::ADDCARRY && V.getOpcode() != ISD::SUBCARRY && | |||
2611 | V.getOpcode() != ISD::UADDO && V.getOpcode() != ISD::USUBO) | |||
2612 | return SDValue(); | |||
2613 | ||||
2614 | EVT VT = V.getNode()->getValueType(0); | |||
2615 | if (!TLI.isOperationLegalOrCustom(V.getOpcode(), VT)) | |||
2616 | return SDValue(); | |||
2617 | ||||
2618 | // If the result is masked, then no matter what kind of bool it is we can | |||
2619 | // return. If it isn't, then we need to make sure the bool type is either 0 or | |||
2620 | // 1 and not other values. | |||
2621 | if (Masked || | |||
2622 | TLI.getBooleanContents(V.getValueType()) == | |||
2623 | TargetLoweringBase::ZeroOrOneBooleanContent) | |||
2624 | return V; | |||
2625 | ||||
2626 | return SDValue(); | |||
2627 | } | |||
2628 | ||||
2629 | /// Given the operands of an add/sub operation, see if the 2nd operand is a | |||
2630 | /// masked 0/1 whose source operand is actually known to be 0/-1. If so, invert | |||
2631 | /// the opcode and bypass the mask operation. | |||
2632 | static SDValue foldAddSubMasked1(bool IsAdd, SDValue N0, SDValue N1, | |||
2633 | SelectionDAG &DAG, const SDLoc &DL) { | |||
2634 | if (N1.getOpcode() != ISD::AND || !isOneOrOneSplat(N1->getOperand(1))) | |||
2635 | return SDValue(); | |||
2636 | ||||
2637 | EVT VT = N0.getValueType(); | |||
2638 | if (DAG.ComputeNumSignBits(N1.getOperand(0)) != VT.getScalarSizeInBits()) | |||
2639 | return SDValue(); | |||
2640 | ||||
2641 | // add N0, (and (AssertSext X, i1), 1) --> sub N0, X | |||
2642 | // sub N0, (and (AssertSext X, i1), 1) --> add N0, X | |||
2643 | return DAG.getNode(IsAdd ? ISD::SUB : ISD::ADD, DL, VT, N0, N1.getOperand(0)); | |||
2644 | } | |||
2645 | ||||
2646 | /// Helper for doing combines based on N0 and N1 being added to each other. | |||
2647 | SDValue DAGCombiner::visitADDLikeCommutative(SDValue N0, SDValue N1, | |||
2648 | SDNode *LocReference) { | |||
2649 | EVT VT = N0.getValueType(); | |||
2650 | SDLoc DL(LocReference); | |||
2651 | ||||
2652 | // fold (add x, shl(0 - y, n)) -> sub(x, shl(y, n)) | |||
2653 | if (N1.getOpcode() == ISD::SHL && N1.getOperand(0).getOpcode() == ISD::SUB && | |||
2654 | isNullOrNullSplat(N1.getOperand(0).getOperand(0))) | |||
2655 | return DAG.getNode(ISD::SUB, DL, VT, N0, | |||
2656 | DAG.getNode(ISD::SHL, DL, VT, | |||
2657 | N1.getOperand(0).getOperand(1), | |||
2658 | N1.getOperand(1))); | |||
2659 | ||||
2660 | if (SDValue V = foldAddSubMasked1(true, N0, N1, DAG, DL)) | |||
2661 | return V; | |||
2662 | ||||
2663 | // Look for: | |||
2664 | // add (add x, 1), y | |||
2665 | // And if the target does not like this form then turn into: | |||
2666 | // sub y, (xor x, -1) | |||
2667 | if (!TLI.preferIncOfAddToSubOfNot(VT) && N0.hasOneUse() && | |||
2668 | N0.getOpcode() == ISD::ADD && isOneOrOneSplat(N0.getOperand(1))) { | |||
2669 | SDValue Not = DAG.getNode(ISD::XOR, DL, VT, N0.getOperand(0), | |||
2670 | DAG.getAllOnesConstant(DL, VT)); | |||
2671 | return DAG.getNode(ISD::SUB, DL, VT, N1, Not); | |||
2672 | } | |||
2673 | ||||
2674 | // Hoist one-use subtraction by non-opaque constant: | |||
2675 | // (x - C) + y -> (x + y) - C | |||
2676 | // This is necessary because SUB(X,C) -> ADD(X,-C) doesn't work for vectors. | |||
2677 | if (N0.hasOneUse() && N0.getOpcode() == ISD::SUB && | |||
2678 | isConstantOrConstantVector(N0.getOperand(1), /*NoOpaques=*/true)) { | |||
2679 | SDValue Add = DAG.getNode(ISD::ADD, DL, VT, N0.getOperand(0), N1); | |||
2680 | return DAG.getNode(ISD::SUB, DL, VT, Add, N0.getOperand(1)); | |||
2681 | } | |||
2682 | // Hoist one-use subtraction from non-opaque constant: | |||
2683 | // (C - x) + y -> (y - x) + C | |||
2684 | if (N0.hasOneUse() && N0.getOpcode() == ISD::SUB && | |||
2685 | isConstantOrConstantVector(N0.getOperand(0), /*NoOpaques=*/true)) { | |||
2686 | SDValue Sub = DAG.getNode(ISD::SUB, DL, VT, N1, N0.getOperand(1)); | |||
2687 | return DAG.getNode(ISD::ADD, DL, VT, Sub, N0.getOperand(0)); | |||
2688 | } | |||
2689 | ||||
2690 | // If the target's bool is represented as 0/1, prefer to make this 'sub 0/1' | |||
2691 | // rather than 'add 0/-1' (the zext should get folded). | |||
2692 | // add (sext i1 Y), X --> sub X, (zext i1 Y) | |||
2693 | if (N0.getOpcode() == ISD::SIGN_EXTEND && | |||
2694 | N0.getOperand(0).getScalarValueSizeInBits() == 1 && | |||
2695 | TLI.getBooleanContents(VT) == TargetLowering::ZeroOrOneBooleanContent) { | |||
2696 | SDValue ZExt = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, N0.getOperand(0)); | |||
2697 | return DAG.getNode(ISD::SUB, DL, VT, N1, ZExt); | |||
2698 | } | |||
2699 | ||||
2700 | // add X, (sextinreg Y i1) -> sub X, (and Y 1) | |||
2701 | if (N1.getOpcode() == ISD::SIGN_EXTEND_INREG) { | |||
2702 | VTSDNode *TN = cast<VTSDNode>(N1.getOperand(1)); | |||
2703 | if (TN->getVT() == MVT::i1) { | |||
2704 | SDValue ZExt = DAG.getNode(ISD::AND, DL, VT, N1.getOperand(0), | |||
2705 | DAG.getConstant(1, DL, VT)); | |||
2706 | return DAG.getNode(ISD::SUB, DL, VT, N0, ZExt); | |||
2707 | } | |||
2708 | } | |||
2709 | ||||
2710 | // (add X, (addcarry Y, 0, Carry)) -> (addcarry X, Y, Carry) | |||
2711 | if (N1.getOpcode() == ISD::ADDCARRY && isNullConstant(N1.getOperand(1)) && | |||
2712 | N1.getResNo() == 0) | |||
2713 | return DAG.getNode(ISD::ADDCARRY, DL, N1->getVTList(), | |||
2714 | N0, N1.getOperand(0), N1.getOperand(2)); | |||
2715 | ||||
2716 | // (add X, Carry) -> (addcarry X, 0, Carry) | |||
2717 | if (TLI.isOperationLegalOrCustom(ISD::ADDCARRY, VT)) | |||
2718 | if (SDValue Carry = getAsCarry(TLI, N1)) | |||
2719 | return DAG.getNode(ISD::ADDCARRY, DL, | |||
2720 | DAG.getVTList(VT, Carry.getValueType()), N0, | |||
2721 | DAG.getConstant(0, DL, VT), Carry); | |||
2722 | ||||
2723 | return SDValue(); | |||
2724 | } | |||
2725 | ||||
2726 | SDValue DAGCombiner::visitADDC(SDNode *N) { | |||
2727 | SDValue N0 = N->getOperand(0); | |||
2728 | SDValue N1 = N->getOperand(1); | |||
2729 | EVT VT = N0.getValueType(); | |||
2730 | SDLoc DL(N); | |||
2731 | ||||
2732 | // If the flag result is dead, turn this into an ADD. | |||
2733 | if (!N->hasAnyUseOfValue(1)) | |||
2734 | return CombineTo(N, DAG.getNode(ISD::ADD, DL, VT, N0, N1), | |||
2735 | DAG.getNode(ISD::CARRY_FALSE, DL, MVT::Glue)); | |||
2736 | ||||
2737 | // canonicalize constant to RHS. | |||
2738 | ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0); | |||
2739 | ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1); | |||
2740 | if (N0C && !N1C) | |||
2741 | return DAG.getNode(ISD::ADDC, DL, N->getVTList(), N1, N0); | |||
2742 | ||||
2743 | // fold (addc x, 0) -> x + no carry out | |||
2744 | if (isNullConstant(N1)) | |||
2745 | return CombineTo(N, N0, DAG.getNode(ISD::CARRY_FALSE, | |||
2746 | DL, MVT::Glue)); | |||
2747 | ||||
2748 | // If it cannot overflow, transform into an add. | |||
2749 | if (DAG.computeOverflowKind(N0, N1) == SelectionDAG::OFK_Never) | |||
2750 | return CombineTo(N, DAG.getNode(ISD::ADD, DL, VT, N0, N1), | |||
2751 | DAG.getNode(ISD::CARRY_FALSE, DL, MVT::Glue)); | |||
2752 | ||||
2753 | return SDValue(); | |||
2754 | } | |||
2755 | ||||
2756 | /** | |||
2757 | * Flips a boolean if it is cheaper to compute. If the Force parameters is set, | |||
2758 | * then the flip also occurs if computing the inverse is the same cost. | |||
2759 | * This function returns an empty SDValue in case it cannot flip the boolean | |||
2760 | * without increasing the cost of the computation. If you want to flip a boolean | |||
2761 | * no matter what, use DAG.getLogicalNOT. | |||
2762 | */ | |||
2763 | static SDValue extractBooleanFlip(SDValue V, SelectionDAG &DAG, | |||
2764 | const TargetLowering &TLI, | |||
2765 | bool Force) { | |||
2766 | if (Force && isa<ConstantSDNode>(V)) | |||
2767 | return DAG.getLogicalNOT(SDLoc(V), V, V.getValueType()); | |||
2768 | ||||
2769 | if (V.getOpcode() != ISD::XOR) | |||
2770 | return SDValue(); | |||
2771 | ||||
2772 | ConstantSDNode *Const = isConstOrConstSplat(V.getOperand(1), false); | |||
2773 | if (!Const) | |||
2774 | return SDValue(); | |||
2775 | ||||
2776 | EVT VT = V.getValueType(); | |||
2777 | ||||
2778 | bool IsFlip = false; | |||
2779 | switch(TLI.getBooleanContents(VT)) { | |||
2780 | case TargetLowering::ZeroOrOneBooleanContent: | |||
2781 | IsFlip = Const->isOne(); | |||
2782 | break; | |||
2783 | case TargetLowering::ZeroOrNegativeOneBooleanContent: | |||
2784 | IsFlip = Const->isAllOnesValue(); | |||
2785 | break; | |||
2786 | case TargetLowering::UndefinedBooleanContent: | |||
2787 | IsFlip = (Const->getAPIntValue() & 0x01) == 1; | |||
2788 | break; | |||
2789 | } | |||
2790 | ||||
2791 | if (IsFlip) | |||
2792 | return V.getOperand(0); | |||
2793 | if (Force) | |||
2794 | return DAG.getLogicalNOT(SDLoc(V), V, V.getValueType()); | |||
2795 | return SDValue(); | |||
2796 | } | |||
2797 | ||||
2798 | SDValue DAGCombiner::visitADDO(SDNode *N) { | |||
2799 | SDValue N0 = N->getOperand(0); | |||
2800 | SDValue N1 = N->getOperand(1); | |||
2801 | EVT VT = N0.getValueType(); | |||
2802 | bool IsSigned = (ISD::SADDO == N->getOpcode()); | |||
2803 | ||||
2804 | EVT CarryVT = N->getValueType(1); | |||
2805 | SDLoc DL(N); | |||
2806 | ||||
2807 | // If the flag result is dead, turn this into an ADD. | |||
2808 | if (!N->hasAnyUseOfValue(1)) | |||
2809 | return CombineTo(N, DAG.getNode(ISD::ADD, DL, VT, N0, N1), | |||
2810 | DAG.getUNDEF(CarryVT)); | |||
2811 | ||||
2812 | // canonicalize constant to RHS. | |||
2813 | if (DAG.isConstantIntBuildVectorOrConstantInt(N0) && | |||
2814 | !DAG.isConstantIntBuildVectorOrConstantInt(N1)) | |||
2815 | return DAG.getNode(N->getOpcode(), DL, N->getVTList(), N1, N0); | |||
2816 | ||||
2817 | // fold (addo x, 0) -> x + no carry out | |||
2818 | if (isNullOrNullSplat(N1)) | |||
2819 | return CombineTo(N, N0, DAG.getConstant(0, DL, CarryVT)); | |||
2820 | ||||
2821 | if (!IsSigned) { | |||
2822 | // If it cannot overflow, transform into an add. | |||
2823 | if (DAG.computeOverflowKind(N0, N1) == SelectionDAG::OFK_Never) | |||
2824 | return CombineTo(N, DAG.getNode(ISD::ADD, DL, VT, N0, N1), | |||
2825 | DAG.getConstant(0, DL, CarryVT)); | |||
2826 | ||||
2827 | // fold (uaddo (xor a, -1), 1) -> (usub 0, a) and flip carry. | |||
2828 | if (isBitwiseNot(N0) && isOneOrOneSplat(N1)) { | |||
2829 | SDValue Sub = DAG.getNode(ISD::USUBO, DL, N->getVTList(), | |||
2830 | DAG.getConstant(0, DL, VT), N0.getOperand(0)); | |||
2831 | return CombineTo( | |||
2832 | N, Sub, DAG.getLogicalNOT(DL, Sub.getValue(1), Sub->getValueType(1))); | |||
2833 | } | |||
2834 | ||||
2835 | if (SDValue Combined = visitUADDOLike(N0, N1, N)) | |||
2836 | return Combined; | |||
2837 | ||||
2838 | if (SDValue Combined = visitUADDOLike(N1, N0, N)) | |||
2839 | return Combined; | |||
2840 | } | |||
2841 | ||||
2842 | return SDValue(); | |||
2843 | } | |||
2844 | ||||
2845 | SDValue DAGCombiner::visitUADDOLike(SDValue N0, SDValue N1, SDNode *N) { | |||
2846 | EVT VT = N0.getValueType(); | |||
2847 | if (VT.isVector()) | |||
2848 | return SDValue(); | |||
2849 | ||||
2850 | // (uaddo X, (addcarry Y, 0, Carry)) -> (addcarry X, Y, Carry) | |||
2851 | // If Y + 1 cannot overflow. | |||
2852 | if (N1.getOpcode() == ISD::ADDCARRY && isNullConstant(N1.getOperand(1))) { | |||
2853 | SDValue Y = N1.getOperand(0); | |||
2854 | SDValue One = DAG.getConstant(1, SDLoc(N), Y.getValueType()); | |||
2855 | if (DAG.computeOverflowKind(Y, One) == SelectionDAG::OFK_Never) | |||
2856 | return DAG.getNode(ISD::ADDCARRY, SDLoc(N), N->getVTList(), N0, Y, | |||
2857 | N1.getOperand(2)); | |||
2858 | } | |||
2859 | ||||
2860 | // (uaddo X, Carry) -> (addcarry X, 0, Carry) | |||
2861 | if (TLI.isOperationLegalOrCustom(ISD::ADDCARRY, VT)) | |||
2862 | if (SDValue Carry = getAsCarry(TLI, N1)) | |||
2863 | return DAG.getNode(ISD::ADDCARRY, SDLoc(N), N->getVTList(), N0, | |||
2864 | DAG.getConstant(0, SDLoc(N), VT), Carry); | |||
2865 | ||||
2866 | return SDValue(); | |||
2867 | } | |||
2868 | ||||
2869 | SDValue DAGCombiner::visitADDE(SDNode *N) { | |||
2870 | SDValue N0 = N->getOperand(0); | |||
2871 | SDValue N1 = N->getOperand(1); | |||
2872 | SDValue CarryIn = N->getOperand(2); | |||
2873 | ||||
2874 | // canonicalize constant to RHS | |||
2875 | ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0); | |||
2876 | ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1); | |||
2877 | if (N0C && !N1C) | |||
2878 | return DAG.getNode(ISD::ADDE, SDLoc(N), N->getVTList(), | |||
2879 | N1, N0, CarryIn); | |||
2880 | ||||
2881 | // fold (adde x, y, false) -> (addc x, y) | |||
2882 | if (CarryIn.getOpcode() == ISD::CARRY_FALSE) | |||
2883 | return DAG.getNode(ISD::ADDC, SDLoc(N), N->getVTList(), N0, N1); | |||
2884 | ||||
2885 | return SDValue(); | |||
2886 | } | |||
2887 | ||||
2888 | SDValue DAGCombiner::visitADDCARRY(SDNode *N) { | |||
2889 | SDValue N0 = N->getOperand(0); | |||
| ||||
2890 | SDValue N1 = N->getOperand(1); | |||
2891 | SDValue CarryIn = N->getOperand(2); | |||
2892 | SDLoc DL(N); | |||
2893 | ||||
2894 | // canonicalize constant to RHS | |||
2895 | ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0); | |||
2896 | ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1); | |||
2897 | if (N0C && !N1C) | |||
2898 | return DAG.getNode(ISD::ADDCARRY, DL, N->getVTList(), N1, N0, CarryIn); | |||
2899 | ||||
2900 | // fold (addcarry x, y, false) -> (uaddo x, y) | |||
2901 | if (isNullConstant(CarryIn)) { | |||
2902 | if (!LegalOperations || | |||
2903 | TLI.isOperationLegalOrCustom(ISD::UADDO, N->getValueType(0))) | |||
2904 | return DAG.getNode(ISD::UADDO, DL, N->getVTList(), N0, N1); | |||
2905 | } | |||
2906 | ||||
2907 | // fold (addcarry 0, 0, X) -> (and (ext/trunc X), 1) and no carry. | |||
2908 | if (isNullConstant(N0) && isNullConstant(N1)) { | |||
2909 | EVT VT = N0.getValueType(); | |||
2910 | EVT CarryVT = CarryIn.getValueType(); | |||
2911 | SDValue CarryExt = DAG.getBoolExtOrTrunc(CarryIn, DL, VT, CarryVT); | |||
2912 | AddToWorklist(CarryExt.getNode()); | |||
2913 | return CombineTo(N, DAG.getNode(ISD::AND, DL, VT, CarryExt, | |||
2914 | DAG.getConstant(1, DL, VT)), | |||
2915 | DAG.getConstant(0, DL, CarryVT)); | |||
2916 | } | |||
2917 | ||||
2918 | if (SDValue Combined = visitADDCARRYLike(N0, N1, CarryIn, N)) | |||
2919 | return Combined; | |||
2920 | ||||
2921 | if (SDValue Combined = visitADDCARRYLike(N1, N0, CarryIn, N)) | |||
2922 | return Combined; | |||
2923 | ||||
2924 | return SDValue(); | |||
2925 | } | |||
2926 | ||||
2927 | SDValue DAGCombiner::visitSADDO_CARRY(SDNode *N) { | |||
2928 | SDValue N0 = N->getOperand(0); | |||
2929 | SDValue N1 = N->getOperand(1); | |||
2930 | SDValue CarryIn = N->getOperand(2); | |||
2931 | SDLoc DL(N); | |||
2932 | ||||
2933 | // canonicalize constant to RHS | |||
2934 | ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0); | |||
2935 | ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1); | |||
2936 | if (N0C && !N1C) | |||
2937 | return DAG.getNode(ISD::SADDO_CARRY, DL, N->getVTList(), N1, N0, CarryIn); | |||
2938 | ||||
2939 | // fold (saddo_carry x, y, false) -> (saddo x, y) | |||
2940 | if (isNullConstant(CarryIn)) { | |||
2941 | if (!LegalOperations || | |||
2942 | TLI.isOperationLegalOrCustom(ISD::SADDO, N->getValueType(0))) | |||
2943 | return DAG.getNode(ISD::SADDO, DL, N->getVTList(), N0, N1); | |||
2944 | } | |||
2945 | ||||
2946 | return SDValue(); | |||
2947 | } | |||
2948 | ||||
2949 | /** | |||
2950 | * If we are facing some sort of diamond carry propapagtion pattern try to | |||
2951 | * break it up to generate something like: | |||
2952 | * (addcarry X, 0, (addcarry A, B, Z):Carry) | |||
2953 | * | |||
2954 | * The end result is usually an increase in operation required, but because the | |||
2955 | * carry is now linearized, other tranforms can kick in and optimize the DAG. | |||
2956 | * | |||
2957 | * Patterns typically look something like | |||
2958 | * (uaddo A, B) | |||
2959 | * / \ | |||
2960 | * Carry Sum | |||
2961 | * | \ | |||
2962 | * | (addcarry *, 0, Z) | |||
2963 | * | / | |||
2964 | * \ Carry | |||
2965 | * | / | |||
2966 | * (addcarry X, *, *) | |||
2967 | * | |||
2968 | * But numerous variation exist. Our goal is to identify A, B, X and Z and | |||
2969 | * produce a combine with a single path for carry propagation. | |||
2970 | */ | |||
2971 | static SDValue combineADDCARRYDiamond(DAGCombiner &Combiner, SelectionDAG &DAG, | |||
2972 | SDValue X, SDValue Carry0, SDValue Carry1, | |||
2973 | SDNode *N) { | |||
2974 | if (Carry1.getResNo() != 1 || Carry0.getResNo() != 1) | |||
2975 | return SDValue(); | |||
2976 | if (Carry1.getOpcode() != ISD::UADDO) | |||
2977 | return SDValue(); | |||
2978 | ||||
2979 | SDValue Z; | |||
2980 | ||||
2981 | /** | |||
2982 | * First look for a suitable Z. It will present itself in the form of | |||
2983 | * (addcarry Y, 0, Z) or its equivalent (uaddo Y, 1) for Z=true | |||
2984 | */ | |||
2985 | if (Carry0.getOpcode() == ISD::ADDCARRY && | |||
2986 | isNullConstant(Carry0.getOperand(1))) { | |||
2987 | Z = Carry0.getOperand(2); | |||
2988 | } else if (Carry0.getOpcode() == ISD::UADDO && | |||
2989 | isOneConstant(Carry0.getOperand(1))) { | |||
2990 | EVT VT = Combiner.getSetCCResultType(Carry0.getValueType()); | |||
2991 | Z = DAG.getConstant(1, SDLoc(Carry0.getOperand(1)), VT); | |||
2992 | } else { | |||
2993 | // We couldn't find a suitable Z. | |||
2994 | return SDValue(); | |||
2995 | } | |||
2996 | ||||
2997 | ||||
2998 | auto cancelDiamond = [&](SDValue A,SDValue B) { | |||
2999 | SDLoc DL(N); | |||
3000 | SDValue NewY = DAG.getNode(ISD::ADDCARRY, DL, Carry0->getVTList(), A, B, Z); | |||
3001 | Combiner.AddToWorklist(NewY.getNode()); | |||
3002 | return DAG.getNode(ISD::ADDCARRY, DL, N->getVTList(), X, | |||
3003 | DAG.getConstant(0, DL, X.getValueType()), | |||
3004 | NewY.getValue(1)); | |||
3005 | }; | |||
3006 | ||||
3007 | /** | |||
3008 | * (uaddo A, B) | |||
3009 | * | | |||
3010 | * Sum | |||
3011 | * | | |||
3012 | * (addcarry *, 0, Z) | |||
3013 | */ | |||
3014 | if (Carry0.getOperand(0) == Carry1.getValue(0)) { | |||
3015 | return cancelDiamond(Carry1.getOperand(0), Carry1.getOperand(1)); | |||
3016 | } | |||
3017 | ||||
3018 | /** | |||
3019 | * (addcarry A, 0, Z) | |||
3020 | * | | |||
3021 | * Sum | |||
3022 | * | | |||
3023 | * (uaddo *, B) | |||
3024 | */ | |||
3025 | if (Carry1.getOperand(0) == Carry0.getValue(0)) { | |||
3026 | return cancelDiamond(Carry0.getOperand(0), Carry1.getOperand(1)); | |||
3027 | } | |||
3028 | ||||
3029 | if (Carry1.getOperand(1) == Carry0.getValue(0)) { | |||
3030 | return cancelDiamond(Carry1.getOperand(0), Carry0.getOperand(0)); | |||
3031 | } | |||
3032 | ||||
3033 | return SDValue(); | |||
3034 | } | |||
3035 | ||||
3036 | // If we are facing some sort of diamond carry/borrow in/out pattern try to | |||
3037 | // match patterns like: | |||
3038 | // | |||
3039 | // (uaddo A, B) CarryIn | |||
3040 | // | \ | | |||
3041 | // | \ | | |||
3042 | // PartialSum PartialCarryOutX / | |||
3043 | // | | / | |||
3044 | // | ____|____________/ | |||
3045 | // | / | | |||
3046 | // (uaddo *, *) \________ | |||
3047 | // | \ \ | |||
3048 | // | \ | | |||
3049 | // | PartialCarryOutY | | |||
3050 | // | \ | | |||
3051 | // | \ / | |||
3052 | // AddCarrySum | ______/ | |||
3053 | // | / | |||
3054 | // CarryOut = (or *, *) | |||
3055 | // | |||
3056 | // And generate ADDCARRY (or SUBCARRY) with two result values: | |||
3057 | // | |||
3058 | // {AddCarrySum, CarryOut} = (addcarry A, B, CarryIn) | |||
3059 | // | |||
3060 | // Our goal is to identify A, B, and CarryIn and produce ADDCARRY/SUBCARRY with | |||
3061 | // a single path for carry/borrow out propagation: | |||
3062 | static SDValue combineCarryDiamond(DAGCombiner &Combiner, SelectionDAG &DAG, | |||
3063 | const TargetLowering &TLI, SDValue Carry0, | |||
3064 | SDValue Carry1, SDNode *N) { | |||
3065 | if (Carry0.getResNo() != 1 || Carry1.getResNo() != 1) | |||
3066 | return SDValue(); | |||
3067 | unsigned Opcode = Carry0.getOpcode(); | |||
3068 | if (Opcode != Carry1.getOpcode()) | |||
3069 | return SDValue(); | |||
3070 | if (Opcode != ISD::UADDO && Opcode != ISD::USUBO) | |||
3071 | return SDValue(); | |||
3072 | ||||
3073 | // Canonicalize the add/sub of A and B as Carry0 and the add/sub of the | |||
3074 | // carry/borrow in as Carry1. (The top and middle uaddo nodes respectively in | |||
3075 | // the above ASCII art.) | |||
3076 | if (Carry1.getOperand(0) != Carry0.getValue(0) && | |||
3077 | Carry1.getOperand(1) != Carry0.getValue(0)) | |||
3078 | std::swap(Carry0, Carry1); | |||
3079 | if (Carry1.getOperand(0) != Carry0.getValue(0) && | |||
3080 | Carry1.getOperand(1) != Carry0.getValue(0)) | |||
3081 | return SDValue(); | |||
3082 | ||||
3083 | // The carry in value must be on the righthand side for subtraction. | |||
3084 | unsigned CarryInOperandNum = | |||
3085 | Carry1.getOperand(0) == Carry0.getValue(0) ? 1 : 0; | |||
3086 | if (Opcode == ISD::USUBO && CarryInOperandNum != 1) | |||
3087 | return SDValue(); | |||
3088 | SDValue CarryIn = Carry1.getOperand(CarryInOperandNum); | |||
3089 | ||||
3090 | unsigned NewOp = Opcode == ISD::UADDO ? ISD::ADDCARRY : ISD::SUBCARRY; | |||
3091 | if (!TLI.isOperationLegalOrCustom(NewOp, Carry0.getValue(0).getValueType())) | |||
3092 | return SDValue(); | |||
3093 | ||||
3094 | // Verify that the carry/borrow in is plausibly a carry/borrow bit. | |||
3095 | // TODO: make getAsCarry() aware of how partial carries are merged. | |||
3096 | if (CarryIn.getOpcode() != ISD::ZERO_EXTEND) | |||
3097 | return SDValue(); | |||
3098 | CarryIn = CarryIn.getOperand(0); | |||
3099 | if (CarryIn.getValueType() != MVT::i1) | |||
3100 | return SDValue(); | |||
3101 | ||||
3102 | SDLoc DL(N); | |||
3103 | SDValue Merged = | |||
3104 | DAG.getNode(NewOp, DL, Carry1->getVTList(), Carry0.getOperand(0), | |||
3105 | Carry0.getOperand(1), CarryIn); | |||
3106 | ||||
3107 | // Please note that because we have proven that the result of the UADDO/USUBO | |||
3108 | // of A and B feeds into the UADDO/USUBO that does the carry/borrow in, we can | |||
3109 | // therefore prove that if the first UADDO/USUBO overflows, the second | |||
3110 | // UADDO/USUBO cannot. For example consider 8-bit numbers where 0xFF is the | |||
3111 | // maximum value. | |||
3112 | // | |||
3113 | // 0xFF + 0xFF == 0xFE with carry but 0xFE + 1 does not carry | |||
3114 | // 0x00 - 0xFF == 1 with a carry/borrow but 1 - 1 == 0 (no carry/borrow) | |||
3115 | // | |||
3116 | // This is important because it means that OR and XOR can be used to merge | |||
3117 | // carry flags; and that AND can return a constant zero. | |||
3118 | // | |||
3119 | // TODO: match other operations that can merge flags (ADD, etc) | |||
3120 | DAG.ReplaceAllUsesOfValueWith(Carry1.getValue(0), Merged.getValue(0)); | |||
3121 | if (N->getOpcode() == ISD::AND) | |||
3122 | return DAG.getConstant(0, DL, MVT::i1); | |||
3123 | return Merged.getValue(1); | |||
3124 | } | |||
3125 | ||||
3126 | SDValue DAGCombiner::visitADDCARRYLike(SDValue N0, SDValue N1, SDValue CarryIn, | |||
3127 | SDNode *N) { | |||
3128 | // fold (addcarry (xor a, -1), b, c) -> (subcarry b, a, !c) and flip carry. | |||
3129 | if (isBitwiseNot(N0)) | |||
3130 | if (SDValue NotC = extractBooleanFlip(CarryIn, DAG, TLI, true)) { | |||
3131 | SDLoc DL(N); | |||
3132 | SDValue Sub = DAG.getNode(ISD::SUBCARRY, DL, N->getVTList(), N1, | |||
3133 | N0.getOperand(0), NotC); | |||
3134 | return CombineTo( | |||
3135 | N, Sub, DAG.getLogicalNOT(DL, Sub.getValue(1), Sub->getValueType(1))); | |||
3136 | } | |||
3137 | ||||
3138 | // Iff the flag result is dead: | |||
3139 | // (addcarry (add|uaddo X, Y), 0, Carry) -> (addcarry X, Y, Carry) | |||
3140 | // Don't do this if the Carry comes from the uaddo. It won't remove the uaddo | |||
3141 | // or the dependency between the instructions. | |||
3142 | if ((N0.getOpcode() == ISD::ADD || | |||
3143 | (N0.getOpcode() == ISD::UADDO && N0.getResNo() == 0 && | |||
3144 | N0.getValue(1) != CarryIn)) && | |||
3145 | isNullConstant(N1) && !N->hasAnyUseOfValue(1)) | |||
3146 | return DAG.getNode(ISD::ADDCARRY, SDLoc(N), N->getVTList(), | |||
3147 | N0.getOperand(0), N0.getOperand(1), CarryIn); | |||
3148 | ||||
3149 | /** | |||
3150 | * When one of the addcarry argument is itself a carry, we may be facing | |||
3151 | * a diamond carry propagation. In which case we try to transform the DAG | |||
3152 | * to ensure linear carry propagation if that is possible. | |||
3153 | */ | |||
3154 | if (auto Y = getAsCarry(TLI, N1)) { | |||
3155 | // Because both are carries, Y and Z can be swapped. | |||
3156 | if (auto R = combineADDCARRYDiamond(*this, DAG, N0, Y, CarryIn, N)) | |||
3157 | return R; | |||
3158 | if (auto R = combineADDCARRYDiamond(*this, DAG, N0, CarryIn, Y, N)) | |||
3159 | return R; | |||
3160 | } | |||
3161 | ||||
3162 | return SDValue(); | |||
3163 | } | |||
3164 | ||||
3165 | // Attempt to create a USUBSAT(LHS, RHS) node with DstVT, performing a | |||
3166 | // clamp/truncation if necessary. | |||
3167 | static SDValue getTruncatedUSUBSAT(EVT DstVT, EVT SrcVT, SDValue LHS, | |||
3168 | SDValue RHS, SelectionDAG &DAG, | |||
3169 | const SDLoc &DL) { | |||
3170 | assert(DstVT.getScalarSizeInBits() <= SrcVT.getScalarSizeInBits() &&((void)0) | |||
3171 | "Illegal truncation")((void)0); | |||
3172 | ||||
3173 | if (DstVT == SrcVT) | |||
3174 | return DAG.getNode(ISD::USUBSAT, DL, DstVT, LHS, RHS); | |||
3175 | ||||
3176 | // If the LHS is zero-extended then we can perform the USUBSAT as DstVT by | |||
3177 | // clamping RHS. | |||
3178 | APInt UpperBits = APInt::getBitsSetFrom(SrcVT.getScalarSizeInBits(), | |||
3179 | DstVT.getScalarSizeInBits()); | |||
3180 | if (!DAG.MaskedValueIsZero(LHS, UpperBits)) | |||
3181 | return SDValue(); | |||
3182 | ||||
3183 | SDValue SatLimit = | |||
3184 | DAG.getConstant(APInt::getLowBitsSet(SrcVT.getScalarSizeInBits(), | |||
3185 | DstVT.getScalarSizeInBits()), | |||
3186 | DL, SrcVT); | |||
3187 | RHS = DAG.getNode(ISD::UMIN, DL, SrcVT, RHS, SatLimit); | |||
3188 | RHS = DAG.getNode(ISD::TRUNCATE, DL, DstVT, RHS); | |||
3189 | LHS = DAG.getNode(ISD::TRUNCATE, DL, DstVT, LHS); | |||
3190 | return DAG.getNode(ISD::USUBSAT, DL, DstVT, LHS, RHS); | |||
3191 | } | |||
3192 | ||||
3193 | // Try to find umax(a,b) - b or a - umin(a,b) patterns that may be converted to | |||
3194 | // usubsat(a,b), optionally as a truncated type. | |||
3195 | SDValue DAGCombiner::foldSubToUSubSat(EVT DstVT, SDNode *N) { | |||
3196 | if (N->getOpcode() != ISD::SUB || | |||
3197 | !(!LegalOperations || hasOperation(ISD::USUBSAT, DstVT))) | |||
3198 | return SDValue(); | |||
3199 | ||||
3200 | EVT SubVT = N->getValueType(0); | |||
3201 | SDValue Op0 = N->getOperand(0); | |||
3202 | SDValue Op1 = N->getOperand(1); | |||
3203 | ||||
3204 | // Try to find umax(a,b) - b or a - umin(a,b) patterns | |||
3205 | // they may be converted to usubsat(a,b). | |||
3206 | if (Op0.getOpcode() == ISD::UMAX && Op0.hasOneUse()) { | |||
3207 | SDValue MaxLHS = Op0.getOperand(0); | |||
3208 | SDValue MaxRHS = Op0.getOperand(1); | |||
3209 | if (MaxLHS == Op1) | |||
3210 | return getTruncatedUSUBSAT(DstVT, SubVT, MaxRHS, Op1, DAG, SDLoc(N)); | |||
3211 | if (MaxRHS == Op1) | |||
3212 | return getTruncatedUSUBSAT(DstVT, SubVT, MaxLHS, Op1, DAG, SDLoc(N)); | |||
3213 | } | |||
3214 | ||||
3215 | if (Op1.getOpcode() == ISD::UMIN && Op1.hasOneUse()) { | |||
3216 | SDValue MinLHS = Op1.getOperand(0); | |||
3217 | SDValue MinRHS = Op1.getOperand(1); | |||
3218 | if (MinLHS == Op0) | |||
3219 | return getTruncatedUSUBSAT(DstVT, SubVT, Op0, MinRHS, DAG, SDLoc(N)); | |||
3220 | if (MinRHS == Op0) | |||
3221 | return getTruncatedUSUBSAT(DstVT, SubVT, Op0, MinLHS, DAG, SDLoc(N)); | |||
3222 | } | |||
3223 | ||||
3224 | // sub(a,trunc(umin(zext(a),b))) -> usubsat(a,trunc(umin(b,SatLimit))) | |||
3225 | if (Op1.getOpcode() == ISD::TRUNCATE && | |||
3226 | Op1.getOperand(0).getOpcode() == ISD::UMIN && | |||
3227 | Op1.getOperand(0).hasOneUse()) { | |||
3228 | SDValue MinLHS = Op1.getOperand(0).getOperand(0); | |||
3229 | SDValue MinRHS = Op1.getOperand(0).getOperand(1); | |||
3230 | if (MinLHS.getOpcode() == ISD::ZERO_EXTEND && MinLHS.getOperand(0) == Op0) | |||
3231 | return getTruncatedUSUBSAT(DstVT, MinLHS.getValueType(), MinLHS, MinRHS, | |||
3232 | DAG, SDLoc(N)); | |||
3233 | if (MinRHS.getOpcode() == ISD::ZERO_EXTEND && MinRHS.getOperand(0) == Op0) | |||
3234 | return getTruncatedUSUBSAT(DstVT, MinLHS.getValueType(), MinRHS, MinLHS, | |||
3235 | DAG, SDLoc(N)); | |||
3236 | } | |||
3237 | ||||
3238 | return SDValue(); | |||
3239 | } | |||
3240 | ||||
3241 | // Since it may not be valid to emit a fold to zero for vector initializers | |||
3242 | // check if we can before folding. | |||
3243 | static SDValue tryFoldToZero(const SDLoc &DL, const TargetLowering &TLI, EVT VT, | |||
3244 | SelectionDAG &DAG, bool LegalOperations) { | |||
3245 | if (!VT.isVector()) | |||
3246 | return DAG.getConstant(0, DL, VT); | |||
3247 | if (!LegalOperations || TLI.isOperationLegal(ISD::BUILD_VECTOR, VT)) | |||
3248 | return DAG.getConstant(0, DL, VT); | |||
3249 | return SDValue(); | |||
3250 | } | |||
3251 | ||||
3252 | SDValue DAGCombiner::visitSUB(SDNode *N) { | |||
3253 | SDValue N0 = N->getOperand(0); | |||
3254 | SDValue N1 = N->getOperand(1); | |||
3255 | EVT VT = N0.getValueType(); | |||
3256 | SDLoc DL(N); | |||
3257 | ||||
3258 | // fold vector ops | |||
3259 | if (VT.isVector()) { | |||
3260 | if (SDValue FoldedVOp = SimplifyVBinOp(N)) | |||
3261 | return FoldedVOp; | |||
3262 | ||||
3263 | // fold (sub x, 0) -> x, vector edition | |||
3264 | if (ISD::isConstantSplatVectorAllZeros(N1.getNode())) | |||
3265 | return N0; | |||
3266 | } | |||
3267 | ||||
3268 | // fold (sub x, x) -> 0 | |||
3269 | // FIXME: Refactor this and xor and other similar operations together. | |||
3270 | if (N0 == N1) | |||
3271 | return tryFoldToZero(DL, TLI, VT, DAG, LegalOperations); | |||
3272 | ||||
3273 | // fold (sub c1, c2) -> c3 | |||
3274 | if (SDValue C = DAG.FoldConstantArithmetic(ISD::SUB, DL, VT, {N0, N1})) | |||
3275 | return C; | |||
3276 | ||||
3277 | if (SDValue NewSel = foldBinOpIntoSelect(N)) | |||
3278 | return NewSel; | |||
3279 | ||||
3280 | ConstantSDNode *N1C = getAsNonOpaqueConstant(N1); | |||
3281 | ||||
3282 | // fold (sub x, c) -> (add x, -c) | |||
3283 | if (N1C) { | |||
3284 | return DAG.getNode(ISD::ADD, DL, VT, N0, | |||
3285 | DAG.getConstant(-N1C->getAPIntValue(), DL, VT)); | |||
3286 | } | |||
3287 | ||||
3288 | if (isNullOrNullSplat(N0)) { | |||
3289 | unsigned BitWidth = VT.getScalarSizeInBits(); | |||
3290 | // Right-shifting everything out but the sign bit followed by negation is | |||
3291 | // the same as flipping arithmetic/logical shift type without the negation: | |||
3292 | // -(X >>u 31) -> (X >>s 31) | |||
3293 | // -(X >>s 31) -> (X >>u 31) | |||
3294 | if (N1->getOpcode() == ISD::SRA || N1->getOpcode() == ISD::SRL) { | |||
3295 | ConstantSDNode *ShiftAmt = isConstOrConstSplat(N1.getOperand(1)); | |||
3296 | if (ShiftAmt && ShiftAmt->getAPIntValue() == (BitWidth - 1)) { | |||
3297 | auto NewSh = N1->getOpcode() == ISD::SRA ? ISD::SRL : ISD::SRA; | |||
3298 | if (!LegalOperations || TLI.isOperationLegal(NewSh, VT)) | |||
3299 | return DAG.getNode(NewSh, DL, VT, N1.getOperand(0), N1.getOperand(1)); | |||
3300 | } | |||
3301 | } | |||
3302 | ||||
3303 | // 0 - X --> 0 if the sub is NUW. | |||
3304 | if (N->getFlags().hasNoUnsignedWrap()) | |||
3305 | return N0; | |||
3306 | ||||
3307 | if (DAG.MaskedValueIsZero(N1, ~APInt::getSignMask(BitWidth))) { | |||
3308 | // N1 is either 0 or the minimum signed value. If the sub is NSW, then | |||
3309 | // N1 must be 0 because negating the minimum signed value is undefined. | |||
3310 | if (N->getFlags().hasNoSignedWrap()) | |||
3311 | return N0; | |||
3312 | ||||
3313 | // 0 - X --> X if X is 0 or the minimum signed value. | |||
3314 | return N1; | |||
3315 | } | |||
3316 | ||||
3317 | // Convert 0 - abs(x). | |||
3318 | SDValue Result; | |||
3319 | if (N1->getOpcode() == ISD::ABS && | |||
3320 | !TLI.isOperationLegalOrCustom(ISD::ABS, VT) && | |||
3321 | TLI.expandABS(N1.getNode(), Result, DAG, true)) | |||
3322 | return Result; | |||
3323 | ||||
3324 | // Fold neg(splat(neg(x)) -> splat(x) | |||
3325 | if (VT.isVector()) { | |||
3326 | SDValue N1S = DAG.getSplatValue(N1, true); | |||
3327 | if (N1S && N1S.getOpcode() == ISD::SUB && | |||
3328 | isNullConstant(N1S.getOperand(0))) { | |||
3329 | if (VT.isScalableVector()) | |||
3330 | return DAG.getSplatVector(VT, DL, N1S.getOperand(1)); | |||
3331 | return DAG.getSplatBuildVector(VT, DL, N1S.getOperand(1)); | |||
3332 | } | |||
3333 | } | |||
3334 | } | |||
3335 | ||||
3336 | // Canonicalize (sub -1, x) -> ~x, i.e. (xor x, -1) | |||
3337 | if (isAllOnesOrAllOnesSplat(N0)) | |||
3338 | return DAG.getNode(ISD::XOR, DL, VT, N1, N0); | |||
3339 | ||||
3340 | // fold (A - (0-B)) -> A+B | |||
3341 | if (N1.getOpcode() == ISD::SUB && isNullOrNullSplat(N1.getOperand(0))) | |||
3342 | return DAG.getNode(ISD::ADD, DL, VT, N0, N1.getOperand(1)); | |||
3343 | ||||
3344 | // fold A-(A-B) -> B | |||
3345 | if (N1.getOpcode() == ISD::SUB && N0 == N1.getOperand(0)) | |||
3346 | return N1.getOperand(1); | |||
3347 | ||||
3348 | // fold (A+B)-A -> B | |||
3349 | if (N0.getOpcode() == ISD::ADD && N0.getOperand(0) == N1) | |||
3350 | return N0.getOperand(1); | |||
3351 | ||||
3352 | // fold (A+B)-B -> A | |||
3353 | if (N0.getOpcode() == ISD::ADD && N0.getOperand(1) == N1) | |||
3354 | return N0.getOperand(0); | |||
3355 | ||||
3356 | // fold (A+C1)-C2 -> A+(C1-C2) | |||
3357 | if (N0.getOpcode() == ISD::ADD && | |||
3358 | isConstantOrConstantVector(N1, /* NoOpaques */ true) && | |||
3359 | isConstantOrConstantVector(N0.getOperand(1), /* NoOpaques */ true)) { | |||
3360 | SDValue NewC = | |||
3361 | DAG.FoldConstantArithmetic(ISD::SUB, DL, VT, {N0.getOperand(1), N1}); | |||
3362 | assert(NewC && "Constant folding failed")((void)0); | |||
3363 | return DAG.getNode(ISD::ADD, DL, VT, N0.getOperand(0), NewC); | |||
3364 | } | |||
3365 | ||||
3366 | // fold C2-(A+C1) -> (C2-C1)-A | |||
3367 | if (N1.getOpcode() == ISD::ADD) { | |||
3368 | SDValue N11 = N1.getOperand(1); | |||
3369 | if (isConstantOrConstantVector(N0, /* NoOpaques */ true) && | |||
3370 | isConstantOrConstantVector(N11, /* NoOpaques */ true)) { | |||
3371 | SDValue NewC = DAG.FoldConstantArithmetic(ISD::SUB, DL, VT, {N0, N11}); | |||
3372 | assert(NewC && "Constant folding failed")((void)0); | |||
3373 | return DAG.getNode(ISD::SUB, DL, VT, NewC, N1.getOperand(0)); | |||
3374 | } | |||
3375 | } | |||
3376 | ||||
3377 | // fold (A-C1)-C2 -> A-(C1+C2) | |||
3378 | if (N0.getOpcode() == ISD::SUB && | |||
3379 | isConstantOrConstantVector(N1, /* NoOpaques */ true) && | |||
3380 | isConstantOrConstantVector(N0.getOperand(1), /* NoOpaques */ true)) { | |||
3381 | SDValue NewC = | |||
3382 | DAG.FoldConstantArithmetic(ISD::ADD, DL, VT, {N0.getOperand(1), N1}); | |||
3383 | assert(NewC && "Constant folding failed")((void)0); | |||
3384 | return DAG.getNode(ISD::SUB, DL, VT, N0.getOperand(0), NewC); | |||
3385 | } | |||
3386 | ||||
3387 | // fold (c1-A)-c2 -> (c1-c2)-A | |||
3388 | if (N0.getOpcode() == ISD::SUB && | |||
3389 | isConstantOrConstantVector(N1, /* NoOpaques */ true) && | |||
3390 | isConstantOrConstantVector(N0.getOperand(0), /* NoOpaques */ true)) { | |||
3391 | SDValue NewC = | |||
3392 | DAG.FoldConstantArithmetic(ISD::SUB, DL, VT, {N0.getOperand(0), N1}); | |||
3393 | assert(NewC && "Constant folding failed")((void)0); | |||
3394 | return DAG.getNode(ISD::SUB, DL, VT, NewC, N0.getOperand(1)); | |||
3395 | } | |||
3396 | ||||
3397 | // fold ((A+(B+or-C))-B) -> A+or-C | |||
3398 | if (N0.getOpcode() == ISD::ADD && | |||
3399 | (N0.getOperand(1).getOpcode() == ISD::SUB || | |||
3400 | N0.getOperand(1).getOpcode() == ISD::ADD) && | |||
3401 | N0.getOperand(1).getOperand(0) == N1) | |||
3402 | return DAG.getNode(N0.getOperand(1).getOpcode(), DL, VT, N0.getOperand(0), | |||
3403 | N0.getOperand(1).getOperand(1)); | |||
3404 | ||||
3405 | // fold ((A+(C+B))-B) -> A+C | |||
3406 | if (N0.getOpcode() == ISD::ADD && N0.getOperand(1).getOpcode() == ISD::ADD && | |||
3407 | N0.getOperand(1).getOperand(1) == N1) | |||
3408 | return DAG.getNode(ISD::ADD, DL, VT, N0.getOperand(0), | |||
3409 | N0.getOperand(1).getOperand(0)); | |||
3410 | ||||
3411 | // fold ((A-(B-C))-C) -> A-B | |||
3412 | if (N0.getOpcode() == ISD::SUB && N0.getOperand(1).getOpcode() == ISD::SUB && | |||
3413 | N0.getOperand(1).getOperand(1) == N1) | |||
3414 | return DAG.getNode(ISD::SUB, DL, VT, N0.getOperand(0), | |||
3415 | N0.getOperand(1).getOperand(0)); | |||
3416 | ||||
3417 | // fold (A-(B-C)) -> A+(C-B) | |||
3418 | if (N1.getOpcode() == ISD::SUB && N1.hasOneUse()) | |||
3419 | return DAG.getNode(ISD::ADD, DL, VT, N0, | |||
3420 | DAG.getNode(ISD::SUB, DL, VT, N1.getOperand(1), | |||
3421 | N1.getOperand(0))); | |||
3422 | ||||
3423 | // A - (A & B) -> A & (~B) | |||
3424 | if (N1.getOpcode() == ISD::AND) { | |||
3425 | SDValue A = N1.getOperand(0); | |||
3426 | SDValue B = N1.getOperand(1); | |||
3427 | if (A != N0) | |||
3428 | std::swap(A, B); | |||
3429 | if (A == N0 && | |||
3430 | (N1.hasOneUse() || isConstantOrConstantVector(B, /*NoOpaques=*/true))) { | |||
3431 | SDValue InvB = | |||
3432 | DAG.getNode(ISD::XOR, DL, VT, B, DAG.getAllOnesConstant(DL, VT)); | |||
3433 | return DAG.getNode(ISD::AND, DL, VT, A, InvB); | |||
3434 | } | |||
3435 | } | |||
3436 | ||||
3437 | // fold (X - (-Y * Z)) -> (X + (Y * Z)) | |||
3438 | if (N1.getOpcode() == ISD::MUL && N1.hasOneUse()) { | |||
3439 | if (N1.getOperand(0).getOpcode() == ISD::SUB && | |||
3440 | isNullOrNullSplat(N1.getOperand(0).getOperand(0))) { | |||
3441 | SDValue Mul = DAG.getNode(ISD::MUL, DL, VT, | |||
3442 | N1.getOperand(0).getOperand(1), | |||
3443 | N1.getOperand(1)); | |||
3444 | return DAG.getNode(ISD::ADD, DL, VT, N0, Mul); | |||
3445 | } | |||
3446 | if (N1.getOperand(1).getOpcode() == ISD::SUB && | |||
3447 | isNullOrNullSplat(N1.getOperand(1).getOperand(0))) { | |||
3448 | SDValue Mul = DAG.getNode(ISD::MUL, DL, VT, | |||
3449 | N1.getOperand(0), | |||
3450 | N1.getOperand(1).getOperand(1)); | |||
3451 | return DAG.getNode(ISD::ADD, DL, VT, N0, Mul); | |||
3452 | } | |||
3453 | } | |||
3454 | ||||
3455 | // If either operand of a sub is undef, the result is undef | |||
3456 | if (N0.isUndef()) | |||
3457 | return N0; | |||
3458 | if (N1.isUndef()) | |||
3459 | return N1; | |||
3460 | ||||
3461 | if (SDValue V = foldAddSubBoolOfMaskedVal(N, DAG)) | |||
3462 | return V; | |||
3463 | ||||
3464 | if (SDValue V = foldAddSubOfSignBit(N, DAG)) | |||
3465 | return V; | |||
3466 | ||||
3467 | if (SDValue V = foldAddSubMasked1(false, N0, N1, DAG, SDLoc(N))) | |||
3468 | return V; | |||
3469 | ||||
3470 | if (SDValue V = foldSubToUSubSat(VT, N)) | |||
3471 | return V; | |||
3472 | ||||
3473 | // (x - y) - 1 -> add (xor y, -1), x | |||
3474 | if (N0.hasOneUse() && N0.getOpcode() == ISD::SUB && isOneOrOneSplat(N1)) { | |||
3475 | SDValue Xor = DAG.getNode(ISD::XOR, DL, VT, N0.getOperand(1), | |||
3476 | DAG.getAllOnesConstant(DL, VT)); | |||
3477 | return DAG.getNode(ISD::ADD, DL, VT, Xor, N0.getOperand(0)); | |||
3478 | } | |||
3479 | ||||
3480 | // Look for: | |||
3481 | // sub y, (xor x, -1) | |||
3482 | // And if the target does not like this form then turn into: | |||
3483 | // add (add x, y), 1 | |||
3484 | if (TLI.preferIncOfAddToSubOfNot(VT) && N1.hasOneUse() && isBitwiseNot(N1)) { | |||
3485 | SDValue Add = DAG.getNode(ISD::ADD, DL, VT, N0, N1.getOperand(0)); | |||
3486 | return DAG.getNode(ISD::ADD, DL, VT, Add, DAG.getConstant(1, DL, VT)); | |||
3487 | } | |||
3488 | ||||
3489 | // Hoist one-use addition by non-opaque constant: | |||
3490 | // (x + C) - y -> (x - y) + C | |||
3491 | if (N0.hasOneUse() && N0.getOpcode() == ISD::ADD && | |||
3492 | isConstantOrConstantVector(N0.getOperand(1), /*NoOpaques=*/true)) { | |||
3493 | SDValue Sub = DAG.getNode(ISD::SUB, DL, VT, N0.getOperand(0), N1); | |||
3494 | return DAG.getNode(ISD::ADD, DL, VT, Sub, N0.getOperand(1)); | |||
3495 | } | |||
3496 | // y - (x + C) -> (y - x) - C | |||
3497 | if (N1.hasOneUse() && N1.getOpcode() == ISD::ADD && | |||
3498 | isConstantOrConstantVector(N1.getOperand(1), /*NoOpaques=*/true)) { | |||
3499 | SDValue Sub = DAG.getNode(ISD::SUB, DL, VT, N0, N1.getOperand(0)); | |||
3500 | return DAG.getNode(ISD::SUB, DL, VT, Sub, N1.getOperand(1)); | |||
3501 | } | |||
3502 | // (x - C) - y -> (x - y) - C | |||
3503 | // This is necessary because SUB(X,C) -> ADD(X,-C) doesn't work for vectors. | |||
3504 | if (N0.hasOneUse() && N0.getOpcode() == ISD::SUB && | |||
3505 | isConstantOrConstantVector(N0.getOperand(1), /*NoOpaques=*/true)) { | |||
3506 | SDValue Sub = DAG.getNode(ISD::SUB, DL, VT, N0.getOperand(0), N1); | |||
3507 | return DAG.getNode(ISD::SUB, DL, VT, Sub, N0.getOperand(1)); | |||
3508 | } | |||
3509 | // (C - x) - y -> C - (x + y) | |||
3510 | if (N0.hasOneUse() && N0.getOpcode() == ISD::SUB && | |||
3511 | isConstantOrConstantVector(N0.getOperand(0), /*NoOpaques=*/true)) { | |||
3512 | SDValue Add = DAG.getNode(ISD::ADD, DL, VT, N0.getOperand(1), N1); | |||
3513 | return DAG.getNode(ISD::SUB, DL, VT, N0.getOperand(0), Add); | |||
3514 | } | |||
3515 | ||||
3516 | // If the target's bool is represented as 0/-1, prefer to make this 'add 0/-1' | |||
3517 | // rather than 'sub 0/1' (the sext should get folded). | |||
3518 | // sub X, (zext i1 Y) --> add X, (sext i1 Y) | |||
3519 | if (N1.getOpcode() == ISD::ZERO_EXTEND && | |||
3520 | N1.getOperand(0).getScalarValueSizeInBits() == 1 && | |||
3521 | TLI.getBooleanContents(VT) == | |||
3522 | TargetLowering::ZeroOrNegativeOneBooleanContent) { | |||
3523 | SDValue SExt = DAG.getNode(ISD::SIGN_EXTEND, DL, VT, N1.getOperand(0)); | |||
3524 | return DAG.getNode(ISD::ADD, DL, VT, N0, SExt); | |||
3525 | } | |||
3526 | ||||
3527 | // fold Y = sra (X, size(X)-1); sub (xor (X, Y), Y) -> (abs X) | |||
3528 | if (TLI.isOperationLegalOrCustom(ISD::ABS, VT)) { | |||
3529 | if (N0.getOpcode() == ISD::XOR && N1.getOpcode() == ISD::SRA) { | |||
3530 | SDValue X0 = N0.getOperand(0), X1 = N0.getOperand(1); | |||
3531 | SDValue S0 = N1.getOperand(0); | |||
3532 | if ((X0 == S0 && X1 == N1) || (X0 == N1 && X1 == S0)) | |||
3533 | if (ConstantSDNode *C = isConstOrConstSplat(N1.getOperand(1))) | |||
3534 | if (C->getAPIntValue() == (VT.getScalarSizeInBits() - 1)) | |||
3535 | return DAG.getNode(ISD::ABS, SDLoc(N), VT, S0); | |||
3536 | } | |||
3537 | } | |||
3538 | ||||
3539 | // If the relocation model supports it, consider symbol offsets. | |||
3540 | if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(N0)) | |||
3541 | if (!LegalOperations && TLI.isOffsetFoldingLegal(GA)) { | |||
3542 | // fold (sub Sym, c) -> Sym-c | |||
3543 | if (N1C && GA->getOpcode() == ISD::GlobalAddress) | |||
3544 | return DAG.getGlobalAddress(GA->getGlobal(), SDLoc(N1C), VT, | |||
3545 | GA->getOffset() - | |||
3546 | (uint64_t)N1C->getSExtValue()); | |||
3547 | // fold (sub Sym+c1, Sym+c2) -> c1-c2 | |||
3548 | if (GlobalAddressSDNode *GB = dyn_cast<GlobalAddressSDNode>(N1)) | |||
3549 | if (GA->getGlobal() == GB->getGlobal()) | |||
3550 | return DAG.getConstant((uint64_t)GA->getOffset() - GB->getOffset(), | |||
3551 | DL, VT); | |||
3552 | } | |||
3553 | ||||
3554 | // sub X, (sextinreg Y i1) -> add X, (and Y 1) | |||
3555 | if (N1.getOpcode() == ISD::SIGN_EXTEND_INREG) { | |||
3556 | VTSDNode *TN = cast<VTSDNode>(N1.getOperand(1)); | |||
3557 | if (TN->getVT() == MVT::i1) { | |||
3558 | SDValue ZExt = DAG.getNode(ISD::AND, DL, VT, N1.getOperand(0), | |||
3559 | DAG.getConstant(1, DL, VT)); | |||
3560 | return DAG.getNode(ISD::ADD, DL, VT, N0, ZExt); | |||
3561 | } | |||
3562 | } | |||
3563 | ||||
3564 | // canonicalize (sub X, (vscale * C)) to (add X, (vscale * -C)) | |||
3565 | if (N1.getOpcode() == ISD::VSCALE) { | |||
3566 | const APInt &IntVal = N1.getConstantOperandAPInt(0); | |||
3567 | return DAG.getNode(ISD::ADD, DL, VT, N0, DAG.getVScale(DL, VT, -IntVal)); | |||
3568 | } | |||
3569 | ||||
3570 | // canonicalize (sub X, step_vector(C)) to (add X, step_vector(-C)) | |||
3571 | if (N1.getOpcode() == ISD::STEP_VECTOR && N1.hasOneUse()) { | |||
3572 | APInt NewStep = -N1.getConstantOperandAPInt(0); | |||
3573 | return DAG.getNode(ISD::ADD, DL, VT, N0, | |||
3574 | DAG.getStepVector(DL, VT, NewStep)); | |||
3575 | } | |||
3576 | ||||
3577 | // Prefer an add for more folding potential and possibly better codegen: | |||
3578 | // sub N0, (lshr N10, width-1) --> add N0, (ashr N10, width-1) | |||
3579 | if (!LegalOperations && N1.getOpcode() == ISD::SRL && N1.hasOneUse()) { | |||
3580 | SDValue ShAmt = N1.getOperand(1); | |||
3581 | ConstantSDNode *ShAmtC = isConstOrConstSplat(ShAmt); | |||
3582 | if (ShAmtC && | |||
3583 | ShAmtC->getAPIntValue() == (N1.getScalarValueSizeInBits() - 1)) { | |||
3584 | SDValue SRA = DAG.getNode(ISD::SRA, DL, VT, N1.getOperand(0), ShAmt); | |||
3585 | return DAG.getNode(ISD::ADD, DL, VT, N0, SRA); | |||
3586 | } | |||
3587 | } | |||
3588 | ||||
3589 | if (TLI.isOperationLegalOrCustom(ISD::ADDCARRY, VT)) { | |||
3590 | // (sub Carry, X) -> (addcarry (sub 0, X), 0, Carry) | |||
3591 | if (SDValue Carry = getAsCarry(TLI, N0)) { | |||
3592 | SDValue X = N1; | |||
3593 | SDValue Zero = DAG.getConstant(0, DL, VT); | |||
3594 | SDValue NegX = DAG.getNode(ISD::SUB, DL, VT, Zero, X); | |||
3595 | return DAG.getNode(ISD::ADDCARRY, DL, | |||
3596 | DAG.getVTList(VT, Carry.getValueType()), NegX, Zero, | |||
3597 | Carry); | |||
3598 | } | |||
3599 | } | |||
3600 | ||||
3601 | return SDValue(); | |||
3602 | } | |||
3603 | ||||
3604 | SDValue DAGCombiner::visitSUBSAT(SDNode *N) { | |||
3605 | SDValue N0 = N->getOperand(0); | |||
3606 | SDValue N1 = N->getOperand(1); | |||
3607 | EVT VT = N0.getValueType(); | |||
3608 | SDLoc DL(N); | |||
3609 | ||||
3610 | // fold vector ops | |||
3611 | if (VT.isVector()) { | |||
3612 | // TODO SimplifyVBinOp | |||
3613 | ||||
3614 | // fold (sub_sat x, 0) -> x, vector edition | |||
3615 | if (ISD::isConstantSplatVectorAllZeros(N1.getNode())) | |||
3616 | return N0; | |||
3617 | } | |||
3618 | ||||
3619 | // fold (sub_sat x, undef) -> 0 | |||
3620 | if (N0.isUndef() || N1.isUndef()) | |||
3621 | return DAG.getConstant(0, DL, VT); | |||
3622 | ||||
3623 | // fold (sub_sat x, x) -> 0 | |||
3624 | if (N0 == N1) | |||
3625 | return DAG.getConstant(0, DL, VT); | |||
3626 | ||||
3627 | // fold (sub_sat c1, c2) -> c3 | |||
3628 | if (SDValue C = DAG.FoldConstantArithmetic(N->getOpcode(), DL, VT, {N0, N1})) | |||
3629 | return C; | |||
3630 | ||||
3631 | // fold (sub_sat x, 0) -> x | |||
3632 | if (isNullConstant(N1)) | |||
3633 | return N0; | |||
3634 | ||||
3635 | return SDValue(); | |||
3636 | } | |||
3637 | ||||
3638 | SDValue DAGCombiner::visitSUBC(SDNode *N) { | |||
3639 | SDValue N0 = N->getOperand(0); | |||
3640 | SDValue N1 = N->getOperand(1); | |||
3641 | EVT VT = N0.getValueType(); | |||
3642 | SDLoc DL(N); | |||
3643 | ||||
3644 | // If the flag result is dead, turn this into an SUB. | |||
3645 | if (!N->hasAnyUseOfValue(1)) | |||
3646 | return CombineTo(N, DAG.getNode(ISD::SUB, DL, VT, N0, N1), | |||
3647 | DAG.getNode(ISD::CARRY_FALSE, DL, MVT::Glue)); | |||
3648 | ||||
3649 | // fold (subc x, x) -> 0 + no borrow | |||
3650 | if (N0 == N1) | |||
3651 | return CombineTo(N, DAG.getConstant(0, DL, VT), | |||
3652 | DAG.getNode(ISD::CARRY_FALSE, DL, MVT::Glue)); | |||
3653 | ||||
3654 | // fold (subc x, 0) -> x + no borrow | |||
3655 | if (isNullConstant(N1)) | |||
3656 | return CombineTo(N, N0, DAG.getNode(ISD::CARRY_FALSE, DL, MVT::Glue)); | |||
3657 | ||||
3658 | // Canonicalize (sub -1, x) -> ~x, i.e. (xor x, -1) + no borrow | |||
3659 | if (isAllOnesConstant(N0)) | |||
3660 | return CombineTo(N, DAG.getNode(ISD::XOR, DL, VT, N1, N0), | |||
3661 | DAG.getNode(ISD::CARRY_FALSE, DL, MVT::Glue)); | |||
3662 | ||||
3663 | return SDValue(); | |||
3664 | } | |||
3665 | ||||
3666 | SDValue DAGCombiner::visitSUBO(SDNode *N) { | |||
3667 | SDValue N0 = N->getOperand(0); | |||
3668 | SDValue N1 = N->getOperand(1); | |||
3669 | EVT VT = N0.getValueType(); | |||
3670 | bool IsSigned = (ISD::SSUBO == N->getOpcode()); | |||
3671 | ||||
3672 | EVT CarryVT = N->getValueType(1); | |||
3673 | SDLoc DL(N); | |||
3674 | ||||
3675 | // If the flag result is dead, turn this into an SUB. | |||
3676 | if (!N->hasAnyUseOfValue(1)) | |||
3677 | return CombineTo(N, DAG.getNode(ISD::SUB, DL, VT, N0, N1), | |||
3678 | DAG.getUNDEF(CarryVT)); | |||
3679 | ||||
3680 | // fold (subo x, x) -> 0 + no borrow | |||
3681 | if (N0 == N1) | |||
3682 | return CombineTo(N, DAG.getConstant(0, DL, VT), | |||
3683 | DAG.getConstant(0, DL, CarryVT)); | |||
3684 | ||||
3685 | ConstantSDNode *N1C = getAsNonOpaqueConstant(N1); | |||
3686 | ||||
3687 | // fold (subox, c) -> (addo x, -c) | |||
3688 | if (IsSigned && N1C && !N1C->getAPIntValue().isMinSignedValue()) { | |||
3689 | return DAG.getNode(ISD::SADDO, DL, N->getVTList(), N0, | |||
3690 | DAG.getConstant(-N1C->getAPIntValue(), DL, VT)); | |||
3691 | } | |||
3692 | ||||
3693 | // fold (subo x, 0) -> x + no borrow | |||
3694 | if (isNullOrNullSplat(N1)) | |||
3695 | return CombineTo(N, N0, DAG.getConstant(0, DL, CarryVT)); | |||
3696 | ||||
3697 | // Canonicalize (usubo -1, x) -> ~x, i.e. (xor x, -1) + no borrow | |||
3698 | if (!IsSigned && isAllOnesOrAllOnesSplat(N0)) | |||
3699 | return CombineTo(N, DAG.getNode(ISD::XOR, DL, VT, N1, N0), | |||
3700 | DAG.getConstant(0, DL, CarryVT)); | |||
3701 | ||||
3702 | return SDValue(); | |||
3703 | } | |||
3704 | ||||
3705 | SDValue DAGCombiner::visitSUBE(SDNode *N) { | |||
3706 | SDValue N0 = N->getOperand(0); | |||
3707 | SDValue N1 = N->getOperand(1); | |||
3708 | SDValue CarryIn = N->getOperand(2); | |||
3709 | ||||
3710 | // fold (sube x, y, false) -> (subc x, y) | |||
3711 | if (CarryIn.getOpcode() == ISD::CARRY_FALSE) | |||
3712 | return DAG.getNode(ISD::SUBC, SDLoc(N), N->getVTList(), N0, N1); | |||
3713 | ||||
3714 | return SDValue(); | |||
3715 | } | |||
3716 | ||||
3717 | SDValue DAGCombiner::visitSUBCARRY(SDNode *N) { | |||
3718 | SDValue N0 = N->getOperand(0); | |||
3719 | SDValue N1 = N->getOperand(1); | |||
3720 | SDValue CarryIn = N->getOperand(2); | |||
3721 | ||||
3722 | // fold (subcarry x, y, false) -> (usubo x, y) | |||
3723 | if (isNullConstant(CarryIn)) { | |||
3724 | if (!LegalOperations || | |||
3725 | TLI.isOperationLegalOrCustom(ISD::USUBO, N->getValueType(0))) | |||
3726 | return DAG.getNode(ISD::USUBO, SDLoc(N), N->getVTList(), N0, N1); | |||
3727 | } | |||
3728 | ||||
3729 | return SDValue(); | |||
3730 | } | |||
3731 | ||||
3732 | SDValue DAGCombiner::visitSSUBO_CARRY(SDNode *N) { | |||
3733 | SDValue N0 = N->getOperand(0); | |||
3734 | SDValue N1 = N->getOperand(1); | |||
3735 | SDValue CarryIn = N->getOperand(2); | |||
3736 | ||||
3737 | // fold (ssubo_carry x, y, false) -> (ssubo x, y) | |||
3738 | if (isNullConstant(CarryIn)) { | |||
3739 | if (!LegalOperations || | |||
3740 | TLI.isOperationLegalOrCustom(ISD::SSUBO, N->getValueType(0))) | |||
3741 | return DAG.getNode(ISD::SSUBO, SDLoc(N), N->getVTList(), N0, N1); | |||
3742 | } | |||
3743 | ||||
3744 | return SDValue(); | |||
3745 | } | |||
3746 | ||||
3747 | // Notice that "mulfix" can be any of SMULFIX, SMULFIXSAT, UMULFIX and | |||
3748 | // UMULFIXSAT here. | |||
3749 | SDValue DAGCombiner::visitMULFIX(SDNode *N) { | |||
3750 | SDValue N0 = N->getOperand(0); | |||
3751 | SDValue N1 = N->getOperand(1); | |||
3752 | SDValue Scale = N->getOperand(2); | |||
3753 | EVT VT = N0.getValueType(); | |||
3754 | ||||
3755 | // fold (mulfix x, undef, scale) -> 0 | |||
3756 | if (N0.isUndef() || N1.isUndef()) | |||
3757 | return DAG.getConstant(0, SDLoc(N), VT); | |||
3758 | ||||
3759 | // Canonicalize constant to RHS (vector doesn't have to splat) | |||
3760 | if (DAG.isConstantIntBuildVectorOrConstantInt(N0) && | |||
3761 | !DAG.isConstantIntBuildVectorOrConstantInt(N1)) | |||
3762 | return DAG.getNode(N->getOpcode(), SDLoc(N), VT, N1, N0, Scale); | |||
3763 | ||||
3764 | // fold (mulfix x, 0, scale) -> 0 | |||
3765 | if (isNullConstant(N1)) | |||
3766 | return DAG.getConstant(0, SDLoc(N), VT); | |||
3767 | ||||
3768 | return SDValue(); | |||
3769 | } | |||
3770 | ||||
3771 | SDValue DAGCombiner::visitMUL(SDNode *N) { | |||
3772 | SDValue N0 = N->getOperand(0); | |||
3773 | SDValue N1 = N->getOperand(1); | |||
3774 | EVT VT = N0.getValueType(); | |||
3775 | ||||
3776 | // fold (mul x, undef) -> 0 | |||
3777 | if (N0.isUndef() || N1.isUndef()) | |||
3778 | return DAG.getConstant(0, SDLoc(N), VT); | |||
3779 | ||||
3780 | bool N1IsConst = false; | |||
3781 | bool N1IsOpaqueConst = false; | |||
3782 | APInt ConstValue1; | |||
3783 | ||||
3784 | // fold vector ops | |||
3785 | if (VT.isVector()) { | |||
3786 | if (SDValue FoldedVOp = SimplifyVBinOp(N)) | |||
3787 | return FoldedVOp; | |||
3788 | ||||
3789 | N1IsConst = ISD::isConstantSplatVector(N1.getNode(), ConstValue1); | |||
3790 | assert((!N1IsConst ||((void)0) | |||
3791 | ConstValue1.getBitWidth() == VT.getScalarSizeInBits()) &&((void)0) | |||
3792 | "Splat APInt should be element width")((void)0); | |||
3793 | } else { | |||
3794 | N1IsConst = isa<ConstantSDNode>(N1); | |||
3795 | if (N1IsConst) { | |||
3796 | ConstValue1 = cast<ConstantSDNode>(N1)->getAPIntValue(); | |||
3797 | N1IsOpaqueConst = cast<ConstantSDNode>(N1)->isOpaque(); | |||
3798 | } | |||
3799 | } | |||
3800 | ||||
3801 | // fold (mul c1, c2) -> c1*c2 | |||
3802 | if (SDValue C = DAG.FoldConstantArithmetic(ISD::MUL, SDLoc(N), VT, {N0, N1})) | |||
3803 | return C; | |||
3804 | ||||
3805 | // canonicalize constant to RHS (vector doesn't have to splat) | |||
3806 | if (DAG.isConstantIntBuildVectorOrConstantInt(N0) && | |||
3807 | !DAG.isConstantIntBuildVectorOrConstantInt(N1)) | |||
3808 | return DAG.getNode(ISD::MUL, SDLoc(N), VT, N1, N0); | |||
3809 | ||||
3810 | // fold (mul x, 0) -> 0 | |||
3811 | if (N1IsConst && ConstValue1.isNullValue()) | |||
3812 | return N1; | |||
3813 | ||||
3814 | // fold (mul x, 1) -> x | |||
3815 | if (N1IsConst && ConstValue1.isOneValue()) | |||
3816 | return N0; | |||
3817 | ||||
3818 | if (SDValue NewSel = foldBinOpIntoSelect(N)) | |||
3819 | return NewSel; | |||
3820 | ||||
3821 | // fold (mul x, -1) -> 0-x | |||
3822 | if (N1IsConst && ConstValue1.isAllOnesValue()) { | |||
3823 | SDLoc DL(N); | |||
3824 | return DAG.getNode(ISD::SUB, DL, VT, | |||
3825 | DAG.getConstant(0, DL, VT), N0); | |||
3826 | } | |||
3827 | ||||
3828 | // fold (mul x, (1 << c)) -> x << c | |||
3829 | if (isConstantOrConstantVector(N1, /*NoOpaques*/ true) && | |||
3830 | DAG.isKnownToBeAPowerOfTwo(N1) && | |||
3831 | (!VT.isVector() || Level <= AfterLegalizeVectorOps)) { | |||
3832 | SDLoc DL(N); | |||
3833 | SDValue LogBase2 = BuildLogBase2(N1, DL); | |||
3834 | EVT ShiftVT = getShiftAmountTy(N0.getValueType()); | |||
3835 | SDValue Trunc = DAG.getZExtOrTrunc(LogBase2, DL, ShiftVT); | |||
3836 | return DAG.getNode(ISD::SHL, DL, VT, N0, Trunc); | |||
3837 | } | |||
3838 | ||||
3839 | // fold (mul x, -(1 << c)) -> -(x << c) or (-x) << c | |||
3840 | if (N1IsConst && !N1IsOpaqueConst && (-ConstValue1).isPowerOf2()) { | |||
3841 | unsigned Log2Val = (-ConstValue1).logBase2(); | |||
3842 | SDLoc DL(N); | |||
3843 | // FIXME: If the input is something that is easily negated (e.g. a | |||
3844 | // single-use add), we should put the negate there. | |||
3845 | return DAG.getNode(ISD::SUB, DL, VT, | |||
3846 | DAG.getConstant(0, DL, VT), | |||
3847 | DAG.getNode(ISD::SHL, DL, VT, N0, | |||
3848 | DAG.getConstant(Log2Val, DL, | |||
3849 | getShiftAmountTy(N0.getValueType())))); | |||
3850 | } | |||
3851 | ||||
3852 | // Try to transform: | |||
3853 | // (1) multiply-by-(power-of-2 +/- 1) into shift and add/sub. | |||
3854 | // mul x, (2^N + 1) --> add (shl x, N), x | |||
3855 | // mul x, (2^N - 1) --> sub (shl x, N), x | |||
3856 | // Examples: x * 33 --> (x << 5) + x | |||
3857 | // x * 15 --> (x << 4) - x | |||
3858 | // x * -33 --> -((x << 5) + x) | |||
3859 | // x * -15 --> -((x << 4) - x) ; this reduces --> x - (x << 4) | |||
3860 | // (2) multiply-by-(power-of-2 +/- power-of-2) into shifts and add/sub. | |||
3861 | // mul x, (2^N + 2^M) --> (add (shl x, N), (shl x, M)) | |||
3862 | // mul x, (2^N - 2^M) --> (sub (shl x, N), (shl x, M)) | |||
3863 | // Examples: x * 0x8800 --> (x << 15) + (x << 11) | |||
3864 | // x * 0xf800 --> (x << 16) - (x << 11) | |||
3865 | // x * -0x8800 --> -((x << 15) + (x << 11)) | |||
3866 | // x * -0xf800 --> -((x << 16) - (x << 11)) ; (x << 11) - (x << 16) | |||
3867 | if (N1IsConst && TLI.decomposeMulByConstant(*DAG.getContext(), VT, N1)) { | |||
3868 | // TODO: We could handle more general decomposition of any constant by | |||
3869 | // having the target set a limit on number of ops and making a | |||
3870 | // callback to determine that sequence (similar to sqrt expansion). | |||
3871 | unsigned MathOp = ISD::DELETED_NODE; | |||
3872 | APInt MulC = ConstValue1.abs(); | |||
3873 | // The constant `2` should be treated as (2^0 + 1). | |||
3874 | unsigned TZeros = MulC == 2 ? 0 : MulC.countTrailingZeros(); | |||
3875 | MulC.lshrInPlace(TZeros); | |||
3876 | if ((MulC - 1).isPowerOf2()) | |||
3877 | MathOp = ISD::ADD; | |||
3878 | else if ((MulC + 1).isPowerOf2()) | |||
3879 | MathOp = ISD::SUB; | |||
3880 | ||||
3881 | if (MathOp != ISD::DELETED_NODE) { | |||
3882 | unsigned ShAmt = | |||
3883 | MathOp == ISD::ADD ? (MulC - 1).logBase2() : (MulC + 1).logBase2(); | |||
3884 | ShAmt += TZeros; | |||
3885 | assert(ShAmt < VT.getScalarSizeInBits() &&((void)0) | |||
3886 | "multiply-by-constant generated out of bounds shift")((void)0); | |||
3887 | SDLoc DL(N); | |||
3888 | SDValue Shl = | |||
3889 | DAG.getNode(ISD::SHL, DL, VT, N0, DAG.getConstant(ShAmt, DL, VT)); | |||
3890 | SDValue R = | |||
3891 | TZeros ? DAG.getNode(MathOp, DL, VT, Shl, | |||
3892 | DAG.getNode(ISD::SHL, DL, VT, N0, | |||
3893 | DAG.getConstant(TZeros, DL, VT))) | |||
3894 | : DAG.getNode(MathOp, DL, VT, Shl, N0); | |||
3895 | if (ConstValue1.isNegative()) | |||
3896 | R = DAG.getNode(ISD::SUB, DL, VT, DAG.getConstant(0, DL, VT), R); | |||
3897 | return R; | |||
3898 | } | |||
3899 | } | |||
3900 | ||||
3901 | // (mul (shl X, c1), c2) -> (mul X, c2 << c1) | |||
3902 | if (N0.getOpcode() == ISD::SHL && | |||
3903 | isConstantOrConstantVector(N1, /* NoOpaques */ true) && | |||
3904 | isConstantOrConstantVector(N0.getOperand(1), /* NoOpaques */ true)) { | |||
3905 | SDValue C3 = DAG.getNode(ISD::SHL, SDLoc(N), VT, N1, N0.getOperand(1)); | |||
3906 | if (isConstantOrConstantVector(C3)) | |||
3907 | return DAG.getNode(ISD::MUL, SDLoc(N), VT, N0.getOperand(0), C3); | |||
3908 | } | |||
3909 | ||||
3910 | // Change (mul (shl X, C), Y) -> (shl (mul X, Y), C) when the shift has one | |||
3911 | // use. | |||
3912 | { | |||
3913 | SDValue Sh(nullptr, 0), Y(nullptr, 0); | |||
3914 | ||||
3915 | // Check for both (mul (shl X, C), Y) and (mul Y, (shl X, C)). | |||
3916 | if (N0.getOpcode() == ISD::SHL && | |||
3917 | isConstantOrConstantVector(N0.getOperand(1)) && | |||
3918 | N0.getNode()->hasOneUse()) { | |||
3919 | Sh = N0; Y = N1; | |||
3920 | } else if (N1.getOpcode() == ISD::SHL && | |||
3921 | isConstantOrConstantVector(N1.getOperand(1)) && | |||
3922 | N1.getNode()->hasOneUse()) { | |||
3923 | Sh = N1; Y = N0; | |||
3924 | } | |||
3925 | ||||
3926 | if (Sh.getNode()) { | |||
3927 | SDValue Mul = DAG.getNode(ISD::MUL, SDLoc(N), VT, Sh.getOperand(0), Y); | |||
3928 | return DAG.getNode(ISD::SHL, SDLoc(N), VT, Mul, Sh.getOperand(1)); | |||
3929 | } | |||
3930 | } | |||
3931 | ||||
3932 | // fold (mul (add x, c1), c2) -> (add (mul x, c2), c1*c2) | |||
3933 | if (DAG.isConstantIntBuildVectorOrConstantInt(N1) && | |||
3934 | N0.getOpcode() == ISD::ADD && | |||
3935 | DAG.isConstantIntBuildVectorOrConstantInt(N0.getOperand(1)) && | |||
3936 | isMulAddWithConstProfitable(N, N0, N1)) | |||
3937 | return DAG.getNode(ISD::ADD, SDLoc(N), VT, | |||
3938 | DAG.getNode(ISD::MUL, SDLoc(N0), VT, | |||
3939 | N0.getOperand(0), N1), | |||
3940 | DAG.getNode(ISD::MUL, SDLoc(N1), VT, | |||
3941 | N0.getOperand(1), N1)); | |||
3942 | ||||
3943 | // Fold (mul (vscale * C0), C1) to (vscale * (C0 * C1)). | |||
3944 | if (N0.getOpcode() == ISD::VSCALE) | |||
3945 | if (ConstantSDNode *NC1 = isConstOrConstSplat(N1)) { | |||
3946 | const APInt &C0 = N0.getConstantOperandAPInt(0); | |||
3947 | const APInt &C1 = NC1->getAPIntValue(); | |||
3948 | return DAG.getVScale(SDLoc(N), VT, C0 * C1); | |||
3949 | } | |||
3950 | ||||
3951 | // Fold (mul step_vector(C0), C1) to (step_vector(C0 * C1)). | |||
3952 | APInt MulVal; | |||
3953 | if (N0.getOpcode() == ISD::STEP_VECTOR) | |||
3954 | if (ISD::isConstantSplatVector(N1.getNode(), MulVal)) { | |||
3955 | const APInt &C0 = N0.getConstantOperandAPInt(0); | |||
3956 | APInt NewStep = C0 * MulVal; | |||
3957 | return DAG.getStepVector(SDLoc(N), VT, NewStep); | |||
3958 | } | |||
3959 | ||||
3960 | // Fold ((mul x, 0/undef) -> 0, | |||
3961 | // (mul x, 1) -> x) -> x) | |||
3962 | // -> and(x, mask) | |||
3963 | // We can replace vectors with '0' and '1' factors with a clearing mask. | |||
3964 | if (VT.isFixedLengthVector()) { | |||
3965 | unsigned NumElts = VT.getVectorNumElements(); | |||
3966 | SmallBitVector ClearMask; | |||
3967 | ClearMask.reserve(NumElts); | |||
3968 | auto IsClearMask = [&ClearMask](ConstantSDNode *V) { | |||
3969 | if (!V || V->isNullValue()) { | |||
3970 | ClearMask.push_back(true); | |||
3971 | return true; | |||
3972 | } | |||
3973 | ClearMask.push_back(false); | |||
3974 | return V->isOne(); | |||
3975 | }; | |||
3976 | if ((!LegalOperations || TLI.isOperationLegalOrCustom(ISD::AND, VT)) && | |||
3977 | ISD::matchUnaryPredicate(N1, IsClearMask, /*AllowUndefs*/ true)) { | |||
3978 | assert(N1.getOpcode() == ISD::BUILD_VECTOR && "Unknown constant vector")((void)0); | |||
3979 | SDLoc DL(N); | |||
3980 | EVT LegalSVT = N1.getOperand(0).getValueType(); | |||
3981 | SDValue Zero = DAG.getConstant(0, DL, LegalSVT); | |||
3982 | SDValue AllOnes = DAG.getAllOnesConstant(DL, LegalSVT); | |||
3983 | SmallVector<SDValue, 16> Mask(NumElts, AllOnes); | |||
3984 | for (unsigned I = 0; I != NumElts; ++I) | |||
3985 | if (ClearMask[I]) | |||
3986 | Mask[I] = Zero; | |||
3987 | return DAG.getNode(ISD::AND, DL, VT, N0, DAG.getBuildVector(VT, DL, Mask)); | |||
3988 | } | |||
3989 | } | |||
3990 | ||||
3991 | // reassociate mul | |||
3992 | if (SDValue RMUL = reassociateOps(ISD::MUL, SDLoc(N), N0, N1, N->getFlags())) | |||
3993 | return RMUL; | |||
3994 | ||||
3995 | return SDValue(); | |||
3996 | } | |||
3997 | ||||
3998 | /// Return true if divmod libcall is available. | |||
3999 | static bool isDivRemLibcallAvailable(SDNode *Node, bool isSigned, | |||
4000 | const TargetLowering &TLI) { | |||
4001 | RTLIB::Libcall LC; | |||
4002 | EVT NodeType = Node->getValueType(0); | |||
4003 | if (!NodeType.isSimple()) | |||
4004 | return false; | |||
4005 | switch (NodeType.getSimpleVT().SimpleTy) { | |||
4006 | default: return false; // No libcall for vector types. | |||
4007 | case MVT::i8: LC= isSigned ? RTLIB::SDIVREM_I8 : RTLIB::UDIVREM_I8; break; | |||
4008 | case MVT::i16: LC= isSigned ? RTLIB::SDIVREM_I16 : RTLIB::UDIVREM_I16; break; | |||
4009 | case MVT::i32: LC= isSigned ? RTLIB::SDIVREM_I32 : RTLIB::UDIVREM_I32; break; | |||
4010 | case MVT::i64: LC= isSigned ? RTLIB::SDIVREM_I64 : RTLIB::UDIVREM_I64; break; | |||
4011 | case MVT::i128: LC= isSigned ? RTLIB::SDIVREM_I128:RTLIB::UDIVREM_I128; break; | |||
4012 | } | |||
4013 | ||||
4014 | return TLI.getLibcallName(LC) != nullptr; | |||
4015 | } | |||
4016 | ||||
4017 | /// Issue divrem if both quotient and remainder are needed. | |||
4018 | SDValue DAGCombiner::useDivRem(SDNode *Node) { | |||
4019 | if (Node->use_empty()) | |||
4020 | return SDValue(); // This is a dead node, leave it alone. | |||
4021 | ||||
4022 | unsigned Opcode = Node->getOpcode(); | |||
4023 | bool isSigned = (Opcode == ISD::SDIV) || (Opcode == ISD::SREM); | |||
4024 | unsigned DivRemOpc = isSigned ? ISD::SDIVREM : ISD::UDIVREM; | |||
4025 | ||||
4026 | // DivMod lib calls can still work on non-legal types if using lib-calls. | |||
4027 | EVT VT = Node->getValueType(0); | |||
4028 | if (VT.isVector() || !VT.isInteger()) | |||
4029 | return SDValue(); | |||
4030 | ||||
4031 | if (!TLI.isTypeLegal(VT) && !TLI.isOperationCustom(DivRemOpc, VT)) | |||
4032 | return SDValue(); | |||
4033 | ||||
4034 | // If DIVREM is going to get expanded into a libcall, | |||
4035 | // but there is no libcall available, then don't combine. | |||
4036 | if (!TLI.isOperationLegalOrCustom(DivRemOpc, VT) && | |||
4037 | !isDivRemLibcallAvailable(Node, isSigned, TLI)) | |||
4038 | return SDValue(); | |||
4039 | ||||
4040 | // If div is legal, it's better to do the normal expansion | |||
4041 | unsigned OtherOpcode = 0; | |||
4042 | if ((Opcode == ISD::SDIV) || (Opcode == ISD::UDIV)) { | |||
4043 | OtherOpcode = isSigned ? ISD::SREM : ISD::UREM; | |||
4044 | if (TLI.isOperationLegalOrCustom(Opcode, VT)) | |||
4045 | return SDValue(); | |||
4046 | } else { | |||
4047 | OtherOpcode = isSigned ? ISD::SDIV : ISD::UDIV; | |||
4048 | if (TLI.isOperationLegalOrCustom(OtherOpcode, VT)) | |||
4049 | return SDValue(); | |||
4050 | } | |||
4051 | ||||
4052 | SDValue Op0 = Node->getOperand(0); | |||
4053 | SDValue Op1 = Node->getOperand(1); | |||
4054 | SDValue combined; | |||
4055 | for (SDNode::use_iterator UI = Op0.getNode()->use_begin(), | |||
4056 | UE = Op0.getNode()->use_end(); UI != UE; ++UI) { | |||
4057 | SDNode *User = *UI; | |||
4058 | if (User == Node || User->getOpcode() == ISD::DELETED_NODE || | |||
4059 | User->use_empty()) | |||
4060 | continue; | |||
4061 | // Convert the other matching node(s), too; | |||
4062 | // otherwise, the DIVREM may get target-legalized into something | |||
4063 | // target-specific that we won't be able to recognize. | |||
4064 | unsigned UserOpc = User->getOpcode(); | |||
4065 | if ((UserOpc == Opcode || UserOpc == OtherOpcode || UserOpc == DivRemOpc) && | |||
4066 | User->getOperand(0) == Op0 && | |||
4067 | User->getOperand(1) == Op1) { | |||
4068 | if (!combined) { | |||
4069 | if (UserOpc == OtherOpcode) { | |||
4070 | SDVTList VTs = DAG.getVTList(VT, VT); | |||
4071 | combined = DAG.getNode(DivRemOpc, SDLoc(Node), VTs, Op0, Op1); | |||
4072 | } else if (UserOpc == DivRemOpc) { | |||
4073 | combined = SDValue(User, 0); | |||
4074 | } else { | |||
4075 | assert(UserOpc == Opcode)((void)0); | |||
4076 | continue; | |||
4077 | } | |||
4078 | } | |||
4079 | if (UserOpc == ISD::SDIV || UserOpc == ISD::UDIV) | |||
4080 | CombineTo(User, combined); | |||
4081 | else if (UserOpc == ISD::SREM || UserOpc == ISD::UREM) | |||
4082 | CombineTo(User, combined.getValue(1)); | |||
4083 | } | |||
4084 | } | |||
4085 | return combined; | |||
4086 | } | |||
4087 | ||||
4088 | static SDValue simplifyDivRem(SDNode *N, SelectionDAG &DAG) { | |||
4089 | SDValue N0 = N->getOperand(0); | |||
4090 | SDValue N1 = N->getOperand(1); | |||
4091 | EVT VT = N->getValueType(0); | |||
4092 | SDLoc DL(N); | |||
4093 | ||||
4094 | unsigned Opc = N->getOpcode(); | |||
4095 | bool IsDiv = (ISD::SDIV == Opc) || (ISD::UDIV == Opc); | |||
4096 | ConstantSDNode *N1C = isConstOrConstSplat(N1); | |||
4097 | ||||
4098 | // X / undef -> undef | |||
4099 | // X % undef -> undef | |||
4100 | // X / 0 -> undef | |||
4101 | // X % 0 -> undef | |||
4102 | // NOTE: This includes vectors where any divisor element is zero/undef. | |||
4103 | if (DAG.isUndef(Opc, {N0, N1})) | |||
4104 | return DAG.getUNDEF(VT); | |||
4105 | ||||
4106 | // undef / X -> 0 | |||
4107 | // undef % X -> 0 | |||
4108 | if (N0.isUndef()) | |||
4109 | return DAG.getConstant(0, DL, VT); | |||
4110 | ||||
4111 | // 0 / X -> 0 | |||
4112 | // 0 % X -> 0 | |||
4113 | ConstantSDNode *N0C = isConstOrConstSplat(N0); | |||
4114 | if (N0C && N0C->isNullValue()) | |||
4115 | return N0; | |||
4116 | ||||
4117 | // X / X -> 1 | |||
4118 | // X % X -> 0 | |||
4119 | if (N0 == N1) | |||
4120 | return DAG.getConstant(IsDiv ? 1 : 0, DL, VT); | |||
4121 | ||||
4122 | // X / 1 -> X | |||
4123 | // X % 1 -> 0 | |||
4124 | // If this is a boolean op (single-bit element type), we can't have | |||
4125 | // division-by-zero or remainder-by-zero, so assume the divisor is 1. | |||
4126 | // TODO: Similarly, if we're zero-extending a boolean divisor, then assume | |||
4127 | // it's a 1. | |||
4128 | if ((N1C && N1C->isOne()) || (VT.getScalarType() == MVT::i1)) | |||
4129 | return IsDiv ? N0 : DAG.getConstant(0, DL, VT); | |||
4130 | ||||
4131 | return SDValue(); | |||
4132 | } | |||
4133 | ||||
4134 | SDValue DAGCombiner::visitSDIV(SDNode *N) { | |||
4135 | SDValue N0 = N->getOperand(0); | |||
4136 | SDValue N1 = N->getOperand(1); | |||
4137 | EVT VT = N->getValueType(0); | |||
4138 | EVT CCVT = getSetCCResultType(VT); | |||
4139 | ||||
4140 | // fold vector ops | |||
4141 | if (VT.isVector()) | |||
4142 | if (SDValue FoldedVOp = SimplifyVBinOp(N)) | |||
4143 | return FoldedVOp; | |||
4144 | ||||
4145 | SDLoc DL(N); | |||
4146 | ||||
4147 | // fold (sdiv c1, c2) -> c1/c2 | |||
4148 | ConstantSDNode *N1C = isConstOrConstSplat(N1); | |||
4149 | if (SDValue C = DAG.FoldConstantArithmetic(ISD::SDIV, DL, VT, {N0, N1})) | |||
4150 | return C; | |||
4151 | ||||
4152 | // fold (sdiv X, -1) -> 0-X | |||
4153 | if (N1C && N1C->isAllOnesValue()) | |||
4154 | return DAG.getNode(ISD::SUB, DL, VT, DAG.getConstant(0, DL, VT), N0); | |||
4155 | ||||
4156 | // fold (sdiv X, MIN_SIGNED) -> select(X == MIN_SIGNED, 1, 0) | |||
4157 | if (N1C && N1C->getAPIntValue().isMinSignedValue()) | |||
4158 | return DAG.getSelect(DL, VT, DAG.getSetCC(DL, CCVT, N0, N1, ISD::SETEQ), | |||
4159 | DAG.getConstant(1, DL, VT), | |||
4160 | DAG.getConstant(0, DL, VT)); | |||
4161 | ||||
4162 | if (SDValue V = simplifyDivRem(N, DAG)) | |||
4163 | return V; | |||
4164 | ||||
4165 | if (SDValue NewSel = foldBinOpIntoSelect(N)) | |||
4166 | return NewSel; | |||
4167 | ||||
4168 | // If we know the sign bits of both operands are zero, strength reduce to a | |||
4169 | // udiv instead. Handles (X&15) /s 4 -> X&15 >> 2 | |||
4170 | if (DAG.SignBitIsZero(N1) && DAG.SignBitIsZero(N0)) | |||
4171 | return DAG.getNode(ISD::UDIV, DL, N1.getValueType(), N0, N1); | |||
4172 | ||||
4173 | if (SDValue V = visitSDIVLike(N0, N1, N)) { | |||
4174 | // If the corresponding remainder node exists, update its users with | |||
4175 | // (Dividend - (Quotient * Divisor). | |||
4176 | if (SDNode *RemNode = DAG.getNodeIfExists(ISD::SREM, N->getVTList(), | |||
4177 | { N0, N1 })) { | |||
4178 | SDValue Mul = DAG.getNode(ISD::MUL, DL, VT, V, N1); | |||
4179 | SDValue Sub = DAG.getNode(ISD::SUB, DL, VT, N0, Mul); | |||
4180 | AddToWorklist(Mul.getNode()); | |||
4181 | AddToWorklist(Sub.getNode()); | |||
4182 | CombineTo(RemNode, Sub); | |||
4183 | } | |||
4184 | return V; | |||
4185 | } | |||
4186 | ||||
4187 | // sdiv, srem -> sdivrem | |||
4188 | // If the divisor is constant, then return DIVREM only if isIntDivCheap() is | |||
4189 | // true. Otherwise, we break the simplification logic in visitREM(). | |||
4190 | AttributeList Attr = DAG.getMachineFunction().getFunction().getAttributes(); | |||
4191 | if (!N1C || TLI.isIntDivCheap(N->getValueType(0), Attr)) | |||
4192 | if (SDValue DivRem = useDivRem(N)) | |||
4193 | return DivRem; | |||
4194 | ||||
4195 | return SDValue(); | |||
4196 | } | |||
4197 | ||||
4198 | SDValue DAGCombiner::visitSDIVLike(SDValue N0, SDValue N1, SDNode *N) { | |||
4199 | SDLoc DL(N); | |||
4200 | EVT VT = N->getValueType(0); | |||
4201 | EVT CCVT = getSetCCResultType(VT); | |||
4202 | unsigned BitWidth = VT.getScalarSizeInBits(); | |||
4203 | ||||
4204 | // Helper for determining whether a value is a power-2 constant scalar or a | |||
4205 | // vector of such elements. | |||
4206 | auto IsPowerOfTwo = [](ConstantSDNode *C) { | |||
4207 | if (C->isNullValue() || C->isOpaque()) | |||
4208 | return false; | |||
4209 | if (C->getAPIntValue().isPowerOf2()) | |||
4210 | return true; | |||
4211 | if ((-C->getAPIntValue()).isPowerOf2()) | |||
4212 | return true; | |||
4213 | return false; | |||
4214 | }; | |||
4215 | ||||
4216 | // fold (sdiv X, pow2) -> simple ops after legalize | |||
4217 | // FIXME: We check for the exact bit here because the generic lowering gives | |||
4218 | // better results in that case. The target-specific lowering should learn how | |||
4219 | // to handle exact sdivs efficiently. | |||
4220 | if (!N->getFlags().hasExact() && ISD::matchUnaryPredicate(N1, IsPowerOfTwo)) { | |||
4221 | // Target-specific implementation of sdiv x, pow2. | |||
4222 | if (SDValue Res = BuildSDIVPow2(N)) | |||
4223 | return Res; | |||
4224 | ||||
4225 | // Create constants that are functions of the shift amount value. | |||
4226 | EVT ShiftAmtTy = getShiftAmountTy(N0.getValueType()); | |||
4227 | SDValue Bits = DAG.getConstant(BitWidth, DL, ShiftAmtTy); | |||
4228 | SDValue C1 = DAG.getNode(ISD::CTTZ, DL, VT, N1); | |||
4229 | C1 = DAG.getZExtOrTrunc(C1, DL, ShiftAmtTy); | |||
4230 | SDValue Inexact = DAG.getNode(ISD::SUB, DL, ShiftAmtTy, Bits, C1); | |||
4231 | if (!isConstantOrConstantVector(Inexact)) | |||
4232 | return SDValue(); | |||
4233 | ||||
4234 | // Splat the sign bit into the register | |||
4235 | SDValue Sign = DAG.getNode(ISD::SRA, DL, VT, N0, | |||
4236 | DAG.getConstant(BitWidth - 1, DL, ShiftAmtTy)); | |||
4237 | AddToWorklist(Sign.getNode()); | |||
4238 | ||||
4239 | // Add (N0 < 0) ? abs2 - 1 : 0; | |||
4240 | SDValue Srl = DAG.getNode(ISD::SRL, DL, VT, Sign, Inexact); | |||
4241 | AddToWorklist(Srl.getNode()); | |||
4242 | SDValue Add = DAG.getNode(ISD::ADD, DL, VT, N0, Srl); | |||
4243 | AddToWorklist(Add.getNode()); | |||
4244 | SDValue Sra = DAG.getNode(ISD::SRA, DL, VT, Add, C1); | |||
4245 | AddToWorklist(Sra.getNode()); | |||
4246 | ||||
4247 | // Special case: (sdiv X, 1) -> X | |||
4248 | // Special Case: (sdiv X, -1) -> 0-X | |||
4249 | SDValue One = DAG.getConstant(1, DL, VT); | |||
4250 | SDValue AllOnes = DAG.getAllOnesConstant(DL, VT); | |||
4251 | SDValue IsOne = DAG.getSetCC(DL, CCVT, N1, One, ISD::SETEQ); | |||
4252 | SDValue IsAllOnes = DAG.getSetCC(DL, CCVT, N1, AllOnes, ISD::SETEQ); | |||
4253 | SDValue IsOneOrAllOnes = DAG.getNode(ISD::OR, DL, CCVT, IsOne, IsAllOnes); | |||
4254 | Sra = DAG.getSelect(DL, VT, IsOneOrAllOnes, N0, Sra); | |||
4255 | ||||
4256 | // If dividing by a positive value, we're done. Otherwise, the result must | |||
4257 | // be negated. | |||
4258 | SDValue Zero = DAG.getConstant(0, DL, VT); | |||
4259 | SDValue Sub = DAG.getNode(ISD::SUB, DL, VT, Zero, Sra); | |||
4260 | ||||
4261 | // FIXME: Use SELECT_CC once we improve SELECT_CC constant-folding. | |||
4262 | SDValue IsNeg = DAG.getSetCC(DL, CCVT, N1, Zero, ISD::SETLT); | |||
4263 | SDValue Res = DAG.getSelect(DL, VT, IsNeg, Sub, Sra); | |||
4264 | return Res; | |||
4265 | } | |||
4266 | ||||
4267 | // If integer divide is expensive and we satisfy the requirements, emit an | |||
4268 | // alternate sequence. Targets may check function attributes for size/speed | |||
4269 | // trade-offs. | |||
4270 | AttributeList Attr = DAG.getMachineFunction().getFunction().getAttributes(); | |||
4271 | if (isConstantOrConstantVector(N1) && | |||
4272 | !TLI.isIntDivCheap(N->getValueType(0), Attr)) | |||
4273 | if (SDValue Op = BuildSDIV(N)) | |||
4274 | return Op; | |||
4275 | ||||
4276 | return SDValue(); | |||
4277 | } | |||
4278 | ||||
4279 | SDValue DAGCombiner::visitUDIV(SDNode *N) { | |||
4280 | SDValue N0 = N->getOperand(0); | |||
4281 | SDValue N1 = N->getOperand(1); | |||
4282 | EVT VT = N->getValueType(0); | |||
4283 | EVT CCVT = getSetCCResultType(VT); | |||
4284 | ||||
4285 | // fold vector ops | |||
4286 | if (VT.isVector()) | |||
4287 | if (SDValue FoldedVOp = SimplifyVBinOp(N)) | |||
4288 | return FoldedVOp; | |||
4289 | ||||
4290 | SDLoc DL(N); | |||
4291 | ||||
4292 | // fold (udiv c1, c2) -> c1/c2 | |||
4293 | ConstantSDNode *N1C = isConstOrConstSplat(N1); | |||
4294 | if (SDValue C = DAG.FoldConstantArithmetic(ISD::UDIV, DL, VT, {N0, N1})) | |||
4295 | return C; | |||
4296 | ||||
4297 | // fold (udiv X, -1) -> select(X == -1, 1, 0) | |||
4298 | if (N1C && N1C->getAPIntValue().isAllOnesValue()) | |||
4299 | return DAG.getSelect(DL, VT, DAG.getSetCC(DL, CCVT, N0, N1, ISD::SETEQ), | |||
4300 | DAG.getConstant(1, DL, VT), | |||
4301 | DAG.getConstant(0, DL, VT)); | |||
4302 | ||||
4303 | if (SDValue V = simplifyDivRem(N, DAG)) | |||
4304 | return V; | |||
4305 | ||||
4306 | if (SDValue NewSel = foldBinOpIntoSelect(N)) | |||
4307 | return NewSel; | |||
4308 | ||||
4309 | if (SDValue V = visitUDIVLike(N0, N1, N)) { | |||
4310 | // If the corresponding remainder node exists, update its users with | |||
4311 | // (Dividend - (Quotient * Divisor). | |||
4312 | if (SDNode *RemNode = DAG.getNodeIfExists(ISD::UREM, N->getVTList(), | |||
4313 | { N0, N1 })) { | |||
4314 | SDValue Mul = DAG.getNode(ISD::MUL, DL, VT, V, N1); | |||
4315 | SDValue Sub = DAG.getNode(ISD::SUB, DL, VT, N0, Mul); | |||
4316 | AddToWorklist(Mul.getNode()); | |||
4317 | AddToWorklist(Sub.getNode()); | |||
4318 | CombineTo(RemNode, Sub); | |||
4319 | } | |||
4320 | return V; | |||
4321 | } | |||
4322 | ||||
4323 | // sdiv, srem -> sdivrem | |||
4324 | // If the divisor is constant, then return DIVREM only if isIntDivCheap() is | |||
4325 | // true. Otherwise, we break the simplification logic in visitREM(). | |||
4326 | AttributeList Attr = DAG.getMachineFunction().getFunction().getAttributes(); | |||
4327 | if (!N1C || TLI.isIntDivCheap(N->getValueType(0), Attr)) | |||
4328 | if (SDValue DivRem = useDivRem(N)) | |||
4329 | return DivRem; | |||
4330 | ||||
4331 | return SDValue(); | |||
4332 | } | |||
4333 | ||||
4334 | SDValue DAGCombiner::visitUDIVLike(SDValue N0, SDValue N1, SDNode *N) { | |||
4335 | SDLoc DL(N); | |||
4336 | EVT VT = N->getValueType(0); | |||
4337 | ||||
4338 | // fold (udiv x, (1 << c)) -> x >>u c | |||
4339 | if (isConstantOrConstantVector(N1, /*NoOpaques*/ true) && | |||
4340 | DAG.isKnownToBeAPowerOfTwo(N1)) { | |||
4341 | SDValue LogBase2 = BuildLogBase2(N1, DL); | |||
4342 | AddToWorklist(LogBase2.getNode()); | |||
4343 | ||||
4344 | EVT ShiftVT = getShiftAmountTy(N0.getValueType()); | |||
4345 | SDValue Trunc = DAG.getZExtOrTrunc(LogBase2, DL, ShiftVT); | |||
4346 | AddToWorklist(Trunc.getNode()); | |||
4347 | return DAG.getNode(ISD::SRL, DL, VT, N0, Trunc); | |||
4348 | } | |||
4349 | ||||
4350 | // fold (udiv x, (shl c, y)) -> x >>u (log2(c)+y) iff c is power of 2 | |||
4351 | if (N1.getOpcode() == ISD::SHL) { | |||
4352 | SDValue N10 = N1.getOperand(0); | |||
4353 | if (isConstantOrConstantVector(N10, /*NoOpaques*/ true) && | |||
4354 | DAG.isKnownToBeAPowerOfTwo(N10)) { | |||
4355 | SDValue LogBase2 = BuildLogBase2(N10, DL); | |||
4356 | AddToWorklist(LogBase2.getNode()); | |||
4357 | ||||
4358 | EVT ADDVT = N1.getOperand(1).getValueType(); | |||
4359 | SDValue Trunc = DAG.getZExtOrTrunc(LogBase2, DL, ADDVT); | |||
4360 | AddToWorklist(Trunc.getNode()); | |||
4361 | SDValue Add = DAG.getNode(ISD::ADD, DL, ADDVT, N1.getOperand(1), Trunc); | |||
4362 | AddToWorklist(Add.getNode()); | |||
4363 | return DAG.getNode(ISD::SRL, DL, VT, N0, Add); | |||
4364 | } | |||
4365 | } | |||
4366 | ||||
4367 | // fold (udiv x, c) -> alternate | |||
4368 | AttributeList Attr = DAG.getMachineFunction().getFunction().getAttributes(); | |||
4369 | if (isConstantOrConstantVector(N1) && | |||
4370 | !TLI.isIntDivCheap(N->getValueType(0), Attr)) | |||
4371 | if (SDValue Op = BuildUDIV(N)) | |||
4372 | return Op; | |||
4373 | ||||
4374 | return SDValue(); | |||
4375 | } | |||
4376 | ||||
4377 | // handles ISD::SREM and ISD::UREM | |||
4378 | SDValue DAGCombiner::visitREM(SDNode *N) { | |||
4379 | unsigned Opcode = N->getOpcode(); | |||
4380 | SDValue N0 = N->getOperand(0); | |||
4381 | SDValue N1 = N->getOperand(1); | |||
4382 | EVT VT = N->getValueType(0); | |||
4383 | EVT CCVT = getSetCCResultType(VT); | |||
4384 | ||||
4385 | bool isSigned = (Opcode == ISD::SREM); | |||
4386 | SDLoc DL(N); | |||
4387 | ||||
4388 | // fold (rem c1, c2) -> c1%c2 | |||
4389 | ConstantSDNode *N1C = isConstOrConstSplat(N1); | |||
4390 | if (SDValue C = DAG.FoldConstantArithmetic(Opcode, DL, VT, {N0, N1})) | |||
4391 | return C; | |||
4392 | ||||
4393 | // fold (urem X, -1) -> select(X == -1, 0, x) | |||
4394 | if (!isSigned && N1C && N1C->getAPIntValue().isAllOnesValue()) | |||
4395 | return DAG.getSelect(DL, VT, DAG.getSetCC(DL, CCVT, N0, N1, ISD::SETEQ), | |||
4396 | DAG.getConstant(0, DL, VT), N0); | |||
4397 | ||||
4398 | if (SDValue V = simplifyDivRem(N, DAG)) | |||
4399 | return V; | |||
4400 | ||||
4401 | if (SDValue NewSel = foldBinOpIntoSelect(N)) | |||
4402 | return NewSel; | |||
4403 | ||||
4404 | if (isSigned) { | |||
4405 | // If we know the sign bits of both operands are zero, strength reduce to a | |||
4406 | // urem instead. Handles (X & 0x0FFFFFFF) %s 16 -> X&15 | |||
4407 | if (DAG.SignBitIsZero(N1) && DAG.SignBitIsZero(N0)) | |||
4408 | return DAG.getNode(ISD::UREM, DL, VT, N0, N1); | |||
4409 | } else { | |||
4410 | if (DAG.isKnownToBeAPowerOfTwo(N1)) { | |||
4411 | // fold (urem x, pow2) -> (and x, pow2-1) | |||
4412 | SDValue NegOne = DAG.getAllOnesConstant(DL, VT); | |||
4413 | SDValue Add = DAG.getNode(ISD::ADD, DL, VT, N1, NegOne); | |||
4414 | AddToWorklist(Add.getNode()); | |||
4415 | return DAG.getNode(ISD::AND, DL, VT, N0, Add); | |||
4416 | } | |||
4417 | if (N1.getOpcode() == ISD::SHL && | |||
4418 | DAG.isKnownToBeAPowerOfTwo(N1.getOperand(0))) { | |||
4419 | // fold (urem x, (shl pow2, y)) -> (and x, (add (shl pow2, y), -1)) | |||
4420 | SDValue NegOne = DAG.getAllOnesConstant(DL, VT); | |||
4421 | SDValue Add = DAG.getNode(ISD::ADD, DL, VT, N1, NegOne); | |||
4422 | AddToWorklist(Add.getNode()); | |||
4423 | return DAG.getNode(ISD::AND, DL, VT, N0, Add); | |||
4424 | } | |||
4425 | } | |||
4426 | ||||
4427 | AttributeList Attr = DAG.getMachineFunction().getFunction().getAttributes(); | |||
4428 | ||||
4429 | // If X/C can be simplified by the division-by-constant logic, lower | |||
4430 | // X%C to the equivalent of X-X/C*C. | |||
4431 | // Reuse the SDIVLike/UDIVLike combines - to avoid mangling nodes, the | |||
4432 | // speculative DIV must not cause a DIVREM conversion. We guard against this | |||
4433 | // by skipping the simplification if isIntDivCheap(). When div is not cheap, | |||
4434 | // combine will not return a DIVREM. Regardless, checking cheapness here | |||
4435 | // makes sense since the simplification results in fatter code. | |||
4436 | if (DAG.isKnownNeverZero(N1) && !TLI.isIntDivCheap(VT, Attr)) { | |||
4437 | SDValue OptimizedDiv = | |||
4438 | isSigned ? visitSDIVLike(N0, N1, N) : visitUDIVLike(N0, N1, N); | |||
4439 | if (OptimizedDiv.getNode()) { | |||
4440 | // If the equivalent Div node also exists, update its users. | |||
4441 | unsigned DivOpcode = isSigned ? ISD::SDIV : ISD::UDIV; | |||
4442 | if (SDNode *DivNode = DAG.getNodeIfExists(DivOpcode, N->getVTList(), | |||
4443 | { N0, N1 })) | |||
4444 | CombineTo(DivNode, OptimizedDiv); | |||
4445 | SDValue Mul = DAG.getNode(ISD::MUL, DL, VT, OptimizedDiv, N1); | |||
4446 | SDValue Sub = DAG.getNode(ISD::SUB, DL, VT, N0, Mul); | |||
4447 | AddToWorklist(OptimizedDiv.getNode()); | |||
4448 | AddToWorklist(Mul.getNode()); | |||
4449 | return Sub; | |||
4450 | } | |||
4451 | } | |||
4452 | ||||
4453 | // sdiv, srem -> sdivrem | |||
4454 | if (SDValue DivRem = useDivRem(N)) | |||
4455 | return DivRem.getValue(1); | |||
4456 | ||||
4457 | return SDValue(); | |||
4458 | } | |||
4459 | ||||
4460 | SDValue DAGCombiner::visitMULHS(SDNode *N) { | |||
4461 | SDValue N0 = N->getOperand(0); | |||
4462 | SDValue N1 = N->getOperand(1); | |||
4463 | EVT VT = N->getValueType(0); | |||
4464 | SDLoc DL(N); | |||
4465 | ||||
4466 | if (VT.isVector()) { | |||
4467 | // fold (mulhs x, 0) -> 0 | |||
4468 | // do not return N0/N1, because undef node may exist. | |||
4469 | if (ISD::isConstantSplatVectorAllZeros(N0.getNode()) || | |||
4470 | ISD::isConstantSplatVectorAllZeros(N1.getNode())) | |||
4471 | return DAG.getConstant(0, DL, VT); | |||
4472 | } | |||
4473 | ||||
4474 | // fold (mulhs c1, c2) | |||
4475 | if (SDValue C = DAG.FoldConstantArithmetic(ISD::MULHS, DL, VT, {N0, N1})) | |||
4476 | return C; | |||
4477 | ||||
4478 | // fold (mulhs x, 0) -> 0 | |||
4479 | if (isNullConstant(N1)) | |||
4480 | return N1; | |||
4481 | // fold (mulhs x, 1) -> (sra x, size(x)-1) | |||
4482 | if (isOneConstant(N1)) | |||
4483 | return DAG.getNode(ISD::SRA, DL, N0.getValueType(), N0, | |||
4484 | DAG.getConstant(N0.getScalarValueSizeInBits() - 1, DL, | |||
4485 | getShiftAmountTy(N0.getValueType()))); | |||
4486 | ||||
4487 | // fold (mulhs x, undef) -> 0 | |||
4488 | if (N0.isUndef() || N1.isUndef()) | |||
4489 | return DAG.getConstant(0, DL, VT); | |||
4490 | ||||
4491 | // If the type twice as wide is legal, transform the mulhs to a wider multiply | |||
4492 | // plus a shift. | |||
4493 | if (!TLI.isOperationLegalOrCustom(ISD::MULHS, VT) && VT.isSimple() && | |||
4494 | !VT.isVector()) { | |||
4495 | MVT Simple = VT.getSimpleVT(); | |||
4496 | unsigned SimpleSize = Simple.getSizeInBits(); | |||
4497 | EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2); | |||
4498 | if (TLI.isOperationLegal(ISD::MUL, NewVT)) { | |||
4499 | N0 = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N0); | |||
4500 | N1 = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N1); | |||
4501 | N1 = DAG.getNode(ISD::MUL, DL, NewVT, N0, N1); | |||
4502 | N1 = DAG.getNode(ISD::SRL, DL, NewVT, N1, | |||
4503 | DAG.getConstant(SimpleSize, DL, | |||
4504 | getShiftAmountTy(N1.getValueType()))); | |||
4505 | return DAG.getNode(ISD::TRUNCATE, DL, VT, N1); | |||
4506 | } | |||
4507 | } | |||
4508 | ||||
4509 | return SDValue(); | |||
4510 | } | |||
4511 | ||||
4512 | SDValue DAGCombiner::visitMULHU(SDNode *N) { | |||
4513 | SDValue N0 = N->getOperand(0); | |||
4514 | SDValue N1 = N->getOperand(1); | |||
4515 | EVT VT = N->getValueType(0); | |||
4516 | SDLoc DL(N); | |||
4517 | ||||
4518 | if (VT.isVector()) { | |||
4519 | // fold (mulhu x, 0) -> 0 | |||
4520 | // do not return N0/N1, because undef node may exist. | |||
4521 | if (ISD::isConstantSplatVectorAllZeros(N0.getNode()) || | |||
4522 | ISD::isConstantSplatVectorAllZeros(N1.getNode())) | |||
4523 | return DAG.getConstant(0, DL, VT); | |||
4524 | } | |||
4525 | ||||
4526 | // fold (mulhu c1, c2) | |||
4527 | if (SDValue C = DAG.FoldConstantArithmetic(ISD::MULHU, DL, VT, {N0, N1})) | |||
4528 | return C; | |||
4529 | ||||
4530 | // fold (mulhu x, 0) -> 0 | |||
4531 | if (isNullConstant(N1)) | |||
4532 | return N1; | |||
4533 | // fold (mulhu x, 1) -> 0 | |||
4534 | if (isOneConstant(N1)) | |||
4535 | return DAG.getConstant(0, DL, N0.getValueType()); | |||
4536 | // fold (mulhu x, undef) -> 0 | |||
4537 | if (N0.isUndef() || N1.isUndef()) | |||
4538 | return DAG.getConstant(0, DL, VT); | |||
4539 | ||||
4540 | // fold (mulhu x, (1 << c)) -> x >> (bitwidth - c) | |||
4541 | if (isConstantOrConstantVector(N1, /*NoOpaques*/ true) && | |||
4542 | DAG.isKnownToBeAPowerOfTwo(N1) && hasOperation(ISD::SRL, VT)) { | |||
4543 | unsigned NumEltBits = VT.getScalarSizeInBits(); | |||
4544 | SDValue LogBase2 = BuildLogBase2(N1, DL); | |||
4545 | SDValue SRLAmt = DAG.getNode( | |||
4546 | ISD::SUB, DL, VT, DAG.getConstant(NumEltBits, DL, VT), LogBase2); | |||
4547 | EVT ShiftVT = getShiftAmountTy(N0.getValueType()); | |||
4548 | SDValue Trunc = DAG.getZExtOrTrunc(SRLAmt, DL, ShiftVT); | |||
4549 | return DAG.getNode(ISD::SRL, DL, VT, N0, Trunc); | |||
4550 | } | |||
4551 | ||||
4552 | // If the type twice as wide is legal, transform the mulhu to a wider multiply | |||
4553 | // plus a shift. | |||
4554 | if (!TLI.isOperationLegalOrCustom(ISD::MULHU, VT) && VT.isSimple() && | |||
4555 | !VT.isVector()) { | |||
4556 | MVT Simple = VT.getSimpleVT(); | |||
4557 | unsigned SimpleSize = Simple.getSizeInBits(); | |||
4558 | EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2); | |||
4559 | if (TLI.isOperationLegal(ISD::MUL, NewVT)) { | |||
4560 | N0 = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N0); | |||
4561 | N1 = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N1); | |||
4562 | N1 = DAG.getNode(ISD::MUL, DL, NewVT, N0, N1); | |||
4563 | N1 = DAG.getNode(ISD::SRL, DL, NewVT, N1, | |||
4564 | DAG.getConstant(SimpleSize, DL, | |||
4565 | getShiftAmountTy(N1.getValueType()))); | |||
4566 | return DAG.getNode(ISD::TRUNCATE, DL, VT, N1); | |||
4567 | } | |||
4568 | } | |||
4569 | ||||
4570 | return SDValue(); | |||
4571 | } | |||
4572 | ||||
4573 | /// Perform optimizations common to nodes that compute two values. LoOp and HiOp | |||
4574 | /// give the opcodes for the two computations that are being performed. Return | |||
4575 | /// true if a simplification was made. | |||
4576 | SDValue DAGCombiner::SimplifyNodeWithTwoResults(SDNode *N, unsigned LoOp, | |||
4577 | unsigned HiOp) { | |||
4578 | // If the high half is not needed, just compute the low half. | |||
4579 | bool HiExists = N->hasAnyUseOfValue(1); | |||
4580 | if (!HiExists && (!LegalOperations || | |||
4581 | TLI.isOperationLegalOrCustom(LoOp, N->getValueType(0)))) { | |||
4582 | SDValue Res = DAG.getNode(LoOp, SDLoc(N), N->getValueType(0), N->ops()); | |||
4583 | return CombineTo(N, Res, Res); | |||
4584 | } | |||
4585 | ||||
4586 | // If the low half is not needed, just compute the high half. | |||
4587 | bool LoExists = N->hasAnyUseOfValue(0); | |||
4588 | if (!LoExists && (!LegalOperations || | |||
4589 | TLI.isOperationLegalOrCustom(HiOp, N->getValueType(1)))) { | |||
4590 | SDValue Res = DAG.getNode(HiOp, SDLoc(N), N->getValueType(1), N->ops()); | |||
4591 | return CombineTo(N, Res, Res); | |||
4592 | } | |||
4593 | ||||
4594 | // If both halves are used, return as it is. | |||
4595 | if (LoExists && HiExists) | |||
4596 | return SDValue(); | |||
4597 | ||||
4598 | // If the two computed results can be simplified separately, separate them. | |||
4599 | if (LoExists) { | |||
4600 | SDValue Lo = DAG.getNode(LoOp, SDLoc(N), N->getValueType(0), N->ops()); | |||
4601 | AddToWorklist(Lo.getNode()); | |||
4602 | SDValue LoOpt = combine(Lo.getNode()); | |||
4603 | if (LoOpt.getNode() && LoOpt.getNode() != Lo.getNode() && | |||
4604 | (!LegalOperations || | |||
4605 | TLI.isOperationLegalOrCustom(LoOpt.getOpcode(), LoOpt.getValueType()))) | |||
4606 | return CombineTo(N, LoOpt, LoOpt); | |||
4607 | } | |||
4608 | ||||
4609 | if (HiExists) { | |||
4610 | SDValue Hi = DAG.getNode(HiOp, SDLoc(N), N->getValueType(1), N->ops()); | |||
4611 | AddToWorklist(Hi.getNode()); | |||
4612 | SDValue HiOpt = combine(Hi.getNode()); | |||
4613 | if (HiOpt.getNode() && HiOpt != Hi && | |||
4614 | (!LegalOperations || | |||
4615 | TLI.isOperationLegalOrCustom(HiOpt.getOpcode(), HiOpt.getValueType()))) | |||
4616 | return CombineTo(N, HiOpt, HiOpt); | |||
4617 | } | |||
4618 | ||||
4619 | return SDValue(); | |||
4620 | } | |||
4621 | ||||
4622 | SDValue DAGCombiner::visitSMUL_LOHI(SDNode *N) { | |||
4623 | if (SDValue Res = SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHS)) | |||
4624 | return Res; | |||
4625 | ||||
4626 | EVT VT = N->getValueType(0); | |||
4627 | SDLoc DL(N); | |||
4628 | ||||
4629 | // If the type is twice as wide is legal, transform the mulhu to a wider | |||
4630 | // multiply plus a shift. | |||
4631 | if (VT.isSimple() && !VT.isVector()) { | |||
4632 | MVT Simple = VT.getSimpleVT(); | |||
4633 | unsigned SimpleSize = Simple.getSizeInBits(); | |||
4634 | EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2); | |||
4635 | if (TLI.isOperationLegal(ISD::MUL, NewVT)) { | |||
4636 | SDValue Lo = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N->getOperand(0)); | |||
4637 | SDValue Hi = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N->getOperand(1)); | |||
4638 | Lo = DAG.getNode(ISD::MUL, DL, NewVT, Lo, Hi); | |||
4639 | // Compute the high part as N1. | |||
4640 | Hi = DAG.getNode(ISD::SRL, DL, NewVT, Lo, | |||
4641 | DAG.getConstant(SimpleSize, DL, | |||
4642 | getShiftAmountTy(Lo.getValueType()))); | |||
4643 | Hi = DAG.getNode(ISD::TRUNCATE, DL, VT, Hi); | |||
4644 | // Compute the low part as N0. | |||
4645 | Lo = DAG.getNode(ISD::TRUNCATE, DL, VT, Lo); | |||
4646 | return CombineTo(N, Lo, Hi); | |||
4647 | } | |||
4648 | } | |||
4649 | ||||
4650 | return SDValue(); | |||
4651 | } | |||
4652 | ||||
4653 | SDValue DAGCombiner::visitUMUL_LOHI(SDNode *N) { | |||
4654 | if (SDValue Res = SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHU)) | |||
4655 | return Res; | |||
4656 | ||||
4657 | EVT VT = N->getValueType(0); | |||
4658 | SDLoc DL(N); | |||
4659 | ||||
4660 | // (umul_lohi N0, 0) -> (0, 0) | |||
4661 | if (isNullConstant(N->getOperand(1))) { | |||
4662 | SDValue Zero = DAG.getConstant(0, DL, VT); | |||
4663 | return CombineTo(N, Zero, Zero); | |||
4664 | } | |||
4665 | ||||
4666 | // (umul_lohi N0, 1) -> (N0, 0) | |||
4667 | if (isOneConstant(N->getOperand(1))) { | |||
4668 | SDValue Zero = DAG.getConstant(0, DL, VT); | |||
4669 | return CombineTo(N, N->getOperand(0), Zero); | |||
4670 | } | |||
4671 | ||||
4672 | // If the type is twice as wide is legal, transform the mulhu to a wider | |||
4673 | // multiply plus a shift. | |||
4674 | if (VT.isSimple() && !VT.isVector()) { | |||
4675 | MVT Simple = VT.getSimpleVT(); | |||
4676 | unsigned SimpleSize = Simple.getSizeInBits(); | |||
4677 | EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2); | |||
4678 | if (TLI.isOperationLegal(ISD::MUL, NewVT)) { | |||
4679 | SDValue Lo = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N->getOperand(0)); | |||
4680 | SDValue Hi = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N->getOperand(1)); | |||
4681 | Lo = DAG.getNode(ISD::MUL, DL, NewVT, Lo, Hi); | |||
4682 | // Compute the high part as N1. | |||
4683 | Hi = DAG.getNode(ISD::SRL, DL, NewVT, Lo, | |||
4684 | DAG.getConstant(SimpleSize, DL, | |||
4685 | getShiftAmountTy(Lo.getValueType()))); | |||
4686 | Hi = DAG.getNode(ISD::TRUNCATE, DL, VT, Hi); | |||
4687 | // Compute the low part as N0. | |||
4688 | Lo = DAG.getNode(ISD::TRUNCATE, DL, VT, Lo); | |||
4689 | return CombineTo(N, Lo, Hi); | |||
4690 | } | |||
4691 | } | |||
4692 | ||||
4693 | return SDValue(); | |||
4694 | } | |||
4695 | ||||
4696 | SDValue DAGCombiner::visitMULO(SDNode *N) { | |||
4697 | SDValue N0 = N->getOperand(0); | |||
4698 | SDValue N1 = N->getOperand(1); | |||
4699 | EVT VT = N0.getValueType(); | |||
4700 | bool IsSigned = (ISD::SMULO == N->getOpcode()); | |||
4701 | ||||
4702 | EVT CarryVT = N->getValueType(1); | |||
4703 | SDLoc DL(N); | |||
4704 | ||||
4705 | ConstantSDNode *N0C = isConstOrConstSplat(N0); | |||
4706 | ConstantSDNode *N1C = isConstOrConstSplat(N1); | |||
4707 | ||||
4708 | // fold operation with constant operands. | |||
4709 | // TODO: Move this to FoldConstantArithmetic when it supports nodes with | |||
4710 | // multiple results. | |||
4711 | if (N0C && N1C) { | |||
4712 | bool Overflow; | |||
4713 | APInt Result = | |||
4714 | IsSigned ? N0C->getAPIntValue().smul_ov(N1C->getAPIntValue(), Overflow) | |||
4715 | : N0C->getAPIntValue().umul_ov(N1C->getAPIntValue(), Overflow); | |||
4716 | return CombineTo(N, DAG.getConstant(Result, DL, VT), | |||
4717 | DAG.getBoolConstant(Overflow, DL, CarryVT, CarryVT)); | |||
4718 | } | |||
4719 | ||||
4720 | // canonicalize constant to RHS. | |||
4721 | if (DAG.isConstantIntBuildVectorOrConstantInt(N0) && | |||
4722 | !DAG.isConstantIntBuildVectorOrConstantInt(N1)) | |||
4723 | return DAG.getNode(N->getOpcode(), DL, N->getVTList(), N1, N0); | |||
4724 | ||||
4725 | // fold (mulo x, 0) -> 0 + no carry out | |||
4726 | if (isNullOrNullSplat(N1)) | |||
4727 | return CombineTo(N, DAG.getConstant(0, DL, VT), | |||
4728 | DAG.getConstant(0, DL, CarryVT)); | |||
4729 | ||||
4730 | // (mulo x, 2) -> (addo x, x) | |||
4731 | if (N1C && N1C->getAPIntValue() == 2) | |||
4732 | return DAG.getNode(IsSigned ? ISD::SADDO : ISD::UADDO, DL, | |||
4733 | N->getVTList(), N0, N0); | |||
4734 | ||||
4735 | if (IsSigned) { | |||
4736 | // A 1 bit SMULO overflows if both inputs are 1. | |||
4737 | if (VT.getScalarSizeInBits() == 1) { | |||
4738 | SDValue And = DAG.getNode(ISD::AND, DL, VT, N0, N1); | |||
4739 | return CombineTo(N, And, | |||
4740 | DAG.getSetCC(DL, CarryVT, And, | |||
4741 | DAG.getConstant(0, DL, VT), ISD::SETNE)); | |||
4742 | } | |||
4743 | ||||
4744 | // Multiplying n * m significant bits yields a result of n + m significant | |||
4745 | // bits. If the total number of significant bits does not exceed the | |||
4746 | // result bit width (minus 1), there is no overflow. | |||
4747 | unsigned SignBits = DAG.ComputeNumSignBits(N0); | |||
4748 | if (SignBits > 1) | |||
4749 | SignBits += DAG.ComputeNumSignBits(N1); | |||
4750 | if (SignBits > VT.getScalarSizeInBits() + 1) | |||
4751 | return CombineTo(N, DAG.getNode(ISD::MUL, DL, VT, N0, N1), | |||
4752 | DAG.getConstant(0, DL, CarryVT)); | |||
4753 | } else { | |||
4754 | KnownBits N1Known = DAG.computeKnownBits(N1); | |||
4755 | KnownBits N0Known = DAG.computeKnownBits(N0); | |||
4756 | bool Overflow; | |||
4757 | (void)N0Known.getMaxValue().umul_ov(N1Known.getMaxValue(), Overflow); | |||
4758 | if (!Overflow) | |||
4759 | return CombineTo(N, DAG.getNode(ISD::MUL, DL, VT, N0, N1), | |||
4760 | DAG.getConstant(0, DL, CarryVT)); | |||
4761 | } | |||
4762 | ||||
4763 | return SDValue(); | |||
4764 | } | |||
4765 | ||||
4766 | SDValue DAGCombiner::visitIMINMAX(SDNode *N) { | |||
4767 | SDValue N0 = N->getOperand(0); | |||
4768 | SDValue N1 = N->getOperand(1); | |||
4769 | EVT VT = N0.getValueType(); | |||
4770 | unsigned Opcode = N->getOpcode(); | |||
4771 | ||||
4772 | // fold vector ops | |||
4773 | if (VT.isVector()) | |||
4774 | if (SDValue FoldedVOp = SimplifyVBinOp(N)) | |||
4775 | return FoldedVOp; | |||
4776 | ||||
4777 | // fold operation with constant operands. | |||
4778 | if (SDValue C = DAG.FoldConstantArithmetic(Opcode, SDLoc(N), VT, {N0, N1})) | |||
4779 | return C; | |||
4780 | ||||
4781 | // canonicalize constant to RHS | |||
4782 | if (DAG.isConstantIntBuildVectorOrConstantInt(N0) && | |||
4783 | !DAG.isConstantIntBuildVectorOrConstantInt(N1)) | |||
4784 | return DAG.getNode(N->getOpcode(), SDLoc(N), VT, N1, N0); | |||
4785 | ||||
4786 | // Is sign bits are zero, flip between UMIN/UMAX and SMIN/SMAX. | |||
4787 | // Only do this if the current op isn't legal and the flipped is. | |||
4788 | if (!TLI.isOperationLegal(Opcode, VT) && | |||
4789 | (N0.isUndef() || DAG.SignBitIsZero(N0)) && | |||
4790 | (N1.isUndef() || DAG.SignBitIsZero(N1))) { | |||
4791 | unsigned AltOpcode; | |||
4792 | switch (Opcode) { | |||
4793 | case ISD::SMIN: AltOpcode = ISD::UMIN; break; | |||
4794 | case ISD::SMAX: AltOpcode = ISD::UMAX; break; | |||
4795 | case ISD::UMIN: AltOpcode = ISD::SMIN; break; | |||
4796 | case ISD::UMAX: AltOpcode = ISD::SMAX; break; | |||
4797 | default: llvm_unreachable("Unknown MINMAX opcode")__builtin_unreachable(); | |||
4798 | } | |||
4799 | if (TLI.isOperationLegal(AltOpcode, VT)) | |||
4800 | return DAG.getNode(AltOpcode, SDLoc(N), VT, N0, N1); | |||
4801 | } | |||
4802 | ||||
4803 | // Simplify the operands using demanded-bits information. | |||
4804 | if (SimplifyDemandedBits(SDValue(N, 0))) | |||
4805 | return SDValue(N, 0); | |||
4806 | ||||
4807 | return SDValue(); | |||
4808 | } | |||
4809 | ||||
4810 | /// If this is a bitwise logic instruction and both operands have the same | |||
4811 | /// opcode, try to sink the other opcode after the logic instruction. | |||
4812 | SDValue DAGCombiner::hoistLogicOpWithSameOpcodeHands(SDNode *N) { | |||
4813 | SDValue N0 = N->getOperand(0), N1 = N->getOperand(1); | |||
4814 | EVT VT = N0.getValueType(); | |||
4815 | unsigned LogicOpcode = N->getOpcode(); | |||
4816 | unsigned HandOpcode = N0.getOpcode(); | |||
4817 | assert((LogicOpcode == ISD::AND || LogicOpcode == ISD::OR ||((void)0) | |||
4818 | LogicOpcode == ISD::XOR) && "Expected logic opcode")((void)0); | |||
4819 | assert(HandOpcode == N1.getOpcode() && "Bad input!")((void)0); | |||
4820 | ||||
4821 | // Bail early if none of these transforms apply. | |||
4822 | if (N0.getNumOperands() == 0) | |||
4823 | return SDValue(); | |||
4824 | ||||
4825 | // FIXME: We should check number of uses of the operands to not increase | |||
4826 | // the instruction count for all transforms. | |||
4827 | ||||
4828 | // Handle size-changing casts. | |||
4829 | SDValue X = N0.getOperand(0); | |||
4830 | SDValue Y = N1.getOperand(0); | |||
4831 | EVT XVT = X.getValueType(); | |||
4832 | SDLoc DL(N); | |||
4833 | if (HandOpcode == ISD::ANY_EXTEND || HandOpcode == ISD::ZERO_EXTEND || | |||
4834 | HandOpcode == ISD::SIGN_EXTEND) { | |||
4835 | // If both operands have other uses, this transform would create extra | |||
4836 | // instructions without eliminating anything. | |||
4837 | if (!N0.hasOneUse() && !N1.hasOneUse()) | |||
4838 | return SDValue(); | |||
4839 | // We need matching integer source types. | |||
4840 | if (XVT != Y.getValueType()) | |||
4841 | return SDValue(); | |||
4842 | // Don't create an illegal op during or after legalization. Don't ever | |||
4843 | // create an unsupported vector op. | |||
4844 | if ((VT.isVector() || LegalOperations) && | |||
4845 | !TLI.isOperationLegalOrCustom(LogicOpcode, XVT)) | |||
4846 | return SDValue(); | |||
4847 | // Avoid infinite looping with PromoteIntBinOp. | |||
4848 | // TODO: Should we apply desirable/legal constraints to all opcodes? | |||
4849 | if (HandOpcode == ISD::ANY_EXTEND && LegalTypes && | |||
4850 | !TLI.isTypeDesirableForOp(LogicOpcode, XVT)) | |||
4851 | return SDValue(); | |||
4852 | // logic_op (hand_op X), (hand_op Y) --> hand_op (logic_op X, Y) | |||
4853 | SDValue Logic = DAG.getNode(LogicOpcode, DL, XVT, X, Y); | |||
4854 | return DAG.getNode(HandOpcode, DL, VT, Logic); | |||
4855 | } | |||
4856 | ||||
4857 | // logic_op (truncate x), (truncate y) --> truncate (logic_op x, y) | |||
4858 | if (HandOpcode == ISD::TRUNCATE) { | |||
4859 | // If both operands have other uses, this transform would create extra | |||
4860 | // instructions without eliminating anything. | |||
4861 | if (!N0.hasOneUse() && !N1.hasOneUse()) | |||
4862 | return SDValue(); | |||
4863 | // We need matching source types. | |||
4864 | if (XVT != Y.getValueType()) | |||
4865 | return SDValue(); | |||
4866 | // Don't create an illegal op during or after legalization. | |||
4867 | if (LegalOperations && !TLI.isOperationLegal(LogicOpcode, XVT)) | |||
4868 | return SDValue(); | |||
4869 | // Be extra careful sinking truncate. If it's free, there's no benefit in | |||
4870 | // widening a binop. Also, don't create a logic op on an illegal type. | |||
4871 | if (TLI.isZExtFree(VT, XVT) && TLI.isTruncateFree(XVT, VT)) | |||
4872 | return SDValue(); | |||
4873 | if (!TLI.isTypeLegal(XVT)) | |||
4874 | return SDValue(); | |||
4875 | SDValue Logic = DAG.getNode(LogicOpcode, DL, XVT, X, Y); | |||
4876 | return DAG.getNode(HandOpcode, DL, VT, Logic); | |||
4877 | } | |||
4878 | ||||
4879 | // For binops SHL/SRL/SRA/AND: | |||
4880 | // logic_op (OP x, z), (OP y, z) --> OP (logic_op x, y), z | |||
4881 | if ((HandOpcode == ISD::SHL || HandOpcode == ISD::SRL || | |||
4882 | HandOpcode == ISD::SRA || HandOpcode == ISD::AND) && | |||
4883 | N0.getOperand(1) == N1.getOperand(1)) { | |||
4884 | // If either operand has other uses, this transform is not an improvement. | |||
4885 | if (!N0.hasOneUse() || !N1.hasOneUse()) | |||
4886 | return SDValue(); | |||
4887 | SDValue Logic = DAG.getNode(LogicOpcode, DL, XVT, X, Y); | |||
4888 | return DAG.getNode(HandOpcode, DL, VT, Logic, N0.getOperand(1)); | |||
4889 | } | |||
4890 | ||||
4891 | // Unary ops: logic_op (bswap x), (bswap y) --> bswap (logic_op x, y) | |||
4892 | if (HandOpcode == ISD::BSWAP) { | |||
4893 | // If either operand has other uses, this transform is not an improvement. | |||
4894 | if (!N0.hasOneUse() || !N1.hasOneUse()) | |||
4895 | return SDValue(); | |||
4896 | SDValue Logic = DAG.getNode(LogicOpcode, DL, XVT, X, Y); | |||
4897 | return DAG.getNode(HandOpcode, DL, VT, Logic); | |||
4898 | } | |||
4899 | ||||
4900 | // Simplify xor/and/or (bitcast(A), bitcast(B)) -> bitcast(op (A,B)) | |||
4901 | // Only perform this optimization up until type legalization, before | |||
4902 | // LegalizeVectorOprs. LegalizeVectorOprs promotes vector operations by | |||
4903 | // adding bitcasts. For example (xor v4i32) is promoted to (v2i64), and | |||
4904 | // we don't want to undo this promotion. | |||
4905 | // We also handle SCALAR_TO_VECTOR because xor/or/and operations are cheaper | |||
4906 | // on scalars. | |||
4907 | if ((HandOpcode == ISD::BITCAST || HandOpcode == ISD::SCALAR_TO_VECTOR) && | |||
4908 | Level <= AfterLegalizeTypes) { | |||
4909 | // Input types must be integer and the same. | |||
4910 | if (XVT.isInteger() && XVT == Y.getValueType() && | |||
4911 | !(VT.isVector() && TLI.isTypeLegal(VT) && | |||
4912 | !XVT.isVector() && !TLI.isTypeLegal(XVT))) { | |||
4913 | SDValue Logic = DAG.getNode(LogicOpcode, DL, XVT, X, Y); | |||
4914 | return DAG.getNode(HandOpcode, DL, VT, Logic); | |||
4915 | } | |||
4916 | } | |||
4917 | ||||
4918 | // Xor/and/or are indifferent to the swizzle operation (shuffle of one value). | |||
4919 | // Simplify xor/and/or (shuff(A), shuff(B)) -> shuff(op (A,B)) | |||
4920 | // If both shuffles use the same mask, and both shuffle within a single | |||
4921 | // vector, then it is worthwhile to move the swizzle after the operation. | |||
4922 | // The type-legalizer generates this pattern when loading illegal | |||
4923 | // vector types from memory. In many cases this allows additional shuffle | |||
4924 | // optimizations. | |||
4925 | // There are other cases where moving the shuffle after the xor/and/or | |||
4926 | // is profitable even if shuffles don't perform a swizzle. | |||
4927 | // If both shuffles use the same mask, and both shuffles have the same first | |||
4928 | // or second operand, then it might still be profitable to move the shuffle | |||
4929 | // after the xor/and/or operation. | |||
4930 | if (HandOpcode == ISD::VECTOR_SHUFFLE && Level < AfterLegalizeDAG) { | |||
4931 | auto *SVN0 = cast<ShuffleVectorSDNode>(N0); | |||
4932 | auto *SVN1 = cast<ShuffleVectorSDNode>(N1); | |||
4933 | assert(X.getValueType() == Y.getValueType() &&((void)0) | |||
4934 | "Inputs to shuffles are not the same type")((void)0); | |||
4935 | ||||
4936 | // Check that both shuffles use the same mask. The masks are known to be of | |||
4937 | // the same length because the result vector type is the same. | |||
4938 | // Check also that shuffles have only one use to avoid introducing extra | |||
4939 | // instructions. | |||
4940 | if (!SVN0->hasOneUse() || !SVN1->hasOneUse() || | |||
4941 | !SVN0->getMask().equals(SVN1->getMask())) | |||
4942 | return SDValue(); | |||
4943 | ||||
4944 | // Don't try to fold this node if it requires introducing a | |||
4945 | // build vector of all zeros that might be illegal at this stage. | |||
4946 | SDValue ShOp = N0.getOperand(1); | |||
4947 | if (LogicOpcode == ISD::XOR && !ShOp.isUndef()) | |||
4948 | ShOp = tryFoldToZero(DL, TLI, VT, DAG, LegalOperations); | |||
4949 | ||||
4950 | // (logic_op (shuf (A, C), shuf (B, C))) --> shuf (logic_op (A, B), C) | |||
4951 | if (N0.getOperand(1) == N1.getOperand(1) && ShOp.getNode()) { | |||
4952 | SDValue Logic = DAG.getNode(LogicOpcode, DL, VT, | |||
4953 | N0.getOperand(0), N1.getOperand(0)); | |||
4954 | return DAG.getVectorShuffle(VT, DL, Logic, ShOp, SVN0->getMask()); | |||
4955 | } | |||
4956 | ||||
4957 | // Don't try to fold this node if it requires introducing a | |||
4958 | // build vector of all zeros that might be illegal at this stage. | |||
4959 | ShOp = N0.getOperand(0); | |||
4960 | if (LogicOpcode == ISD::XOR && !ShOp.isUndef()) | |||
4961 | ShOp = tryFoldToZero(DL, TLI, VT, DAG, LegalOperations); | |||
4962 | ||||
4963 | // (logic_op (shuf (C, A), shuf (C, B))) --> shuf (C, logic_op (A, B)) | |||
4964 | if (N0.getOperand(0) == N1.getOperand(0) && ShOp.getNode()) { | |||
4965 | SDValue Logic = DAG.getNode(LogicOpcode, DL, VT, N0.getOperand(1), | |||
4966 | N1.getOperand(1)); | |||
4967 | return DAG.getVectorShuffle(VT, DL, ShOp, Logic, SVN0->getMask()); | |||
4968 | } | |||
4969 | } | |||
4970 | ||||
4971 | return SDValue(); | |||
4972 | } | |||
4973 | ||||
4974 | /// Try to make (and/or setcc (LL, LR), setcc (RL, RR)) more efficient. | |||
4975 | SDValue DAGCombiner::foldLogicOfSetCCs(bool IsAnd, SDValue N0, SDValue N1, | |||
4976 | const SDLoc &DL) { | |||
4977 | SDValue LL, LR, RL, RR, N0CC, N1CC; | |||
4978 | if (!isSetCCEquivalent(N0, LL, LR, N0CC) || | |||
4979 | !isSetCCEquivalent(N1, RL, RR, N1CC)) | |||
4980 | return SDValue(); | |||
4981 | ||||
4982 | assert(N0.getValueType() == N1.getValueType() &&((void)0) | |||
4983 | "Unexpected operand types for bitwise logic op")((void)0); | |||
4984 | assert(LL.getValueType() == LR.getValueType() &&((void)0) | |||
4985 | RL.getValueType() == RR.getValueType() &&((void)0) | |||
4986 | "Unexpected operand types for setcc")((void)0); | |||
4987 | ||||
4988 | // If we're here post-legalization or the logic op type is not i1, the logic | |||
4989 | // op type must match a setcc result type. Also, all folds require new | |||
4990 | // operations on the left and right operands, so those types must match. | |||
4991 | EVT VT = N0.getValueType(); | |||
4992 | EVT OpVT = LL.getValueType(); | |||
4993 | if (LegalOperations || VT.getScalarType() != MVT::i1) | |||
4994 | if (VT != getSetCCResultType(OpVT)) | |||
4995 | return SDValue(); | |||
4996 | if (OpVT != RL.getValueType()) | |||
4997 | return SDValue(); | |||
4998 | ||||
4999 | ISD::CondCode CC0 = cast<CondCodeSDNode>(N0CC)->get(); | |||
5000 | ISD::CondCode CC1 = cast<CondCodeSDNode>(N1CC)->get(); | |||
5001 | bool IsInteger = OpVT.isInteger(); | |||
5002 | if (LR == RR && CC0 == CC1 && IsInteger) { | |||
5003 | bool IsZero = isNullOrNullSplat(LR); | |||
5004 | bool IsNeg1 = isAllOnesOrAllOnesSplat(LR); | |||
5005 | ||||
5006 | // All bits clear? | |||
5007 | bool AndEqZero = IsAnd && CC1 == ISD::SETEQ && IsZero; | |||
5008 | // All sign bits clear? | |||
5009 | bool AndGtNeg1 = IsAnd && CC1 == ISD::SETGT && IsNeg1; | |||
5010 | // Any bits set? | |||
5011 | bool OrNeZero = !IsAnd && CC1 == ISD::SETNE && IsZero; | |||
5012 | // Any sign bits set? | |||
5013 | bool OrLtZero = !IsAnd && CC1 == ISD::SETLT && IsZero; | |||
5014 | ||||
5015 | // (and (seteq X, 0), (seteq Y, 0)) --> (seteq (or X, Y), 0) | |||
5016 | // (and (setgt X, -1), (setgt Y, -1)) --> (setgt (or X, Y), -1) | |||
5017 | // (or (setne X, 0), (setne Y, 0)) --> (setne (or X, Y), 0) | |||
5018 | // (or (setlt X, 0), (setlt Y, 0)) --> (setlt (or X, Y), 0) | |||
5019 | if (AndEqZero || AndGtNeg1 || OrNeZero || OrLtZero) { | |||
5020 | SDValue Or = DAG.getNode(ISD::OR, SDLoc(N0), OpVT, LL, RL); | |||
5021 | AddToWorklist(Or.getNode()); | |||
5022 | return DAG.getSetCC(DL, VT, Or, LR, CC1); | |||
5023 | } | |||
5024 | ||||
5025 | // All bits set? | |||
5026 | bool AndEqNeg1 = IsAnd && CC1 == ISD::SETEQ && IsNeg1; | |||
5027 | // All sign bits set? | |||
5028 | bool AndLtZero = IsAnd && CC1 == ISD::SETLT && IsZero; | |||
5029 | // Any bits clear? | |||
5030 | bool OrNeNeg1 = !IsAnd && CC1 == ISD::SETNE && IsNeg1; | |||
5031 | // Any sign bits clear? | |||
5032 | bool OrGtNeg1 = !IsAnd && CC1 == ISD::SETGT && IsNeg1; | |||
5033 | ||||
5034 | // (and (seteq X, -1), (seteq Y, -1)) --> (seteq (and X, Y), -1) | |||
5035 | // (and (setlt X, 0), (setlt Y, 0)) --> (setlt (and X, Y), 0) | |||
5036 | // (or (setne X, -1), (setne Y, -1)) --> (setne (and X, Y), -1) | |||
5037 | // (or (setgt X, -1), (setgt Y -1)) --> (setgt (and X, Y), -1) | |||
5038 | if (AndEqNeg1 || AndLtZero || OrNeNeg1 || OrGtNeg1) { | |||
5039 | SDValue And = DAG.getNode(ISD::AND, SDLoc(N0), OpVT, LL, RL); | |||
5040 | AddToWorklist(And.getNode()); | |||
5041 | return DAG.getSetCC(DL, VT, And, LR, CC1); | |||
5042 | } | |||
5043 | } | |||
5044 | ||||
5045 | // TODO: What is the 'or' equivalent of this fold? | |||
5046 | // (and (setne X, 0), (setne X, -1)) --> (setuge (add X, 1), 2) | |||
5047 | if (IsAnd && LL == RL && CC0 == CC1 && OpVT.getScalarSizeInBits() > 1 && | |||
5048 | IsInteger && CC0 == ISD::SETNE && | |||
5049 | ((isNullConstant(LR) && isAllOnesConstant(RR)) || | |||
5050 | (isAllOnesConstant(LR) && isNullConstant(RR)))) { | |||
5051 | SDValue One = DAG.getConstant(1, DL, OpVT); | |||
5052 | SDValue Two = DAG.getConstant(2, DL, OpVT); | |||
5053 | SDValue Add = DAG.getNode(ISD::ADD, SDLoc(N0), OpVT, LL, One); | |||
5054 | AddToWorklist(Add.getNode()); | |||
5055 | return DAG.getSetCC(DL, VT, Add, Two, ISD::SETUGE); | |||
5056 | } | |||
5057 | ||||
5058 | // Try more general transforms if the predicates match and the only user of | |||
5059 | // the compares is the 'and' or 'or'. | |||
5060 | if (IsInteger && TLI.convertSetCCLogicToBitwiseLogic(OpVT) && CC0 == CC1 && | |||
5061 | N0.hasOneUse() && N1.hasOneUse()) { | |||
5062 | // and (seteq A, B), (seteq C, D) --> seteq (or (xor A, B), (xor C, D)), 0 | |||
5063 | // or (setne A, B), (setne C, D) --> setne (or (xor A, B), (xor C, D)), 0 | |||
5064 | if ((IsAnd && CC1 == ISD::SETEQ) || (!IsAnd && CC1 == ISD::SETNE)) { | |||
5065 | SDValue XorL = DAG.getNode(ISD::XOR, SDLoc(N0), OpVT, LL, LR); | |||
5066 | SDValue XorR = DAG.getNode(ISD::XOR, SDLoc(N1), OpVT, RL, RR); | |||
5067 | SDValue Or = DAG.getNode(ISD::OR, DL, OpVT, XorL, XorR); | |||
5068 | SDValue Zero = DAG.getConstant(0, DL, OpVT); | |||
5069 | return DAG.getSetCC(DL, VT, Or, Zero, CC1); | |||
5070 | } | |||
5071 | ||||
5072 | // Turn compare of constants whose difference is 1 bit into add+and+setcc. | |||
5073 | // TODO - support non-uniform vector amounts. | |||
5074 | if ((IsAnd && CC1 == ISD::SETNE) || (!IsAnd && CC1 == ISD::SETEQ)) { | |||
5075 | // Match a shared variable operand and 2 non-opaque constant operands. | |||
5076 | ConstantSDNode *C0 = isConstOrConstSplat(LR); | |||
5077 | ConstantSDNode *C1 = isConstOrConstSplat(RR); | |||
5078 | if (LL == RL && C0 && C1 && !C0->isOpaque() && !C1->isOpaque()) { | |||
5079 | const APInt &CMax = | |||
5080 | APIntOps::umax(C0->getAPIntValue(), C1->getAPIntValue()); | |||
5081 | const APInt &CMin = | |||
5082 | APIntOps::umin(C0->getAPIntValue(), C1->getAPIntValue()); | |||
5083 | // The difference of the constants must be a single bit. | |||
5084 | if ((CMax - CMin).isPowerOf2()) { | |||
5085 | // and/or (setcc X, CMax, ne), (setcc X, CMin, ne/eq) --> | |||
5086 | // setcc ((sub X, CMin), ~(CMax - CMin)), 0, ne/eq | |||
5087 | SDValue Max = DAG.getNode(ISD::UMAX, DL, OpVT, LR, RR); | |||
5088 | SDValue Min = DAG.getNode(ISD::UMIN, DL, OpVT, LR, RR); | |||
5089 | SDValue Offset = DAG.getNode(ISD::SUB, DL, OpVT, LL, Min); | |||
5090 | SDValue Diff = DAG.getNode(ISD::SUB, DL, OpVT, Max, Min); | |||
5091 | SDValue Mask = DAG.getNOT(DL, Diff, OpVT); | |||
5092 | SDValue And = DAG.getNode(ISD::AND, DL, OpVT, Offset, Mask); | |||
5093 | SDValue Zero = DAG.getConstant(0, DL, OpVT); | |||
5094 | return DAG.getSetCC(DL, VT, And, Zero, CC0); | |||
5095 | } | |||
5096 | } | |||
5097 | } | |||
5098 | } | |||
5099 | ||||
5100 | // Canonicalize equivalent operands to LL == RL. | |||
5101 | if (LL == RR && LR == RL) { | |||
5102 | CC1 = ISD::getSetCCSwappedOperands(CC1); | |||
5103 | std::swap(RL, RR); | |||
5104 | } | |||
5105 | ||||
5106 | // (and (setcc X, Y, CC0), (setcc X, Y, CC1)) --> (setcc X, Y, NewCC) | |||
5107 | // (or (setcc X, Y, CC0), (setcc X, Y, CC1)) --> (setcc X, Y, NewCC) | |||
5108 | if (LL == RL && LR == RR) { | |||
5109 | ISD::CondCode NewCC = IsAnd ? ISD::getSetCCAndOperation(CC0, CC1, OpVT) | |||
5110 | : ISD::getSetCCOrOperation(CC0, CC1, OpVT); | |||
5111 | if (NewCC != ISD::SETCC_INVALID && | |||
5112 | (!LegalOperations || | |||
5113 | (TLI.isCondCodeLegal(NewCC, LL.getSimpleValueType()) && | |||
5114 | TLI.isOperationLegal(ISD::SETCC, OpVT)))) | |||
5115 | return DAG.getSetCC(DL, VT, LL, LR, NewCC); | |||
5116 | } | |||
5117 | ||||
5118 | return SDValue(); | |||
5119 | } | |||
5120 | ||||
5121 | /// This contains all DAGCombine rules which reduce two values combined by | |||
5122 | /// an And operation to a single value. This makes them reusable in the context | |||
5123 | /// of visitSELECT(). Rules involving constants are not included as | |||
5124 | /// visitSELECT() already handles those cases. | |||
5125 | SDValue DAGCombiner::visitANDLike(SDValue N0, SDValue N1, SDNode *N) { | |||
5126 | EVT VT = N1.getValueType(); | |||
5127 | SDLoc DL(N); | |||
5128 | ||||
5129 | // fold (and x, undef) -> 0 | |||
5130 | if (N0.isUndef() || N1.isUndef()) | |||
5131 | return DAG.getConstant(0, DL, VT); | |||
5132 | ||||
5133 | if (SDValue V = foldLogicOfSetCCs(true, N0, N1, DL)) | |||
5134 | return V; | |||
5135 | ||||
5136 | // TODO: Rewrite this to return a new 'AND' instead of using CombineTo. | |||
5137 | if (N0.getOpcode() == ISD::ADD && N1.getOpcode() == ISD::SRL && | |||
5138 | VT.getSizeInBits() <= 64 && N0->hasOneUse()) { | |||
5139 | if (ConstantSDNode *ADDI = dyn_cast<ConstantSDNode>(N0.getOperand(1))) { | |||
5140 | if (ConstantSDNode *SRLI = dyn_cast<ConstantSDNode>(N1.getOperand(1))) { | |||
5141 | // Look for (and (add x, c1), (lshr y, c2)). If C1 wasn't a legal | |||
5142 | // immediate for an add, but it is legal if its top c2 bits are set, | |||
5143 | // transform the ADD so the immediate doesn't need to be materialized | |||
5144 | // in a register. | |||
5145 | APInt ADDC = ADDI->getAPIntValue(); | |||
5146 | APInt SRLC = SRLI->getAPIntValue(); | |||
5147 | if (ADDC.getMinSignedBits() <= 64 && | |||
5148 | SRLC.ult(VT.getSizeInBits()) && | |||
5149 | !TLI.isLegalAddImmediate(ADDC.getSExtValue())) { | |||
5150 | APInt Mask = APInt::getHighBitsSet(VT.getSizeInBits(), | |||
5151 | SRLC.getZExtValue()); | |||
5152 | if (DAG.MaskedValueIsZero(N0.getOperand(1), Mask)) { | |||
5153 | ADDC |= Mask; | |||
5154 | if (TLI.isLegalAddImmediate(ADDC.getSExtValue())) { | |||
5155 | SDLoc DL0(N0); | |||
5156 | SDValue NewAdd = | |||
5157 | DAG.getNode(ISD::ADD, DL0, VT, | |||
5158 | N0.getOperand(0), DAG.getConstant(ADDC, DL, VT)); | |||
5159 | CombineTo(N0.getNode(), NewAdd); | |||
5160 | // Return N so it doesn't get rechecked! | |||
5161 | return SDValue(N, 0); | |||
5162 | } | |||
5163 | } | |||
5164 | } | |||
5165 | } | |||
5166 | } | |||
5167 | } | |||
5168 | ||||
5169 | // Reduce bit extract of low half of an integer to the narrower type. | |||
5170 | // (and (srl i64:x, K), KMask) -> | |||
5171 | // (i64 zero_extend (and (srl (i32 (trunc i64:x)), K)), KMask) | |||
5172 | if (N0.getOpcode() == ISD::SRL && N0.hasOneUse()) { | |||
5173 | if (ConstantSDNode *CAnd = dyn_cast<ConstantSDNode>(N1)) { | |||
5174 | if (ConstantSDNode *CShift = dyn_cast<ConstantSDNode>(N0.getOperand(1))) { | |||
5175 | unsigned Size = VT.getSizeInBits(); | |||
5176 | const APInt &AndMask = CAnd->getAPIntValue(); | |||
5177 | unsigned ShiftBits = CShift->getZExtValue(); | |||
5178 | ||||
5179 | // Bail out, this node will probably disappear anyway. | |||
5180 | if (ShiftBits == 0) | |||
5181 | return SDValue(); | |||
5182 | ||||
5183 | unsigned MaskBits = AndMask.countTrailingOnes(); | |||
5184 | EVT HalfVT = EVT::getIntegerVT(*DAG.getContext(), Size / 2); | |||
5185 | ||||
5186 | if (AndMask.isMask() && | |||
5187 | // Required bits must not span the two halves of the integer and | |||
5188 | // must fit in the half size type. | |||
5189 | (ShiftBits + MaskBits <= Size / 2) && | |||
5190 | TLI.isNarrowingProfitable(VT, HalfVT) && | |||
5191 | TLI.isTypeDesirableForOp(ISD::AND, HalfVT) && | |||
5192 | TLI.isTypeDesirableForOp(ISD::SRL, HalfVT) && | |||
5193 | TLI.isTruncateFree(VT, HalfVT) && | |||
5194 | TLI.isZExtFree(HalfVT, VT)) { | |||
5195 | // The isNarrowingProfitable is to avoid regressions on PPC and | |||
5196 | // AArch64 which match a few 64-bit bit insert / bit extract patterns | |||
5197 | // on downstream users of this. Those patterns could probably be | |||
5198 | // extended to handle extensions mixed in. | |||
5199 | ||||
5200 | SDValue SL(N0); | |||
5201 | assert(MaskBits <= Size)((void)0); | |||
5202 | ||||
5203 | // Extracting the highest bit of the low half. | |||
5204 | EVT ShiftVT = TLI.getShiftAmountTy(HalfVT, DAG.getDataLayout()); | |||
5205 | SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SL, HalfVT, | |||
5206 | N0.getOperand(0)); | |||
5207 | ||||
5208 | SDValue NewMask = DAG.getConstant(AndMask.trunc(Size / 2), SL, HalfVT); | |||
5209 | SDValue ShiftK = DAG.getConstant(ShiftBits, SL, ShiftVT); | |||
5210 | SDValue Shift = DAG.getNode(ISD::SRL, SL, HalfVT, Trunc, ShiftK); | |||
5211 | SDValue And = DAG.getNode(ISD::AND, SL, HalfVT, Shift, NewMask); | |||
5212 | return DAG.getNode(ISD::ZERO_EXTEND, SL, VT, And); | |||
5213 | } | |||
5214 | } | |||
5215 | } | |||
5216 | } | |||
5217 | ||||
5218 | return SDValue(); | |||
5219 | } | |||
5220 | ||||
5221 | bool DAGCombiner::isAndLoadExtLoad(ConstantSDNode *AndC, LoadSDNode *LoadN, | |||
5222 | EVT LoadResultTy, EVT &ExtVT) { | |||
5223 | if (!AndC->getAPIntValue().isMask()) | |||
5224 | return false; | |||
5225 | ||||
5226 | unsigned ActiveBits = AndC->getAPIntValue().countTrailingOnes(); | |||
5227 | ||||
5228 | ExtVT = EVT::getIntegerVT(*DAG.getContext(), ActiveBits); | |||
5229 | EVT LoadedVT = LoadN->getMemoryVT(); | |||
5230 | ||||
5231 | if (ExtVT == LoadedVT && | |||
5232 | (!LegalOperations || | |||
5233 | TLI.isLoadExtLegal(ISD::ZEXTLOAD, LoadResultTy, ExtVT))) { | |||
5234 | // ZEXTLOAD will match without needing to change the size of the value being | |||
5235 | // loaded. | |||
5236 | return true; | |||
5237 | } | |||
5238 | ||||
5239 | // Do not change the width of a volatile or atomic loads. | |||
5240 | if (!LoadN->isSimple()) | |||
5241 | return false; | |||
5242 | ||||
5243 | // Do not generate loads of non-round integer types since these can | |||
5244 | // be expensive (and would be wrong if the type is not byte sized). | |||
5245 | if (!LoadedVT.bitsGT(ExtVT) || !ExtVT.isRound()) | |||
5246 | return false; | |||
5247 | ||||
5248 | if (LegalOperations && | |||
5249 | !TLI.isLoadExtLegal(ISD::ZEXTLOAD, LoadResultTy, ExtVT)) | |||
5250 | return false; | |||
5251 | ||||
5252 | if (!TLI.shouldReduceLoadWidth(LoadN, ISD::ZEXTLOAD, ExtVT)) | |||
5253 | return false; | |||
5254 | ||||
5255 | return true; | |||
5256 | } | |||
5257 | ||||
5258 | bool DAGCombiner::isLegalNarrowLdSt(LSBaseSDNode *LDST, | |||
5259 | ISD::LoadExtType ExtType, EVT &MemVT, | |||
5260 | unsigned ShAmt) { | |||
5261 | if (!LDST) | |||
5262 | return false; | |||
5263 | // Only allow byte offsets. | |||
5264 | if (ShAmt % 8) | |||
5265 | return false; | |||
5266 | ||||
5267 | // Do not generate loads of non-round integer types since these can | |||
5268 | // be expensive (and would be wrong if the type is not byte sized). | |||
5269 | if (!MemVT.isRound()) | |||
5270 | return false; | |||
5271 | ||||
5272 | // Don't change the width of a volatile or atomic loads. | |||
5273 | if (!LDST->isSimple()) | |||
5274 | return false; | |||
5275 | ||||
5276 | EVT LdStMemVT = LDST->getMemoryVT(); | |||
5277 | ||||
5278 | // Bail out when changing the scalable property, since we can't be sure that | |||
5279 | // we're actually narrowing here. | |||
5280 | if (LdStMemVT.isScalableVector() != MemVT.isScalableVector()) | |||
5281 | return false; | |||
5282 | ||||
5283 | // Verify that we are actually reducing a load width here. | |||
5284 | if (LdStMemVT.bitsLT(MemVT)) | |||
5285 | return false; | |||
5286 | ||||
5287 | // Ensure that this isn't going to produce an unsupported memory access. | |||
5288 | if (ShAmt) { | |||
5289 | assert(ShAmt % 8 == 0 && "ShAmt is byte offset")((void)0); | |||
5290 | const unsigned ByteShAmt = ShAmt / 8; | |||
5291 | const Align LDSTAlign = LDST->getAlign(); | |||
5292 | const Align NarrowAlign = commonAlignment(LDSTAlign, ByteShAmt); | |||
5293 | if (!TLI.allowsMemoryAccess(*DAG.getContext(), DAG.getDataLayout(), MemVT, | |||
5294 | LDST->getAddressSpace(), NarrowAlign, | |||
5295 | LDST->getMemOperand()->getFlags())) | |||
5296 | return false; | |||
5297 | } | |||
5298 | ||||
5299 | // It's not possible to generate a constant of extended or untyped type. | |||
5300 | EVT PtrType = LDST->getBasePtr().getValueType(); | |||
5301 | if (PtrType == MVT::Untyped || PtrType.isExtended()) | |||
5302 | return false; | |||
5303 | ||||
5304 | if (isa<LoadSDNode>(LDST)) { | |||
5305 | LoadSDNode *Load = cast<LoadSDNode>(LDST); | |||
5306 | // Don't transform one with multiple uses, this would require adding a new | |||
5307 | // load. | |||
5308 | if (!SDValue(Load, 0).hasOneUse()) | |||
5309 | return false; | |||
5310 | ||||
5311 | if (LegalOperations && | |||
5312 | !TLI.isLoadExtLegal(ExtType, Load->getValueType(0), MemVT)) | |||
5313 | return false; | |||
5314 | ||||
5315 | // For the transform to be legal, the load must produce only two values | |||
5316 | // (the value loaded and the chain). Don't transform a pre-increment | |||
5317 | // load, for example, which produces an extra value. Otherwise the | |||
5318 | // transformation is not equivalent, and the downstream logic to replace | |||
5319 | // uses gets things wrong. | |||
5320 | if (Load->getNumValues() > 2) | |||
5321 | return false; | |||
5322 | ||||
5323 | // If the load that we're shrinking is an extload and we're not just | |||
5324 | // discarding the extension we can't simply shrink the load. Bail. | |||
5325 | // TODO: It would be possible to merge the extensions in some cases. | |||
5326 | if (Load->getExtensionType() != ISD::NON_EXTLOAD && | |||
5327 | Load->getMemoryVT().getSizeInBits() < MemVT.getSizeInBits() + ShAmt) | |||
5328 | return false; | |||
5329 | ||||
5330 | if (!TLI.shouldReduceLoadWidth(Load, ExtType, MemVT)) | |||
5331 | return false; | |||
5332 | } else { | |||
5333 | assert(isa<StoreSDNode>(LDST) && "It is not a Load nor a Store SDNode")((void)0); | |||
5334 | StoreSDNode *Store = cast<StoreSDNode>(LDST); | |||
5335 | // Can't write outside the original store | |||
5336 | if (Store->getMemoryVT().getSizeInBits() < MemVT.getSizeInBits() + ShAmt) | |||
5337 | return false; | |||
5338 | ||||
5339 | if (LegalOperations && | |||
5340 | !TLI.isTruncStoreLegal(Store->getValue().getValueType(), MemVT)) | |||
5341 | return false; | |||
5342 | } | |||
5343 | return true; | |||
5344 | } | |||
5345 | ||||
5346 | bool DAGCombiner::SearchForAndLoads(SDNode *N, | |||
5347 | SmallVectorImpl<LoadSDNode*> &Loads, | |||
5348 | SmallPtrSetImpl<SDNode*> &NodesWithConsts, | |||
5349 | ConstantSDNode *Mask, | |||
5350 | SDNode *&NodeToMask) { | |||
5351 | // Recursively search for the operands, looking for loads which can be | |||
5352 | // narrowed. | |||
5353 | for (SDValue Op : N->op_values()) { | |||
5354 | if (Op.getValueType().isVector()) | |||
5355 | return false; | |||
5356 | ||||
5357 | // Some constants may need fixing up later if they are too large. | |||
5358 | if (auto *C = dyn_cast<ConstantSDNode>(Op)) { | |||
5359 | if ((N->getOpcode() == ISD::OR || N->getOpcode() == ISD::XOR) && | |||
5360 | (Mask->getAPIntValue() & C->getAPIntValue()) != C->getAPIntValue()) | |||
5361 | NodesWithConsts.insert(N); | |||
5362 | continue; | |||
5363 | } | |||
5364 | ||||
5365 | if (!Op.hasOneUse()) | |||
5366 | return false; | |||
5367 | ||||
5368 | switch(Op.getOpcode()) { | |||
5369 | case ISD::LOAD: { | |||
5370 | auto *Load = cast<LoadSDNode>(Op); | |||
5371 | EVT ExtVT; | |||
5372 | if (isAndLoadExtLoad(Mask, Load, Load->getValueType(0), ExtVT) && | |||
5373 | isLegalNarrowLdSt(Load, ISD::ZEXTLOAD, ExtVT)) { | |||
5374 | ||||
5375 | // ZEXTLOAD is already small enough. | |||
5376 | if (Load->getExtensionType() == ISD::ZEXTLOAD && | |||
5377 | ExtVT.bitsGE(Load->getMemoryVT())) | |||
5378 | continue; | |||
5379 | ||||
5380 | // Use LE to convert equal sized loads to zext. | |||
5381 | if (ExtVT.bitsLE(Load->getMemoryVT())) | |||
5382 | Loads.push_back(Load); | |||
5383 | ||||
5384 | continue; | |||
5385 | } | |||
5386 | return false; | |||
5387 | } | |||
5388 | case ISD::ZERO_EXTEND: | |||
5389 | case ISD::AssertZext: { | |||
5390 | unsigned ActiveBits = Mask->getAPIntValue().countTrailingOnes(); | |||
5391 | EVT ExtVT = EVT::getIntegerVT(*DAG.getContext(), ActiveBits); | |||
5392 | EVT VT = Op.getOpcode() == ISD::AssertZext ? | |||
5393 | cast<VTSDNode>(Op.getOperand(1))->getVT() : | |||
5394 | Op.getOperand(0).getValueType(); | |||
5395 | ||||
5396 | // We can accept extending nodes if the mask is wider or an equal | |||
5397 | // width to the original type. | |||
5398 | if (ExtVT.bitsGE(VT)) | |||
5399 | continue; | |||
5400 | break; | |||
5401 | } | |||
5402 | case ISD::OR: | |||
5403 | case ISD::XOR: | |||
5404 | case ISD::AND: | |||
5405 | if (!SearchForAndLoads(Op.getNode(), Loads, NodesWithConsts, Mask, | |||
5406 | NodeToMask)) | |||
5407 | return false; | |||
5408 | continue; | |||
5409 | } | |||
5410 | ||||
5411 | // Allow one node which will masked along with any loads found. | |||
5412 | if (NodeToMask) | |||
5413 | return false; | |||
5414 | ||||
5415 | // Also ensure that the node to be masked only produces one data result. | |||
5416 | NodeToMask = Op.getNode(); | |||
5417 | if (NodeToMask->getNumValues() > 1) { | |||
5418 | bool HasValue = false; | |||
5419 | for (unsigned i = 0, e = NodeToMask->getNumValues(); i < e; ++i) { | |||
5420 | MVT VT = SDValue(NodeToMask, i).getSimpleValueType(); | |||
5421 | if (VT != MVT::Glue && VT != MVT::Other) { | |||
5422 | if (HasValue) { | |||
5423 | NodeToMask = nullptr; | |||
5424 | return false; | |||
5425 | } | |||
5426 | HasValue = true; | |||
5427 | } | |||
5428 | } | |||
5429 | assert(HasValue && "Node to be masked has no data result?")((void)0); | |||
5430 | } | |||
5431 | } | |||
5432 | return true; | |||
5433 | } | |||
5434 | ||||
5435 | bool DAGCombiner::BackwardsPropagateMask(SDNode *N) { | |||
5436 | auto *Mask = dyn_cast<ConstantSDNode>(N->getOperand(1)); | |||
5437 | if (!Mask) | |||
5438 | return false; | |||
5439 | ||||
5440 | if (!Mask->getAPIntValue().isMask()) | |||
5441 | return false; | |||
5442 | ||||
5443 | // No need to do anything if the and directly uses a load. | |||
5444 | if (isa<LoadSDNode>(N->getOperand(0))) | |||
5445 | return false; | |||
5446 | ||||
5447 | SmallVector<LoadSDNode*, 8> Loads; | |||
5448 | SmallPtrSet<SDNode*, 2> NodesWithConsts; | |||
5449 | SDNode *FixupNode = nullptr; | |||
5450 | if (SearchForAndLoads(N, Loads, NodesWithConsts, Mask, FixupNode)) { | |||
5451 | if (Loads.size() == 0) | |||
5452 | return false; | |||
5453 | ||||
5454 | LLVM_DEBUG(dbgs() << "Backwards propagate AND: "; N->dump())do { } while (false); | |||
5455 | SDValue MaskOp = N->getOperand(1); | |||
5456 | ||||
5457 | // If it exists, fixup the single node we allow in the tree that needs | |||
5458 | // masking. | |||
5459 | if (FixupNode) { | |||
5460 | LLVM_DEBUG(dbgs() << "First, need to fix up: "; FixupNode->dump())do { } while (false); | |||
5461 | SDValue And = DAG.getNode(ISD::AND, SDLoc(FixupNode), | |||
5462 | FixupNode->getValueType(0), | |||
5463 | SDValue(FixupNode, 0), MaskOp); | |||
5464 | DAG.ReplaceAllUsesOfValueWith(SDValue(FixupNode, 0), And); | |||
5465 | if (And.getOpcode() == ISD ::AND) | |||
5466 | DAG.UpdateNodeOperands(And.getNode(), SDValue(FixupNode, 0), MaskOp); | |||
5467 | } | |||
5468 | ||||
5469 | // Narrow any constants that need it. | |||
5470 | for (auto *LogicN : NodesWithConsts) { | |||
5471 | SDValue Op0 = LogicN->getOperand(0); | |||
5472 | SDValue Op1 = LogicN->getOperand(1); | |||
5473 | ||||
5474 | if (isa<ConstantSDNode>(Op0)) | |||
5475 | std::swap(Op0, Op1); | |||
5476 | ||||
5477 | SDValue And = DAG.getNode(ISD::AND, SDLoc(Op1), Op1.getValueType(), | |||
5478 | Op1, MaskOp); | |||
5479 | ||||
5480 | DAG.UpdateNodeOperands(LogicN, Op0, And); | |||
5481 | } | |||
5482 | ||||
5483 | // Create narrow loads. | |||
5484 | for (auto *Load : Loads) { | |||
5485 | LLVM_DEBUG(dbgs() << "Propagate AND back to: "; Load->dump())do { } while (false); | |||
5486 | SDValue And = DAG.getNode(ISD::AND, SDLoc(Load), Load->getValueType(0), | |||
5487 | SDValue(Load, 0), MaskOp); | |||
5488 | DAG.ReplaceAllUsesOfValueWith(SDValue(Load, 0), And); | |||
5489 | if (And.getOpcode() == ISD ::AND) | |||
5490 | And = SDValue( | |||
5491 | DAG.UpdateNodeOperands(And.getNode(), SDValue(Load, 0), MaskOp), 0); | |||
5492 | SDValue NewLoad = ReduceLoadWidth(And.getNode()); | |||
5493 | assert(NewLoad &&((void)0) | |||
5494 | "Shouldn't be masking the load if it can't be narrowed")((void)0); | |||
5495 | CombineTo(Load, NewLoad, NewLoad.getValue(1)); | |||
5496 | } | |||
5497 | DAG.ReplaceAllUsesWith(N, N->getOperand(0).getNode()); | |||
5498 | return true; | |||
5499 | } | |||
5500 | return false; | |||
5501 | } | |||
5502 | ||||
5503 | // Unfold | |||
5504 | // x & (-1 'logical shift' y) | |||
5505 | // To | |||
5506 | // (x 'opposite logical shift' y) 'logical shift' y | |||
5507 | // if it is better for performance. | |||
5508 | SDValue DAGCombiner::unfoldExtremeBitClearingToShifts(SDNode *N) { | |||
5509 | assert(N->getOpcode() == ISD::AND)((void)0); | |||
5510 | ||||
5511 | SDValue N0 = N->getOperand(0); | |||
5512 | SDValue N1 = N->getOperand(1); | |||
5513 | ||||
5514 | // Do we actually prefer shifts over mask? | |||
5515 | if (!TLI.shouldFoldMaskToVariableShiftPair(N0)) | |||
5516 | return SDValue(); | |||
5517 | ||||
5518 | // Try to match (-1 '[outer] logical shift' y) | |||
5519 | unsigned OuterShift; | |||
5520 | unsigned InnerShift; // The opposite direction to the OuterShift. | |||
5521 | SDValue Y; // Shift amount. | |||
5522 | auto matchMask = [&OuterShift, &InnerShift, &Y](SDValue M) -> bool { | |||
5523 | if (!M.hasOneUse()) | |||
5524 | return false; | |||
5525 | OuterShift = M->getOpcode(); | |||
5526 | if (OuterShift == ISD::SHL) | |||
5527 | InnerShift = ISD::SRL; | |||
5528 | else if (OuterShift == ISD::SRL) | |||
5529 | InnerShift = ISD::SHL; | |||
5530 | else | |||
5531 | return false; | |||
5532 | if (!isAllOnesConstant(M->getOperand(0))) | |||
5533 | return false; | |||
5534 | Y = M->getOperand(1); | |||
5535 | return true; | |||
5536 | }; | |||
5537 | ||||
5538 | SDValue X; | |||
5539 | if (matchMask(N1)) | |||
5540 | X = N0; | |||
5541 | else if (matchMask(N0)) | |||
5542 | X = N1; | |||
5543 | else | |||
5544 | return SDValue(); | |||
5545 | ||||
5546 | SDLoc DL(N); | |||
5547 | EVT VT = N->getValueType(0); | |||
5548 | ||||
5549 | // tmp = x 'opposite logical shift' y | |||
5550 | SDValue T0 = DAG.getNode(InnerShift, DL, VT, X, Y); | |||
5551 | // ret = tmp 'logical shift' y | |||
5552 | SDValue T1 = DAG.getNode(OuterShift, DL, VT, T0, Y); | |||
5553 | ||||
5554 | return T1; | |||
5555 | } | |||
5556 | ||||
5557 | /// Try to replace shift/logic that tests if a bit is clear with mask + setcc. | |||
5558 | /// For a target with a bit test, this is expected to become test + set and save | |||
5559 | /// at least 1 instruction. | |||
5560 | static SDValue combineShiftAnd1ToBitTest(SDNode *And, SelectionDAG &DAG) { | |||
5561 | assert(And->getOpcode() == ISD::AND && "Expected an 'and' op")((void)0); | |||
5562 | ||||
5563 | // This is probably not worthwhile without a supported type. | |||
5564 | EVT VT = And->getValueType(0); | |||
5565 | const TargetLowering &TLI = DAG.getTargetLoweringInfo(); | |||
5566 | if (!TLI.isTypeLegal(VT)) | |||
5567 | return SDValue(); | |||
5568 | ||||
5569 | // Look through an optional extension and find a 'not'. | |||
5570 | // TODO: Should we favor test+set even without the 'not' op? | |||
5571 | SDValue Not = And->getOperand(0), And1 = And->getOperand(1); | |||
5572 | if (Not.getOpcode() == ISD::ANY_EXTEND) | |||
5573 | Not = Not.getOperand(0); | |||
5574 | if (!isBitwiseNot(Not) || !Not.hasOneUse() || !isOneConstant(And1)) | |||
5575 | return SDValue(); | |||
5576 | ||||
5577 | // Look though an optional truncation. The source operand may not be the same | |||
5578 | // type as the original 'and', but that is ok because we are masking off | |||
5579 | // everything but the low bit. | |||
5580 | SDValue Srl = Not.getOperand(0); | |||
5581 | if (Srl.getOpcode() == ISD::TRUNCATE) | |||
5582 | Srl = Srl.getOperand(0); | |||
5583 | ||||
5584 | // Match a shift-right by constant. | |||
5585 | if (Srl.getOpcode() != ISD::SRL || !Srl.hasOneUse() || | |||
5586 | !isa<ConstantSDNode>(Srl.getOperand(1))) | |||
5587 | return SDValue(); | |||
5588 | ||||
5589 | // We might have looked through casts that make this transform invalid. | |||
5590 | // TODO: If the source type is wider than the result type, do the mask and | |||
5591 | // compare in the source type. | |||
5592 | const APInt &ShiftAmt = Srl.getConstantOperandAPInt(1); | |||
5593 | unsigned VTBitWidth = VT.getSizeInBits(); | |||
5594 | if (ShiftAmt.uge(VTBitWidth)) | |||
5595 | return SDValue(); | |||
5596 | ||||
5597 | // Turn this into a bit-test pattern using mask op + setcc: | |||
5598 | // and (not (srl X, C)), 1 --> (and X, 1<<C) == 0 | |||
5599 | SDLoc DL(And); | |||
5600 | SDValue X = DAG.getZExtOrTrunc(Srl.getOperand(0), DL, VT); | |||
5601 | EVT CCVT = TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT); | |||
5602 | SDValue Mask = DAG.getConstant( | |||
5603 | APInt::getOneBitSet(VTBitWidth, ShiftAmt.getZExtValue()), DL, VT); | |||
5604 | SDValue NewAnd = DAG.getNode(ISD::AND, DL, VT, X, Mask); | |||
5605 | SDValue Zero = DAG.getConstant(0, DL, VT); | |||
5606 | SDValue Setcc = DAG.getSetCC(DL, CCVT, NewAnd, Zero, ISD::SETEQ); | |||
5607 | return DAG.getZExtOrTrunc(Setcc, DL, VT); | |||
5608 | } | |||
5609 | ||||
5610 | SDValue DAGCombiner::visitAND(SDNode *N) { | |||
5611 | SDValue N0 = N->getOperand(0); | |||
5612 | SDValue N1 = N->getOperand(1); | |||
5613 | EVT VT = N1.getValueType(); | |||
5614 | ||||
5615 | // x & x --> x | |||
5616 | if (N0 == N1) | |||
5617 | return N0; | |||
5618 | ||||
5619 | // fold vector ops | |||
5620 | if (VT.isVector()) { | |||
5621 | if (SDValue FoldedVOp = SimplifyVBinOp(N)) | |||
5622 | return FoldedVOp; | |||
5623 | ||||
5624 | // fold (and x, 0) -> 0, vector edition | |||
5625 | if (ISD::isConstantSplatVectorAllZeros(N0.getNode())) | |||
5626 | // do not return N0, because undef node may exist in N0 | |||
5627 | return DAG.getConstant(APInt::getNullValue(N0.getScalarValueSizeInBits()), | |||
5628 | SDLoc(N), N0.getValueType()); | |||
5629 | if (ISD::isConstantSplatVectorAllZeros(N1.getNode())) | |||
5630 | // do not return N1, because undef node may exist in N1 | |||
5631 | return DAG.getConstant(APInt::getNullValue(N1.getScalarValueSizeInBits()), | |||
5632 | SDLoc(N), N1.getValueType()); | |||
5633 | ||||
5634 | // fold (and x, -1) -> x, vector edition | |||
5635 | if (ISD::isConstantSplatVectorAllOnes(N0.getNode())) | |||
5636 | return N1; | |||
5637 | if (ISD::isConstantSplatVectorAllOnes(N1.getNode())) | |||
5638 | return N0; | |||
5639 | ||||
5640 | // fold (and (masked_load) (build_vec (x, ...))) to zext_masked_load | |||
5641 | auto *MLoad = dyn_cast<MaskedLoadSDNode>(N0); | |||
5642 | auto *BVec = dyn_cast<BuildVectorSDNode>(N1); | |||
5643 | if (MLoad && BVec && MLoad->getExtensionType() == ISD::EXTLOAD && | |||
5644 | N0.hasOneUse() && N1.hasOneUse()) { | |||
5645 | EVT LoadVT = MLoad->getMemoryVT(); | |||
5646 | EVT ExtVT = VT; | |||
5647 | if (TLI.isLoadExtLegal(ISD::ZEXTLOAD, ExtVT, LoadVT)) { | |||
5648 | // For this AND to be a zero extension of the masked load the elements | |||
5649 | // of the BuildVec must mask the bottom bits of the extended element | |||
5650 | // type | |||
5651 | if (ConstantSDNode *Splat = BVec->getConstantSplatNode()) { | |||
5652 | uint64_t ElementSize = | |||
5653 | LoadVT.getVectorElementType().getScalarSizeInBits(); | |||
5654 | if (Splat->getAPIntValue().isMask(ElementSize)) { | |||
5655 | return DAG.getMaskedLoad( | |||
5656 | ExtVT, SDLoc(N), MLoad->getChain(), MLoad->getBasePtr(), | |||
5657 | MLoad->getOffset(), MLoad->getMask(), MLoad->getPassThru(), | |||
5658 | LoadVT, MLoad->getMemOperand(), MLoad->getAddressingMode(), | |||
5659 | ISD::ZEXTLOAD, MLoad->isExpandingLoad()); | |||
5660 | } | |||
5661 | } | |||
5662 | } | |||
5663 | } | |||
5664 | } | |||
5665 | ||||
5666 | // fold (and c1, c2) -> c1&c2 | |||
5667 | ConstantSDNode *N1C = isConstOrConstSplat(N1); | |||
5668 | if (SDValue C = DAG.FoldConstantArithmetic(ISD::AND, SDLoc(N), VT, {N0, N1})) | |||
5669 | return C; | |||
5670 | ||||
5671 | // canonicalize constant to RHS | |||
5672 | if (DAG.isConstantIntBuildVectorOrConstantInt(N0) && | |||
5673 | !DAG.isConstantIntBuildVectorOrConstantInt(N1)) | |||
5674 | return DAG.getNode(ISD::AND, SDLoc(N), VT, N1, N0); | |||
5675 | ||||
5676 | // fold (and x, -1) -> x | |||
5677 | if (isAllOnesConstant(N1)) | |||
5678 | return N0; | |||
5679 | ||||
5680 | // if (and x, c) is known to be zero, return 0 | |||
5681 | unsigned BitWidth = VT.getScalarSizeInBits(); | |||
5682 | if (N1C && DAG.MaskedValueIsZero(SDValue(N, 0), | |||
5683 | APInt::getAllOnesValue(BitWidth))) | |||
5684 | return DAG.getConstant(0, SDLoc(N), VT); | |||
5685 | ||||
5686 | if (SDValue NewSel = foldBinOpIntoSelect(N)) | |||
5687 | return NewSel; | |||
5688 | ||||
5689 | // reassociate and | |||
5690 | if (SDValue RAND = reassociateOps(ISD::AND, SDLoc(N), N0, N1, N->getFlags())) | |||
5691 | return RAND; | |||
5692 | ||||
5693 | // Try to convert a constant mask AND into a shuffle clear mask. | |||
5694 | if (VT.isVector()) | |||
5695 | if (SDValue Shuffle = XformToShuffleWithZero(N)) | |||
5696 | return Shuffle; | |||
5697 | ||||
5698 | if (SDValue Combined = combineCarryDiamond(*this, DAG, TLI, N0, N1, N)) | |||
5699 | return Combined; | |||
5700 | ||||
5701 | // fold (and (or x, C), D) -> D if (C & D) == D | |||
5702 | auto MatchSubset = [](ConstantSDNode *LHS, ConstantSDNode *RHS) { | |||
5703 | return RHS->getAPIntValue().isSubsetOf(LHS->getAPIntValue()); | |||
5704 | }; | |||
5705 | if (N0.getOpcode() == ISD::OR && | |||
5706 | ISD::matchBinaryPredicate(N0.getOperand(1), N1, MatchSubset)) | |||
5707 | return N1; | |||
5708 | // fold (and (any_ext V), c) -> (zero_ext V) if 'and' only clears top bits. | |||
5709 | if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) { | |||
5710 | SDValue N0Op0 = N0.getOperand(0); | |||
5711 | APInt Mask = ~N1C->getAPIntValue(); | |||
5712 | Mask = Mask.trunc(N0Op0.getScalarValueSizeInBits()); | |||
5713 | if (DAG.MaskedValueIsZero(N0Op0, Mask)) { | |||
5714 | SDValue Zext = DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), | |||
5715 | N0.getValueType(), N0Op0); | |||
5716 | ||||
5717 | // Replace uses of the AND with uses of the Zero extend node. | |||
5718 | CombineTo(N, Zext); | |||
5719 | ||||
5720 | // We actually want to replace all uses of the any_extend with the | |||
5721 | // zero_extend, to avoid duplicating things. This will later cause this | |||
5722 | // AND to be folded. | |||
5723 | CombineTo(N0.getNode(), Zext); | |||
5724 | return SDValue(N, 0); // Return N so it doesn't get rechecked! | |||
5725 | } | |||
5726 | } | |||
5727 | ||||
5728 | // similarly fold (and (X (load ([non_ext|any_ext|zero_ext] V))), c) -> | |||
5729 | // (X (load ([non_ext|zero_ext] V))) if 'and' only clears top bits which must | |||
5730 | // already be zero by virtue of the width of the base type of the load. | |||
5731 | // | |||
5732 | // the 'X' node here can either be nothing or an extract_vector_elt to catch | |||
5733 | // more cases. | |||
5734 | if ((N0.getOpcode() == ISD::EXTRACT_VECTOR_ELT && | |||
5735 | N0.getValueSizeInBits() == N0.getOperand(0).getScalarValueSizeInBits() && | |||
5736 | N0.getOperand(0).getOpcode() == ISD::LOAD && | |||
5737 | N0.getOperand(0).getResNo() == 0) || | |||
5738 | (N0.getOpcode() == ISD::LOAD && N0.getResNo() == 0)) { | |||
5739 | LoadSDNode *Load = cast<LoadSDNode>( (N0.getOpcode() == ISD::LOAD) ? | |||
5740 | N0 : N0.getOperand(0) ); | |||
5741 | ||||
5742 | // Get the constant (if applicable) the zero'th operand is being ANDed with. | |||
5743 | // This can be a pure constant or a vector splat, in which case we treat the | |||
5744 | // vector as a scalar and use the splat value. | |||
5745 | APInt Constant = APInt::getNullValue(1); | |||
5746 | if (const ConstantSDNode *C = dyn_cast<ConstantSDNode>(N1)) { | |||
5747 | Constant = C->getAPIntValue(); | |||
5748 | } else if (BuildVectorSDNode *Vector = dyn_cast<BuildVectorSDNode>(N1)) { | |||
5749 | APInt SplatValue, SplatUndef; | |||
5750 | unsigned SplatBitSize; | |||
5751 | bool HasAnyUndefs; | |||
5752 | bool IsSplat = Vector->isConstantSplat(SplatValue, SplatUndef, | |||
5753 | SplatBitSize, HasAnyUndefs); | |||
5754 | if (IsSplat) { | |||
5755 | // Undef bits can contribute to a possible optimisation if set, so | |||
5756 | // set them. | |||
5757 | SplatValue |= SplatUndef; | |||
5758 | ||||
5759 | // The splat value may be something like "0x00FFFFFF", which means 0 for | |||
5760 | // the first vector value and FF for the rest, repeating. We need a mask | |||
5761 | // that will apply equally to all members of the vector, so AND all the | |||
5762 | // lanes of the constant together. | |||
5763 | unsigned EltBitWidth = Vector->getValueType(0).getScalarSizeInBits(); | |||
5764 | ||||
5765 | // If the splat value has been compressed to a bitlength lower | |||
5766 | // than the size of the vector lane, we need to re-expand it to | |||
5767 | // the lane size. | |||
5768 | if (EltBitWidth > SplatBitSize) | |||
5769 | for (SplatValue = SplatValue.zextOrTrunc(EltBitWidth); | |||
5770 | SplatBitSize < EltBitWidth; SplatBitSize = SplatBitSize * 2) | |||
5771 | SplatValue |= SplatValue.shl(SplatBitSize); | |||
5772 | ||||
5773 | // Make sure that variable 'Constant' is only set if 'SplatBitSize' is a | |||
5774 | // multiple of 'BitWidth'. Otherwise, we could propagate a wrong value. | |||
5775 | if ((SplatBitSize % EltBitWidth) == 0) { | |||
5776 | Constant = APInt::getAllOnesValue(EltBitWidth); | |||
5777 | for (unsigned i = 0, n = (SplatBitSize / EltBitWidth); i < n; ++i) | |||
5778 | Constant &= SplatValue.extractBits(EltBitWidth, i * EltBitWidth); | |||
5779 | } | |||
5780 | } | |||
5781 | } | |||
5782 | ||||
5783 | // If we want to change an EXTLOAD to a ZEXTLOAD, ensure a ZEXTLOAD is | |||
5784 | // actually legal and isn't going to get expanded, else this is a false | |||
5785 | // optimisation. | |||
5786 | bool CanZextLoadProfitably = TLI.isLoadExtLegal(ISD::ZEXTLOAD, | |||
5787 | Load->getValueType(0), | |||
5788 | Load->getMemoryVT()); | |||
5789 | ||||
5790 | // Resize the constant to the same size as the original memory access before | |||
5791 | // extension. If it is still the AllOnesValue then this AND is completely | |||
5792 | // unneeded. | |||
5793 | Constant = Constant.zextOrTrunc(Load->getMemoryVT().getScalarSizeInBits()); | |||
5794 | ||||
5795 | bool B; | |||
5796 | switch (Load->getExtensionType()) { | |||
5797 | default: B = false; break; | |||
5798 | case ISD::EXTLOAD: B = CanZextLoadProfitably; break; | |||
5799 | case ISD::ZEXTLOAD: | |||
5800 | case ISD::NON_EXTLOAD: B = true; break; | |||
5801 | } | |||
5802 | ||||
5803 | if (B && Constant.isAllOnesValue()) { | |||
5804 | // If the load type was an EXTLOAD, convert to ZEXTLOAD in order to | |||
5805 | // preserve semantics once we get rid of the AND. | |||
5806 | SDValue NewLoad(Load, 0); | |||
5807 | ||||
5808 | // Fold the AND away. NewLoad may get replaced immediately. | |||
5809 | CombineTo(N, (N0.getNode() == Load) ? NewLoad : N0); | |||
5810 | ||||
5811 | if (Load->getExtensionType() == ISD::EXTLOAD) { | |||
5812 | NewLoad = DAG.getLoad(Load->getAddressingMode(), ISD::ZEXTLOAD, | |||
5813 | Load->getValueType(0), SDLoc(Load), | |||
5814 | Load->getChain(), Load->getBasePtr(), | |||
5815 | Load->getOffset(), Load->getMemoryVT(), | |||
5816 | Load->getMemOperand()); | |||
5817 | // Replace uses of the EXTLOAD with the new ZEXTLOAD. | |||
5818 | if (Load->getNumValues() == 3) { | |||
5819 | // PRE/POST_INC loads have 3 values. | |||
5820 | SDValue To[] = { NewLoad.getValue(0), NewLoad.getValue(1), | |||
5821 | NewLoad.getValue(2) }; | |||
5822 | CombineTo(Load, To, 3, true); | |||
5823 | } else { | |||
5824 | CombineTo(Load, NewLoad.getValue(0), NewLoad.getValue(1)); | |||
5825 | } | |||
5826 | } | |||
5827 | ||||
5828 | return SDValue(N, 0); // Return N so it doesn't get rechecked! | |||
5829 | } | |||
5830 | } | |||
5831 | ||||
5832 | // fold (and (masked_gather x)) -> (zext_masked_gather x) | |||
5833 | if (auto *GN0 = dyn_cast<MaskedGatherSDNode>(N0)) { | |||
5834 | EVT MemVT = GN0->getMemoryVT(); | |||
5835 | EVT ScalarVT = MemVT.getScalarType(); | |||
5836 | ||||
5837 | if (SDValue(GN0, 0).hasOneUse() && | |||
5838 | isConstantSplatVectorMaskForType(N1.getNode(), ScalarVT) && | |||
5839 | TLI.isVectorLoadExtDesirable(SDValue(SDValue(GN0, 0)))) { | |||
5840 | SDValue Ops[] = {GN0->getChain(), GN0->getPassThru(), GN0->getMask(), | |||
5841 | GN0->getBasePtr(), GN0->getIndex(), GN0->getScale()}; | |||
5842 | ||||
5843 | SDValue ZExtLoad = DAG.getMaskedGather( | |||
5844 | DAG.getVTList(VT, MVT::Other), MemVT, SDLoc(N), Ops, | |||
5845 | GN0->getMemOperand(), GN0->getIndexType(), ISD::ZEXTLOAD); | |||
5846 | ||||
5847 | CombineTo(N, ZExtLoad); | |||
5848 | AddToWorklist(ZExtLoad.getNode()); | |||
5849 | // Avoid recheck of N. | |||
5850 | return SDValue(N, 0); | |||
5851 | } | |||
5852 | } | |||
5853 | ||||
5854 | // fold (and (load x), 255) -> (zextload x, i8) | |||
5855 | // fold (and (extload x, i16), 255) -> (zextload x, i8) | |||
5856 | // fold (and (any_ext (extload x, i16)), 255) -> (zextload x, i8) | |||
5857 | if (!VT.isVector() && N1C && (N0.getOpcode() == ISD::LOAD || | |||
5858 | (N0.getOpcode() == ISD::ANY_EXTEND && | |||
5859 | N0.getOperand(0).getOpcode() == ISD::LOAD))) { | |||
5860 | if (SDValue Res = ReduceLoadWidth(N)) { | |||
5861 | LoadSDNode *LN0 = N0->getOpcode() == ISD::ANY_EXTEND | |||
5862 | ? cast<LoadSDNode>(N0.getOperand(0)) : cast<LoadSDNode>(N0); | |||
5863 | AddToWorklist(N); | |||
5864 | DAG.ReplaceAllUsesOfValueWith(SDValue(LN0, 0), Res); | |||
5865 | return SDValue(N, 0); | |||
5866 | } | |||
5867 | } | |||
5868 | ||||
5869 | if (LegalTypes) { | |||
5870 | // Attempt to propagate the AND back up to the leaves which, if they're | |||
5871 | // loads, can be combined to narrow loads and the AND node can be removed. | |||
5872 | // Perform after legalization so that extend nodes will already be | |||
5873 | // combined into the loads. | |||
5874 | if (BackwardsPropagateMask(N)) | |||
5875 | return SDValue(N, 0); | |||
5876 | } | |||
5877 | ||||
5878 | if (SDValue Combined = visitANDLike(N0, N1, N)) | |||
5879 | return Combined; | |||
5880 | ||||
5881 | // Simplify: (and (op x...), (op y...)) -> (op (and x, y)) | |||
5882 | if (N0.getOpcode() == N1.getOpcode()) | |||
5883 | if (SDValue V = hoistLogicOpWithSameOpcodeHands(N)) | |||
5884 | return V; | |||
5885 | ||||
5886 | // Masking the negated extension of a boolean is just the zero-extended | |||
5887 | // boolean: | |||
5888 | // and (sub 0, zext(bool X)), 1 --> zext(bool X) | |||
5889 | // and (sub 0, sext(bool X)), 1 --> zext(bool X) | |||
5890 | // | |||
5891 | // Note: the SimplifyDemandedBits fold below can make an information-losing | |||
5892 | // transform, and then we have no way to find this better fold. | |||
5893 | if (N1C && N1C->isOne() && N0.getOpcode() == ISD::SUB) { | |||
5894 | if (isNullOrNullSplat(N0.getOperand(0))) { | |||
5895 | SDValue SubRHS = N0.getOperand(1); | |||
5896 | if (SubRHS.getOpcode() == ISD::ZERO_EXTEND && | |||
5897 | SubRHS.getOperand(0).getScalarValueSizeInBits() == 1) | |||
5898 | return SubRHS; | |||
5899 | if (SubRHS.getOpcode() == ISD::SIGN_EXTEND && | |||
5900 | SubRHS.getOperand(0).getScalarValueSizeInBits() == 1) | |||
5901 | return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT, SubRHS.getOperand(0)); | |||
5902 | } | |||
5903 | } | |||
5904 | ||||
5905 | // fold (and (sign_extend_inreg x, i16 to i32), 1) -> (and x, 1) | |||
5906 | // fold (and (sra)) -> (and (srl)) when possible. | |||
5907 | if (SimplifyDemandedBits(SDValue(N, 0))) | |||
5908 | return SDValue(N, 0); | |||
5909 | ||||
5910 | // fold (zext_inreg (extload x)) -> (zextload x) | |||
5911 | // fold (zext_inreg (sextload x)) -> (zextload x) iff load has one use | |||
5912 | if (ISD::isUNINDEXEDLoad(N0.getNode()) && | |||
5913 | (ISD::isEXTLoad(N0.getNode()) || | |||
5914 | (ISD::isSEXTLoad(N0.getNode()) && N0.hasOneUse()))) { | |||
5915 | LoadSDNode *LN0 = cast<LoadSDNode>(N0); | |||
5916 | EVT MemVT = LN0->getMemoryVT(); | |||
5917 | // If we zero all the possible extended bits, then we can turn this into | |||
5918 | // a zextload if we are running before legalize or the operation is legal. | |||
5919 | unsigned ExtBitSize = N1.getScalarValueSizeInBits(); | |||
5920 | unsigned MemBitSize = MemVT.getScalarSizeInBits(); | |||
5921 | APInt ExtBits = APInt::getHighBitsSet(ExtBitSize, ExtBitSize - MemBitSize); | |||
5922 | if (DAG.MaskedValueIsZero(N1, ExtBits) && | |||
5923 | ((!LegalOperations && LN0->isSimple()) || | |||
5924 | TLI.isLoadExtLegal(ISD::ZEXTLOAD, VT, MemVT))) { | |||
5925 | SDValue ExtLoad = | |||
5926 | DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N0), VT, LN0->getChain(), | |||
5927 | LN0->getBasePtr(), MemVT, LN0->getMemOperand()); | |||
5928 | AddToWorklist(N); | |||
5929 | CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1)); | |||
5930 | return SDValue(N, 0); // Return N so it doesn't get rechecked! | |||
5931 | } | |||
5932 | } | |||
5933 | ||||
5934 | // fold (and (or (srl N, 8), (shl N, 8)), 0xffff) -> (srl (bswap N), const) | |||
5935 | if (N1C && N1C->getAPIntValue() == 0xffff && N0.getOpcode() == ISD::OR) { | |||
5936 | if (SDValue BSwap = MatchBSwapHWordLow(N0.getNode(), N0.getOperand(0), | |||
5937 | N0.getOperand(1), false)) | |||
5938 | return BSwap; | |||
5939 | } | |||
5940 | ||||
5941 | if (SDValue Shifts = unfoldExtremeBitClearingToShifts(N)) | |||
5942 | return Shifts; | |||
5943 | ||||
5944 | if (TLI.hasBitTest(N0, N1)) | |||
5945 | if (SDValue V = combineShiftAnd1ToBitTest(N, DAG)) | |||
5946 | return V; | |||
5947 | ||||
5948 | // Recognize the following pattern: | |||
5949 | // | |||
5950 | // AndVT = (and (sign_extend NarrowVT to AndVT) #bitmask) | |||
5951 | // | |||
5952 | // where bitmask is a mask that clears the upper bits of AndVT. The | |||
5953 | // number of bits in bitmask must be a power of two. | |||
5954 | auto IsAndZeroExtMask = [](SDValue LHS, SDValue RHS) { | |||
5955 | if (LHS->getOpcode() != ISD::SIGN_EXTEND) | |||
5956 | return false; | |||
5957 | ||||
5958 | auto *C = dyn_cast<ConstantSDNode>(RHS); | |||
5959 | if (!C) | |||
5960 | return false; | |||
5961 | ||||
5962 | if (!C->getAPIntValue().isMask( | |||
5963 | LHS.getOperand(0).getValueType().getFixedSizeInBits())) | |||
5964 | return false; | |||
5965 | ||||
5966 | return true; | |||
5967 | }; | |||
5968 | ||||
5969 | // Replace (and (sign_extend ...) #bitmask) with (zero_extend ...). | |||
5970 | if (IsAndZeroExtMask(N0, N1)) | |||
5971 | return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT, N0.getOperand(0)); | |||
5972 | ||||
5973 | return SDValue(); | |||
5974 | } | |||
5975 | ||||
5976 | /// Match (a >> 8) | (a << 8) as (bswap a) >> 16. | |||
5977 | SDValue DAGCombiner::MatchBSwapHWordLow(SDNode *N, SDValue N0, SDValue N1, | |||
5978 | bool DemandHighBits) { | |||
5979 | if (!LegalOperations) | |||
5980 | return SDValue(); | |||
5981 | ||||
5982 | EVT VT = N->getValueType(0); | |||
5983 | if (VT != MVT::i64 && VT != MVT::i32 && VT != MVT::i16) | |||
5984 | return SDValue(); | |||
5985 | if (!TLI.isOperationLegalOrCustom(ISD::BSWAP, VT)) | |||
5986 | return SDValue(); | |||
5987 | ||||
5988 | // Recognize (and (shl a, 8), 0xff00), (and (srl a, 8), 0xff) | |||
5989 | bool LookPassAnd0 = false; | |||
5990 | bool LookPassAnd1 = false; | |||
5991 | if (N0.getOpcode() == ISD::AND && N0.getOperand(0).getOpcode() == ISD::SRL) | |||
5992 | std::swap(N0, N1); | |||
5993 | if (N1.getOpcode() == ISD::AND && N1.getOperand(0).getOpcode() == ISD::SHL) | |||
5994 | std::swap(N0, N1); | |||
5995 | if (N0.getOpcode() == ISD::AND) { | |||
5996 | if (!N0.getNode()->hasOneUse()) | |||
5997 | return SDValue(); | |||
5998 | ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1)); | |||
5999 | // Also handle 0xffff since the LHS is guaranteed to have zeros there. | |||
6000 | // This is needed for X86. | |||
6001 | if (!N01C || (N01C->getZExtValue() != 0xFF00 && | |||
6002 | N01C->getZExtValue() != 0xFFFF)) | |||
6003 | return SDValue(); | |||
6004 | N0 = N0.getOperand(0); | |||
6005 | LookPassAnd0 = true; | |||
6006 | } | |||
6007 | ||||
6008 | if (N1.getOpcode() == ISD::AND) { | |||
6009 | if (!N1.getNode()->hasOneUse()) | |||
6010 | return SDValue(); | |||
6011 | ConstantSDNode *N11C = dyn_cast<ConstantSDNode>(N1.getOperand(1)); | |||
6012 | if (!N11C || N11C->getZExtValue() != 0xFF) | |||
6013 | return SDValue(); | |||
6014 | N1 = N1.getOperand(0); | |||
6015 | LookPassAnd1 = true; | |||
6016 | } | |||
6017 | ||||
6018 | if (N0.getOpcode() == ISD::SRL && N1.getOpcode() == ISD::SHL) | |||
6019 | std::swap(N0, N1); | |||
6020 | if (N0.getOpcode() != ISD::SHL || N1.getOpcode() != ISD::SRL) | |||
6021 | return SDValue(); | |||
6022 | if (!N0.getNode()->hasOneUse() || !N1.getNode()->hasOneUse()) | |||
6023 | return SDValue(); | |||
6024 | ||||
6025 | ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1)); | |||
6026 | ConstantSDNode *N11C = dyn_cast<ConstantSDNode>(N1.getOperand(1)); | |||
6027 | if (!N01C || !N11C) | |||
6028 | return SDValue(); | |||
6029 | if (N01C->getZExtValue() != 8 || N11C->getZExtValue() != 8) | |||
6030 | return SDValue(); | |||
6031 | ||||
6032 | // Look for (shl (and a, 0xff), 8), (srl (and a, 0xff00), 8) | |||
6033 | SDValue N00 = N0->getOperand(0); | |||
6034 | if (!LookPassAnd0 && N00.getOpcode() == ISD::AND) { | |||
6035 | if (!N00.getNode()->hasOneUse()) | |||
6036 | return SDValue(); | |||
6037 | ConstantSDNode *N001C = dyn_cast<ConstantSDNode>(N00.getOperand(1)); | |||
6038 | if (!N001C || N001C->getZExtValue() != 0xFF) | |||
6039 | return SDValue(); | |||
6040 | N00 = N00.getOperand(0); | |||
6041 | LookPassAnd0 = true; | |||
6042 | } | |||
6043 | ||||
6044 | SDValue N10 = N1->getOperand(0); | |||
6045 | if (!LookPassAnd1 && N10.getOpcode() == ISD::AND) { | |||
6046 | if (!N10.getNode()->hasOneUse()) | |||
6047 | return SDValue(); | |||
6048 | ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N10.getOperand(1)); | |||
6049 | // Also allow 0xFFFF since the bits will be shifted out. This is needed | |||
6050 | // for X86. | |||
6051 | if (!N101C || (N101C->getZExtValue() != 0xFF00 && | |||
6052 | N101C->getZExtValue() != 0xFFFF)) | |||
6053 | return SDValue(); | |||
6054 | N10 = N10.getOperand(0); | |||
6055 | LookPassAnd1 = true; | |||
6056 | } | |||
6057 | ||||
6058 | if (N00 != N10) | |||
6059 | return SDValue(); | |||
6060 | ||||
6061 | // Make sure everything beyond the low halfword gets set to zero since the SRL | |||
6062 | // 16 will clear the top bits. | |||
6063 | unsigned OpSizeInBits = VT.getSizeInBits(); | |||
6064 | if (DemandHighBits && OpSizeInBits > 16) { | |||
6065 | // If the left-shift isn't masked out then the only way this is a bswap is | |||
6066 | // if all bits beyond the low 8 are 0. In that case the entire pattern | |||
6067 | // reduces to a left shift anyway: leave it for other parts of the combiner. | |||
6068 | if (!LookPassAnd0) | |||
6069 | return SDValue(); | |||
6070 | ||||
6071 | // However, if the right shift isn't masked out then it might be because | |||
6072 | // it's not needed. See if we can spot that too. | |||
6073 | if (!LookPassAnd1 && | |||
6074 | !DAG.MaskedValueIsZero( | |||
6075 | N10, APInt::getHighBitsSet(OpSizeInBits, OpSizeInBits - 16))) | |||
6076 | return SDValue(); | |||
6077 | } | |||
6078 | ||||
6079 | SDValue Res = DAG.getNode(ISD::BSWAP, SDLoc(N), VT, N00); | |||
6080 | if (OpSizeInBits > 16) { | |||
6081 | SDLoc DL(N); | |||
6082 | Res = DAG.getNode(ISD::SRL, DL, VT, Res, | |||
6083 | DAG.getConstant(OpSizeInBits - 16, DL, | |||
6084 | getShiftAmountTy(VT))); | |||
6085 | } | |||
6086 | return Res; | |||
6087 | } | |||
6088 | ||||
6089 | /// Return true if the specified node is an element that makes up a 32-bit | |||
6090 | /// packed halfword byteswap. | |||
6091 | /// ((x & 0x000000ff) << 8) | | |||
6092 | /// ((x & 0x0000ff00) >> 8) | | |||
6093 | /// ((x & 0x00ff0000) << 8) | | |||
6094 | /// ((x & 0xff000000) >> 8) | |||
6095 | static bool isBSwapHWordElement(SDValue N, MutableArrayRef<SDNode *> Parts) { | |||
6096 | if (!N.getNode()->hasOneUse()) | |||
6097 | return false; | |||
6098 | ||||
6099 | unsigned Opc = N.getOpcode(); | |||
6100 | if (Opc != ISD::AND && Opc != ISD::SHL && Opc != ISD::SRL) | |||
6101 | return false; | |||
6102 | ||||
6103 | SDValue N0 = N.getOperand(0); | |||
6104 | unsigned Opc0 = N0.getOpcode(); | |||
6105 | if (Opc0 != ISD::AND && Opc0 != ISD::SHL && Opc0 != ISD::SRL) | |||
6106 | return false; | |||
6107 | ||||
6108 | ConstantSDNode *N1C = nullptr; | |||
6109 | // SHL or SRL: look upstream for AND mask operand | |||
6110 | if (Opc == ISD::AND) | |||
6111 | N1C = dyn_cast<ConstantSDNode>(N.getOperand(1)); | |||
6112 | else if (Opc0 == ISD::AND) | |||
6113 | N1C = dyn_cast<ConstantSDNode>(N0.getOperand(1)); | |||
6114 | if (!N1C) | |||
6115 | return false; | |||
6116 | ||||
6117 | unsigned MaskByteOffset; | |||
6118 | switch (N1C->getZExtValue()) { | |||
6119 | default: | |||
6120 | return false; | |||
6121 | case 0xFF: MaskByteOffset = 0; break; | |||
6122 | case 0xFF00: MaskByteOffset = 1; break; | |||
6123 | case 0xFFFF: | |||
6124 | // In case demanded bits didn't clear the bits that will be shifted out. | |||
6125 | // This is needed for X86. | |||
6126 | if (Opc == ISD::SRL || (Opc == ISD::AND && Opc0 == ISD::SHL)) { | |||
6127 | MaskByteOffset = 1; | |||
6128 | break; | |||
6129 | } | |||
6130 | return false; | |||
6131 | case 0xFF0000: MaskByteOffset = 2; break; | |||
6132 | case 0xFF000000: MaskByteOffset = 3; break; | |||
6133 | } | |||
6134 | ||||
6135 | // Look for (x & 0xff) << 8 as well as ((x << 8) & 0xff00). | |||
6136 | if (Opc == ISD::AND) { | |||
6137 | if (MaskByteOffset == 0 || MaskByteOffset == 2) { | |||
6138 | // (x >> 8) & 0xff | |||
6139 | // (x >> 8) & 0xff0000 | |||
6140 | if (Opc0 != ISD::SRL) | |||
6141 | return false; | |||
6142 | ConstantSDNode *C = dyn_cast<ConstantSDNode>(N0.getOperand(1)); | |||
6143 | if (!C || C->getZExtValue() != 8) | |||
6144 | return false; | |||
6145 | } else { | |||
6146 | // (x << 8) & 0xff00 | |||
6147 | // (x << 8) & 0xff000000 | |||
6148 | if (Opc0 != ISD::SHL) | |||
6149 | return false; | |||
6150 | ConstantSDNode *C = dyn_cast<ConstantSDNode>(N0.getOperand(1)); | |||
6151 | if (!C || C->getZExtValue() != 8) | |||
6152 | return false; | |||
6153 | } | |||
6154 | } else if (Opc == ISD::SHL) { | |||
6155 | // (x & 0xff) << 8 | |||
6156 | // (x & 0xff0000) << 8 | |||
6157 | if (MaskByteOffset != 0 && MaskByteOffset != 2) | |||
6158 | return false; | |||
6159 | ConstantSDNode *C = dyn_cast<ConstantSDNode>(N.getOperand(1)); | |||
6160 | if (!C || C->getZExtValue() != 8) | |||
6161 | return false; | |||
6162 | } else { // Opc == ISD::SRL | |||