File: | src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Support/GenericDomTree.h |
Warning: | line 494, column 12 Called C++ object pointer is null |
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1 | //===- SIFixSGPRCopies.cpp - Remove potential VGPR => SGPR copies ---------===// | |||
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 | /// \file | |||
10 | /// Copies from VGPR to SGPR registers are illegal and the register coalescer | |||
11 | /// will sometimes generate these illegal copies in situations like this: | |||
12 | /// | |||
13 | /// Register Class <vsrc> is the union of <vgpr> and <sgpr> | |||
14 | /// | |||
15 | /// BB0: | |||
16 | /// %0 <sgpr> = SCALAR_INST | |||
17 | /// %1 <vsrc> = COPY %0 <sgpr> | |||
18 | /// ... | |||
19 | /// BRANCH %cond BB1, BB2 | |||
20 | /// BB1: | |||
21 | /// %2 <vgpr> = VECTOR_INST | |||
22 | /// %3 <vsrc> = COPY %2 <vgpr> | |||
23 | /// BB2: | |||
24 | /// %4 <vsrc> = PHI %1 <vsrc>, <%bb.0>, %3 <vrsc>, <%bb.1> | |||
25 | /// %5 <vgpr> = VECTOR_INST %4 <vsrc> | |||
26 | /// | |||
27 | /// | |||
28 | /// The coalescer will begin at BB0 and eliminate its copy, then the resulting | |||
29 | /// code will look like this: | |||
30 | /// | |||
31 | /// BB0: | |||
32 | /// %0 <sgpr> = SCALAR_INST | |||
33 | /// ... | |||
34 | /// BRANCH %cond BB1, BB2 | |||
35 | /// BB1: | |||
36 | /// %2 <vgpr> = VECTOR_INST | |||
37 | /// %3 <vsrc> = COPY %2 <vgpr> | |||
38 | /// BB2: | |||
39 | /// %4 <sgpr> = PHI %0 <sgpr>, <%bb.0>, %3 <vsrc>, <%bb.1> | |||
40 | /// %5 <vgpr> = VECTOR_INST %4 <sgpr> | |||
41 | /// | |||
42 | /// Now that the result of the PHI instruction is an SGPR, the register | |||
43 | /// allocator is now forced to constrain the register class of %3 to | |||
44 | /// <sgpr> so we end up with final code like this: | |||
45 | /// | |||
46 | /// BB0: | |||
47 | /// %0 <sgpr> = SCALAR_INST | |||
48 | /// ... | |||
49 | /// BRANCH %cond BB1, BB2 | |||
50 | /// BB1: | |||
51 | /// %2 <vgpr> = VECTOR_INST | |||
52 | /// %3 <sgpr> = COPY %2 <vgpr> | |||
53 | /// BB2: | |||
54 | /// %4 <sgpr> = PHI %0 <sgpr>, <%bb.0>, %3 <sgpr>, <%bb.1> | |||
55 | /// %5 <vgpr> = VECTOR_INST %4 <sgpr> | |||
56 | /// | |||
57 | /// Now this code contains an illegal copy from a VGPR to an SGPR. | |||
58 | /// | |||
59 | /// In order to avoid this problem, this pass searches for PHI instructions | |||
60 | /// which define a <vsrc> register and constrains its definition class to | |||
61 | /// <vgpr> if the user of the PHI's definition register is a vector instruction. | |||
62 | /// If the PHI's definition class is constrained to <vgpr> then the coalescer | |||
63 | /// will be unable to perform the COPY removal from the above example which | |||
64 | /// ultimately led to the creation of an illegal COPY. | |||
65 | //===----------------------------------------------------------------------===// | |||
66 | ||||
67 | #include "AMDGPU.h" | |||
68 | #include "GCNSubtarget.h" | |||
69 | #include "MCTargetDesc/AMDGPUMCTargetDesc.h" | |||
70 | #include "llvm/CodeGen/MachineDominators.h" | |||
71 | #include "llvm/InitializePasses.h" | |||
72 | #include "llvm/Target/TargetMachine.h" | |||
73 | ||||
74 | using namespace llvm; | |||
75 | ||||
76 | #define DEBUG_TYPE"si-fix-sgpr-copies" "si-fix-sgpr-copies" | |||
77 | ||||
78 | static cl::opt<bool> EnableM0Merge( | |||
79 | "amdgpu-enable-merge-m0", | |||
80 | cl::desc("Merge and hoist M0 initializations"), | |||
81 | cl::init(true)); | |||
82 | ||||
83 | namespace { | |||
84 | ||||
85 | class SIFixSGPRCopies : public MachineFunctionPass { | |||
86 | MachineDominatorTree *MDT; | |||
87 | ||||
88 | public: | |||
89 | static char ID; | |||
90 | ||||
91 | MachineRegisterInfo *MRI; | |||
92 | const SIRegisterInfo *TRI; | |||
93 | const SIInstrInfo *TII; | |||
94 | ||||
95 | SIFixSGPRCopies() : MachineFunctionPass(ID) {} | |||
96 | ||||
97 | bool runOnMachineFunction(MachineFunction &MF) override; | |||
98 | ||||
99 | MachineBasicBlock *processPHINode(MachineInstr &MI); | |||
100 | ||||
101 | StringRef getPassName() const override { return "SI Fix SGPR copies"; } | |||
102 | ||||
103 | void getAnalysisUsage(AnalysisUsage &AU) const override { | |||
104 | AU.addRequired<MachineDominatorTree>(); | |||
105 | AU.addPreserved<MachineDominatorTree>(); | |||
106 | AU.setPreservesCFG(); | |||
107 | MachineFunctionPass::getAnalysisUsage(AU); | |||
108 | } | |||
109 | }; | |||
110 | ||||
111 | } // end anonymous namespace | |||
112 | ||||
113 | INITIALIZE_PASS_BEGIN(SIFixSGPRCopies, DEBUG_TYPE,static void *initializeSIFixSGPRCopiesPassOnce(PassRegistry & Registry) { | |||
114 | "SI Fix SGPR copies", false, false)static void *initializeSIFixSGPRCopiesPassOnce(PassRegistry & Registry) { | |||
115 | INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree)initializeMachineDominatorTreePass(Registry); | |||
116 | INITIALIZE_PASS_END(SIFixSGPRCopies, DEBUG_TYPE,PassInfo *PI = new PassInfo( "SI Fix SGPR copies", "si-fix-sgpr-copies" , &SIFixSGPRCopies::ID, PassInfo::NormalCtor_t(callDefaultCtor <SIFixSGPRCopies>), false, false); Registry.registerPass (*PI, true); return PI; } static llvm::once_flag InitializeSIFixSGPRCopiesPassFlag ; void llvm::initializeSIFixSGPRCopiesPass(PassRegistry & Registry) { llvm::call_once(InitializeSIFixSGPRCopiesPassFlag , initializeSIFixSGPRCopiesPassOnce, std::ref(Registry)); } | |||
117 | "SI Fix SGPR copies", false, false)PassInfo *PI = new PassInfo( "SI Fix SGPR copies", "si-fix-sgpr-copies" , &SIFixSGPRCopies::ID, PassInfo::NormalCtor_t(callDefaultCtor <SIFixSGPRCopies>), false, false); Registry.registerPass (*PI, true); return PI; } static llvm::once_flag InitializeSIFixSGPRCopiesPassFlag ; void llvm::initializeSIFixSGPRCopiesPass(PassRegistry & Registry) { llvm::call_once(InitializeSIFixSGPRCopiesPassFlag , initializeSIFixSGPRCopiesPassOnce, std::ref(Registry)); } | |||
118 | ||||
119 | char SIFixSGPRCopies::ID = 0; | |||
120 | ||||
121 | char &llvm::SIFixSGPRCopiesID = SIFixSGPRCopies::ID; | |||
122 | ||||
123 | FunctionPass *llvm::createSIFixSGPRCopiesPass() { | |||
124 | return new SIFixSGPRCopies(); | |||
125 | } | |||
126 | ||||
127 | static bool hasVectorOperands(const MachineInstr &MI, | |||
128 | const SIRegisterInfo *TRI) { | |||
129 | const MachineRegisterInfo &MRI = MI.getParent()->getParent()->getRegInfo(); | |||
130 | for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) { | |||
131 | if (!MI.getOperand(i).isReg() || !MI.getOperand(i).getReg().isVirtual()) | |||
132 | continue; | |||
133 | ||||
134 | if (TRI->hasVectorRegisters(MRI.getRegClass(MI.getOperand(i).getReg()))) | |||
135 | return true; | |||
136 | } | |||
137 | return false; | |||
138 | } | |||
139 | ||||
140 | static std::pair<const TargetRegisterClass *, const TargetRegisterClass *> | |||
141 | getCopyRegClasses(const MachineInstr &Copy, | |||
142 | const SIRegisterInfo &TRI, | |||
143 | const MachineRegisterInfo &MRI) { | |||
144 | Register DstReg = Copy.getOperand(0).getReg(); | |||
145 | Register SrcReg = Copy.getOperand(1).getReg(); | |||
146 | ||||
147 | const TargetRegisterClass *SrcRC = SrcReg.isVirtual() | |||
148 | ? MRI.getRegClass(SrcReg) | |||
149 | : TRI.getPhysRegClass(SrcReg); | |||
150 | ||||
151 | // We don't really care about the subregister here. | |||
152 | // SrcRC = TRI.getSubRegClass(SrcRC, Copy.getOperand(1).getSubReg()); | |||
153 | ||||
154 | const TargetRegisterClass *DstRC = DstReg.isVirtual() | |||
155 | ? MRI.getRegClass(DstReg) | |||
156 | : TRI.getPhysRegClass(DstReg); | |||
157 | ||||
158 | return std::make_pair(SrcRC, DstRC); | |||
159 | } | |||
160 | ||||
161 | static bool isVGPRToSGPRCopy(const TargetRegisterClass *SrcRC, | |||
162 | const TargetRegisterClass *DstRC, | |||
163 | const SIRegisterInfo &TRI) { | |||
164 | return SrcRC != &AMDGPU::VReg_1RegClass && TRI.isSGPRClass(DstRC) && | |||
165 | TRI.hasVectorRegisters(SrcRC); | |||
166 | } | |||
167 | ||||
168 | static bool isSGPRToVGPRCopy(const TargetRegisterClass *SrcRC, | |||
169 | const TargetRegisterClass *DstRC, | |||
170 | const SIRegisterInfo &TRI) { | |||
171 | return DstRC != &AMDGPU::VReg_1RegClass && TRI.isSGPRClass(SrcRC) && | |||
172 | TRI.hasVectorRegisters(DstRC); | |||
173 | } | |||
174 | ||||
175 | static bool tryChangeVGPRtoSGPRinCopy(MachineInstr &MI, | |||
176 | const SIRegisterInfo *TRI, | |||
177 | const SIInstrInfo *TII) { | |||
178 | MachineRegisterInfo &MRI = MI.getParent()->getParent()->getRegInfo(); | |||
179 | auto &Src = MI.getOperand(1); | |||
180 | Register DstReg = MI.getOperand(0).getReg(); | |||
181 | Register SrcReg = Src.getReg(); | |||
182 | if (!SrcReg.isVirtual() || !DstReg.isVirtual()) | |||
183 | return false; | |||
184 | ||||
185 | for (const auto &MO : MRI.reg_nodbg_operands(DstReg)) { | |||
186 | const auto *UseMI = MO.getParent(); | |||
187 | if (UseMI == &MI) | |||
188 | continue; | |||
189 | if (MO.isDef() || UseMI->getParent() != MI.getParent() || | |||
190 | UseMI->getOpcode() <= TargetOpcode::GENERIC_OP_END) | |||
191 | return false; | |||
192 | ||||
193 | unsigned OpIdx = UseMI->getOperandNo(&MO); | |||
194 | if (OpIdx >= UseMI->getDesc().getNumOperands() || | |||
195 | !TII->isOperandLegal(*UseMI, OpIdx, &Src)) | |||
196 | return false; | |||
197 | } | |||
198 | // Change VGPR to SGPR destination. | |||
199 | MRI.setRegClass(DstReg, TRI->getEquivalentSGPRClass(MRI.getRegClass(DstReg))); | |||
200 | return true; | |||
201 | } | |||
202 | ||||
203 | // Distribute an SGPR->VGPR copy of a REG_SEQUENCE into a VGPR REG_SEQUENCE. | |||
204 | // | |||
205 | // SGPRx = ... | |||
206 | // SGPRy = REG_SEQUENCE SGPRx, sub0 ... | |||
207 | // VGPRz = COPY SGPRy | |||
208 | // | |||
209 | // ==> | |||
210 | // | |||
211 | // VGPRx = COPY SGPRx | |||
212 | // VGPRz = REG_SEQUENCE VGPRx, sub0 | |||
213 | // | |||
214 | // This exposes immediate folding opportunities when materializing 64-bit | |||
215 | // immediates. | |||
216 | static bool foldVGPRCopyIntoRegSequence(MachineInstr &MI, | |||
217 | const SIRegisterInfo *TRI, | |||
218 | const SIInstrInfo *TII, | |||
219 | MachineRegisterInfo &MRI) { | |||
220 | assert(MI.isRegSequence())((void)0); | |||
221 | ||||
222 | Register DstReg = MI.getOperand(0).getReg(); | |||
223 | if (!TRI->isSGPRClass(MRI.getRegClass(DstReg))) | |||
224 | return false; | |||
225 | ||||
226 | if (!MRI.hasOneUse(DstReg)) | |||
227 | return false; | |||
228 | ||||
229 | MachineInstr &CopyUse = *MRI.use_instr_begin(DstReg); | |||
230 | if (!CopyUse.isCopy()) | |||
231 | return false; | |||
232 | ||||
233 | // It is illegal to have vreg inputs to a physreg defining reg_sequence. | |||
234 | if (CopyUse.getOperand(0).getReg().isPhysical()) | |||
235 | return false; | |||
236 | ||||
237 | const TargetRegisterClass *SrcRC, *DstRC; | |||
238 | std::tie(SrcRC, DstRC) = getCopyRegClasses(CopyUse, *TRI, MRI); | |||
239 | ||||
240 | if (!isSGPRToVGPRCopy(SrcRC, DstRC, *TRI)) | |||
241 | return false; | |||
242 | ||||
243 | if (tryChangeVGPRtoSGPRinCopy(CopyUse, TRI, TII)) | |||
244 | return true; | |||
245 | ||||
246 | // TODO: Could have multiple extracts? | |||
247 | unsigned SubReg = CopyUse.getOperand(1).getSubReg(); | |||
248 | if (SubReg != AMDGPU::NoSubRegister) | |||
249 | return false; | |||
250 | ||||
251 | MRI.setRegClass(DstReg, DstRC); | |||
252 | ||||
253 | // SGPRx = ... | |||
254 | // SGPRy = REG_SEQUENCE SGPRx, sub0 ... | |||
255 | // VGPRz = COPY SGPRy | |||
256 | ||||
257 | // => | |||
258 | // VGPRx = COPY SGPRx | |||
259 | // VGPRz = REG_SEQUENCE VGPRx, sub0 | |||
260 | ||||
261 | MI.getOperand(0).setReg(CopyUse.getOperand(0).getReg()); | |||
262 | bool IsAGPR = TRI->hasAGPRs(DstRC); | |||
263 | ||||
264 | for (unsigned I = 1, N = MI.getNumOperands(); I != N; I += 2) { | |||
265 | Register SrcReg = MI.getOperand(I).getReg(); | |||
266 | unsigned SrcSubReg = MI.getOperand(I).getSubReg(); | |||
267 | ||||
268 | const TargetRegisterClass *SrcRC = MRI.getRegClass(SrcReg); | |||
269 | assert(TRI->isSGPRClass(SrcRC) &&((void)0) | |||
270 | "Expected SGPR REG_SEQUENCE to only have SGPR inputs")((void)0); | |||
271 | ||||
272 | SrcRC = TRI->getSubRegClass(SrcRC, SrcSubReg); | |||
273 | const TargetRegisterClass *NewSrcRC = TRI->getEquivalentVGPRClass(SrcRC); | |||
274 | ||||
275 | Register TmpReg = MRI.createVirtualRegister(NewSrcRC); | |||
276 | ||||
277 | BuildMI(*MI.getParent(), &MI, MI.getDebugLoc(), TII->get(AMDGPU::COPY), | |||
278 | TmpReg) | |||
279 | .add(MI.getOperand(I)); | |||
280 | ||||
281 | if (IsAGPR) { | |||
282 | const TargetRegisterClass *NewSrcRC = TRI->getEquivalentAGPRClass(SrcRC); | |||
283 | Register TmpAReg = MRI.createVirtualRegister(NewSrcRC); | |||
284 | unsigned Opc = NewSrcRC == &AMDGPU::AGPR_32RegClass ? | |||
285 | AMDGPU::V_ACCVGPR_WRITE_B32_e64 : AMDGPU::COPY; | |||
286 | BuildMI(*MI.getParent(), &MI, MI.getDebugLoc(), TII->get(Opc), | |||
287 | TmpAReg) | |||
288 | .addReg(TmpReg, RegState::Kill); | |||
289 | TmpReg = TmpAReg; | |||
290 | } | |||
291 | ||||
292 | MI.getOperand(I).setReg(TmpReg); | |||
293 | } | |||
294 | ||||
295 | CopyUse.eraseFromParent(); | |||
296 | return true; | |||
297 | } | |||
298 | ||||
299 | static bool isSafeToFoldImmIntoCopy(const MachineInstr *Copy, | |||
300 | const MachineInstr *MoveImm, | |||
301 | const SIInstrInfo *TII, | |||
302 | unsigned &SMovOp, | |||
303 | int64_t &Imm) { | |||
304 | if (Copy->getOpcode() != AMDGPU::COPY) | |||
305 | return false; | |||
306 | ||||
307 | if (!MoveImm->isMoveImmediate()) | |||
308 | return false; | |||
309 | ||||
310 | const MachineOperand *ImmOp = | |||
311 | TII->getNamedOperand(*MoveImm, AMDGPU::OpName::src0); | |||
312 | if (!ImmOp->isImm()) | |||
313 | return false; | |||
314 | ||||
315 | // FIXME: Handle copies with sub-regs. | |||
316 | if (Copy->getOperand(0).getSubReg()) | |||
317 | return false; | |||
318 | ||||
319 | switch (MoveImm->getOpcode()) { | |||
320 | default: | |||
321 | return false; | |||
322 | case AMDGPU::V_MOV_B32_e32: | |||
323 | SMovOp = AMDGPU::S_MOV_B32; | |||
324 | break; | |||
325 | case AMDGPU::V_MOV_B64_PSEUDO: | |||
326 | SMovOp = AMDGPU::S_MOV_B64; | |||
327 | break; | |||
328 | } | |||
329 | Imm = ImmOp->getImm(); | |||
330 | return true; | |||
331 | } | |||
332 | ||||
333 | template <class UnaryPredicate> | |||
334 | bool searchPredecessors(const MachineBasicBlock *MBB, | |||
335 | const MachineBasicBlock *CutOff, | |||
336 | UnaryPredicate Predicate) { | |||
337 | if (MBB == CutOff) | |||
338 | return false; | |||
339 | ||||
340 | DenseSet<const MachineBasicBlock *> Visited; | |||
341 | SmallVector<MachineBasicBlock *, 4> Worklist(MBB->predecessors()); | |||
342 | ||||
343 | while (!Worklist.empty()) { | |||
344 | MachineBasicBlock *MBB = Worklist.pop_back_val(); | |||
345 | ||||
346 | if (!Visited.insert(MBB).second) | |||
347 | continue; | |||
348 | if (MBB == CutOff) | |||
349 | continue; | |||
350 | if (Predicate(MBB)) | |||
351 | return true; | |||
352 | ||||
353 | Worklist.append(MBB->pred_begin(), MBB->pred_end()); | |||
354 | } | |||
355 | ||||
356 | return false; | |||
357 | } | |||
358 | ||||
359 | // Checks if there is potential path From instruction To instruction. | |||
360 | // If CutOff is specified and it sits in between of that path we ignore | |||
361 | // a higher portion of the path and report it is not reachable. | |||
362 | static bool isReachable(const MachineInstr *From, | |||
363 | const MachineInstr *To, | |||
364 | const MachineBasicBlock *CutOff, | |||
365 | MachineDominatorTree &MDT) { | |||
366 | if (MDT.dominates(From, To)) | |||
367 | return true; | |||
368 | ||||
369 | const MachineBasicBlock *MBBFrom = From->getParent(); | |||
370 | const MachineBasicBlock *MBBTo = To->getParent(); | |||
371 | ||||
372 | // Do predecessor search. | |||
373 | // We should almost never get here since we do not usually produce M0 stores | |||
374 | // other than -1. | |||
375 | return searchPredecessors(MBBTo, CutOff, [MBBFrom] | |||
376 | (const MachineBasicBlock *MBB) { return MBB == MBBFrom; }); | |||
377 | } | |||
378 | ||||
379 | // Return the first non-prologue instruction in the block. | |||
380 | static MachineBasicBlock::iterator | |||
381 | getFirstNonPrologue(MachineBasicBlock *MBB, const TargetInstrInfo *TII) { | |||
382 | MachineBasicBlock::iterator I = MBB->getFirstNonPHI(); | |||
383 | while (I != MBB->end() && TII->isBasicBlockPrologue(*I)) | |||
384 | ++I; | |||
385 | ||||
386 | return I; | |||
387 | } | |||
388 | ||||
389 | // Hoist and merge identical SGPR initializations into a common predecessor. | |||
390 | // This is intended to combine M0 initializations, but can work with any | |||
391 | // SGPR. A VGPR cannot be processed since we cannot guarantee vector | |||
392 | // executioon. | |||
393 | static bool hoistAndMergeSGPRInits(unsigned Reg, | |||
394 | const MachineRegisterInfo &MRI, | |||
395 | const TargetRegisterInfo *TRI, | |||
396 | MachineDominatorTree &MDT, | |||
397 | const TargetInstrInfo *TII) { | |||
398 | // List of inits by immediate value. | |||
399 | using InitListMap = std::map<unsigned, std::list<MachineInstr *>>; | |||
400 | InitListMap Inits; | |||
401 | // List of clobbering instructions. | |||
402 | SmallVector<MachineInstr*, 8> Clobbers; | |||
403 | // List of instructions marked for deletion. | |||
404 | SmallSet<MachineInstr*, 8> MergedInstrs; | |||
405 | ||||
406 | bool Changed = false; | |||
407 | ||||
408 | for (auto &MI : MRI.def_instructions(Reg)) { | |||
409 | MachineOperand *Imm = nullptr; | |||
410 | for (auto &MO : MI.operands()) { | |||
411 | if ((MO.isReg() && ((MO.isDef() && MO.getReg() != Reg) || !MO.isDef())) || | |||
412 | (!MO.isImm() && !MO.isReg()) || (MO.isImm() && Imm)) { | |||
413 | Imm = nullptr; | |||
414 | break; | |||
415 | } else if (MO.isImm()) | |||
416 | Imm = &MO; | |||
417 | } | |||
418 | if (Imm) | |||
419 | Inits[Imm->getImm()].push_front(&MI); | |||
420 | else | |||
421 | Clobbers.push_back(&MI); | |||
422 | } | |||
423 | ||||
424 | for (auto &Init : Inits) { | |||
425 | auto &Defs = Init.second; | |||
426 | ||||
427 | for (auto I1 = Defs.begin(), E = Defs.end(); I1 != E; ) { | |||
428 | MachineInstr *MI1 = *I1; | |||
429 | ||||
430 | for (auto I2 = std::next(I1); I2 != E; ) { | |||
431 | MachineInstr *MI2 = *I2; | |||
432 | ||||
433 | // Check any possible interference | |||
434 | auto interferes = [&](MachineBasicBlock::iterator From, | |||
435 | MachineBasicBlock::iterator To) -> bool { | |||
436 | ||||
437 | assert(MDT.dominates(&*To, &*From))((void)0); | |||
438 | ||||
439 | auto interferes = [&MDT, From, To](MachineInstr* &Clobber) -> bool { | |||
440 | const MachineBasicBlock *MBBFrom = From->getParent(); | |||
441 | const MachineBasicBlock *MBBTo = To->getParent(); | |||
442 | bool MayClobberFrom = isReachable(Clobber, &*From, MBBTo, MDT); | |||
443 | bool MayClobberTo = isReachable(Clobber, &*To, MBBTo, MDT); | |||
444 | if (!MayClobberFrom && !MayClobberTo) | |||
445 | return false; | |||
446 | if ((MayClobberFrom && !MayClobberTo) || | |||
447 | (!MayClobberFrom && MayClobberTo)) | |||
448 | return true; | |||
449 | // Both can clobber, this is not an interference only if both are | |||
450 | // dominated by Clobber and belong to the same block or if Clobber | |||
451 | // properly dominates To, given that To >> From, so it dominates | |||
452 | // both and located in a common dominator. | |||
453 | return !((MBBFrom == MBBTo && | |||
454 | MDT.dominates(Clobber, &*From) && | |||
455 | MDT.dominates(Clobber, &*To)) || | |||
456 | MDT.properlyDominates(Clobber->getParent(), MBBTo)); | |||
457 | }; | |||
458 | ||||
459 | return (llvm::any_of(Clobbers, interferes)) || | |||
460 | (llvm::any_of(Inits, [&](InitListMap::value_type &C) { | |||
461 | return C.first != Init.first && | |||
462 | llvm::any_of(C.second, interferes); | |||
463 | })); | |||
464 | }; | |||
465 | ||||
466 | if (MDT.dominates(MI1, MI2)) { | |||
467 | if (!interferes(MI2, MI1)) { | |||
468 | LLVM_DEBUG(dbgs()do { } while (false) | |||
469 | << "Erasing from "do { } while (false) | |||
470 | << printMBBReference(*MI2->getParent()) << " " << *MI2)do { } while (false); | |||
471 | MergedInstrs.insert(MI2); | |||
472 | Changed = true; | |||
473 | ++I2; | |||
474 | continue; | |||
475 | } | |||
476 | } else if (MDT.dominates(MI2, MI1)) { | |||
477 | if (!interferes(MI1, MI2)) { | |||
478 | LLVM_DEBUG(dbgs()do { } while (false) | |||
479 | << "Erasing from "do { } while (false) | |||
480 | << printMBBReference(*MI1->getParent()) << " " << *MI1)do { } while (false); | |||
481 | MergedInstrs.insert(MI1); | |||
482 | Changed = true; | |||
483 | ++I1; | |||
484 | break; | |||
485 | } | |||
486 | } else { | |||
487 | auto *MBB = MDT.findNearestCommonDominator(MI1->getParent(), | |||
488 | MI2->getParent()); | |||
489 | if (!MBB) { | |||
490 | ++I2; | |||
491 | continue; | |||
492 | } | |||
493 | ||||
494 | MachineBasicBlock::iterator I = getFirstNonPrologue(MBB, TII); | |||
495 | if (!interferes(MI1, I) && !interferes(MI2, I)) { | |||
496 | LLVM_DEBUG(dbgs()do { } while (false) | |||
497 | << "Erasing from "do { } while (false) | |||
498 | << printMBBReference(*MI1->getParent()) << " " << *MI1do { } while (false) | |||
499 | << "and moving from "do { } while (false) | |||
500 | << printMBBReference(*MI2->getParent()) << " to "do { } while (false) | |||
501 | << printMBBReference(*I->getParent()) << " " << *MI2)do { } while (false); | |||
502 | I->getParent()->splice(I, MI2->getParent(), MI2); | |||
503 | MergedInstrs.insert(MI1); | |||
504 | Changed = true; | |||
505 | ++I1; | |||
506 | break; | |||
507 | } | |||
508 | } | |||
509 | ++I2; | |||
510 | } | |||
511 | ++I1; | |||
512 | } | |||
513 | } | |||
514 | ||||
515 | // Remove initializations that were merged into another. | |||
516 | for (auto &Init : Inits) { | |||
517 | auto &Defs = Init.second; | |||
518 | auto I = Defs.begin(); | |||
519 | while (I != Defs.end()) { | |||
520 | if (MergedInstrs.count(*I)) { | |||
521 | (*I)->eraseFromParent(); | |||
522 | I = Defs.erase(I); | |||
523 | } else | |||
524 | ++I; | |||
525 | } | |||
526 | } | |||
527 | ||||
528 | // Try to schedule SGPR initializations as early as possible in the MBB. | |||
529 | for (auto &Init : Inits) { | |||
530 | auto &Defs = Init.second; | |||
531 | for (auto MI : Defs) { | |||
532 | auto MBB = MI->getParent(); | |||
533 | MachineInstr &BoundaryMI = *getFirstNonPrologue(MBB, TII); | |||
534 | MachineBasicBlock::reverse_iterator B(BoundaryMI); | |||
535 | // Check if B should actually be a boundary. If not set the previous | |||
536 | // instruction as the boundary instead. | |||
537 | if (!TII->isBasicBlockPrologue(*B)) | |||
538 | B++; | |||
539 | ||||
540 | auto R = std::next(MI->getReverseIterator()); | |||
541 | const unsigned Threshold = 50; | |||
542 | // Search until B or Threshold for a place to insert the initialization. | |||
543 | for (unsigned I = 0; R != B && I < Threshold; ++R, ++I) | |||
544 | if (R->readsRegister(Reg, TRI) || R->definesRegister(Reg, TRI) || | |||
545 | TII->isSchedulingBoundary(*R, MBB, *MBB->getParent())) | |||
546 | break; | |||
547 | ||||
548 | // Move to directly after R. | |||
549 | if (&*--R != MI) | |||
550 | MBB->splice(*R, MBB, MI); | |||
551 | } | |||
552 | } | |||
553 | ||||
554 | if (Changed) | |||
555 | MRI.clearKillFlags(Reg); | |||
556 | ||||
557 | return Changed; | |||
558 | } | |||
559 | ||||
560 | bool SIFixSGPRCopies::runOnMachineFunction(MachineFunction &MF) { | |||
561 | // Only need to run this in SelectionDAG path. | |||
562 | if (MF.getProperties().hasProperty( | |||
| ||||
563 | MachineFunctionProperties::Property::Selected)) | |||
564 | return false; | |||
565 | ||||
566 | const GCNSubtarget &ST = MF.getSubtarget<GCNSubtarget>(); | |||
567 | MRI = &MF.getRegInfo(); | |||
568 | TRI = ST.getRegisterInfo(); | |||
569 | TII = ST.getInstrInfo(); | |||
570 | MDT = &getAnalysis<MachineDominatorTree>(); | |||
571 | ||||
572 | for (MachineFunction::iterator BI = MF.begin(), BE = MF.end(); | |||
573 | BI != BE; ++BI) { | |||
574 | MachineBasicBlock *MBB = &*BI; | |||
575 | for (MachineBasicBlock::iterator I = MBB->begin(), E = MBB->end(); I != E; | |||
576 | ++I) { | |||
577 | MachineInstr &MI = *I; | |||
578 | ||||
579 | switch (MI.getOpcode()) { | |||
580 | default: | |||
581 | continue; | |||
582 | case AMDGPU::COPY: | |||
583 | case AMDGPU::WQM: | |||
584 | case AMDGPU::STRICT_WQM: | |||
585 | case AMDGPU::SOFT_WQM: | |||
586 | case AMDGPU::STRICT_WWM: { | |||
587 | Register DstReg = MI.getOperand(0).getReg(); | |||
588 | ||||
589 | const TargetRegisterClass *SrcRC, *DstRC; | |||
590 | std::tie(SrcRC, DstRC) = getCopyRegClasses(MI, *TRI, *MRI); | |||
591 | ||||
592 | if (!DstReg.isVirtual()) { | |||
593 | // If the destination register is a physical register there isn't | |||
594 | // really much we can do to fix this. | |||
595 | // Some special instructions use M0 as an input. Some even only use | |||
596 | // the first lane. Insert a readfirstlane and hope for the best. | |||
597 | if (DstReg == AMDGPU::M0 && TRI->hasVectorRegisters(SrcRC)) { | |||
598 | Register TmpReg | |||
599 | = MRI->createVirtualRegister(&AMDGPU::SReg_32_XM0RegClass); | |||
600 | ||||
601 | BuildMI(*MBB, MI, MI.getDebugLoc(), | |||
602 | TII->get(AMDGPU::V_READFIRSTLANE_B32), TmpReg) | |||
603 | .add(MI.getOperand(1)); | |||
604 | MI.getOperand(1).setReg(TmpReg); | |||
605 | } | |||
606 | ||||
607 | continue; | |||
608 | } | |||
609 | ||||
610 | if (isVGPRToSGPRCopy(SrcRC, DstRC, *TRI)) { | |||
611 | Register SrcReg = MI.getOperand(1).getReg(); | |||
612 | if (!SrcReg.isVirtual()) { | |||
613 | MachineBasicBlock *NewBB = TII->moveToVALU(MI, MDT); | |||
614 | if (NewBB && NewBB != MBB) { | |||
615 | MBB = NewBB; | |||
616 | E = MBB->end(); | |||
617 | BI = MachineFunction::iterator(MBB); | |||
618 | BE = MF.end(); | |||
619 | } | |||
620 | assert((!NewBB || NewBB == I->getParent()) &&((void)0) | |||
621 | "moveToVALU did not return the right basic block")((void)0); | |||
622 | break; | |||
623 | } | |||
624 | ||||
625 | MachineInstr *DefMI = MRI->getVRegDef(SrcReg); | |||
626 | unsigned SMovOp; | |||
627 | int64_t Imm; | |||
628 | // If we are just copying an immediate, we can replace the copy with | |||
629 | // s_mov_b32. | |||
630 | if (isSafeToFoldImmIntoCopy(&MI, DefMI, TII, SMovOp, Imm)) { | |||
631 | MI.getOperand(1).ChangeToImmediate(Imm); | |||
632 | MI.addImplicitDefUseOperands(MF); | |||
633 | MI.setDesc(TII->get(SMovOp)); | |||
634 | break; | |||
635 | } | |||
636 | MachineBasicBlock *NewBB = TII->moveToVALU(MI, MDT); | |||
637 | if (NewBB && NewBB != MBB) { | |||
638 | MBB = NewBB; | |||
639 | E = MBB->end(); | |||
640 | BI = MachineFunction::iterator(MBB); | |||
641 | BE = MF.end(); | |||
642 | } | |||
643 | assert((!NewBB || NewBB == I->getParent()) &&((void)0) | |||
644 | "moveToVALU did not return the right basic block")((void)0); | |||
645 | } else if (isSGPRToVGPRCopy(SrcRC, DstRC, *TRI)) { | |||
646 | tryChangeVGPRtoSGPRinCopy(MI, TRI, TII); | |||
647 | } | |||
648 | ||||
649 | break; | |||
650 | } | |||
651 | case AMDGPU::PHI: { | |||
652 | MachineBasicBlock *NewBB = processPHINode(MI); | |||
653 | if (NewBB && NewBB != MBB) { | |||
654 | MBB = NewBB; | |||
655 | E = MBB->end(); | |||
656 | BI = MachineFunction::iterator(MBB); | |||
657 | BE = MF.end(); | |||
658 | } | |||
659 | assert((!NewBB || NewBB == I->getParent()) &&((void)0) | |||
660 | "moveToVALU did not return the right basic block")((void)0); | |||
661 | break; | |||
662 | } | |||
663 | case AMDGPU::REG_SEQUENCE: { | |||
664 | if (TRI->hasVectorRegisters(TII->getOpRegClass(MI, 0)) || | |||
665 | !hasVectorOperands(MI, TRI)) { | |||
666 | foldVGPRCopyIntoRegSequence(MI, TRI, TII, *MRI); | |||
667 | continue; | |||
668 | } | |||
669 | ||||
670 | LLVM_DEBUG(dbgs() << "Fixing REG_SEQUENCE: " << MI)do { } while (false); | |||
671 | ||||
672 | MachineBasicBlock *NewBB = TII->moveToVALU(MI, MDT); | |||
673 | if (NewBB && NewBB != MBB) { | |||
674 | MBB = NewBB; | |||
675 | E = MBB->end(); | |||
676 | BI = MachineFunction::iterator(MBB); | |||
677 | BE = MF.end(); | |||
678 | } | |||
679 | assert((!NewBB || NewBB == I->getParent()) &&((void)0) | |||
680 | "moveToVALU did not return the right basic block")((void)0); | |||
681 | break; | |||
682 | } | |||
683 | case AMDGPU::INSERT_SUBREG: { | |||
684 | const TargetRegisterClass *DstRC, *Src0RC, *Src1RC; | |||
685 | DstRC = MRI->getRegClass(MI.getOperand(0).getReg()); | |||
686 | Src0RC = MRI->getRegClass(MI.getOperand(1).getReg()); | |||
687 | Src1RC = MRI->getRegClass(MI.getOperand(2).getReg()); | |||
688 | if (TRI->isSGPRClass(DstRC) && | |||
689 | (TRI->hasVectorRegisters(Src0RC) || | |||
690 | TRI->hasVectorRegisters(Src1RC))) { | |||
691 | LLVM_DEBUG(dbgs() << " Fixing INSERT_SUBREG: " << MI)do { } while (false); | |||
692 | MachineBasicBlock *NewBB = TII->moveToVALU(MI, MDT); | |||
693 | if (NewBB && NewBB != MBB) { | |||
694 | MBB = NewBB; | |||
695 | E = MBB->end(); | |||
696 | BI = MachineFunction::iterator(MBB); | |||
697 | BE = MF.end(); | |||
698 | } | |||
699 | assert((!NewBB || NewBB == I->getParent()) &&((void)0) | |||
700 | "moveToVALU did not return the right basic block")((void)0); | |||
701 | } | |||
702 | break; | |||
703 | } | |||
704 | case AMDGPU::V_WRITELANE_B32: { | |||
705 | // Some architectures allow more than one constant bus access without | |||
706 | // SGPR restriction | |||
707 | if (ST.getConstantBusLimit(MI.getOpcode()) != 1) | |||
708 | break; | |||
709 | ||||
710 | // Writelane is special in that it can use SGPR and M0 (which would | |||
711 | // normally count as using the constant bus twice - but in this case it | |||
712 | // is allowed since the lane selector doesn't count as a use of the | |||
713 | // constant bus). However, it is still required to abide by the 1 SGPR | |||
714 | // rule. Apply a fix here as we might have multiple SGPRs after | |||
715 | // legalizing VGPRs to SGPRs | |||
716 | int Src0Idx = | |||
717 | AMDGPU::getNamedOperandIdx(MI.getOpcode(), AMDGPU::OpName::src0); | |||
718 | int Src1Idx = | |||
719 | AMDGPU::getNamedOperandIdx(MI.getOpcode(), AMDGPU::OpName::src1); | |||
720 | MachineOperand &Src0 = MI.getOperand(Src0Idx); | |||
721 | MachineOperand &Src1 = MI.getOperand(Src1Idx); | |||
722 | ||||
723 | // Check to see if the instruction violates the 1 SGPR rule | |||
724 | if ((Src0.isReg() && TRI->isSGPRReg(*MRI, Src0.getReg()) && | |||
725 | Src0.getReg() != AMDGPU::M0) && | |||
726 | (Src1.isReg() && TRI->isSGPRReg(*MRI, Src1.getReg()) && | |||
727 | Src1.getReg() != AMDGPU::M0)) { | |||
728 | ||||
729 | // Check for trivially easy constant prop into one of the operands | |||
730 | // If this is the case then perform the operation now to resolve SGPR | |||
731 | // issue. If we don't do that here we will always insert a mov to m0 | |||
732 | // that can't be resolved in later operand folding pass | |||
733 | bool Resolved = false; | |||
734 | for (MachineOperand *MO : {&Src0, &Src1}) { | |||
735 | if (MO->getReg().isVirtual()) { | |||
736 | MachineInstr *DefMI = MRI->getVRegDef(MO->getReg()); | |||
737 | if (DefMI && TII->isFoldableCopy(*DefMI)) { | |||
738 | const MachineOperand &Def = DefMI->getOperand(0); | |||
739 | if (Def.isReg() && | |||
740 | MO->getReg() == Def.getReg() && | |||
741 | MO->getSubReg() == Def.getSubReg()) { | |||
742 | const MachineOperand &Copied = DefMI->getOperand(1); | |||
743 | if (Copied.isImm() && | |||
744 | TII->isInlineConstant(APInt(64, Copied.getImm(), true))) { | |||
745 | MO->ChangeToImmediate(Copied.getImm()); | |||
746 | Resolved = true; | |||
747 | break; | |||
748 | } | |||
749 | } | |||
750 | } | |||
751 | } | |||
752 | } | |||
753 | ||||
754 | if (!Resolved) { | |||
755 | // Haven't managed to resolve by replacing an SGPR with an immediate | |||
756 | // Move src1 to be in M0 | |||
757 | BuildMI(*MI.getParent(), MI, MI.getDebugLoc(), | |||
758 | TII->get(AMDGPU::COPY), AMDGPU::M0) | |||
759 | .add(Src1); | |||
760 | Src1.ChangeToRegister(AMDGPU::M0, false); | |||
761 | } | |||
762 | } | |||
763 | break; | |||
764 | } | |||
765 | } | |||
766 | } | |||
767 | } | |||
768 | ||||
769 | if (MF.getTarget().getOptLevel() > CodeGenOpt::None && EnableM0Merge) | |||
770 | hoistAndMergeSGPRInits(AMDGPU::M0, *MRI, TRI, *MDT, TII); | |||
771 | ||||
772 | return true; | |||
773 | } | |||
774 | ||||
775 | MachineBasicBlock *SIFixSGPRCopies::processPHINode(MachineInstr &MI) { | |||
776 | unsigned numVGPRUses = 0; | |||
777 | bool AllAGPRUses = true; | |||
778 | SetVector<const MachineInstr *> worklist; | |||
779 | SmallSet<const MachineInstr *, 4> Visited; | |||
780 | SetVector<MachineInstr *> PHIOperands; | |||
781 | MachineBasicBlock *CreatedBB = nullptr; | |||
782 | worklist.insert(&MI); | |||
783 | Visited.insert(&MI); | |||
784 | while (!worklist.empty()) { | |||
785 | const MachineInstr *Instr = worklist.pop_back_val(); | |||
786 | Register Reg = Instr->getOperand(0).getReg(); | |||
787 | for (const auto &Use : MRI->use_operands(Reg)) { | |||
788 | const MachineInstr *UseMI = Use.getParent(); | |||
789 | AllAGPRUses &= (UseMI->isCopy() && | |||
790 | TRI->isAGPR(*MRI, UseMI->getOperand(0).getReg())) || | |||
791 | TRI->isAGPR(*MRI, Use.getReg()); | |||
792 | if (UseMI->isCopy() || UseMI->isRegSequence()) { | |||
793 | if (UseMI->isCopy() && | |||
794 | UseMI->getOperand(0).getReg().isPhysical() && | |||
795 | !TRI->isSGPRReg(*MRI, UseMI->getOperand(0).getReg())) { | |||
796 | numVGPRUses++; | |||
797 | } | |||
798 | if (Visited.insert(UseMI).second) | |||
799 | worklist.insert(UseMI); | |||
800 | ||||
801 | continue; | |||
802 | } | |||
803 | ||||
804 | if (UseMI->isPHI()) { | |||
805 | const TargetRegisterClass *UseRC = MRI->getRegClass(Use.getReg()); | |||
806 | if (!TRI->isSGPRReg(*MRI, Use.getReg()) && | |||
807 | UseRC != &AMDGPU::VReg_1RegClass) | |||
808 | numVGPRUses++; | |||
809 | continue; | |||
810 | } | |||
811 | ||||
812 | const TargetRegisterClass *OpRC = | |||
813 | TII->getOpRegClass(*UseMI, UseMI->getOperandNo(&Use)); | |||
814 | if (!TRI->isSGPRClass(OpRC) && OpRC != &AMDGPU::VS_32RegClass && | |||
815 | OpRC != &AMDGPU::VS_64RegClass) { | |||
816 | numVGPRUses++; | |||
817 | } | |||
818 | } | |||
819 | } | |||
820 | ||||
821 | Register PHIRes = MI.getOperand(0).getReg(); | |||
822 | const TargetRegisterClass *RC0 = MRI->getRegClass(PHIRes); | |||
823 | if (AllAGPRUses && numVGPRUses && !TRI->hasAGPRs(RC0)) { | |||
824 | LLVM_DEBUG(dbgs() << "Moving PHI to AGPR: " << MI)do { } while (false); | |||
825 | MRI->setRegClass(PHIRes, TRI->getEquivalentAGPRClass(RC0)); | |||
826 | for (unsigned I = 1, N = MI.getNumOperands(); I != N; I += 2) { | |||
827 | MachineInstr *DefMI = MRI->getVRegDef(MI.getOperand(I).getReg()); | |||
828 | if (DefMI && DefMI->isPHI()) | |||
829 | PHIOperands.insert(DefMI); | |||
830 | } | |||
831 | } | |||
832 | ||||
833 | bool hasVGPRInput = false; | |||
834 | for (unsigned i = 1; i < MI.getNumOperands(); i += 2) { | |||
835 | Register InputReg = MI.getOperand(i).getReg(); | |||
836 | MachineInstr *Def = MRI->getVRegDef(InputReg); | |||
837 | if (TRI->isVectorRegister(*MRI, InputReg)) { | |||
838 | if (Def->isCopy()) { | |||
839 | Register SrcReg = Def->getOperand(1).getReg(); | |||
840 | const TargetRegisterClass *RC = | |||
841 | TRI->getRegClassForReg(*MRI, SrcReg); | |||
842 | if (TRI->isSGPRClass(RC)) | |||
843 | continue; | |||
844 | } | |||
845 | hasVGPRInput = true; | |||
846 | break; | |||
847 | } | |||
848 | else if (Def->isCopy() && | |||
849 | TRI->isVectorRegister(*MRI, Def->getOperand(1).getReg())) { | |||
850 | Register SrcReg = Def->getOperand(1).getReg(); | |||
851 | MachineInstr *SrcDef = MRI->getVRegDef(SrcReg); | |||
852 | unsigned SMovOp; | |||
853 | int64_t Imm; | |||
854 | if (!isSafeToFoldImmIntoCopy(Def, SrcDef, TII, SMovOp, Imm)) { | |||
855 | hasVGPRInput = true; | |||
856 | break; | |||
857 | } else { | |||
858 | // Formally, if we did not do this right away | |||
859 | // it would be done on the next iteration of the | |||
860 | // runOnMachineFunction main loop. But why not if we can? | |||
861 | MachineFunction *MF = MI.getParent()->getParent(); | |||
862 | Def->getOperand(1).ChangeToImmediate(Imm); | |||
863 | Def->addImplicitDefUseOperands(*MF); | |||
864 | Def->setDesc(TII->get(SMovOp)); | |||
865 | } | |||
866 | } | |||
867 | } | |||
868 | ||||
869 | if ((!TRI->isVectorRegister(*MRI, PHIRes) && | |||
870 | RC0 != &AMDGPU::VReg_1RegClass) && | |||
871 | (hasVGPRInput || numVGPRUses > 1)) { | |||
872 | LLVM_DEBUG(dbgs() << "Fixing PHI: " << MI)do { } while (false); | |||
873 | CreatedBB = TII->moveToVALU(MI); | |||
874 | } | |||
875 | else { | |||
876 | LLVM_DEBUG(dbgs() << "Legalizing PHI: " << MI)do { } while (false); | |||
877 | TII->legalizeOperands(MI, MDT); | |||
878 | } | |||
879 | ||||
880 | // Propagate register class back to PHI operands which are PHI themselves. | |||
881 | while (!PHIOperands.empty()) { | |||
882 | processPHINode(*PHIOperands.pop_back_val()); | |||
883 | } | |||
884 | return CreatedBB; | |||
885 | } |
1 | //==- llvm/CodeGen/MachineDominators.h - Machine Dom Calculation -*- C++ -*-==// |
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 file defines classes mirroring those in llvm/Analysis/Dominators.h, |
10 | // but for target-specific code rather than target-independent IR. |
11 | // |
12 | //===----------------------------------------------------------------------===// |
13 | |
14 | #ifndef LLVM_CODEGEN_MACHINEDOMINATORS_H |
15 | #define LLVM_CODEGEN_MACHINEDOMINATORS_H |
16 | |
17 | #include "llvm/ADT/SmallSet.h" |
18 | #include "llvm/ADT/SmallVector.h" |
19 | #include "llvm/CodeGen/MachineBasicBlock.h" |
20 | #include "llvm/CodeGen/MachineFunctionPass.h" |
21 | #include "llvm/CodeGen/MachineInstr.h" |
22 | #include "llvm/Support/GenericDomTree.h" |
23 | #include "llvm/Support/GenericDomTreeConstruction.h" |
24 | #include <cassert> |
25 | #include <memory> |
26 | |
27 | namespace llvm { |
28 | |
29 | template <> |
30 | inline void DominatorTreeBase<MachineBasicBlock, false>::addRoot( |
31 | MachineBasicBlock *MBB) { |
32 | this->Roots.push_back(MBB); |
33 | } |
34 | |
35 | extern template class DomTreeNodeBase<MachineBasicBlock>; |
36 | extern template class DominatorTreeBase<MachineBasicBlock, false>; // DomTree |
37 | extern template class DominatorTreeBase<MachineBasicBlock, true>; // PostDomTree |
38 | |
39 | using MachineDomTreeNode = DomTreeNodeBase<MachineBasicBlock>; |
40 | |
41 | //===------------------------------------- |
42 | /// DominatorTree Class - Concrete subclass of DominatorTreeBase that is used to |
43 | /// compute a normal dominator tree. |
44 | /// |
45 | class MachineDominatorTree : public MachineFunctionPass { |
46 | using DomTreeT = DomTreeBase<MachineBasicBlock>; |
47 | |
48 | /// Helper structure used to hold all the basic blocks |
49 | /// involved in the split of a critical edge. |
50 | struct CriticalEdge { |
51 | MachineBasicBlock *FromBB; |
52 | MachineBasicBlock *ToBB; |
53 | MachineBasicBlock *NewBB; |
54 | }; |
55 | |
56 | /// Pile up all the critical edges to be split. |
57 | /// The splitting of a critical edge is local and thus, it is possible |
58 | /// to apply several of those changes at the same time. |
59 | mutable SmallVector<CriticalEdge, 32> CriticalEdgesToSplit; |
60 | |
61 | /// Remember all the basic blocks that are inserted during |
62 | /// edge splitting. |
63 | /// Invariant: NewBBs == all the basic blocks contained in the NewBB |
64 | /// field of all the elements of CriticalEdgesToSplit. |
65 | /// I.e., forall elt in CriticalEdgesToSplit, it exists BB in NewBBs |
66 | /// such as BB == elt.NewBB. |
67 | mutable SmallSet<MachineBasicBlock *, 32> NewBBs; |
68 | |
69 | /// The DominatorTreeBase that is used to compute a normal dominator tree. |
70 | std::unique_ptr<DomTreeT> DT; |
71 | |
72 | /// Apply all the recorded critical edges to the DT. |
73 | /// This updates the underlying DT information in a way that uses |
74 | /// the fast query path of DT as much as possible. |
75 | /// |
76 | /// \post CriticalEdgesToSplit.empty(). |
77 | void applySplitCriticalEdges() const; |
78 | |
79 | public: |
80 | static char ID; // Pass ID, replacement for typeid |
81 | |
82 | MachineDominatorTree(); |
83 | explicit MachineDominatorTree(MachineFunction &MF) : MachineFunctionPass(ID) { |
84 | calculate(MF); |
85 | } |
86 | |
87 | DomTreeT &getBase() { |
88 | if (!DT) DT.reset(new DomTreeT()); |
89 | applySplitCriticalEdges(); |
90 | return *DT; |
91 | } |
92 | |
93 | void getAnalysisUsage(AnalysisUsage &AU) const override; |
94 | |
95 | MachineBasicBlock *getRoot() const { |
96 | applySplitCriticalEdges(); |
97 | return DT->getRoot(); |
98 | } |
99 | |
100 | MachineDomTreeNode *getRootNode() const { |
101 | applySplitCriticalEdges(); |
102 | return DT->getRootNode(); |
103 | } |
104 | |
105 | bool runOnMachineFunction(MachineFunction &F) override; |
106 | |
107 | void calculate(MachineFunction &F); |
108 | |
109 | bool dominates(const MachineDomTreeNode *A, |
110 | const MachineDomTreeNode *B) const { |
111 | applySplitCriticalEdges(); |
112 | return DT->dominates(A, B); |
113 | } |
114 | |
115 | bool dominates(const MachineBasicBlock *A, const MachineBasicBlock *B) const { |
116 | applySplitCriticalEdges(); |
117 | return DT->dominates(A, B); |
118 | } |
119 | |
120 | // dominates - Return true if A dominates B. This performs the |
121 | // special checks necessary if A and B are in the same basic block. |
122 | bool dominates(const MachineInstr *A, const MachineInstr *B) const { |
123 | applySplitCriticalEdges(); |
124 | const MachineBasicBlock *BBA = A->getParent(), *BBB = B->getParent(); |
125 | if (BBA != BBB) return DT->dominates(BBA, BBB); |
126 | |
127 | // Loop through the basic block until we find A or B. |
128 | MachineBasicBlock::const_iterator I = BBA->begin(); |
129 | for (; &*I != A && &*I != B; ++I) |
130 | /*empty*/ ; |
131 | |
132 | return &*I == A; |
133 | } |
134 | |
135 | bool properlyDominates(const MachineDomTreeNode *A, |
136 | const MachineDomTreeNode *B) const { |
137 | applySplitCriticalEdges(); |
138 | return DT->properlyDominates(A, B); |
139 | } |
140 | |
141 | bool properlyDominates(const MachineBasicBlock *A, |
142 | const MachineBasicBlock *B) const { |
143 | applySplitCriticalEdges(); |
144 | return DT->properlyDominates(A, B); |
145 | } |
146 | |
147 | /// findNearestCommonDominator - Find nearest common dominator basic block |
148 | /// for basic block A and B. If there is no such block then return NULL. |
149 | MachineBasicBlock *findNearestCommonDominator(MachineBasicBlock *A, |
150 | MachineBasicBlock *B) { |
151 | applySplitCriticalEdges(); |
152 | return DT->findNearestCommonDominator(A, B); |
153 | } |
154 | |
155 | MachineDomTreeNode *operator[](MachineBasicBlock *BB) const { |
156 | applySplitCriticalEdges(); |
157 | return DT->getNode(BB); |
158 | } |
159 | |
160 | /// getNode - return the (Post)DominatorTree node for the specified basic |
161 | /// block. This is the same as using operator[] on this class. |
162 | /// |
163 | MachineDomTreeNode *getNode(MachineBasicBlock *BB) const { |
164 | applySplitCriticalEdges(); |
165 | return DT->getNode(BB); |
166 | } |
167 | |
168 | /// addNewBlock - Add a new node to the dominator tree information. This |
169 | /// creates a new node as a child of DomBB dominator node,linking it into |
170 | /// the children list of the immediate dominator. |
171 | MachineDomTreeNode *addNewBlock(MachineBasicBlock *BB, |
172 | MachineBasicBlock *DomBB) { |
173 | applySplitCriticalEdges(); |
174 | return DT->addNewBlock(BB, DomBB); |
175 | } |
176 | |
177 | /// changeImmediateDominator - This method is used to update the dominator |
178 | /// tree information when a node's immediate dominator changes. |
179 | /// |
180 | void changeImmediateDominator(MachineBasicBlock *N, |
181 | MachineBasicBlock *NewIDom) { |
182 | applySplitCriticalEdges(); |
183 | DT->changeImmediateDominator(N, NewIDom); |
184 | } |
185 | |
186 | void changeImmediateDominator(MachineDomTreeNode *N, |
187 | MachineDomTreeNode *NewIDom) { |
188 | applySplitCriticalEdges(); |
189 | DT->changeImmediateDominator(N, NewIDom); |
190 | } |
191 | |
192 | /// eraseNode - Removes a node from the dominator tree. Block must not |
193 | /// dominate any other blocks. Removes node from its immediate dominator's |
194 | /// children list. Deletes dominator node associated with basic block BB. |
195 | void eraseNode(MachineBasicBlock *BB) { |
196 | applySplitCriticalEdges(); |
197 | DT->eraseNode(BB); |
198 | } |
199 | |
200 | /// splitBlock - BB is split and now it has one successor. Update dominator |
201 | /// tree to reflect this change. |
202 | void splitBlock(MachineBasicBlock* NewBB) { |
203 | applySplitCriticalEdges(); |
204 | DT->splitBlock(NewBB); |
205 | } |
206 | |
207 | /// isReachableFromEntry - Return true if A is dominated by the entry |
208 | /// block of the function containing it. |
209 | bool isReachableFromEntry(const MachineBasicBlock *A) { |
210 | applySplitCriticalEdges(); |
211 | return DT->isReachableFromEntry(A); |
212 | } |
213 | |
214 | void releaseMemory() override; |
215 | |
216 | void verifyAnalysis() const override; |
217 | |
218 | void print(raw_ostream &OS, const Module*) const override; |
219 | |
220 | /// Record that the critical edge (FromBB, ToBB) has been |
221 | /// split with NewBB. |
222 | /// This is best to use this method instead of directly update the |
223 | /// underlying information, because this helps mitigating the |
224 | /// number of time the DT information is invalidated. |
225 | /// |
226 | /// \note Do not use this method with regular edges. |
227 | /// |
228 | /// \note To benefit from the compile time improvement incurred by this |
229 | /// method, the users of this method have to limit the queries to the DT |
230 | /// interface between two edges splitting. In other words, they have to |
231 | /// pack the splitting of critical edges as much as possible. |
232 | void recordSplitCriticalEdge(MachineBasicBlock *FromBB, |
233 | MachineBasicBlock *ToBB, |
234 | MachineBasicBlock *NewBB) { |
235 | bool Inserted = NewBBs.insert(NewBB).second; |
236 | (void)Inserted; |
237 | assert(Inserted &&((void)0) |
238 | "A basic block inserted via edge splitting cannot appear twice")((void)0); |
239 | CriticalEdgesToSplit.push_back({FromBB, ToBB, NewBB}); |
240 | } |
241 | }; |
242 | |
243 | //===------------------------------------- |
244 | /// DominatorTree GraphTraits specialization so the DominatorTree can be |
245 | /// iterable by generic graph iterators. |
246 | /// |
247 | |
248 | template <class Node, class ChildIterator> |
249 | struct MachineDomTreeGraphTraitsBase { |
250 | using NodeRef = Node *; |
251 | using ChildIteratorType = ChildIterator; |
252 | |
253 | static NodeRef getEntryNode(NodeRef N) { return N; } |
254 | static ChildIteratorType child_begin(NodeRef N) { return N->begin(); } |
255 | static ChildIteratorType child_end(NodeRef N) { return N->end(); } |
256 | }; |
257 | |
258 | template <class T> struct GraphTraits; |
259 | |
260 | template <> |
261 | struct GraphTraits<MachineDomTreeNode *> |
262 | : public MachineDomTreeGraphTraitsBase<MachineDomTreeNode, |
263 | MachineDomTreeNode::const_iterator> { |
264 | }; |
265 | |
266 | template <> |
267 | struct GraphTraits<const MachineDomTreeNode *> |
268 | : public MachineDomTreeGraphTraitsBase<const MachineDomTreeNode, |
269 | MachineDomTreeNode::const_iterator> { |
270 | }; |
271 | |
272 | template <> struct GraphTraits<MachineDominatorTree*> |
273 | : public GraphTraits<MachineDomTreeNode *> { |
274 | static NodeRef getEntryNode(MachineDominatorTree *DT) { |
275 | return DT->getRootNode(); |
276 | } |
277 | }; |
278 | |
279 | } // end namespace llvm |
280 | |
281 | #endif // LLVM_CODEGEN_MACHINEDOMINATORS_H |
1 | //===- GenericDomTree.h - Generic dominator trees for graphs ----*- C++ -*-===// | |||
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 | /// \file | |||
9 | /// | |||
10 | /// This file defines a set of templates that efficiently compute a dominator | |||
11 | /// tree over a generic graph. This is used typically in LLVM for fast | |||
12 | /// dominance queries on the CFG, but is fully generic w.r.t. the underlying | |||
13 | /// graph types. | |||
14 | /// | |||
15 | /// Unlike ADT/* graph algorithms, generic dominator tree has more requirements | |||
16 | /// on the graph's NodeRef. The NodeRef should be a pointer and, | |||
17 | /// NodeRef->getParent() must return the parent node that is also a pointer. | |||
18 | /// | |||
19 | /// FIXME: Maybe GenericDomTree needs a TreeTraits, instead of GraphTraits. | |||
20 | /// | |||
21 | //===----------------------------------------------------------------------===// | |||
22 | ||||
23 | #ifndef LLVM_SUPPORT_GENERICDOMTREE_H | |||
24 | #define LLVM_SUPPORT_GENERICDOMTREE_H | |||
25 | ||||
26 | #include "llvm/ADT/DenseMap.h" | |||
27 | #include "llvm/ADT/GraphTraits.h" | |||
28 | #include "llvm/ADT/STLExtras.h" | |||
29 | #include "llvm/ADT/SmallPtrSet.h" | |||
30 | #include "llvm/ADT/SmallVector.h" | |||
31 | #include "llvm/Support/CFGDiff.h" | |||
32 | #include "llvm/Support/CFGUpdate.h" | |||
33 | #include "llvm/Support/raw_ostream.h" | |||
34 | #include <algorithm> | |||
35 | #include <cassert> | |||
36 | #include <cstddef> | |||
37 | #include <iterator> | |||
38 | #include <memory> | |||
39 | #include <type_traits> | |||
40 | #include <utility> | |||
41 | ||||
42 | namespace llvm { | |||
43 | ||||
44 | template <typename NodeT, bool IsPostDom> | |||
45 | class DominatorTreeBase; | |||
46 | ||||
47 | namespace DomTreeBuilder { | |||
48 | template <typename DomTreeT> | |||
49 | struct SemiNCAInfo; | |||
50 | } // namespace DomTreeBuilder | |||
51 | ||||
52 | /// Base class for the actual dominator tree node. | |||
53 | template <class NodeT> class DomTreeNodeBase { | |||
54 | friend class PostDominatorTree; | |||
55 | friend class DominatorTreeBase<NodeT, false>; | |||
56 | friend class DominatorTreeBase<NodeT, true>; | |||
57 | friend struct DomTreeBuilder::SemiNCAInfo<DominatorTreeBase<NodeT, false>>; | |||
58 | friend struct DomTreeBuilder::SemiNCAInfo<DominatorTreeBase<NodeT, true>>; | |||
59 | ||||
60 | NodeT *TheBB; | |||
61 | DomTreeNodeBase *IDom; | |||
62 | unsigned Level; | |||
63 | SmallVector<DomTreeNodeBase *, 4> Children; | |||
64 | mutable unsigned DFSNumIn = ~0; | |||
65 | mutable unsigned DFSNumOut = ~0; | |||
66 | ||||
67 | public: | |||
68 | DomTreeNodeBase(NodeT *BB, DomTreeNodeBase *iDom) | |||
69 | : TheBB(BB), IDom(iDom), Level(IDom ? IDom->Level + 1 : 0) {} | |||
70 | ||||
71 | using iterator = typename SmallVector<DomTreeNodeBase *, 4>::iterator; | |||
72 | using const_iterator = | |||
73 | typename SmallVector<DomTreeNodeBase *, 4>::const_iterator; | |||
74 | ||||
75 | iterator begin() { return Children.begin(); } | |||
76 | iterator end() { return Children.end(); } | |||
77 | const_iterator begin() const { return Children.begin(); } | |||
78 | const_iterator end() const { return Children.end(); } | |||
79 | ||||
80 | DomTreeNodeBase *const &back() const { return Children.back(); } | |||
81 | DomTreeNodeBase *&back() { return Children.back(); } | |||
82 | ||||
83 | iterator_range<iterator> children() { return make_range(begin(), end()); } | |||
84 | iterator_range<const_iterator> children() const { | |||
85 | return make_range(begin(), end()); | |||
86 | } | |||
87 | ||||
88 | NodeT *getBlock() const { return TheBB; } | |||
89 | DomTreeNodeBase *getIDom() const { return IDom; } | |||
90 | unsigned getLevel() const { return Level; } | |||
91 | ||||
92 | std::unique_ptr<DomTreeNodeBase> addChild( | |||
93 | std::unique_ptr<DomTreeNodeBase> C) { | |||
94 | Children.push_back(C.get()); | |||
95 | return C; | |||
96 | } | |||
97 | ||||
98 | bool isLeaf() const { return Children.empty(); } | |||
99 | size_t getNumChildren() const { return Children.size(); } | |||
100 | ||||
101 | void clearAllChildren() { Children.clear(); } | |||
102 | ||||
103 | bool compare(const DomTreeNodeBase *Other) const { | |||
104 | if (getNumChildren() != Other->getNumChildren()) | |||
105 | return true; | |||
106 | ||||
107 | if (Level != Other->Level) return true; | |||
108 | ||||
109 | SmallPtrSet<const NodeT *, 4> OtherChildren; | |||
110 | for (const DomTreeNodeBase *I : *Other) { | |||
111 | const NodeT *Nd = I->getBlock(); | |||
112 | OtherChildren.insert(Nd); | |||
113 | } | |||
114 | ||||
115 | for (const DomTreeNodeBase *I : *this) { | |||
116 | const NodeT *N = I->getBlock(); | |||
117 | if (OtherChildren.count(N) == 0) | |||
118 | return true; | |||
119 | } | |||
120 | return false; | |||
121 | } | |||
122 | ||||
123 | void setIDom(DomTreeNodeBase *NewIDom) { | |||
124 | assert(IDom && "No immediate dominator?")((void)0); | |||
125 | if (IDom == NewIDom) return; | |||
126 | ||||
127 | auto I = find(IDom->Children, this); | |||
128 | assert(I != IDom->Children.end() &&((void)0) | |||
129 | "Not in immediate dominator children set!")((void)0); | |||
130 | // I am no longer your child... | |||
131 | IDom->Children.erase(I); | |||
132 | ||||
133 | // Switch to new dominator | |||
134 | IDom = NewIDom; | |||
135 | IDom->Children.push_back(this); | |||
136 | ||||
137 | UpdateLevel(); | |||
138 | } | |||
139 | ||||
140 | /// getDFSNumIn/getDFSNumOut - These return the DFS visitation order for nodes | |||
141 | /// in the dominator tree. They are only guaranteed valid if | |||
142 | /// updateDFSNumbers() has been called. | |||
143 | unsigned getDFSNumIn() const { return DFSNumIn; } | |||
144 | unsigned getDFSNumOut() const { return DFSNumOut; } | |||
145 | ||||
146 | private: | |||
147 | // Return true if this node is dominated by other. Use this only if DFS info | |||
148 | // is valid. | |||
149 | bool DominatedBy(const DomTreeNodeBase *other) const { | |||
150 | return this->DFSNumIn >= other->DFSNumIn && | |||
151 | this->DFSNumOut <= other->DFSNumOut; | |||
152 | } | |||
153 | ||||
154 | void UpdateLevel() { | |||
155 | assert(IDom)((void)0); | |||
156 | if (Level == IDom->Level + 1) return; | |||
157 | ||||
158 | SmallVector<DomTreeNodeBase *, 64> WorkStack = {this}; | |||
159 | ||||
160 | while (!WorkStack.empty()) { | |||
161 | DomTreeNodeBase *Current = WorkStack.pop_back_val(); | |||
162 | Current->Level = Current->IDom->Level + 1; | |||
163 | ||||
164 | for (DomTreeNodeBase *C : *Current) { | |||
165 | assert(C->IDom)((void)0); | |||
166 | if (C->Level != C->IDom->Level + 1) WorkStack.push_back(C); | |||
167 | } | |||
168 | } | |||
169 | } | |||
170 | }; | |||
171 | ||||
172 | template <class NodeT> | |||
173 | raw_ostream &operator<<(raw_ostream &O, const DomTreeNodeBase<NodeT> *Node) { | |||
174 | if (Node->getBlock()) | |||
175 | Node->getBlock()->printAsOperand(O, false); | |||
176 | else | |||
177 | O << " <<exit node>>"; | |||
178 | ||||
179 | O << " {" << Node->getDFSNumIn() << "," << Node->getDFSNumOut() << "} [" | |||
180 | << Node->getLevel() << "]\n"; | |||
181 | ||||
182 | return O; | |||
183 | } | |||
184 | ||||
185 | template <class NodeT> | |||
186 | void PrintDomTree(const DomTreeNodeBase<NodeT> *N, raw_ostream &O, | |||
187 | unsigned Lev) { | |||
188 | O.indent(2 * Lev) << "[" << Lev << "] " << N; | |||
189 | for (typename DomTreeNodeBase<NodeT>::const_iterator I = N->begin(), | |||
190 | E = N->end(); | |||
191 | I != E; ++I) | |||
192 | PrintDomTree<NodeT>(*I, O, Lev + 1); | |||
193 | } | |||
194 | ||||
195 | namespace DomTreeBuilder { | |||
196 | // The routines below are provided in a separate header but referenced here. | |||
197 | template <typename DomTreeT> | |||
198 | void Calculate(DomTreeT &DT); | |||
199 | ||||
200 | template <typename DomTreeT> | |||
201 | void CalculateWithUpdates(DomTreeT &DT, | |||
202 | ArrayRef<typename DomTreeT::UpdateType> Updates); | |||
203 | ||||
204 | template <typename DomTreeT> | |||
205 | void InsertEdge(DomTreeT &DT, typename DomTreeT::NodePtr From, | |||
206 | typename DomTreeT::NodePtr To); | |||
207 | ||||
208 | template <typename DomTreeT> | |||
209 | void DeleteEdge(DomTreeT &DT, typename DomTreeT::NodePtr From, | |||
210 | typename DomTreeT::NodePtr To); | |||
211 | ||||
212 | template <typename DomTreeT> | |||
213 | void ApplyUpdates(DomTreeT &DT, | |||
214 | GraphDiff<typename DomTreeT::NodePtr, | |||
215 | DomTreeT::IsPostDominator> &PreViewCFG, | |||
216 | GraphDiff<typename DomTreeT::NodePtr, | |||
217 | DomTreeT::IsPostDominator> *PostViewCFG); | |||
218 | ||||
219 | template <typename DomTreeT> | |||
220 | bool Verify(const DomTreeT &DT, typename DomTreeT::VerificationLevel VL); | |||
221 | } // namespace DomTreeBuilder | |||
222 | ||||
223 | /// Core dominator tree base class. | |||
224 | /// | |||
225 | /// This class is a generic template over graph nodes. It is instantiated for | |||
226 | /// various graphs in the LLVM IR or in the code generator. | |||
227 | template <typename NodeT, bool IsPostDom> | |||
228 | class DominatorTreeBase { | |||
229 | public: | |||
230 | static_assert(std::is_pointer<typename GraphTraits<NodeT *>::NodeRef>::value, | |||
231 | "Currently DominatorTreeBase supports only pointer nodes"); | |||
232 | using NodeType = NodeT; | |||
233 | using NodePtr = NodeT *; | |||
234 | using ParentPtr = decltype(std::declval<NodeT *>()->getParent()); | |||
235 | static_assert(std::is_pointer<ParentPtr>::value, | |||
236 | "Currently NodeT's parent must be a pointer type"); | |||
237 | using ParentType = std::remove_pointer_t<ParentPtr>; | |||
238 | static constexpr bool IsPostDominator = IsPostDom; | |||
239 | ||||
240 | using UpdateType = cfg::Update<NodePtr>; | |||
241 | using UpdateKind = cfg::UpdateKind; | |||
242 | static constexpr UpdateKind Insert = UpdateKind::Insert; | |||
243 | static constexpr UpdateKind Delete = UpdateKind::Delete; | |||
244 | ||||
245 | enum class VerificationLevel { Fast, Basic, Full }; | |||
246 | ||||
247 | protected: | |||
248 | // Dominators always have a single root, postdominators can have more. | |||
249 | SmallVector<NodeT *, IsPostDom ? 4 : 1> Roots; | |||
250 | ||||
251 | using DomTreeNodeMapType = | |||
252 | DenseMap<NodeT *, std::unique_ptr<DomTreeNodeBase<NodeT>>>; | |||
253 | DomTreeNodeMapType DomTreeNodes; | |||
254 | DomTreeNodeBase<NodeT> *RootNode = nullptr; | |||
255 | ParentPtr Parent = nullptr; | |||
256 | ||||
257 | mutable bool DFSInfoValid = false; | |||
258 | mutable unsigned int SlowQueries = 0; | |||
259 | ||||
260 | friend struct DomTreeBuilder::SemiNCAInfo<DominatorTreeBase>; | |||
261 | ||||
262 | public: | |||
263 | DominatorTreeBase() {} | |||
264 | ||||
265 | DominatorTreeBase(DominatorTreeBase &&Arg) | |||
266 | : Roots(std::move(Arg.Roots)), | |||
267 | DomTreeNodes(std::move(Arg.DomTreeNodes)), | |||
268 | RootNode(Arg.RootNode), | |||
269 | Parent(Arg.Parent), | |||
270 | DFSInfoValid(Arg.DFSInfoValid), | |||
271 | SlowQueries(Arg.SlowQueries) { | |||
272 | Arg.wipe(); | |||
273 | } | |||
274 | ||||
275 | DominatorTreeBase &operator=(DominatorTreeBase &&RHS) { | |||
276 | Roots = std::move(RHS.Roots); | |||
277 | DomTreeNodes = std::move(RHS.DomTreeNodes); | |||
278 | RootNode = RHS.RootNode; | |||
279 | Parent = RHS.Parent; | |||
280 | DFSInfoValid = RHS.DFSInfoValid; | |||
281 | SlowQueries = RHS.SlowQueries; | |||
282 | RHS.wipe(); | |||
283 | return *this; | |||
284 | } | |||
285 | ||||
286 | DominatorTreeBase(const DominatorTreeBase &) = delete; | |||
287 | DominatorTreeBase &operator=(const DominatorTreeBase &) = delete; | |||
288 | ||||
289 | /// Iteration over roots. | |||
290 | /// | |||
291 | /// This may include multiple blocks if we are computing post dominators. | |||
292 | /// For forward dominators, this will always be a single block (the entry | |||
293 | /// block). | |||
294 | using root_iterator = typename SmallVectorImpl<NodeT *>::iterator; | |||
295 | using const_root_iterator = typename SmallVectorImpl<NodeT *>::const_iterator; | |||
296 | ||||
297 | root_iterator root_begin() { return Roots.begin(); } | |||
298 | const_root_iterator root_begin() const { return Roots.begin(); } | |||
299 | root_iterator root_end() { return Roots.end(); } | |||
300 | const_root_iterator root_end() const { return Roots.end(); } | |||
301 | ||||
302 | size_t root_size() const { return Roots.size(); } | |||
303 | ||||
304 | iterator_range<root_iterator> roots() { | |||
305 | return make_range(root_begin(), root_end()); | |||
306 | } | |||
307 | iterator_range<const_root_iterator> roots() const { | |||
308 | return make_range(root_begin(), root_end()); | |||
309 | } | |||
310 | ||||
311 | /// isPostDominator - Returns true if analysis based of postdoms | |||
312 | /// | |||
313 | bool isPostDominator() const { return IsPostDominator; } | |||
314 | ||||
315 | /// compare - Return false if the other dominator tree base matches this | |||
316 | /// dominator tree base. Otherwise return true. | |||
317 | bool compare(const DominatorTreeBase &Other) const { | |||
318 | if (Parent != Other.Parent) return true; | |||
319 | ||||
320 | if (Roots.size() != Other.Roots.size()) | |||
321 | return true; | |||
322 | ||||
323 | if (!std::is_permutation(Roots.begin(), Roots.end(), Other.Roots.begin())) | |||
324 | return true; | |||
325 | ||||
326 | const DomTreeNodeMapType &OtherDomTreeNodes = Other.DomTreeNodes; | |||
327 | if (DomTreeNodes.size() != OtherDomTreeNodes.size()) | |||
328 | return true; | |||
329 | ||||
330 | for (const auto &DomTreeNode : DomTreeNodes) { | |||
331 | NodeT *BB = DomTreeNode.first; | |||
332 | typename DomTreeNodeMapType::const_iterator OI = | |||
333 | OtherDomTreeNodes.find(BB); | |||
334 | if (OI == OtherDomTreeNodes.end()) | |||
335 | return true; | |||
336 | ||||
337 | DomTreeNodeBase<NodeT> &MyNd = *DomTreeNode.second; | |||
338 | DomTreeNodeBase<NodeT> &OtherNd = *OI->second; | |||
339 | ||||
340 | if (MyNd.compare(&OtherNd)) | |||
341 | return true; | |||
342 | } | |||
343 | ||||
344 | return false; | |||
345 | } | |||
346 | ||||
347 | /// getNode - return the (Post)DominatorTree node for the specified basic | |||
348 | /// block. This is the same as using operator[] on this class. The result | |||
349 | /// may (but is not required to) be null for a forward (backwards) | |||
350 | /// statically unreachable block. | |||
351 | DomTreeNodeBase<NodeT> *getNode(const NodeT *BB) const { | |||
352 | auto I = DomTreeNodes.find(BB); | |||
353 | if (I != DomTreeNodes.end()) | |||
354 | return I->second.get(); | |||
355 | return nullptr; | |||
356 | } | |||
357 | ||||
358 | /// See getNode. | |||
359 | DomTreeNodeBase<NodeT> *operator[](const NodeT *BB) const { | |||
360 | return getNode(BB); | |||
361 | } | |||
362 | ||||
363 | /// getRootNode - This returns the entry node for the CFG of the function. If | |||
364 | /// this tree represents the post-dominance relations for a function, however, | |||
365 | /// this root may be a node with the block == NULL. This is the case when | |||
366 | /// there are multiple exit nodes from a particular function. Consumers of | |||
367 | /// post-dominance information must be capable of dealing with this | |||
368 | /// possibility. | |||
369 | /// | |||
370 | DomTreeNodeBase<NodeT> *getRootNode() { return RootNode; } | |||
371 | const DomTreeNodeBase<NodeT> *getRootNode() const { return RootNode; } | |||
372 | ||||
373 | /// Get all nodes dominated by R, including R itself. | |||
374 | void getDescendants(NodeT *R, SmallVectorImpl<NodeT *> &Result) const { | |||
375 | Result.clear(); | |||
376 | const DomTreeNodeBase<NodeT> *RN = getNode(R); | |||
377 | if (!RN) | |||
378 | return; // If R is unreachable, it will not be present in the DOM tree. | |||
379 | SmallVector<const DomTreeNodeBase<NodeT> *, 8> WL; | |||
380 | WL.push_back(RN); | |||
381 | ||||
382 | while (!WL.empty()) { | |||
383 | const DomTreeNodeBase<NodeT> *N = WL.pop_back_val(); | |||
384 | Result.push_back(N->getBlock()); | |||
385 | WL.append(N->begin(), N->end()); | |||
386 | } | |||
387 | } | |||
388 | ||||
389 | /// properlyDominates - Returns true iff A dominates B and A != B. | |||
390 | /// Note that this is not a constant time operation! | |||
391 | /// | |||
392 | bool properlyDominates(const DomTreeNodeBase<NodeT> *A, | |||
393 | const DomTreeNodeBase<NodeT> *B) const { | |||
394 | if (!A || !B) | |||
395 | return false; | |||
396 | if (A == B) | |||
397 | return false; | |||
398 | return dominates(A, B); | |||
399 | } | |||
400 | ||||
401 | bool properlyDominates(const NodeT *A, const NodeT *B) const; | |||
402 | ||||
403 | /// isReachableFromEntry - Return true if A is dominated by the entry | |||
404 | /// block of the function containing it. | |||
405 | bool isReachableFromEntry(const NodeT *A) const { | |||
406 | assert(!this->isPostDominator() &&((void)0) | |||
407 | "This is not implemented for post dominators")((void)0); | |||
408 | return isReachableFromEntry(getNode(const_cast<NodeT *>(A))); | |||
409 | } | |||
410 | ||||
411 | bool isReachableFromEntry(const DomTreeNodeBase<NodeT> *A) const { return A; } | |||
412 | ||||
413 | /// dominates - Returns true iff A dominates B. Note that this is not a | |||
414 | /// constant time operation! | |||
415 | /// | |||
416 | bool dominates(const DomTreeNodeBase<NodeT> *A, | |||
417 | const DomTreeNodeBase<NodeT> *B) const { | |||
418 | // A node trivially dominates itself. | |||
419 | if (B == A) | |||
420 | return true; | |||
421 | ||||
422 | // An unreachable node is dominated by anything. | |||
423 | if (!isReachableFromEntry(B)) | |||
424 | return true; | |||
425 | ||||
426 | // And dominates nothing. | |||
427 | if (!isReachableFromEntry(A)) | |||
428 | return false; | |||
429 | ||||
430 | if (B->getIDom() == A) return true; | |||
431 | ||||
432 | if (A->getIDom() == B) return false; | |||
433 | ||||
434 | // A can only dominate B if it is higher in the tree. | |||
435 | if (A->getLevel() >= B->getLevel()) return false; | |||
436 | ||||
437 | // Compare the result of the tree walk and the dfs numbers, if expensive | |||
438 | // checks are enabled. | |||
439 | #ifdef EXPENSIVE_CHECKS | |||
440 | assert((!DFSInfoValid ||((void)0) | |||
441 | (dominatedBySlowTreeWalk(A, B) == B->DominatedBy(A))) &&((void)0) | |||
442 | "Tree walk disagrees with dfs numbers!")((void)0); | |||
443 | #endif | |||
444 | ||||
445 | if (DFSInfoValid) | |||
446 | return B->DominatedBy(A); | |||
447 | ||||
448 | // If we end up with too many slow queries, just update the | |||
449 | // DFS numbers on the theory that we are going to keep querying. | |||
450 | SlowQueries++; | |||
451 | if (SlowQueries > 32) { | |||
452 | updateDFSNumbers(); | |||
453 | return B->DominatedBy(A); | |||
454 | } | |||
455 | ||||
456 | return dominatedBySlowTreeWalk(A, B); | |||
457 | } | |||
458 | ||||
459 | bool dominates(const NodeT *A, const NodeT *B) const; | |||
460 | ||||
461 | NodeT *getRoot() const { | |||
462 | assert(this->Roots.size() == 1 && "Should always have entry node!")((void)0); | |||
463 | return this->Roots[0]; | |||
464 | } | |||
465 | ||||
466 | /// Find nearest common dominator basic block for basic block A and B. A and B | |||
467 | /// must have tree nodes. | |||
468 | NodeT *findNearestCommonDominator(NodeT *A, NodeT *B) const { | |||
469 | assert(A && B && "Pointers are not valid")((void)0); | |||
470 | assert(A->getParent() == B->getParent() &&((void)0) | |||
471 | "Two blocks are not in same function")((void)0); | |||
472 | ||||
473 | // If either A or B is a entry block then it is nearest common dominator | |||
474 | // (for forward-dominators). | |||
475 | if (!isPostDominator()) { | |||
476 | NodeT &Entry = A->getParent()->front(); | |||
477 | if (A == &Entry || B == &Entry) | |||
478 | return &Entry; | |||
479 | } | |||
480 | ||||
481 | DomTreeNodeBase<NodeT> *NodeA = getNode(A); | |||
482 | DomTreeNodeBase<NodeT> *NodeB = getNode(B); | |||
483 | assert(NodeA && "A must be in the tree")((void)0); | |||
484 | assert(NodeB && "B must be in the tree")((void)0); | |||
485 | ||||
486 | // Use level information to go up the tree until the levels match. Then | |||
487 | // continue going up til we arrive at the same node. | |||
488 | while (NodeA != NodeB) { | |||
489 | if (NodeA->getLevel() < NodeB->getLevel()) std::swap(NodeA, NodeB); | |||
490 | ||||
491 | NodeA = NodeA->IDom; | |||
492 | } | |||
493 | ||||
494 | return NodeA->getBlock(); | |||
| ||||
495 | } | |||
496 | ||||
497 | const NodeT *findNearestCommonDominator(const NodeT *A, | |||
498 | const NodeT *B) const { | |||
499 | // Cast away the const qualifiers here. This is ok since | |||
500 | // const is re-introduced on the return type. | |||
501 | return findNearestCommonDominator(const_cast<NodeT *>(A), | |||
502 | const_cast<NodeT *>(B)); | |||
503 | } | |||
504 | ||||
505 | bool isVirtualRoot(const DomTreeNodeBase<NodeT> *A) const { | |||
506 | return isPostDominator() && !A->getBlock(); | |||
507 | } | |||
508 | ||||
509 | //===--------------------------------------------------------------------===// | |||
510 | // API to update (Post)DominatorTree information based on modifications to | |||
511 | // the CFG... | |||
512 | ||||
513 | /// Inform the dominator tree about a sequence of CFG edge insertions and | |||
514 | /// deletions and perform a batch update on the tree. | |||
515 | /// | |||
516 | /// This function should be used when there were multiple CFG updates after | |||
517 | /// the last dominator tree update. It takes care of performing the updates | |||
518 | /// in sync with the CFG and optimizes away the redundant operations that | |||
519 | /// cancel each other. | |||
520 | /// The functions expects the sequence of updates to be balanced. Eg.: | |||
521 | /// - {{Insert, A, B}, {Delete, A, B}, {Insert, A, B}} is fine, because | |||
522 | /// logically it results in a single insertions. | |||
523 | /// - {{Insert, A, B}, {Insert, A, B}} is invalid, because it doesn't make | |||
524 | /// sense to insert the same edge twice. | |||
525 | /// | |||
526 | /// What's more, the functions assumes that it's safe to ask every node in the | |||
527 | /// CFG about its children and inverse children. This implies that deletions | |||
528 | /// of CFG edges must not delete the CFG nodes before calling this function. | |||
529 | /// | |||
530 | /// The applyUpdates function can reorder the updates and remove redundant | |||
531 | /// ones internally. The batch updater is also able to detect sequences of | |||
532 | /// zero and exactly one update -- it's optimized to do less work in these | |||
533 | /// cases. | |||
534 | /// | |||
535 | /// Note that for postdominators it automatically takes care of applying | |||
536 | /// updates on reverse edges internally (so there's no need to swap the | |||
537 | /// From and To pointers when constructing DominatorTree::UpdateType). | |||
538 | /// The type of updates is the same for DomTreeBase<T> and PostDomTreeBase<T> | |||
539 | /// with the same template parameter T. | |||
540 | /// | |||
541 | /// \param Updates An unordered sequence of updates to perform. The current | |||
542 | /// CFG and the reverse of these updates provides the pre-view of the CFG. | |||
543 | /// | |||
544 | void applyUpdates(ArrayRef<UpdateType> Updates) { | |||
545 | GraphDiff<NodePtr, IsPostDominator> PreViewCFG( | |||
546 | Updates, /*ReverseApplyUpdates=*/true); | |||
547 | DomTreeBuilder::ApplyUpdates(*this, PreViewCFG, nullptr); | |||
548 | } | |||
549 | ||||
550 | /// \param Updates An unordered sequence of updates to perform. The current | |||
551 | /// CFG and the reverse of these updates provides the pre-view of the CFG. | |||
552 | /// \param PostViewUpdates An unordered sequence of update to perform in order | |||
553 | /// to obtain a post-view of the CFG. The DT will be updated assuming the | |||
554 | /// obtained PostViewCFG is the desired end state. | |||
555 | void applyUpdates(ArrayRef<UpdateType> Updates, | |||
556 | ArrayRef<UpdateType> PostViewUpdates) { | |||
557 | if (Updates.empty()) { | |||
558 | GraphDiff<NodePtr, IsPostDom> PostViewCFG(PostViewUpdates); | |||
559 | DomTreeBuilder::ApplyUpdates(*this, PostViewCFG, &PostViewCFG); | |||
560 | } else { | |||
561 | // PreViewCFG needs to merge Updates and PostViewCFG. The updates in | |||
562 | // Updates need to be reversed, and match the direction in PostViewCFG. | |||
563 | // The PostViewCFG is created with updates reversed (equivalent to changes | |||
564 | // made to the CFG), so the PreViewCFG needs all the updates reverse | |||
565 | // applied. | |||
566 | SmallVector<UpdateType> AllUpdates(Updates.begin(), Updates.end()); | |||
567 | append_range(AllUpdates, PostViewUpdates); | |||
568 | GraphDiff<NodePtr, IsPostDom> PreViewCFG(AllUpdates, | |||
569 | /*ReverseApplyUpdates=*/true); | |||
570 | GraphDiff<NodePtr, IsPostDom> PostViewCFG(PostViewUpdates); | |||
571 | DomTreeBuilder::ApplyUpdates(*this, PreViewCFG, &PostViewCFG); | |||
572 | } | |||
573 | } | |||
574 | ||||
575 | /// Inform the dominator tree about a CFG edge insertion and update the tree. | |||
576 | /// | |||
577 | /// This function has to be called just before or just after making the update | |||
578 | /// on the actual CFG. There cannot be any other updates that the dominator | |||
579 | /// tree doesn't know about. | |||
580 | /// | |||
581 | /// Note that for postdominators it automatically takes care of inserting | |||
582 | /// a reverse edge internally (so there's no need to swap the parameters). | |||
583 | /// | |||
584 | void insertEdge(NodeT *From, NodeT *To) { | |||
585 | assert(From)((void)0); | |||
586 | assert(To)((void)0); | |||
587 | assert(From->getParent() == Parent)((void)0); | |||
588 | assert(To->getParent() == Parent)((void)0); | |||
589 | DomTreeBuilder::InsertEdge(*this, From, To); | |||
590 | } | |||
591 | ||||
592 | /// Inform the dominator tree about a CFG edge deletion and update the tree. | |||
593 | /// | |||
594 | /// This function has to be called just after making the update on the actual | |||
595 | /// CFG. An internal functions checks if the edge doesn't exist in the CFG in | |||
596 | /// DEBUG mode. There cannot be any other updates that the | |||
597 | /// dominator tree doesn't know about. | |||
598 | /// | |||
599 | /// Note that for postdominators it automatically takes care of deleting | |||
600 | /// a reverse edge internally (so there's no need to swap the parameters). | |||
601 | /// | |||
602 | void deleteEdge(NodeT *From, NodeT *To) { | |||
603 | assert(From)((void)0); | |||
604 | assert(To)((void)0); | |||
605 | assert(From->getParent() == Parent)((void)0); | |||
606 | assert(To->getParent() == Parent)((void)0); | |||
607 | DomTreeBuilder::DeleteEdge(*this, From, To); | |||
608 | } | |||
609 | ||||
610 | /// Add a new node to the dominator tree information. | |||
611 | /// | |||
612 | /// This creates a new node as a child of DomBB dominator node, linking it | |||
613 | /// into the children list of the immediate dominator. | |||
614 | /// | |||
615 | /// \param BB New node in CFG. | |||
616 | /// \param DomBB CFG node that is dominator for BB. | |||
617 | /// \returns New dominator tree node that represents new CFG node. | |||
618 | /// | |||
619 | DomTreeNodeBase<NodeT> *addNewBlock(NodeT *BB, NodeT *DomBB) { | |||
620 | assert(getNode(BB) == nullptr && "Block already in dominator tree!")((void)0); | |||
621 | DomTreeNodeBase<NodeT> *IDomNode = getNode(DomBB); | |||
622 | assert(IDomNode && "Not immediate dominator specified for block!")((void)0); | |||
623 | DFSInfoValid = false; | |||
624 | return createChild(BB, IDomNode); | |||
625 | } | |||
626 | ||||
627 | /// Add a new node to the forward dominator tree and make it a new root. | |||
628 | /// | |||
629 | /// \param BB New node in CFG. | |||
630 | /// \returns New dominator tree node that represents new CFG node. | |||
631 | /// | |||
632 | DomTreeNodeBase<NodeT> *setNewRoot(NodeT *BB) { | |||
633 | assert(getNode(BB) == nullptr && "Block already in dominator tree!")((void)0); | |||
634 | assert(!this->isPostDominator() &&((void)0) | |||
635 | "Cannot change root of post-dominator tree")((void)0); | |||
636 | DFSInfoValid = false; | |||
637 | DomTreeNodeBase<NodeT> *NewNode = createNode(BB); | |||
638 | if (Roots.empty()) { | |||
639 | addRoot(BB); | |||
640 | } else { | |||
641 | assert(Roots.size() == 1)((void)0); | |||
642 | NodeT *OldRoot = Roots.front(); | |||
643 | auto &OldNode = DomTreeNodes[OldRoot]; | |||
644 | OldNode = NewNode->addChild(std::move(DomTreeNodes[OldRoot])); | |||
645 | OldNode->IDom = NewNode; | |||
646 | OldNode->UpdateLevel(); | |||
647 | Roots[0] = BB; | |||
648 | } | |||
649 | return RootNode = NewNode; | |||
650 | } | |||
651 | ||||
652 | /// changeImmediateDominator - This method is used to update the dominator | |||
653 | /// tree information when a node's immediate dominator changes. | |||
654 | /// | |||
655 | void changeImmediateDominator(DomTreeNodeBase<NodeT> *N, | |||
656 | DomTreeNodeBase<NodeT> *NewIDom) { | |||
657 | assert(N && NewIDom && "Cannot change null node pointers!")((void)0); | |||
658 | DFSInfoValid = false; | |||
659 | N->setIDom(NewIDom); | |||
660 | } | |||
661 | ||||
662 | void changeImmediateDominator(NodeT *BB, NodeT *NewBB) { | |||
663 | changeImmediateDominator(getNode(BB), getNode(NewBB)); | |||
664 | } | |||
665 | ||||
666 | /// eraseNode - Removes a node from the dominator tree. Block must not | |||
667 | /// dominate any other blocks. Removes node from its immediate dominator's | |||
668 | /// children list. Deletes dominator node associated with basic block BB. | |||
669 | void eraseNode(NodeT *BB) { | |||
670 | DomTreeNodeBase<NodeT> *Node = getNode(BB); | |||
671 | assert(Node && "Removing node that isn't in dominator tree.")((void)0); | |||
672 | assert(Node->isLeaf() && "Node is not a leaf node.")((void)0); | |||
673 | ||||
674 | DFSInfoValid = false; | |||
675 | ||||
676 | // Remove node from immediate dominator's children list. | |||
677 | DomTreeNodeBase<NodeT> *IDom = Node->getIDom(); | |||
678 | if (IDom) { | |||
679 | const auto I = find(IDom->Children, Node); | |||
680 | assert(I != IDom->Children.end() &&((void)0) | |||
681 | "Not in immediate dominator children set!")((void)0); | |||
682 | // I am no longer your child... | |||
683 | IDom->Children.erase(I); | |||
684 | } | |||
685 | ||||
686 | DomTreeNodes.erase(BB); | |||
687 | ||||
688 | if (!IsPostDom) return; | |||
689 | ||||
690 | // Remember to update PostDominatorTree roots. | |||
691 | auto RIt = llvm::find(Roots, BB); | |||
692 | if (RIt != Roots.end()) { | |||
693 | std::swap(*RIt, Roots.back()); | |||
694 | Roots.pop_back(); | |||
695 | } | |||
696 | } | |||
697 | ||||
698 | /// splitBlock - BB is split and now it has one successor. Update dominator | |||
699 | /// tree to reflect this change. | |||
700 | void splitBlock(NodeT *NewBB) { | |||
701 | if (IsPostDominator) | |||
702 | Split<Inverse<NodeT *>>(NewBB); | |||
703 | else | |||
704 | Split<NodeT *>(NewBB); | |||
705 | } | |||
706 | ||||
707 | /// print - Convert to human readable form | |||
708 | /// | |||
709 | void print(raw_ostream &O) const { | |||
710 | O << "=============================--------------------------------\n"; | |||
711 | if (IsPostDominator) | |||
712 | O << "Inorder PostDominator Tree: "; | |||
713 | else | |||
714 | O << "Inorder Dominator Tree: "; | |||
715 | if (!DFSInfoValid) | |||
716 | O << "DFSNumbers invalid: " << SlowQueries << " slow queries."; | |||
717 | O << "\n"; | |||
718 | ||||
719 | // The postdom tree can have a null root if there are no returns. | |||
720 | if (getRootNode()) PrintDomTree<NodeT>(getRootNode(), O, 1); | |||
721 | O << "Roots: "; | |||
722 | for (const NodePtr Block : Roots) { | |||
723 | Block->printAsOperand(O, false); | |||
724 | O << " "; | |||
725 | } | |||
726 | O << "\n"; | |||
727 | } | |||
728 | ||||
729 | public: | |||
730 | /// updateDFSNumbers - Assign In and Out numbers to the nodes while walking | |||
731 | /// dominator tree in dfs order. | |||
732 | void updateDFSNumbers() const { | |||
733 | if (DFSInfoValid) { | |||
734 | SlowQueries = 0; | |||
735 | return; | |||
736 | } | |||
737 | ||||
738 | SmallVector<std::pair<const DomTreeNodeBase<NodeT> *, | |||
739 | typename DomTreeNodeBase<NodeT>::const_iterator>, | |||
740 | 32> WorkStack; | |||
741 | ||||
742 | const DomTreeNodeBase<NodeT> *ThisRoot = getRootNode(); | |||
743 | assert((!Parent || ThisRoot) && "Empty constructed DomTree")((void)0); | |||
744 | if (!ThisRoot) | |||
745 | return; | |||
746 | ||||
747 | // Both dominators and postdominators have a single root node. In the case | |||
748 | // case of PostDominatorTree, this node is a virtual root. | |||
749 | WorkStack.push_back({ThisRoot, ThisRoot->begin()}); | |||
750 | ||||
751 | unsigned DFSNum = 0; | |||
752 | ThisRoot->DFSNumIn = DFSNum++; | |||
753 | ||||
754 | while (!WorkStack.empty()) { | |||
755 | const DomTreeNodeBase<NodeT> *Node = WorkStack.back().first; | |||
756 | const auto ChildIt = WorkStack.back().second; | |||
757 | ||||
758 | // If we visited all of the children of this node, "recurse" back up the | |||
759 | // stack setting the DFOutNum. | |||
760 | if (ChildIt == Node->end()) { | |||
761 | Node->DFSNumOut = DFSNum++; | |||
762 | WorkStack.pop_back(); | |||
763 | } else { | |||
764 | // Otherwise, recursively visit this child. | |||
765 | const DomTreeNodeBase<NodeT> *Child = *ChildIt; | |||
766 | ++WorkStack.back().second; | |||
767 | ||||
768 | WorkStack.push_back({Child, Child->begin()}); | |||
769 | Child->DFSNumIn = DFSNum++; | |||
770 | } | |||
771 | } | |||
772 | ||||
773 | SlowQueries = 0; | |||
774 | DFSInfoValid = true; | |||
775 | } | |||
776 | ||||
777 | /// recalculate - compute a dominator tree for the given function | |||
778 | void recalculate(ParentType &Func) { | |||
779 | Parent = &Func; | |||
780 | DomTreeBuilder::Calculate(*this); | |||
781 | } | |||
782 | ||||
783 | void recalculate(ParentType &Func, ArrayRef<UpdateType> Updates) { | |||
784 | Parent = &Func; | |||
785 | DomTreeBuilder::CalculateWithUpdates(*this, Updates); | |||
786 | } | |||
787 | ||||
788 | /// verify - checks if the tree is correct. There are 3 level of verification: | |||
789 | /// - Full -- verifies if the tree is correct by making sure all the | |||
790 | /// properties (including the parent and the sibling property) | |||
791 | /// hold. | |||
792 | /// Takes O(N^3) time. | |||
793 | /// | |||
794 | /// - Basic -- checks if the tree is correct, but compares it to a freshly | |||
795 | /// constructed tree instead of checking the sibling property. | |||
796 | /// Takes O(N^2) time. | |||
797 | /// | |||
798 | /// - Fast -- checks basic tree structure and compares it with a freshly | |||
799 | /// constructed tree. | |||
800 | /// Takes O(N^2) time worst case, but is faster in practise (same | |||
801 | /// as tree construction). | |||
802 | bool verify(VerificationLevel VL = VerificationLevel::Full) const { | |||
803 | return DomTreeBuilder::Verify(*this, VL); | |||
804 | } | |||
805 | ||||
806 | void reset() { | |||
807 | DomTreeNodes.clear(); | |||
808 | Roots.clear(); | |||
809 | RootNode = nullptr; | |||
810 | Parent = nullptr; | |||
811 | DFSInfoValid = false; | |||
812 | SlowQueries = 0; | |||
813 | } | |||
814 | ||||
815 | protected: | |||
816 | void addRoot(NodeT *BB) { this->Roots.push_back(BB); } | |||
817 | ||||
818 | DomTreeNodeBase<NodeT> *createChild(NodeT *BB, DomTreeNodeBase<NodeT> *IDom) { | |||
819 | return (DomTreeNodes[BB] = IDom->addChild( | |||
820 | std::make_unique<DomTreeNodeBase<NodeT>>(BB, IDom))) | |||
821 | .get(); | |||
822 | } | |||
823 | ||||
824 | DomTreeNodeBase<NodeT> *createNode(NodeT *BB) { | |||
825 | return (DomTreeNodes[BB] = | |||
826 | std::make_unique<DomTreeNodeBase<NodeT>>(BB, nullptr)) | |||
827 | .get(); | |||
828 | } | |||
829 | ||||
830 | // NewBB is split and now it has one successor. Update dominator tree to | |||
831 | // reflect this change. | |||
832 | template <class N> | |||
833 | void Split(typename GraphTraits<N>::NodeRef NewBB) { | |||
834 | using GraphT = GraphTraits<N>; | |||
835 | using NodeRef = typename GraphT::NodeRef; | |||
836 | assert(std::distance(GraphT::child_begin(NewBB),((void)0) | |||
837 | GraphT::child_end(NewBB)) == 1 &&((void)0) | |||
838 | "NewBB should have a single successor!")((void)0); | |||
839 | NodeRef NewBBSucc = *GraphT::child_begin(NewBB); | |||
840 | ||||
841 | SmallVector<NodeRef, 4> PredBlocks(children<Inverse<N>>(NewBB)); | |||
842 | ||||
843 | assert(!PredBlocks.empty() && "No predblocks?")((void)0); | |||
844 | ||||
845 | bool NewBBDominatesNewBBSucc = true; | |||
846 | for (auto Pred : children<Inverse<N>>(NewBBSucc)) { | |||
847 | if (Pred != NewBB && !dominates(NewBBSucc, Pred) && | |||
848 | isReachableFromEntry(Pred)) { | |||
849 | NewBBDominatesNewBBSucc = false; | |||
850 | break; | |||
851 | } | |||
852 | } | |||
853 | ||||
854 | // Find NewBB's immediate dominator and create new dominator tree node for | |||
855 | // NewBB. | |||
856 | NodeT *NewBBIDom = nullptr; | |||
857 | unsigned i = 0; | |||
858 | for (i = 0; i < PredBlocks.size(); ++i) | |||
859 | if (isReachableFromEntry(PredBlocks[i])) { | |||
860 | NewBBIDom = PredBlocks[i]; | |||
861 | break; | |||
862 | } | |||
863 | ||||
864 | // It's possible that none of the predecessors of NewBB are reachable; | |||
865 | // in that case, NewBB itself is unreachable, so nothing needs to be | |||
866 | // changed. | |||
867 | if (!NewBBIDom) return; | |||
868 | ||||
869 | for (i = i + 1; i < PredBlocks.size(); ++i) { | |||
870 | if (isReachableFromEntry(PredBlocks[i])) | |||
871 | NewBBIDom = findNearestCommonDominator(NewBBIDom, PredBlocks[i]); | |||
872 | } | |||
873 | ||||
874 | // Create the new dominator tree node... and set the idom of NewBB. | |||
875 | DomTreeNodeBase<NodeT> *NewBBNode = addNewBlock(NewBB, NewBBIDom); | |||
876 | ||||
877 | // If NewBB strictly dominates other blocks, then it is now the immediate | |||
878 | // dominator of NewBBSucc. Update the dominator tree as appropriate. | |||
879 | if (NewBBDominatesNewBBSucc) { | |||
880 | DomTreeNodeBase<NodeT> *NewBBSuccNode = getNode(NewBBSucc); | |||
881 | changeImmediateDominator(NewBBSuccNode, NewBBNode); | |||
882 | } | |||
883 | } | |||
884 | ||||
885 | private: | |||
886 | bool dominatedBySlowTreeWalk(const DomTreeNodeBase<NodeT> *A, | |||
887 | const DomTreeNodeBase<NodeT> *B) const { | |||
888 | assert(A != B)((void)0); | |||
889 | assert(isReachableFromEntry(B))((void)0); | |||
890 | assert(isReachableFromEntry(A))((void)0); | |||
891 | ||||
892 | const unsigned ALevel = A->getLevel(); | |||
893 | const DomTreeNodeBase<NodeT> *IDom; | |||
894 | ||||
895 | // Don't walk nodes above A's subtree. When we reach A's level, we must | |||
896 | // either find A or be in some other subtree not dominated by A. | |||
897 | while ((IDom = B->getIDom()) != nullptr && IDom->getLevel() >= ALevel) | |||
898 | B = IDom; // Walk up the tree | |||
899 | ||||
900 | return B == A; | |||
901 | } | |||
902 | ||||
903 | /// Wipe this tree's state without releasing any resources. | |||
904 | /// | |||
905 | /// This is essentially a post-move helper only. It leaves the object in an | |||
906 | /// assignable and destroyable state, but otherwise invalid. | |||
907 | void wipe() { | |||
908 | DomTreeNodes.clear(); | |||
909 | RootNode = nullptr; | |||
910 | Parent = nullptr; | |||
911 | } | |||
912 | }; | |||
913 | ||||
914 | template <typename T> | |||
915 | using DomTreeBase = DominatorTreeBase<T, false>; | |||
916 | ||||
917 | template <typename T> | |||
918 | using PostDomTreeBase = DominatorTreeBase<T, true>; | |||
919 | ||||
920 | // These two functions are declared out of line as a workaround for building | |||
921 | // with old (< r147295) versions of clang because of pr11642. | |||
922 | template <typename NodeT, bool IsPostDom> | |||
923 | bool DominatorTreeBase<NodeT, IsPostDom>::dominates(const NodeT *A, | |||
924 | const NodeT *B) const { | |||
925 | if (A == B) | |||
926 | return true; | |||
927 | ||||
928 | // Cast away the const qualifiers here. This is ok since | |||
929 | // this function doesn't actually return the values returned | |||
930 | // from getNode. | |||
931 | return dominates(getNode(const_cast<NodeT *>(A)), | |||
932 | getNode(const_cast<NodeT *>(B))); | |||
933 | } | |||
934 | template <typename NodeT, bool IsPostDom> | |||
935 | bool DominatorTreeBase<NodeT, IsPostDom>::properlyDominates( | |||
936 | const NodeT *A, const NodeT *B) const { | |||
937 | if (A == B) | |||
938 | return false; | |||
939 | ||||
940 | // Cast away the const qualifiers here. This is ok since | |||
941 | // this function doesn't actually return the values returned | |||
942 | // from getNode. | |||
943 | return dominates(getNode(const_cast<NodeT *>(A)), | |||
944 | getNode(const_cast<NodeT *>(B))); | |||
945 | } | |||
946 | ||||
947 | } // end namespace llvm | |||
948 | ||||
949 | #endif // LLVM_SUPPORT_GENERICDOMTREE_H |
1 | //===- llvm/ADT/DenseMap.h - Dense probed hash table ------------*- C++ -*-===// |
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 file defines the DenseMap class. |
10 | // |
11 | //===----------------------------------------------------------------------===// |
12 | |
13 | #ifndef LLVM_ADT_DENSEMAP_H |
14 | #define LLVM_ADT_DENSEMAP_H |
15 | |
16 | #include "llvm/ADT/DenseMapInfo.h" |
17 | #include "llvm/ADT/EpochTracker.h" |
18 | #include "llvm/Support/AlignOf.h" |
19 | #include "llvm/Support/Compiler.h" |
20 | #include "llvm/Support/MathExtras.h" |
21 | #include "llvm/Support/MemAlloc.h" |
22 | #include "llvm/Support/ReverseIteration.h" |
23 | #include "llvm/Support/type_traits.h" |
24 | #include <algorithm> |
25 | #include <cassert> |
26 | #include <cstddef> |
27 | #include <cstring> |
28 | #include <initializer_list> |
29 | #include <iterator> |
30 | #include <new> |
31 | #include <type_traits> |
32 | #include <utility> |
33 | |
34 | namespace llvm { |
35 | |
36 | namespace detail { |
37 | |
38 | // We extend a pair to allow users to override the bucket type with their own |
39 | // implementation without requiring two members. |
40 | template <typename KeyT, typename ValueT> |
41 | struct DenseMapPair : public std::pair<KeyT, ValueT> { |
42 | using std::pair<KeyT, ValueT>::pair; |
43 | |
44 | KeyT &getFirst() { return std::pair<KeyT, ValueT>::first; } |
45 | const KeyT &getFirst() const { return std::pair<KeyT, ValueT>::first; } |
46 | ValueT &getSecond() { return std::pair<KeyT, ValueT>::second; } |
47 | const ValueT &getSecond() const { return std::pair<KeyT, ValueT>::second; } |
48 | }; |
49 | |
50 | } // end namespace detail |
51 | |
52 | template <typename KeyT, typename ValueT, |
53 | typename KeyInfoT = DenseMapInfo<KeyT>, |
54 | typename Bucket = llvm::detail::DenseMapPair<KeyT, ValueT>, |
55 | bool IsConst = false> |
56 | class DenseMapIterator; |
57 | |
58 | template <typename DerivedT, typename KeyT, typename ValueT, typename KeyInfoT, |
59 | typename BucketT> |
60 | class DenseMapBase : public DebugEpochBase { |
61 | template <typename T> |
62 | using const_arg_type_t = typename const_pointer_or_const_ref<T>::type; |
63 | |
64 | public: |
65 | using size_type = unsigned; |
66 | using key_type = KeyT; |
67 | using mapped_type = ValueT; |
68 | using value_type = BucketT; |
69 | |
70 | using iterator = DenseMapIterator<KeyT, ValueT, KeyInfoT, BucketT>; |
71 | using const_iterator = |
72 | DenseMapIterator<KeyT, ValueT, KeyInfoT, BucketT, true>; |
73 | |
74 | inline iterator begin() { |
75 | // When the map is empty, avoid the overhead of advancing/retreating past |
76 | // empty buckets. |
77 | if (empty()) |
78 | return end(); |
79 | if (shouldReverseIterate<KeyT>()) |
80 | return makeIterator(getBucketsEnd() - 1, getBuckets(), *this); |
81 | return makeIterator(getBuckets(), getBucketsEnd(), *this); |
82 | } |
83 | inline iterator end() { |
84 | return makeIterator(getBucketsEnd(), getBucketsEnd(), *this, true); |
85 | } |
86 | inline const_iterator begin() const { |
87 | if (empty()) |
88 | return end(); |
89 | if (shouldReverseIterate<KeyT>()) |
90 | return makeConstIterator(getBucketsEnd() - 1, getBuckets(), *this); |
91 | return makeConstIterator(getBuckets(), getBucketsEnd(), *this); |
92 | } |
93 | inline const_iterator end() const { |
94 | return makeConstIterator(getBucketsEnd(), getBucketsEnd(), *this, true); |
95 | } |
96 | |
97 | LLVM_NODISCARD[[clang::warn_unused_result]] bool empty() const { |
98 | return getNumEntries() == 0; |
99 | } |
100 | unsigned size() const { return getNumEntries(); } |
101 | |
102 | /// Grow the densemap so that it can contain at least \p NumEntries items |
103 | /// before resizing again. |
104 | void reserve(size_type NumEntries) { |
105 | auto NumBuckets = getMinBucketToReserveForEntries(NumEntries); |
106 | incrementEpoch(); |
107 | if (NumBuckets > getNumBuckets()) |
108 | grow(NumBuckets); |
109 | } |
110 | |
111 | void clear() { |
112 | incrementEpoch(); |
113 | if (getNumEntries() == 0 && getNumTombstones() == 0) return; |
114 | |
115 | // If the capacity of the array is huge, and the # elements used is small, |
116 | // shrink the array. |
117 | if (getNumEntries() * 4 < getNumBuckets() && getNumBuckets() > 64) { |
118 | shrink_and_clear(); |
119 | return; |
120 | } |
121 | |
122 | const KeyT EmptyKey = getEmptyKey(), TombstoneKey = getTombstoneKey(); |
123 | if (std::is_trivially_destructible<ValueT>::value) { |
124 | // Use a simpler loop when values don't need destruction. |
125 | for (BucketT *P = getBuckets(), *E = getBucketsEnd(); P != E; ++P) |
126 | P->getFirst() = EmptyKey; |
127 | } else { |
128 | unsigned NumEntries = getNumEntries(); |
129 | for (BucketT *P = getBuckets(), *E = getBucketsEnd(); P != E; ++P) { |
130 | if (!KeyInfoT::isEqual(P->getFirst(), EmptyKey)) { |
131 | if (!KeyInfoT::isEqual(P->getFirst(), TombstoneKey)) { |
132 | P->getSecond().~ValueT(); |
133 | --NumEntries; |
134 | } |
135 | P->getFirst() = EmptyKey; |
136 | } |
137 | } |
138 | assert(NumEntries == 0 && "Node count imbalance!")((void)0); |
139 | } |
140 | setNumEntries(0); |
141 | setNumTombstones(0); |
142 | } |
143 | |
144 | /// Return 1 if the specified key is in the map, 0 otherwise. |
145 | size_type count(const_arg_type_t<KeyT> Val) const { |
146 | const BucketT *TheBucket; |
147 | return LookupBucketFor(Val, TheBucket) ? 1 : 0; |
148 | } |
149 | |
150 | iterator find(const_arg_type_t<KeyT> Val) { |
151 | BucketT *TheBucket; |
152 | if (LookupBucketFor(Val, TheBucket)) |
153 | return makeIterator(TheBucket, |
154 | shouldReverseIterate<KeyT>() ? getBuckets() |
155 | : getBucketsEnd(), |
156 | *this, true); |
157 | return end(); |
158 | } |
159 | const_iterator find(const_arg_type_t<KeyT> Val) const { |
160 | const BucketT *TheBucket; |
161 | if (LookupBucketFor(Val, TheBucket)) |
162 | return makeConstIterator(TheBucket, |
163 | shouldReverseIterate<KeyT>() ? getBuckets() |
164 | : getBucketsEnd(), |
165 | *this, true); |
166 | return end(); |
167 | } |
168 | |
169 | /// Alternate version of find() which allows a different, and possibly |
170 | /// less expensive, key type. |
171 | /// The DenseMapInfo is responsible for supplying methods |
172 | /// getHashValue(LookupKeyT) and isEqual(LookupKeyT, KeyT) for each key |
173 | /// type used. |
174 | template<class LookupKeyT> |
175 | iterator find_as(const LookupKeyT &Val) { |
176 | BucketT *TheBucket; |
177 | if (LookupBucketFor(Val, TheBucket)) |
178 | return makeIterator(TheBucket, |
179 | shouldReverseIterate<KeyT>() ? getBuckets() |
180 | : getBucketsEnd(), |
181 | *this, true); |
182 | return end(); |
183 | } |
184 | template<class LookupKeyT> |
185 | const_iterator find_as(const LookupKeyT &Val) const { |
186 | const BucketT *TheBucket; |
187 | if (LookupBucketFor(Val, TheBucket)) |
188 | return makeConstIterator(TheBucket, |
189 | shouldReverseIterate<KeyT>() ? getBuckets() |
190 | : getBucketsEnd(), |
191 | *this, true); |
192 | return end(); |
193 | } |
194 | |
195 | /// lookup - Return the entry for the specified key, or a default |
196 | /// constructed value if no such entry exists. |
197 | ValueT lookup(const_arg_type_t<KeyT> Val) const { |
198 | const BucketT *TheBucket; |
199 | if (LookupBucketFor(Val, TheBucket)) |
200 | return TheBucket->getSecond(); |
201 | return ValueT(); |
202 | } |
203 | |
204 | // Inserts key,value pair into the map if the key isn't already in the map. |
205 | // If the key is already in the map, it returns false and doesn't update the |
206 | // value. |
207 | std::pair<iterator, bool> insert(const std::pair<KeyT, ValueT> &KV) { |
208 | return try_emplace(KV.first, KV.second); |
209 | } |
210 | |
211 | // Inserts key,value pair into the map if the key isn't already in the map. |
212 | // If the key is already in the map, it returns false and doesn't update the |
213 | // value. |
214 | std::pair<iterator, bool> insert(std::pair<KeyT, ValueT> &&KV) { |
215 | return try_emplace(std::move(KV.first), std::move(KV.second)); |
216 | } |
217 | |
218 | // Inserts key,value pair into the map if the key isn't already in the map. |
219 | // The value is constructed in-place if the key is not in the map, otherwise |
220 | // it is not moved. |
221 | template <typename... Ts> |
222 | std::pair<iterator, bool> try_emplace(KeyT &&Key, Ts &&... Args) { |
223 | BucketT *TheBucket; |
224 | if (LookupBucketFor(Key, TheBucket)) |
225 | return std::make_pair(makeIterator(TheBucket, |
226 | shouldReverseIterate<KeyT>() |
227 | ? getBuckets() |
228 | : getBucketsEnd(), |
229 | *this, true), |
230 | false); // Already in map. |
231 | |
232 | // Otherwise, insert the new element. |
233 | TheBucket = |
234 | InsertIntoBucket(TheBucket, std::move(Key), std::forward<Ts>(Args)...); |
235 | return std::make_pair(makeIterator(TheBucket, |
236 | shouldReverseIterate<KeyT>() |
237 | ? getBuckets() |
238 | : getBucketsEnd(), |
239 | *this, true), |
240 | true); |
241 | } |
242 | |
243 | // Inserts key,value pair into the map if the key isn't already in the map. |
244 | // The value is constructed in-place if the key is not in the map, otherwise |
245 | // it is not moved. |
246 | template <typename... Ts> |
247 | std::pair<iterator, bool> try_emplace(const KeyT &Key, Ts &&... Args) { |
248 | BucketT *TheBucket; |
249 | if (LookupBucketFor(Key, TheBucket)) |
250 | return std::make_pair(makeIterator(TheBucket, |
251 | shouldReverseIterate<KeyT>() |
252 | ? getBuckets() |
253 | : getBucketsEnd(), |
254 | *this, true), |
255 | false); // Already in map. |
256 | |
257 | // Otherwise, insert the new element. |
258 | TheBucket = InsertIntoBucket(TheBucket, Key, std::forward<Ts>(Args)...); |
259 | return std::make_pair(makeIterator(TheBucket, |
260 | shouldReverseIterate<KeyT>() |
261 | ? getBuckets() |
262 | : getBucketsEnd(), |
263 | *this, true), |
264 | true); |
265 | } |
266 | |
267 | /// Alternate version of insert() which allows a different, and possibly |
268 | /// less expensive, key type. |
269 | /// The DenseMapInfo is responsible for supplying methods |
270 | /// getHashValue(LookupKeyT) and isEqual(LookupKeyT, KeyT) for each key |
271 | /// type used. |
272 | template <typename LookupKeyT> |
273 | std::pair<iterator, bool> insert_as(std::pair<KeyT, ValueT> &&KV, |
274 | const LookupKeyT &Val) { |
275 | BucketT *TheBucket; |
276 | if (LookupBucketFor(Val, TheBucket)) |
277 | return std::make_pair(makeIterator(TheBucket, |
278 | shouldReverseIterate<KeyT>() |
279 | ? getBuckets() |
280 | : getBucketsEnd(), |
281 | *this, true), |
282 | false); // Already in map. |
283 | |
284 | // Otherwise, insert the new element. |
285 | TheBucket = InsertIntoBucketWithLookup(TheBucket, std::move(KV.first), |
286 | std::move(KV.second), Val); |
287 | return std::make_pair(makeIterator(TheBucket, |
288 | shouldReverseIterate<KeyT>() |
289 | ? getBuckets() |
290 | : getBucketsEnd(), |
291 | *this, true), |
292 | true); |
293 | } |
294 | |
295 | /// insert - Range insertion of pairs. |
296 | template<typename InputIt> |
297 | void insert(InputIt I, InputIt E) { |
298 | for (; I != E; ++I) |
299 | insert(*I); |
300 | } |
301 | |
302 | bool erase(const KeyT &Val) { |
303 | BucketT *TheBucket; |
304 | if (!LookupBucketFor(Val, TheBucket)) |
305 | return false; // not in map. |
306 | |
307 | TheBucket->getSecond().~ValueT(); |
308 | TheBucket->getFirst() = getTombstoneKey(); |
309 | decrementNumEntries(); |
310 | incrementNumTombstones(); |
311 | return true; |
312 | } |
313 | void erase(iterator I) { |
314 | BucketT *TheBucket = &*I; |
315 | TheBucket->getSecond().~ValueT(); |
316 | TheBucket->getFirst() = getTombstoneKey(); |
317 | decrementNumEntries(); |
318 | incrementNumTombstones(); |
319 | } |
320 | |
321 | value_type& FindAndConstruct(const KeyT &Key) { |
322 | BucketT *TheBucket; |
323 | if (LookupBucketFor(Key, TheBucket)) |
324 | return *TheBucket; |
325 | |
326 | return *InsertIntoBucket(TheBucket, Key); |
327 | } |
328 | |
329 | ValueT &operator[](const KeyT &Key) { |
330 | return FindAndConstruct(Key).second; |
331 | } |
332 | |
333 | value_type& FindAndConstruct(KeyT &&Key) { |
334 | BucketT *TheBucket; |
335 | if (LookupBucketFor(Key, TheBucket)) |
336 | return *TheBucket; |
337 | |
338 | return *InsertIntoBucket(TheBucket, std::move(Key)); |
339 | } |
340 | |
341 | ValueT &operator[](KeyT &&Key) { |
342 | return FindAndConstruct(std::move(Key)).second; |
343 | } |
344 | |
345 | /// isPointerIntoBucketsArray - Return true if the specified pointer points |
346 | /// somewhere into the DenseMap's array of buckets (i.e. either to a key or |
347 | /// value in the DenseMap). |
348 | bool isPointerIntoBucketsArray(const void *Ptr) const { |
349 | return Ptr >= getBuckets() && Ptr < getBucketsEnd(); |
350 | } |
351 | |
352 | /// getPointerIntoBucketsArray() - Return an opaque pointer into the buckets |
353 | /// array. In conjunction with the previous method, this can be used to |
354 | /// determine whether an insertion caused the DenseMap to reallocate. |
355 | const void *getPointerIntoBucketsArray() const { return getBuckets(); } |
356 | |
357 | protected: |
358 | DenseMapBase() = default; |
359 | |
360 | void destroyAll() { |
361 | if (getNumBuckets() == 0) // Nothing to do. |
362 | return; |
363 | |
364 | const KeyT EmptyKey = getEmptyKey(), TombstoneKey = getTombstoneKey(); |
365 | for (BucketT *P = getBuckets(), *E = getBucketsEnd(); P != E; ++P) { |
366 | if (!KeyInfoT::isEqual(P->getFirst(), EmptyKey) && |
367 | !KeyInfoT::isEqual(P->getFirst(), TombstoneKey)) |
368 | P->getSecond().~ValueT(); |
369 | P->getFirst().~KeyT(); |
370 | } |
371 | } |
372 | |
373 | void initEmpty() { |
374 | setNumEntries(0); |
375 | setNumTombstones(0); |
376 | |
377 | assert((getNumBuckets() & (getNumBuckets()-1)) == 0 &&((void)0) |
378 | "# initial buckets must be a power of two!")((void)0); |
379 | const KeyT EmptyKey = getEmptyKey(); |
380 | for (BucketT *B = getBuckets(), *E = getBucketsEnd(); B != E; ++B) |
381 | ::new (&B->getFirst()) KeyT(EmptyKey); |
382 | } |
383 | |
384 | /// Returns the number of buckets to allocate to ensure that the DenseMap can |
385 | /// accommodate \p NumEntries without need to grow(). |
386 | unsigned getMinBucketToReserveForEntries(unsigned NumEntries) { |
387 | // Ensure that "NumEntries * 4 < NumBuckets * 3" |
388 | if (NumEntries == 0) |
389 | return 0; |
390 | // +1 is required because of the strict equality. |
391 | // For example if NumEntries is 48, we need to return 401. |
392 | return NextPowerOf2(NumEntries * 4 / 3 + 1); |
393 | } |
394 | |
395 | void moveFromOldBuckets(BucketT *OldBucketsBegin, BucketT *OldBucketsEnd) { |
396 | initEmpty(); |
397 | |
398 | // Insert all the old elements. |
399 | const KeyT EmptyKey = getEmptyKey(); |
400 | const KeyT TombstoneKey = getTombstoneKey(); |
401 | for (BucketT *B = OldBucketsBegin, *E = OldBucketsEnd; B != E; ++B) { |
402 | if (!KeyInfoT::isEqual(B->getFirst(), EmptyKey) && |
403 | !KeyInfoT::isEqual(B->getFirst(), TombstoneKey)) { |
404 | // Insert the key/value into the new table. |
405 | BucketT *DestBucket; |
406 | bool FoundVal = LookupBucketFor(B->getFirst(), DestBucket); |
407 | (void)FoundVal; // silence warning. |
408 | assert(!FoundVal && "Key already in new map?")((void)0); |
409 | DestBucket->getFirst() = std::move(B->getFirst()); |
410 | ::new (&DestBucket->getSecond()) ValueT(std::move(B->getSecond())); |
411 | incrementNumEntries(); |
412 | |
413 | // Free the value. |
414 | B->getSecond().~ValueT(); |
415 | } |
416 | B->getFirst().~KeyT(); |
417 | } |
418 | } |
419 | |
420 | template <typename OtherBaseT> |
421 | void copyFrom( |
422 | const DenseMapBase<OtherBaseT, KeyT, ValueT, KeyInfoT, BucketT> &other) { |
423 | assert(&other != this)((void)0); |
424 | assert(getNumBuckets() == other.getNumBuckets())((void)0); |
425 | |
426 | setNumEntries(other.getNumEntries()); |
427 | setNumTombstones(other.getNumTombstones()); |
428 | |
429 | if (std::is_trivially_copyable<KeyT>::value && |
430 | std::is_trivially_copyable<ValueT>::value) |
431 | memcpy(reinterpret_cast<void *>(getBuckets()), other.getBuckets(), |
432 | getNumBuckets() * sizeof(BucketT)); |
433 | else |
434 | for (size_t i = 0; i < getNumBuckets(); ++i) { |
435 | ::new (&getBuckets()[i].getFirst()) |
436 | KeyT(other.getBuckets()[i].getFirst()); |
437 | if (!KeyInfoT::isEqual(getBuckets()[i].getFirst(), getEmptyKey()) && |
438 | !KeyInfoT::isEqual(getBuckets()[i].getFirst(), getTombstoneKey())) |
439 | ::new (&getBuckets()[i].getSecond()) |
440 | ValueT(other.getBuckets()[i].getSecond()); |
441 | } |
442 | } |
443 | |
444 | static unsigned getHashValue(const KeyT &Val) { |
445 | return KeyInfoT::getHashValue(Val); |
446 | } |
447 | |
448 | template<typename LookupKeyT> |
449 | static unsigned getHashValue(const LookupKeyT &Val) { |
450 | return KeyInfoT::getHashValue(Val); |
451 | } |
452 | |
453 | static const KeyT getEmptyKey() { |
454 | static_assert(std::is_base_of<DenseMapBase, DerivedT>::value, |
455 | "Must pass the derived type to this template!"); |
456 | return KeyInfoT::getEmptyKey(); |
457 | } |
458 | |
459 | static const KeyT getTombstoneKey() { |
460 | return KeyInfoT::getTombstoneKey(); |
461 | } |
462 | |
463 | private: |
464 | iterator makeIterator(BucketT *P, BucketT *E, |
465 | DebugEpochBase &Epoch, |
466 | bool NoAdvance=false) { |
467 | if (shouldReverseIterate<KeyT>()) { |
468 | BucketT *B = P == getBucketsEnd() ? getBuckets() : P + 1; |
469 | return iterator(B, E, Epoch, NoAdvance); |
470 | } |
471 | return iterator(P, E, Epoch, NoAdvance); |
472 | } |
473 | |
474 | const_iterator makeConstIterator(const BucketT *P, const BucketT *E, |
475 | const DebugEpochBase &Epoch, |
476 | const bool NoAdvance=false) const { |
477 | if (shouldReverseIterate<KeyT>()) { |
478 | const BucketT *B = P == getBucketsEnd() ? getBuckets() : P + 1; |
479 | return const_iterator(B, E, Epoch, NoAdvance); |
480 | } |
481 | return const_iterator(P, E, Epoch, NoAdvance); |
482 | } |
483 | |
484 | unsigned getNumEntries() const { |
485 | return static_cast<const DerivedT *>(this)->getNumEntries(); |
486 | } |
487 | |
488 | void setNumEntries(unsigned Num) { |
489 | static_cast<DerivedT *>(this)->setNumEntries(Num); |
490 | } |
491 | |
492 | void incrementNumEntries() { |
493 | setNumEntries(getNumEntries() + 1); |
494 | } |
495 | |
496 | void decrementNumEntries() { |
497 | setNumEntries(getNumEntries() - 1); |
498 | } |
499 | |
500 | unsigned getNumTombstones() const { |
501 | return static_cast<const DerivedT *>(this)->getNumTombstones(); |
502 | } |
503 | |
504 | void setNumTombstones(unsigned Num) { |
505 | static_cast<DerivedT *>(this)->setNumTombstones(Num); |
506 | } |
507 | |
508 | void incrementNumTombstones() { |
509 | setNumTombstones(getNumTombstones() + 1); |
510 | } |
511 | |
512 | void decrementNumTombstones() { |
513 | setNumTombstones(getNumTombstones() - 1); |
514 | } |
515 | |
516 | const BucketT *getBuckets() const { |
517 | return static_cast<const DerivedT *>(this)->getBuckets(); |
518 | } |
519 | |
520 | BucketT *getBuckets() { |
521 | return static_cast<DerivedT *>(this)->getBuckets(); |
522 | } |
523 | |
524 | unsigned getNumBuckets() const { |
525 | return static_cast<const DerivedT *>(this)->getNumBuckets(); |
526 | } |
527 | |
528 | BucketT *getBucketsEnd() { |
529 | return getBuckets() + getNumBuckets(); |
530 | } |
531 | |
532 | const BucketT *getBucketsEnd() const { |
533 | return getBuckets() + getNumBuckets(); |
534 | } |
535 | |
536 | void grow(unsigned AtLeast) { |
537 | static_cast<DerivedT *>(this)->grow(AtLeast); |
538 | } |
539 | |
540 | void shrink_and_clear() { |
541 | static_cast<DerivedT *>(this)->shrink_and_clear(); |
542 | } |
543 | |
544 | template <typename KeyArg, typename... ValueArgs> |
545 | BucketT *InsertIntoBucket(BucketT *TheBucket, KeyArg &&Key, |
546 | ValueArgs &&... Values) { |
547 | TheBucket = InsertIntoBucketImpl(Key, Key, TheBucket); |
548 | |
549 | TheBucket->getFirst() = std::forward<KeyArg>(Key); |
550 | ::new (&TheBucket->getSecond()) ValueT(std::forward<ValueArgs>(Values)...); |
551 | return TheBucket; |
552 | } |
553 | |
554 | template <typename LookupKeyT> |
555 | BucketT *InsertIntoBucketWithLookup(BucketT *TheBucket, KeyT &&Key, |
556 | ValueT &&Value, LookupKeyT &Lookup) { |
557 | TheBucket = InsertIntoBucketImpl(Key, Lookup, TheBucket); |
558 | |
559 | TheBucket->getFirst() = std::move(Key); |
560 | ::new (&TheBucket->getSecond()) ValueT(std::move(Value)); |
561 | return TheBucket; |
562 | } |
563 | |
564 | template <typename LookupKeyT> |
565 | BucketT *InsertIntoBucketImpl(const KeyT &Key, const LookupKeyT &Lookup, |
566 | BucketT *TheBucket) { |
567 | incrementEpoch(); |
568 | |
569 | // If the load of the hash table is more than 3/4, or if fewer than 1/8 of |
570 | // the buckets are empty (meaning that many are filled with tombstones), |
571 | // grow the table. |
572 | // |
573 | // The later case is tricky. For example, if we had one empty bucket with |
574 | // tons of tombstones, failing lookups (e.g. for insertion) would have to |
575 | // probe almost the entire table until it found the empty bucket. If the |
576 | // table completely filled with tombstones, no lookup would ever succeed, |
577 | // causing infinite loops in lookup. |
578 | unsigned NewNumEntries = getNumEntries() + 1; |
579 | unsigned NumBuckets = getNumBuckets(); |
580 | if (LLVM_UNLIKELY(NewNumEntries * 4 >= NumBuckets * 3)__builtin_expect((bool)(NewNumEntries * 4 >= NumBuckets * 3 ), false)) { |
581 | this->grow(NumBuckets * 2); |
582 | LookupBucketFor(Lookup, TheBucket); |
583 | NumBuckets = getNumBuckets(); |
584 | } else if (LLVM_UNLIKELY(NumBuckets-(NewNumEntries+getNumTombstones()) <=__builtin_expect((bool)(NumBuckets-(NewNumEntries+getNumTombstones ()) <= NumBuckets/8), false) |
585 | NumBuckets/8)__builtin_expect((bool)(NumBuckets-(NewNumEntries+getNumTombstones ()) <= NumBuckets/8), false)) { |
586 | this->grow(NumBuckets); |
587 | LookupBucketFor(Lookup, TheBucket); |
588 | } |
589 | assert(TheBucket)((void)0); |
590 | |
591 | // Only update the state after we've grown our bucket space appropriately |
592 | // so that when growing buckets we have self-consistent entry count. |
593 | incrementNumEntries(); |
594 | |
595 | // If we are writing over a tombstone, remember this. |
596 | const KeyT EmptyKey = getEmptyKey(); |
597 | if (!KeyInfoT::isEqual(TheBucket->getFirst(), EmptyKey)) |
598 | decrementNumTombstones(); |
599 | |
600 | return TheBucket; |
601 | } |
602 | |
603 | /// LookupBucketFor - Lookup the appropriate bucket for Val, returning it in |
604 | /// FoundBucket. If the bucket contains the key and a value, this returns |
605 | /// true, otherwise it returns a bucket with an empty marker or tombstone and |
606 | /// returns false. |
607 | template<typename LookupKeyT> |
608 | bool LookupBucketFor(const LookupKeyT &Val, |
609 | const BucketT *&FoundBucket) const { |
610 | const BucketT *BucketsPtr = getBuckets(); |
611 | const unsigned NumBuckets = getNumBuckets(); |
612 | |
613 | if (NumBuckets == 0) { |
614 | FoundBucket = nullptr; |
615 | return false; |
616 | } |
617 | |
618 | // FoundTombstone - Keep track of whether we find a tombstone while probing. |
619 | const BucketT *FoundTombstone = nullptr; |
620 | const KeyT EmptyKey = getEmptyKey(); |
621 | const KeyT TombstoneKey = getTombstoneKey(); |
622 | assert(!KeyInfoT::isEqual(Val, EmptyKey) &&((void)0) |
623 | !KeyInfoT::isEqual(Val, TombstoneKey) &&((void)0) |
624 | "Empty/Tombstone value shouldn't be inserted into map!")((void)0); |
625 | |
626 | unsigned BucketNo = getHashValue(Val) & (NumBuckets-1); |
627 | unsigned ProbeAmt = 1; |
628 | while (true) { |
629 | const BucketT *ThisBucket = BucketsPtr + BucketNo; |
630 | // Found Val's bucket? If so, return it. |
631 | if (LLVM_LIKELY(KeyInfoT::isEqual(Val, ThisBucket->getFirst()))__builtin_expect((bool)(KeyInfoT::isEqual(Val, ThisBucket-> getFirst())), true)) { |
632 | FoundBucket = ThisBucket; |
633 | return true; |
634 | } |
635 | |
636 | // If we found an empty bucket, the key doesn't exist in the set. |
637 | // Insert it and return the default value. |
638 | if (LLVM_LIKELY(KeyInfoT::isEqual(ThisBucket->getFirst(), EmptyKey))__builtin_expect((bool)(KeyInfoT::isEqual(ThisBucket->getFirst (), EmptyKey)), true)) { |
639 | // If we've already seen a tombstone while probing, fill it in instead |
640 | // of the empty bucket we eventually probed to. |
641 | FoundBucket = FoundTombstone ? FoundTombstone : ThisBucket; |
642 | return false; |
643 | } |
644 | |
645 | // If this is a tombstone, remember it. If Val ends up not in the map, we |
646 | // prefer to return it than something that would require more probing. |
647 | if (KeyInfoT::isEqual(ThisBucket->getFirst(), TombstoneKey) && |
648 | !FoundTombstone) |
649 | FoundTombstone = ThisBucket; // Remember the first tombstone found. |
650 | |
651 | // Otherwise, it's a hash collision or a tombstone, continue quadratic |
652 | // probing. |
653 | BucketNo += ProbeAmt++; |
654 | BucketNo &= (NumBuckets-1); |
655 | } |
656 | } |
657 | |
658 | template <typename LookupKeyT> |
659 | bool LookupBucketFor(const LookupKeyT &Val, BucketT *&FoundBucket) { |
660 | const BucketT *ConstFoundBucket; |
661 | bool Result = const_cast<const DenseMapBase *>(this) |
662 | ->LookupBucketFor(Val, ConstFoundBucket); |
663 | FoundBucket = const_cast<BucketT *>(ConstFoundBucket); |
664 | return Result; |
665 | } |
666 | |
667 | public: |
668 | /// Return the approximate size (in bytes) of the actual map. |
669 | /// This is just the raw memory used by DenseMap. |
670 | /// If entries are pointers to objects, the size of the referenced objects |
671 | /// are not included. |
672 | size_t getMemorySize() const { |
673 | return getNumBuckets() * sizeof(BucketT); |
674 | } |
675 | }; |
676 | |
677 | /// Equality comparison for DenseMap. |
678 | /// |
679 | /// Iterates over elements of LHS confirming that each (key, value) pair in LHS |
680 | /// is also in RHS, and that no additional pairs are in RHS. |
681 | /// Equivalent to N calls to RHS.find and N value comparisons. Amortized |
682 | /// complexity is linear, worst case is O(N^2) (if every hash collides). |
683 | template <typename DerivedT, typename KeyT, typename ValueT, typename KeyInfoT, |
684 | typename BucketT> |
685 | bool operator==( |
686 | const DenseMapBase<DerivedT, KeyT, ValueT, KeyInfoT, BucketT> &LHS, |
687 | const DenseMapBase<DerivedT, KeyT, ValueT, KeyInfoT, BucketT> &RHS) { |
688 | if (LHS.size() != RHS.size()) |
689 | return false; |
690 | |
691 | for (auto &KV : LHS) { |
692 | auto I = RHS.find(KV.first); |
693 | if (I == RHS.end() || I->second != KV.second) |
694 | return false; |
695 | } |
696 | |
697 | return true; |
698 | } |
699 | |
700 | /// Inequality comparison for DenseMap. |
701 | /// |
702 | /// Equivalent to !(LHS == RHS). See operator== for performance notes. |
703 | template <typename DerivedT, typename KeyT, typename ValueT, typename KeyInfoT, |
704 | typename BucketT> |
705 | bool operator!=( |
706 | const DenseMapBase<DerivedT, KeyT, ValueT, KeyInfoT, BucketT> &LHS, |
707 | const DenseMapBase<DerivedT, KeyT, ValueT, KeyInfoT, BucketT> &RHS) { |
708 | return !(LHS == RHS); |
709 | } |
710 | |
711 | template <typename KeyT, typename ValueT, |
712 | typename KeyInfoT = DenseMapInfo<KeyT>, |
713 | typename BucketT = llvm::detail::DenseMapPair<KeyT, ValueT>> |
714 | class DenseMap : public DenseMapBase<DenseMap<KeyT, ValueT, KeyInfoT, BucketT>, |
715 | KeyT, ValueT, KeyInfoT, BucketT> { |
716 | friend class DenseMapBase<DenseMap, KeyT, ValueT, KeyInfoT, BucketT>; |
717 | |
718 | // Lift some types from the dependent base class into this class for |
719 | // simplicity of referring to them. |
720 | using BaseT = DenseMapBase<DenseMap, KeyT, ValueT, KeyInfoT, BucketT>; |
721 | |
722 | BucketT *Buckets; |
723 | unsigned NumEntries; |
724 | unsigned NumTombstones; |
725 | unsigned NumBuckets; |
726 | |
727 | public: |
728 | /// Create a DenseMap with an optional \p InitialReserve that guarantee that |
729 | /// this number of elements can be inserted in the map without grow() |
730 | explicit DenseMap(unsigned InitialReserve = 0) { init(InitialReserve); } |
731 | |
732 | DenseMap(const DenseMap &other) : BaseT() { |
733 | init(0); |
734 | copyFrom(other); |
735 | } |
736 | |
737 | DenseMap(DenseMap &&other) : BaseT() { |
738 | init(0); |
739 | swap(other); |
740 | } |
741 | |
742 | template<typename InputIt> |
743 | DenseMap(const InputIt &I, const InputIt &E) { |
744 | init(std::distance(I, E)); |
745 | this->insert(I, E); |
746 | } |
747 | |
748 | DenseMap(std::initializer_list<typename BaseT::value_type> Vals) { |
749 | init(Vals.size()); |
750 | this->insert(Vals.begin(), Vals.end()); |
751 | } |
752 | |
753 | ~DenseMap() { |
754 | this->destroyAll(); |
755 | deallocate_buffer(Buckets, sizeof(BucketT) * NumBuckets, alignof(BucketT)); |
756 | } |
757 | |
758 | void swap(DenseMap& RHS) { |
759 | this->incrementEpoch(); |
760 | RHS.incrementEpoch(); |
761 | std::swap(Buckets, RHS.Buckets); |
762 | std::swap(NumEntries, RHS.NumEntries); |
763 | std::swap(NumTombstones, RHS.NumTombstones); |
764 | std::swap(NumBuckets, RHS.NumBuckets); |
765 | } |
766 | |
767 | DenseMap& operator=(const DenseMap& other) { |
768 | if (&other != this) |
769 | copyFrom(other); |
770 | return *this; |
771 | } |
772 | |
773 | DenseMap& operator=(DenseMap &&other) { |
774 | this->destroyAll(); |
775 | deallocate_buffer(Buckets, sizeof(BucketT) * NumBuckets, alignof(BucketT)); |
776 | init(0); |
777 | swap(other); |
778 | return *this; |
779 | } |
780 | |
781 | void copyFrom(const DenseMap& other) { |
782 | this->destroyAll(); |
783 | deallocate_buffer(Buckets, sizeof(BucketT) * NumBuckets, alignof(BucketT)); |
784 | if (allocateBuckets(other.NumBuckets)) { |
785 | this->BaseT::copyFrom(other); |
786 | } else { |
787 | NumEntries = 0; |
788 | NumTombstones = 0; |
789 | } |
790 | } |
791 | |
792 | void init(unsigned InitNumEntries) { |
793 | auto InitBuckets = BaseT::getMinBucketToReserveForEntries(InitNumEntries); |
794 | if (allocateBuckets(InitBuckets)) { |
795 | this->BaseT::initEmpty(); |
796 | } else { |
797 | NumEntries = 0; |
798 | NumTombstones = 0; |
799 | } |
800 | } |
801 | |
802 | void grow(unsigned AtLeast) { |
803 | unsigned OldNumBuckets = NumBuckets; |
804 | BucketT *OldBuckets = Buckets; |
805 | |
806 | allocateBuckets(std::max<unsigned>(64, static_cast<unsigned>(NextPowerOf2(AtLeast-1)))); |
807 | assert(Buckets)((void)0); |
808 | if (!OldBuckets) { |
809 | this->BaseT::initEmpty(); |
810 | return; |
811 | } |
812 | |
813 | this->moveFromOldBuckets(OldBuckets, OldBuckets+OldNumBuckets); |
814 | |
815 | // Free the old table. |
816 | deallocate_buffer(OldBuckets, sizeof(BucketT) * OldNumBuckets, |
817 | alignof(BucketT)); |
818 | } |
819 | |
820 | void shrink_and_clear() { |
821 | unsigned OldNumBuckets = NumBuckets; |
822 | unsigned OldNumEntries = NumEntries; |
823 | this->destroyAll(); |
824 | |
825 | // Reduce the number of buckets. |
826 | unsigned NewNumBuckets = 0; |
827 | if (OldNumEntries) |
828 | NewNumBuckets = std::max(64, 1 << (Log2_32_Ceil(OldNumEntries) + 1)); |
829 | if (NewNumBuckets == NumBuckets) { |
830 | this->BaseT::initEmpty(); |
831 | return; |
832 | } |
833 | |
834 | deallocate_buffer(Buckets, sizeof(BucketT) * OldNumBuckets, |
835 | alignof(BucketT)); |
836 | init(NewNumBuckets); |
837 | } |
838 | |
839 | private: |
840 | unsigned getNumEntries() const { |
841 | return NumEntries; |
842 | } |
843 | |
844 | void setNumEntries(unsigned Num) { |
845 | NumEntries = Num; |
846 | } |
847 | |
848 | unsigned getNumTombstones() const { |
849 | return NumTombstones; |
850 | } |
851 | |
852 | void setNumTombstones(unsigned Num) { |
853 | NumTombstones = Num; |
854 | } |
855 | |
856 | BucketT *getBuckets() const { |
857 | return Buckets; |
858 | } |
859 | |
860 | unsigned getNumBuckets() const { |
861 | return NumBuckets; |
862 | } |
863 | |
864 | bool allocateBuckets(unsigned Num) { |
865 | NumBuckets = Num; |
866 | if (NumBuckets == 0) { |
867 | Buckets = nullptr; |
868 | return false; |
869 | } |
870 | |
871 | Buckets = static_cast<BucketT *>( |
872 | allocate_buffer(sizeof(BucketT) * NumBuckets, alignof(BucketT))); |
873 | return true; |
874 | } |
875 | }; |
876 | |
877 | template <typename KeyT, typename ValueT, unsigned InlineBuckets = 4, |
878 | typename KeyInfoT = DenseMapInfo<KeyT>, |
879 | typename BucketT = llvm::detail::DenseMapPair<KeyT, ValueT>> |
880 | class SmallDenseMap |
881 | : public DenseMapBase< |
882 | SmallDenseMap<KeyT, ValueT, InlineBuckets, KeyInfoT, BucketT>, KeyT, |
883 | ValueT, KeyInfoT, BucketT> { |
884 | friend class DenseMapBase<SmallDenseMap, KeyT, ValueT, KeyInfoT, BucketT>; |
885 | |
886 | // Lift some types from the dependent base class into this class for |
887 | // simplicity of referring to them. |
888 | using BaseT = DenseMapBase<SmallDenseMap, KeyT, ValueT, KeyInfoT, BucketT>; |
889 | |
890 | static_assert(isPowerOf2_64(InlineBuckets), |
891 | "InlineBuckets must be a power of 2."); |
892 | |
893 | unsigned Small : 1; |
894 | unsigned NumEntries : 31; |
895 | unsigned NumTombstones; |
896 | |
897 | struct LargeRep { |
898 | BucketT *Buckets; |
899 | unsigned NumBuckets; |
900 | }; |
901 | |
902 | /// A "union" of an inline bucket array and the struct representing |
903 | /// a large bucket. This union will be discriminated by the 'Small' bit. |
904 | AlignedCharArrayUnion<BucketT[InlineBuckets], LargeRep> storage; |
905 | |
906 | public: |
907 | explicit SmallDenseMap(unsigned NumInitBuckets = 0) { |
908 | init(NumInitBuckets); |
909 | } |
910 | |
911 | SmallDenseMap(const SmallDenseMap &other) : BaseT() { |
912 | init(0); |
913 | copyFrom(other); |
914 | } |
915 | |
916 | SmallDenseMap(SmallDenseMap &&other) : BaseT() { |
917 | init(0); |
918 | swap(other); |
919 | } |
920 | |
921 | template<typename InputIt> |
922 | SmallDenseMap(const InputIt &I, const InputIt &E) { |
923 | init(NextPowerOf2(std::distance(I, E))); |
924 | this->insert(I, E); |
925 | } |
926 | |
927 | SmallDenseMap(std::initializer_list<typename BaseT::value_type> Vals) |
928 | : SmallDenseMap(Vals.begin(), Vals.end()) {} |
929 | |
930 | ~SmallDenseMap() { |
931 | this->destroyAll(); |
932 | deallocateBuckets(); |
933 | } |
934 | |
935 | void swap(SmallDenseMap& RHS) { |
936 | unsigned TmpNumEntries = RHS.NumEntries; |
937 | RHS.NumEntries = NumEntries; |
938 | NumEntries = TmpNumEntries; |
939 | std::swap(NumTombstones, RHS.NumTombstones); |
940 | |
941 | const KeyT EmptyKey = this->getEmptyKey(); |
942 | const KeyT TombstoneKey = this->getTombstoneKey(); |
943 | if (Small && RHS.Small) { |
944 | // If we're swapping inline bucket arrays, we have to cope with some of |
945 | // the tricky bits of DenseMap's storage system: the buckets are not |
946 | // fully initialized. Thus we swap every key, but we may have |
947 | // a one-directional move of the value. |
948 | for (unsigned i = 0, e = InlineBuckets; i != e; ++i) { |
949 | BucketT *LHSB = &getInlineBuckets()[i], |
950 | *RHSB = &RHS.getInlineBuckets()[i]; |
951 | bool hasLHSValue = (!KeyInfoT::isEqual(LHSB->getFirst(), EmptyKey) && |
952 | !KeyInfoT::isEqual(LHSB->getFirst(), TombstoneKey)); |
953 | bool hasRHSValue = (!KeyInfoT::isEqual(RHSB->getFirst(), EmptyKey) && |
954 | !KeyInfoT::isEqual(RHSB->getFirst(), TombstoneKey)); |
955 | if (hasLHSValue && hasRHSValue) { |
956 | // Swap together if we can... |
957 | std::swap(*LHSB, *RHSB); |
958 | continue; |
959 | } |
960 | // Swap separately and handle any asymmetry. |
961 | std::swap(LHSB->getFirst(), RHSB->getFirst()); |
962 | if (hasLHSValue) { |
963 | ::new (&RHSB->getSecond()) ValueT(std::move(LHSB->getSecond())); |
964 | LHSB->getSecond().~ValueT(); |
965 | } else if (hasRHSValue) { |
966 | ::new (&LHSB->getSecond()) ValueT(std::move(RHSB->getSecond())); |
967 | RHSB->getSecond().~ValueT(); |
968 | } |
969 | } |
970 | return; |
971 | } |
972 | if (!Small && !RHS.Small) { |
973 | std::swap(getLargeRep()->Buckets, RHS.getLargeRep()->Buckets); |
974 | std::swap(getLargeRep()->NumBuckets, RHS.getLargeRep()->NumBuckets); |
975 | return; |
976 | } |
977 | |
978 | SmallDenseMap &SmallSide = Small ? *this : RHS; |
979 | SmallDenseMap &LargeSide = Small ? RHS : *this; |
980 | |
981 | // First stash the large side's rep and move the small side across. |
982 | LargeRep TmpRep = std::move(*LargeSide.getLargeRep()); |
983 | LargeSide.getLargeRep()->~LargeRep(); |
984 | LargeSide.Small = true; |
985 | // This is similar to the standard move-from-old-buckets, but the bucket |
986 | // count hasn't actually rotated in this case. So we have to carefully |
987 | // move construct the keys and values into their new locations, but there |
988 | // is no need to re-hash things. |
989 | for (unsigned i = 0, e = InlineBuckets; i != e; ++i) { |
990 | BucketT *NewB = &LargeSide.getInlineBuckets()[i], |
991 | *OldB = &SmallSide.getInlineBuckets()[i]; |
992 | ::new (&NewB->getFirst()) KeyT(std::move(OldB->getFirst())); |
993 | OldB->getFirst().~KeyT(); |
994 | if (!KeyInfoT::isEqual(NewB->getFirst(), EmptyKey) && |
995 | !KeyInfoT::isEqual(NewB->getFirst(), TombstoneKey)) { |
996 | ::new (&NewB->getSecond()) ValueT(std::move(OldB->getSecond())); |
997 | OldB->getSecond().~ValueT(); |
998 | } |
999 | } |
1000 | |
1001 | // The hard part of moving the small buckets across is done, just move |
1002 | // the TmpRep into its new home. |
1003 | SmallSide.Small = false; |
1004 | new (SmallSide.getLargeRep()) LargeRep(std::move(TmpRep)); |
1005 | } |
1006 | |
1007 | SmallDenseMap& operator=(const SmallDenseMap& other) { |
1008 | if (&other != this) |
1009 | copyFrom(other); |
1010 | return *this; |
1011 | } |
1012 | |
1013 | SmallDenseMap& operator=(SmallDenseMap &&other) { |
1014 | this->destroyAll(); |
1015 | deallocateBuckets(); |
1016 | init(0); |
1017 | swap(other); |
1018 | return *this; |
1019 | } |
1020 | |
1021 | void copyFrom(const SmallDenseMap& other) { |
1022 | this->destroyAll(); |
1023 | deallocateBuckets(); |
1024 | Small = true; |
1025 | if (other.getNumBuckets() > InlineBuckets) { |
1026 | Small = false; |
1027 | new (getLargeRep()) LargeRep(allocateBuckets(other.getNumBuckets())); |
1028 | } |
1029 | this->BaseT::copyFrom(other); |
1030 | } |
1031 | |
1032 | void init(unsigned InitBuckets) { |
1033 | Small = true; |
1034 | if (InitBuckets > InlineBuckets) { |
1035 | Small = false; |
1036 | new (getLargeRep()) LargeRep(allocateBuckets(InitBuckets)); |
1037 | } |
1038 | this->BaseT::initEmpty(); |
1039 | } |
1040 | |
1041 | void grow(unsigned AtLeast) { |
1042 | if (AtLeast > InlineBuckets) |
1043 | AtLeast = std::max<unsigned>(64, NextPowerOf2(AtLeast-1)); |
1044 | |
1045 | if (Small) { |
1046 | // First move the inline buckets into a temporary storage. |
1047 | AlignedCharArrayUnion<BucketT[InlineBuckets]> TmpStorage; |
1048 | BucketT *TmpBegin = reinterpret_cast<BucketT *>(&TmpStorage); |
1049 | BucketT *TmpEnd = TmpBegin; |
1050 | |
1051 | // Loop over the buckets, moving non-empty, non-tombstones into the |
1052 | // temporary storage. Have the loop move the TmpEnd forward as it goes. |
1053 | const KeyT EmptyKey = this->getEmptyKey(); |
1054 | const KeyT TombstoneKey = this->getTombstoneKey(); |
1055 | for (BucketT *P = getBuckets(), *E = P + InlineBuckets; P != E; ++P) { |
1056 | if (!KeyInfoT::isEqual(P->getFirst(), EmptyKey) && |
1057 | !KeyInfoT::isEqual(P->getFirst(), TombstoneKey)) { |
1058 | assert(size_t(TmpEnd - TmpBegin) < InlineBuckets &&((void)0) |
1059 | "Too many inline buckets!")((void)0); |
1060 | ::new (&TmpEnd->getFirst()) KeyT(std::move(P->getFirst())); |
1061 | ::new (&TmpEnd->getSecond()) ValueT(std::move(P->getSecond())); |
1062 | ++TmpEnd; |
1063 | P->getSecond().~ValueT(); |
1064 | } |
1065 | P->getFirst().~KeyT(); |
1066 | } |
1067 | |
1068 | // AtLeast == InlineBuckets can happen if there are many tombstones, |
1069 | // and grow() is used to remove them. Usually we always switch to the |
1070 | // large rep here. |
1071 | if (AtLeast > InlineBuckets) { |
1072 | Small = false; |
1073 | new (getLargeRep()) LargeRep(allocateBuckets(AtLeast)); |
1074 | } |
1075 | this->moveFromOldBuckets(TmpBegin, TmpEnd); |
1076 | return; |
1077 | } |
1078 | |
1079 | LargeRep OldRep = std::move(*getLargeRep()); |
1080 | getLargeRep()->~LargeRep(); |
1081 | if (AtLeast <= InlineBuckets) { |
1082 | Small = true; |
1083 | } else { |
1084 | new (getLargeRep()) LargeRep(allocateBuckets(AtLeast)); |
1085 | } |
1086 | |
1087 | this->moveFromOldBuckets(OldRep.Buckets, OldRep.Buckets+OldRep.NumBuckets); |
1088 | |
1089 | // Free the old table. |
1090 | deallocate_buffer(OldRep.Buckets, sizeof(BucketT) * OldRep.NumBuckets, |
1091 | alignof(BucketT)); |
1092 | } |
1093 | |
1094 | void shrink_and_clear() { |
1095 | unsigned OldSize = this->size(); |
1096 | this->destroyAll(); |
1097 | |
1098 | // Reduce the number of buckets. |
1099 | unsigned NewNumBuckets = 0; |
1100 | if (OldSize) { |
1101 | NewNumBuckets = 1 << (Log2_32_Ceil(OldSize) + 1); |
1102 | if (NewNumBuckets > InlineBuckets && NewNumBuckets < 64u) |
1103 | NewNumBuckets = 64; |
1104 | } |
1105 | if ((Small && NewNumBuckets <= InlineBuckets) || |
1106 | (!Small && NewNumBuckets == getLargeRep()->NumBuckets)) { |
1107 | this->BaseT::initEmpty(); |
1108 | return; |
1109 | } |
1110 | |
1111 | deallocateBuckets(); |
1112 | init(NewNumBuckets); |
1113 | } |
1114 | |
1115 | private: |
1116 | unsigned getNumEntries() const { |
1117 | return NumEntries; |
1118 | } |
1119 | |
1120 | void setNumEntries(unsigned Num) { |
1121 | // NumEntries is hardcoded to be 31 bits wide. |
1122 | assert(Num < (1U << 31) && "Cannot support more than 1<<31 entries")((void)0); |
1123 | NumEntries = Num; |
1124 | } |
1125 | |
1126 | unsigned getNumTombstones() const { |
1127 | return NumTombstones; |
1128 | } |
1129 | |
1130 | void setNumTombstones(unsigned Num) { |
1131 | NumTombstones = Num; |
1132 | } |
1133 | |
1134 | const BucketT *getInlineBuckets() const { |
1135 | assert(Small)((void)0); |
1136 | // Note that this cast does not violate aliasing rules as we assert that |
1137 | // the memory's dynamic type is the small, inline bucket buffer, and the |
1138 | // 'storage' is a POD containing a char buffer. |
1139 | return reinterpret_cast<const BucketT *>(&storage); |
1140 | } |
1141 | |
1142 | BucketT *getInlineBuckets() { |
1143 | return const_cast<BucketT *>( |
1144 | const_cast<const SmallDenseMap *>(this)->getInlineBuckets()); |
1145 | } |
1146 | |
1147 | const LargeRep *getLargeRep() const { |
1148 | assert(!Small)((void)0); |
1149 | // Note, same rule about aliasing as with getInlineBuckets. |
1150 | return reinterpret_cast<const LargeRep *>(&storage); |
1151 | } |
1152 | |
1153 | LargeRep *getLargeRep() { |
1154 | return const_cast<LargeRep *>( |
1155 | const_cast<const SmallDenseMap *>(this)->getLargeRep()); |
1156 | } |
1157 | |
1158 | const BucketT *getBuckets() const { |
1159 | return Small ? getInlineBuckets() : getLargeRep()->Buckets; |
1160 | } |
1161 | |
1162 | BucketT *getBuckets() { |
1163 | return const_cast<BucketT *>( |
1164 | const_cast<const SmallDenseMap *>(this)->getBuckets()); |
1165 | } |
1166 | |
1167 | unsigned getNumBuckets() const { |
1168 | return Small ? InlineBuckets : getLargeRep()->NumBuckets; |
1169 | } |
1170 | |
1171 | void deallocateBuckets() { |
1172 | if (Small) |
1173 | return; |
1174 | |
1175 | deallocate_buffer(getLargeRep()->Buckets, |
1176 | sizeof(BucketT) * getLargeRep()->NumBuckets, |
1177 | alignof(BucketT)); |
1178 | getLargeRep()->~LargeRep(); |
1179 | } |
1180 | |
1181 | LargeRep allocateBuckets(unsigned Num) { |
1182 | assert(Num > InlineBuckets && "Must allocate more buckets than are inline")((void)0); |
1183 | LargeRep Rep = {static_cast<BucketT *>(allocate_buffer( |
1184 | sizeof(BucketT) * Num, alignof(BucketT))), |
1185 | Num}; |
1186 | return Rep; |
1187 | } |
1188 | }; |
1189 | |
1190 | template <typename KeyT, typename ValueT, typename KeyInfoT, typename Bucket, |
1191 | bool IsConst> |
1192 | class DenseMapIterator : DebugEpochBase::HandleBase { |
1193 | friend class DenseMapIterator<KeyT, ValueT, KeyInfoT, Bucket, true>; |
1194 | friend class DenseMapIterator<KeyT, ValueT, KeyInfoT, Bucket, false>; |
1195 | |
1196 | public: |
1197 | using difference_type = ptrdiff_t; |
1198 | using value_type = |
1199 | typename std::conditional<IsConst, const Bucket, Bucket>::type; |
1200 | using pointer = value_type *; |
1201 | using reference = value_type &; |
1202 | using iterator_category = std::forward_iterator_tag; |
1203 | |
1204 | private: |
1205 | pointer Ptr = nullptr; |
1206 | pointer End = nullptr; |
1207 | |
1208 | public: |
1209 | DenseMapIterator() = default; |
1210 | |
1211 | DenseMapIterator(pointer Pos, pointer E, const DebugEpochBase &Epoch, |
1212 | bool NoAdvance = false) |
1213 | : DebugEpochBase::HandleBase(&Epoch), Ptr(Pos), End(E) { |
1214 | assert(isHandleInSync() && "invalid construction!")((void)0); |
1215 | |
1216 | if (NoAdvance) return; |
1217 | if (shouldReverseIterate<KeyT>()) { |
1218 | RetreatPastEmptyBuckets(); |
1219 | return; |
1220 | } |
1221 | AdvancePastEmptyBuckets(); |
1222 | } |
1223 | |
1224 | // Converting ctor from non-const iterators to const iterators. SFINAE'd out |
1225 | // for const iterator destinations so it doesn't end up as a user defined copy |
1226 | // constructor. |
1227 | template <bool IsConstSrc, |
1228 | typename = std::enable_if_t<!IsConstSrc && IsConst>> |
1229 | DenseMapIterator( |
1230 | const DenseMapIterator<KeyT, ValueT, KeyInfoT, Bucket, IsConstSrc> &I) |
1231 | : DebugEpochBase::HandleBase(I), Ptr(I.Ptr), End(I.End) {} |
1232 | |
1233 | reference operator*() const { |
1234 | assert(isHandleInSync() && "invalid iterator access!")((void)0); |
1235 | assert(Ptr != End && "dereferencing end() iterator")((void)0); |
1236 | if (shouldReverseIterate<KeyT>()) |
1237 | return Ptr[-1]; |
1238 | return *Ptr; |
1239 | } |
1240 | pointer operator->() const { |
1241 | assert(isHandleInSync() && "invalid iterator access!")((void)0); |
1242 | assert(Ptr != End && "dereferencing end() iterator")((void)0); |
1243 | if (shouldReverseIterate<KeyT>()) |
1244 | return &(Ptr[-1]); |
1245 | return Ptr; |
1246 | } |
1247 | |
1248 | friend bool operator==(const DenseMapIterator &LHS, |
1249 | const DenseMapIterator &RHS) { |
1250 | assert((!LHS.Ptr || LHS.isHandleInSync()) && "handle not in sync!")((void)0); |
1251 | assert((!RHS.Ptr || RHS.isHandleInSync()) && "handle not in sync!")((void)0); |
1252 | assert(LHS.getEpochAddress() == RHS.getEpochAddress() &&((void)0) |
1253 | "comparing incomparable iterators!")((void)0); |
1254 | return LHS.Ptr == RHS.Ptr; |
1255 | } |
1256 | |
1257 | friend bool operator!=(const DenseMapIterator &LHS, |
1258 | const DenseMapIterator &RHS) { |
1259 | return !(LHS == RHS); |
1260 | } |
1261 | |
1262 | inline DenseMapIterator& operator++() { // Preincrement |
1263 | assert(isHandleInSync() && "invalid iterator access!")((void)0); |
1264 | assert(Ptr != End && "incrementing end() iterator")((void)0); |
1265 | if (shouldReverseIterate<KeyT>()) { |
1266 | --Ptr; |
1267 | RetreatPastEmptyBuckets(); |
1268 | return *this; |
1269 | } |
1270 | ++Ptr; |
1271 | AdvancePastEmptyBuckets(); |
1272 | return *this; |
1273 | } |
1274 | DenseMapIterator operator++(int) { // Postincrement |
1275 | assert(isHandleInSync() && "invalid iterator access!")((void)0); |
1276 | DenseMapIterator tmp = *this; ++*this; return tmp; |
1277 | } |
1278 | |
1279 | private: |
1280 | void AdvancePastEmptyBuckets() { |
1281 | assert(Ptr <= End)((void)0); |
1282 | const KeyT Empty = KeyInfoT::getEmptyKey(); |
1283 | const KeyT Tombstone = KeyInfoT::getTombstoneKey(); |
1284 | |
1285 | while (Ptr != End && (KeyInfoT::isEqual(Ptr->getFirst(), Empty) || |
1286 | KeyInfoT::isEqual(Ptr->getFirst(), Tombstone))) |
1287 | ++Ptr; |
1288 | } |
1289 | |
1290 | void RetreatPastEmptyBuckets() { |
1291 | assert(Ptr >= End)((void)0); |
1292 | const KeyT Empty = KeyInfoT::getEmptyKey(); |
1293 | const KeyT Tombstone = KeyInfoT::getTombstoneKey(); |
1294 | |
1295 | while (Ptr != End && (KeyInfoT::isEqual(Ptr[-1].getFirst(), Empty) || |
1296 | KeyInfoT::isEqual(Ptr[-1].getFirst(), Tombstone))) |
1297 | --Ptr; |
1298 | } |
1299 | }; |
1300 | |
1301 | template <typename KeyT, typename ValueT, typename KeyInfoT> |
1302 | inline size_t capacity_in_bytes(const DenseMap<KeyT, ValueT, KeyInfoT> &X) { |
1303 | return X.getMemorySize(); |
1304 | } |
1305 | |
1306 | } // end namespace llvm |
1307 | |
1308 | #endif // LLVM_ADT_DENSEMAP_H |