Bug Summary

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

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name SplitKit.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model static -mframe-pointer=all -relaxed-aliasing -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/gnu/usr.bin/clang/libLLVM/obj -resource-dir /usr/local/lib/clang/13.0.0 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Analysis -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ASMParser -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/BinaryFormat -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Bitcode -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Bitcode -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Bitstream -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /include/llvm/CodeGen -I /include/llvm/CodeGen/PBQP -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/IR -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/IR -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Coroutines -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ProfileData/Coverage -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/CodeView -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/DWARF -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/MSF -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/PDB -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Demangle -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ExecutionEngine -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ExecutionEngine/JITLink -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ExecutionEngine/Orc -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend/OpenACC -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend/OpenMP -I /include/llvm/CodeGen/GlobalISel -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/IRReader -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/InstCombine -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/Transforms/InstCombine -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/LTO -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Linker -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/MC -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/MC/MCParser -I /include/llvm/CodeGen/MIRParser -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Object -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Option -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Passes -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ProfileData -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Scalar -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ADT -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Support -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/Symbolize -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Target -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Utils -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Vectorize -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/IPO -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include -I /usr/src/gnu/usr.bin/clang/libLLVM/../include -I /usr/src/gnu/usr.bin/clang/libLLVM/obj -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include -D NDEBUG -D __STDC_LIMIT_MACROS -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D LLVM_PREFIX="/usr" -internal-isystem /usr/include/c++/v1 -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/usr/src/gnu/usr.bin/clang/libLLVM/obj -ferror-limit 19 -fvisibility-inlines-hidden -fwrapv -stack-protector 2 -fno-rtti -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/ben/Projects/vmm/scan-build/2022-01-12-194120-40624-1 -x c++ /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/CodeGen/SplitKit.cpp

/usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/CodeGen/SplitKit.cpp

1//===- SplitKit.cpp - Toolkit for splitting live ranges -------------------===//
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 contains the SplitAnalysis class as well as mutator functions for
10// live range splitting.
11//
12//===----------------------------------------------------------------------===//
13
14#include "SplitKit.h"
15#include "llvm/ADT/None.h"
16#include "llvm/ADT/STLExtras.h"
17#include "llvm/ADT/Statistic.h"
18#include "llvm/Analysis/AliasAnalysis.h"
19#include "llvm/CodeGen/LiveRangeEdit.h"
20#include "llvm/CodeGen/MachineBlockFrequencyInfo.h"
21#include "llvm/CodeGen/MachineDominators.h"
22#include "llvm/CodeGen/MachineInstr.h"
23#include "llvm/CodeGen/MachineInstrBuilder.h"
24#include "llvm/CodeGen/MachineLoopInfo.h"
25#include "llvm/CodeGen/MachineOperand.h"
26#include "llvm/CodeGen/MachineRegisterInfo.h"
27#include "llvm/CodeGen/TargetInstrInfo.h"
28#include "llvm/CodeGen/TargetOpcodes.h"
29#include "llvm/CodeGen/TargetRegisterInfo.h"
30#include "llvm/CodeGen/TargetSubtargetInfo.h"
31#include "llvm/CodeGen/VirtRegMap.h"
32#include "llvm/Config/llvm-config.h"
33#include "llvm/IR/DebugLoc.h"
34#include "llvm/Support/Allocator.h"
35#include "llvm/Support/BlockFrequency.h"
36#include "llvm/Support/Debug.h"
37#include "llvm/Support/ErrorHandling.h"
38#include "llvm/Support/raw_ostream.h"
39#include <algorithm>
40#include <cassert>
41#include <iterator>
42#include <limits>
43#include <tuple>
44
45using namespace llvm;
46
47#define DEBUG_TYPE"regalloc" "regalloc"
48
49STATISTIC(NumFinished, "Number of splits finished")static llvm::Statistic NumFinished = {"regalloc", "NumFinished"
, "Number of splits finished"}
;
50STATISTIC(NumSimple, "Number of splits that were simple")static llvm::Statistic NumSimple = {"regalloc", "NumSimple", "Number of splits that were simple"
}
;
51STATISTIC(NumCopies, "Number of copies inserted for splitting")static llvm::Statistic NumCopies = {"regalloc", "NumCopies", "Number of copies inserted for splitting"
}
;
52STATISTIC(NumRemats, "Number of rematerialized defs for splitting")static llvm::Statistic NumRemats = {"regalloc", "NumRemats", "Number of rematerialized defs for splitting"
}
;
53STATISTIC(NumRepairs, "Number of invalid live ranges repaired")static llvm::Statistic NumRepairs = {"regalloc", "NumRepairs"
, "Number of invalid live ranges repaired"}
;
54
55//===----------------------------------------------------------------------===//
56// Last Insert Point Analysis
57//===----------------------------------------------------------------------===//
58
59InsertPointAnalysis::InsertPointAnalysis(const LiveIntervals &lis,
60 unsigned BBNum)
61 : LIS(lis), LastInsertPoint(BBNum) {}
62
63SlotIndex
64InsertPointAnalysis::computeLastInsertPoint(const LiveInterval &CurLI,
65 const MachineBasicBlock &MBB) {
66 unsigned Num = MBB.getNumber();
67 std::pair<SlotIndex, SlotIndex> &LIP = LastInsertPoint[Num];
68 SlotIndex MBBEnd = LIS.getMBBEndIdx(&MBB);
69
70 SmallVector<const MachineBasicBlock *, 1> ExceptionalSuccessors;
71 bool EHPadSuccessor = false;
72 for (const MachineBasicBlock *SMBB : MBB.successors()) {
73 if (SMBB->isEHPad()) {
74 ExceptionalSuccessors.push_back(SMBB);
75 EHPadSuccessor = true;
76 } else if (SMBB->isInlineAsmBrIndirectTarget())
77 ExceptionalSuccessors.push_back(SMBB);
78 }
79
80 // Compute insert points on the first call. The pair is independent of the
81 // current live interval.
82 if (!LIP.first.isValid()) {
83 MachineBasicBlock::const_iterator FirstTerm = MBB.getFirstTerminator();
84 if (FirstTerm == MBB.end())
85 LIP.first = MBBEnd;
86 else
87 LIP.first = LIS.getInstructionIndex(*FirstTerm);
88
89 // If there is a landing pad or inlineasm_br successor, also find the
90 // instruction. If there is no such instruction, we don't need to do
91 // anything special. We assume there cannot be multiple instructions that
92 // are Calls with EHPad successors or INLINEASM_BR in a block. Further, we
93 // assume that if there are any, they will be after any other call
94 // instructions in the block.
95 if (ExceptionalSuccessors.empty())
96 return LIP.first;
97 for (const MachineInstr &MI : llvm::reverse(MBB)) {
98 if ((EHPadSuccessor && MI.isCall()) ||
99 MI.getOpcode() == TargetOpcode::INLINEASM_BR) {
100 LIP.second = LIS.getInstructionIndex(MI);
101 break;
102 }
103 }
104 }
105
106 // If CurLI is live into a landing pad successor, move the last insert point
107 // back to the call that may throw.
108 if (!LIP.second)
109 return LIP.first;
110
111 if (none_of(ExceptionalSuccessors, [&](const MachineBasicBlock *EHPad) {
112 return LIS.isLiveInToMBB(CurLI, EHPad);
113 }))
114 return LIP.first;
115
116 // Find the value leaving MBB.
117 const VNInfo *VNI = CurLI.getVNInfoBefore(MBBEnd);
118 if (!VNI)
119 return LIP.first;
120
121 // The def of statepoint instruction is a gc relocation and it should be alive
122 // in landing pad. So we cannot split interval after statepoint instruction.
123 if (SlotIndex::isSameInstr(VNI->def, LIP.second))
124 if (auto *I = LIS.getInstructionFromIndex(LIP.second))
125 if (I->getOpcode() == TargetOpcode::STATEPOINT)
126 return LIP.second;
127
128 // If the value leaving MBB was defined after the call in MBB, it can't
129 // really be live-in to the landing pad. This can happen if the landing pad
130 // has a PHI, and this register is undef on the exceptional edge.
131 // <rdar://problem/10664933>
132 if (!SlotIndex::isEarlierInstr(VNI->def, LIP.second) && VNI->def < MBBEnd)
133 return LIP.first;
134
135 // Value is properly live-in to the landing pad.
136 // Only allow inserts before the call.
137 return LIP.second;
138}
139
140MachineBasicBlock::iterator
141InsertPointAnalysis::getLastInsertPointIter(const LiveInterval &CurLI,
142 MachineBasicBlock &MBB) {
143 SlotIndex LIP = getLastInsertPoint(CurLI, MBB);
144 if (LIP == LIS.getMBBEndIdx(&MBB))
145 return MBB.end();
146 return LIS.getInstructionFromIndex(LIP);
147}
148
149//===----------------------------------------------------------------------===//
150// Split Analysis
151//===----------------------------------------------------------------------===//
152
153SplitAnalysis::SplitAnalysis(const VirtRegMap &vrm, const LiveIntervals &lis,
154 const MachineLoopInfo &mli)
155 : MF(vrm.getMachineFunction()), VRM(vrm), LIS(lis), Loops(mli),
156 TII(*MF.getSubtarget().getInstrInfo()), IPA(lis, MF.getNumBlockIDs()) {}
157
158void SplitAnalysis::clear() {
159 UseSlots.clear();
160 UseBlocks.clear();
161 ThroughBlocks.clear();
162 CurLI = nullptr;
163 DidRepairRange = false;
164}
165
166/// analyzeUses - Count instructions, basic blocks, and loops using CurLI.
167void SplitAnalysis::analyzeUses() {
168 assert(UseSlots.empty() && "Call clear first")((void)0);
169
170 // First get all the defs from the interval values. This provides the correct
171 // slots for early clobbers.
172 for (const VNInfo *VNI : CurLI->valnos)
173 if (!VNI->isPHIDef() && !VNI->isUnused())
174 UseSlots.push_back(VNI->def);
175
176 // Get use slots form the use-def chain.
177 const MachineRegisterInfo &MRI = MF.getRegInfo();
178 for (MachineOperand &MO : MRI.use_nodbg_operands(CurLI->reg()))
179 if (!MO.isUndef())
180 UseSlots.push_back(LIS.getInstructionIndex(*MO.getParent()).getRegSlot());
181
182 array_pod_sort(UseSlots.begin(), UseSlots.end());
183
184 // Remove duplicates, keeping the smaller slot for each instruction.
185 // That is what we want for early clobbers.
186 UseSlots.erase(std::unique(UseSlots.begin(), UseSlots.end(),
187 SlotIndex::isSameInstr),
188 UseSlots.end());
189
190 // Compute per-live block info.
191 if (!calcLiveBlockInfo()) {
192 // FIXME: calcLiveBlockInfo found inconsistencies in the live range.
193 // I am looking at you, RegisterCoalescer!
194 DidRepairRange = true;
195 ++NumRepairs;
196 LLVM_DEBUG(dbgs() << "*** Fixing inconsistent live interval! ***\n")do { } while (false);
197 const_cast<LiveIntervals&>(LIS)
198 .shrinkToUses(const_cast<LiveInterval*>(CurLI));
199 UseBlocks.clear();
200 ThroughBlocks.clear();
201 bool fixed = calcLiveBlockInfo();
202 (void)fixed;
203 assert(fixed && "Couldn't fix broken live interval")((void)0);
204 }
205
206 LLVM_DEBUG(dbgs() << "Analyze counted " << UseSlots.size() << " instrs in "do { } while (false)
207 << UseBlocks.size() << " blocks, through "do { } while (false)
208 << NumThroughBlocks << " blocks.\n")do { } while (false);
209}
210
211/// calcLiveBlockInfo - Fill the LiveBlocks array with information about blocks
212/// where CurLI is live.
213bool SplitAnalysis::calcLiveBlockInfo() {
214 ThroughBlocks.resize(MF.getNumBlockIDs());
215 NumThroughBlocks = NumGapBlocks = 0;
216 if (CurLI->empty())
217 return true;
218
219 LiveInterval::const_iterator LVI = CurLI->begin();
220 LiveInterval::const_iterator LVE = CurLI->end();
221
222 SmallVectorImpl<SlotIndex>::const_iterator UseI, UseE;
223 UseI = UseSlots.begin();
224 UseE = UseSlots.end();
225
226 // Loop over basic blocks where CurLI is live.
227 MachineFunction::iterator MFI =
228 LIS.getMBBFromIndex(LVI->start)->getIterator();
229 while (true) {
230 BlockInfo BI;
231 BI.MBB = &*MFI;
232 SlotIndex Start, Stop;
233 std::tie(Start, Stop) = LIS.getSlotIndexes()->getMBBRange(BI.MBB);
234
235 // If the block contains no uses, the range must be live through. At one
236 // point, RegisterCoalescer could create dangling ranges that ended
237 // mid-block.
238 if (UseI == UseE || *UseI >= Stop) {
239 ++NumThroughBlocks;
240 ThroughBlocks.set(BI.MBB->getNumber());
241 // The range shouldn't end mid-block if there are no uses. This shouldn't
242 // happen.
243 if (LVI->end < Stop)
244 return false;
245 } else {
246 // This block has uses. Find the first and last uses in the block.
247 BI.FirstInstr = *UseI;
248 assert(BI.FirstInstr >= Start)((void)0);
249 do ++UseI;
250 while (UseI != UseE && *UseI < Stop);
251 BI.LastInstr = UseI[-1];
252 assert(BI.LastInstr < Stop)((void)0);
253
254 // LVI is the first live segment overlapping MBB.
255 BI.LiveIn = LVI->start <= Start;
256
257 // When not live in, the first use should be a def.
258 if (!BI.LiveIn) {
259 assert(LVI->start == LVI->valno->def && "Dangling Segment start")((void)0);
260 assert(LVI->start == BI.FirstInstr && "First instr should be a def")((void)0);
261 BI.FirstDef = BI.FirstInstr;
262 }
263
264 // Look for gaps in the live range.
265 BI.LiveOut = true;
266 while (LVI->end < Stop) {
267 SlotIndex LastStop = LVI->end;
268 if (++LVI == LVE || LVI->start >= Stop) {
269 BI.LiveOut = false;
270 BI.LastInstr = LastStop;
271 break;
272 }
273
274 if (LastStop < LVI->start) {
275 // There is a gap in the live range. Create duplicate entries for the
276 // live-in snippet and the live-out snippet.
277 ++NumGapBlocks;
278
279 // Push the Live-in part.
280 BI.LiveOut = false;
281 UseBlocks.push_back(BI);
282 UseBlocks.back().LastInstr = LastStop;
283
284 // Set up BI for the live-out part.
285 BI.LiveIn = false;
286 BI.LiveOut = true;
287 BI.FirstInstr = BI.FirstDef = LVI->start;
288 }
289
290 // A Segment that starts in the middle of the block must be a def.
291 assert(LVI->start == LVI->valno->def && "Dangling Segment start")((void)0);
292 if (!BI.FirstDef)
293 BI.FirstDef = LVI->start;
294 }
295
296 UseBlocks.push_back(BI);
297
298 // LVI is now at LVE or LVI->end >= Stop.
299 if (LVI == LVE)
300 break;
301 }
302
303 // Live segment ends exactly at Stop. Move to the next segment.
304 if (LVI->end == Stop && ++LVI == LVE)
305 break;
306
307 // Pick the next basic block.
308 if (LVI->start < Stop)
309 ++MFI;
310 else
311 MFI = LIS.getMBBFromIndex(LVI->start)->getIterator();
312 }
313
314 assert(getNumLiveBlocks() == countLiveBlocks(CurLI) && "Bad block count")((void)0);
315 return true;
316}
317
318unsigned SplitAnalysis::countLiveBlocks(const LiveInterval *cli) const {
319 if (cli->empty())
320 return 0;
321 LiveInterval *li = const_cast<LiveInterval*>(cli);
322 LiveInterval::iterator LVI = li->begin();
323 LiveInterval::iterator LVE = li->end();
324 unsigned Count = 0;
325
326 // Loop over basic blocks where li is live.
327 MachineFunction::const_iterator MFI =
328 LIS.getMBBFromIndex(LVI->start)->getIterator();
329 SlotIndex Stop = LIS.getMBBEndIdx(&*MFI);
330 while (true) {
331 ++Count;
332 LVI = li->advanceTo(LVI, Stop);
333 if (LVI == LVE)
334 return Count;
335 do {
336 ++MFI;
337 Stop = LIS.getMBBEndIdx(&*MFI);
338 } while (Stop <= LVI->start);
339 }
340}
341
342bool SplitAnalysis::isOriginalEndpoint(SlotIndex Idx) const {
343 unsigned OrigReg = VRM.getOriginal(CurLI->reg());
344 const LiveInterval &Orig = LIS.getInterval(OrigReg);
345 assert(!Orig.empty() && "Splitting empty interval?")((void)0);
346 LiveInterval::const_iterator I = Orig.find(Idx);
347
348 // Range containing Idx should begin at Idx.
349 if (I != Orig.end() && I->start <= Idx)
350 return I->start == Idx;
351
352 // Range does not contain Idx, previous must end at Idx.
353 return I != Orig.begin() && (--I)->end == Idx;
354}
355
356void SplitAnalysis::analyze(const LiveInterval *li) {
357 clear();
358 CurLI = li;
359 analyzeUses();
360}
361
362//===----------------------------------------------------------------------===//
363// Split Editor
364//===----------------------------------------------------------------------===//
365
366/// Create a new SplitEditor for editing the LiveInterval analyzed by SA.
367SplitEditor::SplitEditor(SplitAnalysis &SA, AliasAnalysis &AA,
368 LiveIntervals &LIS, VirtRegMap &VRM,
369 MachineDominatorTree &MDT,
370 MachineBlockFrequencyInfo &MBFI, VirtRegAuxInfo &VRAI)
371 : SA(SA), AA(AA), LIS(LIS), VRM(VRM),
372 MRI(VRM.getMachineFunction().getRegInfo()), MDT(MDT),
373 TII(*VRM.getMachineFunction().getSubtarget().getInstrInfo()),
374 TRI(*VRM.getMachineFunction().getSubtarget().getRegisterInfo()),
375 MBFI(MBFI), VRAI(VRAI), RegAssign(Allocator) {}
376
377void SplitEditor::reset(LiveRangeEdit &LRE, ComplementSpillMode SM) {
378 Edit = &LRE;
379 SpillMode = SM;
380 OpenIdx = 0;
381 RegAssign.clear();
382 Values.clear();
383
384 // Reset the LiveIntervalCalc instances needed for this spill mode.
385 LICalc[0].reset(&VRM.getMachineFunction(), LIS.getSlotIndexes(), &MDT,
386 &LIS.getVNInfoAllocator());
387 if (SpillMode)
388 LICalc[1].reset(&VRM.getMachineFunction(), LIS.getSlotIndexes(), &MDT,
389 &LIS.getVNInfoAllocator());
390
391 // We don't need an AliasAnalysis since we will only be performing
392 // cheap-as-a-copy remats anyway.
393 Edit->anyRematerializable(nullptr);
394}
395
396#if !defined(NDEBUG1) || defined(LLVM_ENABLE_DUMP)
397LLVM_DUMP_METHOD__attribute__((noinline)) void SplitEditor::dump() const {
398 if (RegAssign.empty()) {
399 dbgs() << " empty\n";
400 return;
401 }
402
403 for (RegAssignMap::const_iterator I = RegAssign.begin(); I.valid(); ++I)
404 dbgs() << " [" << I.start() << ';' << I.stop() << "):" << I.value();
405 dbgs() << '\n';
406}
407#endif
408
409LiveInterval::SubRange &SplitEditor::getSubRangeForMaskExact(LaneBitmask LM,
410 LiveInterval &LI) {
411 for (LiveInterval::SubRange &S : LI.subranges())
412 if (S.LaneMask == LM)
413 return S;
414 llvm_unreachable("SubRange for this mask not found")__builtin_unreachable();
415}
416
417LiveInterval::SubRange &SplitEditor::getSubRangeForMask(LaneBitmask LM,
418 LiveInterval &LI) {
419 for (LiveInterval::SubRange &S : LI.subranges())
420 if ((S.LaneMask & LM) == LM)
421 return S;
422 llvm_unreachable("SubRange for this mask not found")__builtin_unreachable();
423}
424
425void SplitEditor::addDeadDef(LiveInterval &LI, VNInfo *VNI, bool Original) {
426 if (!LI.hasSubRanges()) {
427 LI.createDeadDef(VNI);
428 return;
429 }
430
431 SlotIndex Def = VNI->def;
432 if (Original) {
433 // If we are transferring a def from the original interval, make sure
434 // to only update the subranges for which the original subranges had
435 // a def at this location.
436 for (LiveInterval::SubRange &S : LI.subranges()) {
437 auto &PS = getSubRangeForMask(S.LaneMask, Edit->getParent());
438 VNInfo *PV = PS.getVNInfoAt(Def);
439 if (PV != nullptr && PV->def == Def)
440 S.createDeadDef(Def, LIS.getVNInfoAllocator());
441 }
442 } else {
443 // This is a new def: either from rematerialization, or from an inserted
444 // copy. Since rematerialization can regenerate a definition of a sub-
445 // register, we need to check which subranges need to be updated.
446 const MachineInstr *DefMI = LIS.getInstructionFromIndex(Def);
447 assert(DefMI != nullptr)((void)0);
448 LaneBitmask LM;
449 for (const MachineOperand &DefOp : DefMI->defs()) {
450 Register R = DefOp.getReg();
451 if (R != LI.reg())
452 continue;
453 if (unsigned SR = DefOp.getSubReg())
454 LM |= TRI.getSubRegIndexLaneMask(SR);
455 else {
456 LM = MRI.getMaxLaneMaskForVReg(R);
457 break;
458 }
459 }
460 for (LiveInterval::SubRange &S : LI.subranges())
461 if ((S.LaneMask & LM).any())
462 S.createDeadDef(Def, LIS.getVNInfoAllocator());
463 }
464}
465
466VNInfo *SplitEditor::defValue(unsigned RegIdx,
467 const VNInfo *ParentVNI,
468 SlotIndex Idx,
469 bool Original) {
470 assert(ParentVNI && "Mapping NULL value")((void)0);
471 assert(Idx.isValid() && "Invalid SlotIndex")((void)0);
472 assert(Edit->getParent().getVNInfoAt(Idx) == ParentVNI && "Bad Parent VNI")((void)0);
473 LiveInterval *LI = &LIS.getInterval(Edit->get(RegIdx));
474
475 // Create a new value.
476 VNInfo *VNI = LI->getNextValue(Idx, LIS.getVNInfoAllocator());
477
478 bool Force = LI->hasSubRanges();
479 ValueForcePair FP(Force ? nullptr : VNI, Force);
480 // Use insert for lookup, so we can add missing values with a second lookup.
481 std::pair<ValueMap::iterator, bool> InsP =
482 Values.insert(std::make_pair(std::make_pair(RegIdx, ParentVNI->id), FP));
483
484 // This was the first time (RegIdx, ParentVNI) was mapped, and it is not
485 // forced. Keep it as a simple def without any liveness.
486 if (!Force && InsP.second)
487 return VNI;
488
489 // If the previous value was a simple mapping, add liveness for it now.
490 if (VNInfo *OldVNI = InsP.first->second.getPointer()) {
491 addDeadDef(*LI, OldVNI, Original);
492
493 // No longer a simple mapping. Switch to a complex mapping. If the
494 // interval has subranges, make it a forced mapping.
495 InsP.first->second = ValueForcePair(nullptr, Force);
496 }
497
498 // This is a complex mapping, add liveness for VNI
499 addDeadDef(*LI, VNI, Original);
500 return VNI;
501}
502
503void SplitEditor::forceRecompute(unsigned RegIdx, const VNInfo &ParentVNI) {
504 ValueForcePair &VFP = Values[std::make_pair(RegIdx, ParentVNI.id)];
505 VNInfo *VNI = VFP.getPointer();
506
507 // ParentVNI was either unmapped or already complex mapped. Either way, just
508 // set the force bit.
509 if (!VNI) {
510 VFP.setInt(true);
511 return;
512 }
513
514 // This was previously a single mapping. Make sure the old def is represented
515 // by a trivial live range.
516 addDeadDef(LIS.getInterval(Edit->get(RegIdx)), VNI, false);
517
518 // Mark as complex mapped, forced.
519 VFP = ValueForcePair(nullptr, true);
520}
521
522SlotIndex SplitEditor::buildSingleSubRegCopy(Register FromReg, Register ToReg,
523 MachineBasicBlock &MBB, MachineBasicBlock::iterator InsertBefore,
524 unsigned SubIdx, LiveInterval &DestLI, bool Late, SlotIndex Def) {
525 const MCInstrDesc &Desc = TII.get(TargetOpcode::COPY);
526 bool FirstCopy = !Def.isValid();
527 MachineInstr *CopyMI = BuildMI(MBB, InsertBefore, DebugLoc(), Desc)
528 .addReg(ToReg, RegState::Define | getUndefRegState(FirstCopy)
529 | getInternalReadRegState(!FirstCopy), SubIdx)
530 .addReg(FromReg, 0, SubIdx);
531
532 BumpPtrAllocator &Allocator = LIS.getVNInfoAllocator();
533 SlotIndexes &Indexes = *LIS.getSlotIndexes();
534 if (FirstCopy) {
535 Def = Indexes.insertMachineInstrInMaps(*CopyMI, Late).getRegSlot();
536 } else {
537 CopyMI->bundleWithPred();
538 }
539 LaneBitmask LaneMask = TRI.getSubRegIndexLaneMask(SubIdx);
540 DestLI.refineSubRanges(Allocator, LaneMask,
541 [Def, &Allocator](LiveInterval::SubRange &SR) {
542 SR.createDeadDef(Def, Allocator);
543 },
544 Indexes, TRI);
545 return Def;
546}
547
548SlotIndex SplitEditor::buildCopy(Register FromReg, Register ToReg,
549 LaneBitmask LaneMask, MachineBasicBlock &MBB,
550 MachineBasicBlock::iterator InsertBefore, bool Late, unsigned RegIdx) {
551 const MCInstrDesc &Desc = TII.get(TargetOpcode::COPY);
552 if (LaneMask.all() || LaneMask == MRI.getMaxLaneMaskForVReg(FromReg)) {
553 // The full vreg is copied.
554 MachineInstr *CopyMI =
555 BuildMI(MBB, InsertBefore, DebugLoc(), Desc, ToReg).addReg(FromReg);
556 SlotIndexes &Indexes = *LIS.getSlotIndexes();
557 return Indexes.insertMachineInstrInMaps(*CopyMI, Late).getRegSlot();
558 }
559
560 // Only a subset of lanes needs to be copied. The following is a simple
561 // heuristic to construct a sequence of COPYs. We could add a target
562 // specific callback if this turns out to be suboptimal.
563 LiveInterval &DestLI = LIS.getInterval(Edit->get(RegIdx));
564
565 // First pass: Try to find a perfectly matching subregister index. If none
566 // exists find the one covering the most lanemask bits.
567 const TargetRegisterClass *RC = MRI.getRegClass(FromReg);
568 assert(RC == MRI.getRegClass(ToReg) && "Should have same reg class")((void)0);
569
570 SmallVector<unsigned, 8> Indexes;
571
572 // Abort if we cannot possibly implement the COPY with the given indexes.
573 if (!TRI.getCoveringSubRegIndexes(MRI, RC, LaneMask, Indexes))
574 report_fatal_error("Impossible to implement partial COPY");
575
576 SlotIndex Def;
577 for (unsigned BestIdx : Indexes) {
578 Def = buildSingleSubRegCopy(FromReg, ToReg, MBB, InsertBefore, BestIdx,
579 DestLI, Late, Def);
580 }
581
582 return Def;
583}
584
585VNInfo *SplitEditor::defFromParent(unsigned RegIdx,
586 VNInfo *ParentVNI,
587 SlotIndex UseIdx,
588 MachineBasicBlock &MBB,
589 MachineBasicBlock::iterator I) {
590 SlotIndex Def;
591 LiveInterval *LI = &LIS.getInterval(Edit->get(RegIdx));
592
593 // We may be trying to avoid interference that ends at a deleted instruction,
594 // so always begin RegIdx 0 early and all others late.
595 bool Late = RegIdx != 0;
596
597 // Attempt cheap-as-a-copy rematerialization.
598 unsigned Original = VRM.getOriginal(Edit->get(RegIdx));
599 LiveInterval &OrigLI = LIS.getInterval(Original);
600 VNInfo *OrigVNI = OrigLI.getVNInfoAt(UseIdx);
601
602 Register Reg = LI->reg();
603 bool DidRemat = false;
604 if (OrigVNI) {
605 LiveRangeEdit::Remat RM(ParentVNI);
606 RM.OrigMI = LIS.getInstructionFromIndex(OrigVNI->def);
607 if (Edit->canRematerializeAt(RM, OrigVNI, UseIdx, true)) {
608 Def = Edit->rematerializeAt(MBB, I, Reg, RM, TRI, Late);
609 ++NumRemats;
610 DidRemat = true;
611 }
612 }
613 if (!DidRemat) {
614 LaneBitmask LaneMask;
615 if (OrigLI.hasSubRanges()) {
616 LaneMask = LaneBitmask::getNone();
617 for (LiveInterval::SubRange &S : OrigLI.subranges()) {
618 if (S.liveAt(UseIdx))
619 LaneMask |= S.LaneMask;
620 }
621 } else {
622 LaneMask = LaneBitmask::getAll();
623 }
624
625 if (LaneMask.none()) {
626 const MCInstrDesc &Desc = TII.get(TargetOpcode::IMPLICIT_DEF);
627 MachineInstr *ImplicitDef = BuildMI(MBB, I, DebugLoc(), Desc, Reg);
628 SlotIndexes &Indexes = *LIS.getSlotIndexes();
629 Def = Indexes.insertMachineInstrInMaps(*ImplicitDef, Late).getRegSlot();
630 } else {
631 ++NumCopies;
632 Def = buildCopy(Edit->getReg(), Reg, LaneMask, MBB, I, Late, RegIdx);
633 }
634 }
635
636 // Define the value in Reg.
637 return defValue(RegIdx, ParentVNI, Def, false);
638}
639
640/// Create a new virtual register and live interval.
641unsigned SplitEditor::openIntv() {
642 // Create the complement as index 0.
643 if (Edit->empty())
644 Edit->createEmptyInterval();
645
646 // Create the open interval.
647 OpenIdx = Edit->size();
648 Edit->createEmptyInterval();
649 return OpenIdx;
650}
651
652void SplitEditor::selectIntv(unsigned Idx) {
653 assert(Idx != 0 && "Cannot select the complement interval")((void)0);
654 assert(Idx < Edit->size() && "Can only select previously opened interval")((void)0);
655 LLVM_DEBUG(dbgs() << " selectIntv " << OpenIdx << " -> " << Idx << '\n')do { } while (false);
656 OpenIdx = Idx;
657}
658
659SlotIndex SplitEditor::enterIntvBefore(SlotIndex Idx) {
660 assert(OpenIdx && "openIntv not called before enterIntvBefore")((void)0);
661 LLVM_DEBUG(dbgs() << " enterIntvBefore " << Idx)do { } while (false);
662 Idx = Idx.getBaseIndex();
663 VNInfo *ParentVNI = Edit->getParent().getVNInfoAt(Idx);
664 if (!ParentVNI) {
665 LLVM_DEBUG(dbgs() << ": not live\n")do { } while (false);
666 return Idx;
667 }
668 LLVM_DEBUG(dbgs() << ": valno " << ParentVNI->id << '\n')do { } while (false);
669 MachineInstr *MI = LIS.getInstructionFromIndex(Idx);
670 assert(MI && "enterIntvBefore called with invalid index")((void)0);
671
672 VNInfo *VNI = defFromParent(OpenIdx, ParentVNI, Idx, *MI->getParent(), MI);
673 return VNI->def;
674}
675
676SlotIndex SplitEditor::enterIntvAfter(SlotIndex Idx) {
677 assert(OpenIdx && "openIntv not called before enterIntvAfter")((void)0);
678 LLVM_DEBUG(dbgs() << " enterIntvAfter " << Idx)do { } while (false);
679 Idx = Idx.getBoundaryIndex();
680 VNInfo *ParentVNI = Edit->getParent().getVNInfoAt(Idx);
681 if (!ParentVNI) {
682 LLVM_DEBUG(dbgs() << ": not live\n")do { } while (false);
683 return Idx;
684 }
685 LLVM_DEBUG(dbgs() << ": valno " << ParentVNI->id << '\n')do { } while (false);
686 MachineInstr *MI = LIS.getInstructionFromIndex(Idx);
687 assert(MI && "enterIntvAfter called with invalid index")((void)0);
688
689 VNInfo *VNI = defFromParent(OpenIdx, ParentVNI, Idx, *MI->getParent(),
690 std::next(MachineBasicBlock::iterator(MI)));
691 return VNI->def;
692}
693
694SlotIndex SplitEditor::enterIntvAtEnd(MachineBasicBlock &MBB) {
695 assert(OpenIdx && "openIntv not called before enterIntvAtEnd")((void)0);
696 SlotIndex End = LIS.getMBBEndIdx(&MBB);
697 SlotIndex Last = End.getPrevSlot();
698 LLVM_DEBUG(dbgs() << " enterIntvAtEnd " << printMBBReference(MBB) << ", "do { } while (false)
699 << Last)do { } while (false);
700 VNInfo *ParentVNI = Edit->getParent().getVNInfoAt(Last);
701 if (!ParentVNI) {
702 LLVM_DEBUG(dbgs() << ": not live\n")do { } while (false);
703 return End;
704 }
705 SlotIndex LSP = SA.getLastSplitPoint(&MBB);
706 if (LSP < Last) {
707 // It could be that the use after LSP is a def, and thus the ParentVNI
708 // just selected starts at that def. For this case to exist, the def
709 // must be part of a tied def/use pair (as otherwise we'd have split
710 // distinct live ranges into individual live intervals), and thus we
711 // can insert the def into the VNI of the use and the tied def/use
712 // pair can live in the resulting interval.
713 Last = LSP;
714 ParentVNI = Edit->getParent().getVNInfoAt(Last);
715 if (!ParentVNI) {
716 // undef use --> undef tied def
717 LLVM_DEBUG(dbgs() << ": tied use not live\n")do { } while (false);
718 return End;
719 }
720 }
721
722 LLVM_DEBUG(dbgs() << ": valno " << ParentVNI->id)do { } while (false);
723 VNInfo *VNI = defFromParent(OpenIdx, ParentVNI, Last, MBB,
724 SA.getLastSplitPointIter(&MBB));
725 RegAssign.insert(VNI->def, End, OpenIdx);
726 LLVM_DEBUG(dump())do { } while (false);
727 return VNI->def;
728}
729
730/// useIntv - indicate that all instructions in MBB should use OpenLI.
731void SplitEditor::useIntv(const MachineBasicBlock &MBB) {
732 useIntv(LIS.getMBBStartIdx(&MBB), LIS.getMBBEndIdx(&MBB));
733}
734
735void SplitEditor::useIntv(SlotIndex Start, SlotIndex End) {
736 assert(OpenIdx && "openIntv not called before useIntv")((void)0);
737 LLVM_DEBUG(dbgs() << " useIntv [" << Start << ';' << End << "):")do { } while (false);
738 RegAssign.insert(Start, End, OpenIdx);
739 LLVM_DEBUG(dump())do { } while (false);
740}
741
742SlotIndex SplitEditor::leaveIntvAfter(SlotIndex Idx) {
743 assert(OpenIdx && "openIntv not called before leaveIntvAfter")((void)0);
744 LLVM_DEBUG(dbgs() << " leaveIntvAfter " << Idx)do { } while (false);
745
746 // The interval must be live beyond the instruction at Idx.
747 SlotIndex Boundary = Idx.getBoundaryIndex();
748 VNInfo *ParentVNI = Edit->getParent().getVNInfoAt(Boundary);
749 if (!ParentVNI) {
750 LLVM_DEBUG(dbgs() << ": not live\n")do { } while (false);
751 return Boundary.getNextSlot();
752 }
753 LLVM_DEBUG(dbgs() << ": valno " << ParentVNI->id << '\n')do { } while (false);
754 MachineInstr *MI = LIS.getInstructionFromIndex(Boundary);
755 assert(MI && "No instruction at index")((void)0);
756
757 // In spill mode, make live ranges as short as possible by inserting the copy
758 // before MI. This is only possible if that instruction doesn't redefine the
759 // value. The inserted COPY is not a kill, and we don't need to recompute
760 // the source live range. The spiller also won't try to hoist this copy.
761 if (SpillMode && !SlotIndex::isSameInstr(ParentVNI->def, Idx) &&
762 MI->readsVirtualRegister(Edit->getReg())) {
763 forceRecompute(0, *ParentVNI);
764 defFromParent(0, ParentVNI, Idx, *MI->getParent(), MI);
765 return Idx;
766 }
767
768 VNInfo *VNI = defFromParent(0, ParentVNI, Boundary, *MI->getParent(),
769 std::next(MachineBasicBlock::iterator(MI)));
770 return VNI->def;
771}
772
773SlotIndex SplitEditor::leaveIntvBefore(SlotIndex Idx) {
774 assert(OpenIdx && "openIntv not called before leaveIntvBefore")((void)0);
775 LLVM_DEBUG(dbgs() << " leaveIntvBefore " << Idx)do { } while (false);
776
777 // The interval must be live into the instruction at Idx.
778 Idx = Idx.getBaseIndex();
779 VNInfo *ParentVNI = Edit->getParent().getVNInfoAt(Idx);
780 if (!ParentVNI) {
781 LLVM_DEBUG(dbgs() << ": not live\n")do { } while (false);
782 return Idx.getNextSlot();
783 }
784 LLVM_DEBUG(dbgs() << ": valno " << ParentVNI->id << '\n')do { } while (false);
785
786 MachineInstr *MI = LIS.getInstructionFromIndex(Idx);
787 assert(MI && "No instruction at index")((void)0);
788 VNInfo *VNI = defFromParent(0, ParentVNI, Idx, *MI->getParent(), MI);
789 return VNI->def;
790}
791
792SlotIndex SplitEditor::leaveIntvAtTop(MachineBasicBlock &MBB) {
793 assert(OpenIdx && "openIntv not called before leaveIntvAtTop")((void)0);
794 SlotIndex Start = LIS.getMBBStartIdx(&MBB);
795 LLVM_DEBUG(dbgs() << " leaveIntvAtTop " << printMBBReference(MBB) << ", "do { } while (false)
796 << Start)do { } while (false);
797
798 VNInfo *ParentVNI = Edit->getParent().getVNInfoAt(Start);
799 if (!ParentVNI) {
800 LLVM_DEBUG(dbgs() << ": not live\n")do { } while (false);
801 return Start;
802 }
803
804 VNInfo *VNI = defFromParent(0, ParentVNI, Start, MBB,
805 MBB.SkipPHIsLabelsAndDebug(MBB.begin()));
806 RegAssign.insert(Start, VNI->def, OpenIdx);
807 LLVM_DEBUG(dump())do { } while (false);
808 return VNI->def;
809}
810
811static bool hasTiedUseOf(MachineInstr &MI, unsigned Reg) {
812 return any_of(MI.defs(), [Reg](const MachineOperand &MO) {
813 return MO.isReg() && MO.isTied() && MO.getReg() == Reg;
814 });
815}
816
817void SplitEditor::overlapIntv(SlotIndex Start, SlotIndex End) {
818 assert(OpenIdx && "openIntv not called before overlapIntv")((void)0);
819 const VNInfo *ParentVNI = Edit->getParent().getVNInfoAt(Start);
820 assert(ParentVNI == Edit->getParent().getVNInfoBefore(End) &&((void)0)
821 "Parent changes value in extended range")((void)0);
822 assert(LIS.getMBBFromIndex(Start) == LIS.getMBBFromIndex(End) &&((void)0)
823 "Range cannot span basic blocks")((void)0);
824
825 // The complement interval will be extended as needed by LICalc.extend().
826 if (ParentVNI)
827 forceRecompute(0, *ParentVNI);
828
829 // If the last use is tied to a def, we can't mark it as live for the
830 // interval which includes only the use. That would cause the tied pair
831 // to end up in two different intervals.
832 if (auto *MI = LIS.getInstructionFromIndex(End))
833 if (hasTiedUseOf(*MI, Edit->getReg())) {
834 LLVM_DEBUG(dbgs() << "skip overlap due to tied def at end\n")do { } while (false);
835 return;
836 }
837
838 LLVM_DEBUG(dbgs() << " overlapIntv [" << Start << ';' << End << "):")do { } while (false);
839 RegAssign.insert(Start, End, OpenIdx);
840 LLVM_DEBUG(dump())do { } while (false);
841}
842
843//===----------------------------------------------------------------------===//
844// Spill modes
845//===----------------------------------------------------------------------===//
846
847void SplitEditor::removeBackCopies(SmallVectorImpl<VNInfo*> &Copies) {
848 LiveInterval *LI = &LIS.getInterval(Edit->get(0));
849 LLVM_DEBUG(dbgs() << "Removing " << Copies.size() << " back-copies.\n")do { } while (false);
850 RegAssignMap::iterator AssignI;
851 AssignI.setMap(RegAssign);
852
853 for (const VNInfo *C : Copies) {
854 SlotIndex Def = C->def;
855 MachineInstr *MI = LIS.getInstructionFromIndex(Def);
856 assert(MI && "No instruction for back-copy")((void)0);
857
858 MachineBasicBlock *MBB = MI->getParent();
859 MachineBasicBlock::iterator MBBI(MI);
860 bool AtBegin;
861 do AtBegin = MBBI == MBB->begin();
862 while (!AtBegin && (--MBBI)->isDebugOrPseudoInstr());
863
864 LLVM_DEBUG(dbgs() << "Removing " << Def << '\t' << *MI)do { } while (false);
865 LIS.removeVRegDefAt(*LI, Def);
866 LIS.RemoveMachineInstrFromMaps(*MI);
867 MI->eraseFromParent();
868
869 // Adjust RegAssign if a register assignment is killed at Def. We want to
870 // avoid calculating the live range of the source register if possible.
871 AssignI.find(Def.getPrevSlot());
872 if (!AssignI.valid() || AssignI.start() >= Def)
873 continue;
874 // If MI doesn't kill the assigned register, just leave it.
875 if (AssignI.stop() != Def)
876 continue;
877 unsigned RegIdx = AssignI.value();
878 // We could hoist back-copy right after another back-copy. As a result
879 // MMBI points to copy instruction which is actually dead now.
880 // We cannot set its stop to MBBI which will be the same as start and
881 // interval does not support that.
882 SlotIndex Kill =
883 AtBegin ? SlotIndex() : LIS.getInstructionIndex(*MBBI).getRegSlot();
884 if (AtBegin || !MBBI->readsVirtualRegister(Edit->getReg()) ||
885 Kill <= AssignI.start()) {
886 LLVM_DEBUG(dbgs() << " cannot find simple kill of RegIdx " << RegIdxdo { } while (false)
887 << '\n')do { } while (false);
888 forceRecompute(RegIdx, *Edit->getParent().getVNInfoAt(Def));
889 } else {
890 LLVM_DEBUG(dbgs() << " move kill to " << Kill << '\t' << *MBBI)do { } while (false);
891 AssignI.setStop(Kill);
892 }
893 }
894}
895
896MachineBasicBlock*
897SplitEditor::findShallowDominator(MachineBasicBlock *MBB,
898 MachineBasicBlock *DefMBB) {
899 if (MBB == DefMBB)
900 return MBB;
901 assert(MDT.dominates(DefMBB, MBB) && "MBB must be dominated by the def.")((void)0);
902
903 const MachineLoopInfo &Loops = SA.Loops;
904 const MachineLoop *DefLoop = Loops.getLoopFor(DefMBB);
905 MachineDomTreeNode *DefDomNode = MDT[DefMBB];
906
907 // Best candidate so far.
908 MachineBasicBlock *BestMBB = MBB;
909 unsigned BestDepth = std::numeric_limits<unsigned>::max();
910
911 while (true) {
912 const MachineLoop *Loop = Loops.getLoopFor(MBB);
913
914 // MBB isn't in a loop, it doesn't get any better. All dominators have a
915 // higher frequency by definition.
916 if (!Loop) {
917 LLVM_DEBUG(dbgs() << "Def in " << printMBBReference(*DefMBB)do { } while (false)
918 << " dominates " << printMBBReference(*MBB)do { } while (false)
919 << " at depth 0\n")do { } while (false);
920 return MBB;
921 }
922
923 // We'll never be able to exit the DefLoop.
924 if (Loop == DefLoop) {
925 LLVM_DEBUG(dbgs() << "Def in " << printMBBReference(*DefMBB)do { } while (false)
926 << " dominates " << printMBBReference(*MBB)do { } while (false)
927 << " in the same loop\n")do { } while (false);
928 return MBB;
929 }
930
931 // Least busy dominator seen so far.
932 unsigned Depth = Loop->getLoopDepth();
933 if (Depth < BestDepth) {
934 BestMBB = MBB;
935 BestDepth = Depth;
936 LLVM_DEBUG(dbgs() << "Def in " << printMBBReference(*DefMBB)do { } while (false)
937 << " dominates " << printMBBReference(*MBB)do { } while (false)
938 << " at depth " << Depth << '\n')do { } while (false);
939 }
940
941 // Leave loop by going to the immediate dominator of the loop header.
942 // This is a bigger stride than simply walking up the dominator tree.
943 MachineDomTreeNode *IDom = MDT[Loop->getHeader()]->getIDom();
944
945 // Too far up the dominator tree?
946 if (!IDom || !MDT.dominates(DefDomNode, IDom))
947 return BestMBB;
948
949 MBB = IDom->getBlock();
950 }
951}
952
953void SplitEditor::computeRedundantBackCopies(
954 DenseSet<unsigned> &NotToHoistSet, SmallVectorImpl<VNInfo *> &BackCopies) {
955 LiveInterval *LI = &LIS.getInterval(Edit->get(0));
956 LiveInterval *Parent = &Edit->getParent();
957 SmallVector<SmallPtrSet<VNInfo *, 8>, 8> EqualVNs(Parent->getNumValNums());
958 SmallPtrSet<VNInfo *, 8> DominatedVNIs;
959
960 // Aggregate VNIs having the same value as ParentVNI.
961 for (VNInfo *VNI : LI->valnos) {
962 if (VNI->isUnused())
963 continue;
964 VNInfo *ParentVNI = Edit->getParent().getVNInfoAt(VNI->def);
965 EqualVNs[ParentVNI->id].insert(VNI);
966 }
967
968 // For VNI aggregation of each ParentVNI, collect dominated, i.e.,
969 // redundant VNIs to BackCopies.
970 for (unsigned i = 0, e = Parent->getNumValNums(); i != e; ++i) {
971 VNInfo *ParentVNI = Parent->getValNumInfo(i);
972 if (!NotToHoistSet.count(ParentVNI->id))
973 continue;
974 SmallPtrSetIterator<VNInfo *> It1 = EqualVNs[ParentVNI->id].begin();
975 SmallPtrSetIterator<VNInfo *> It2 = It1;
976 for (; It1 != EqualVNs[ParentVNI->id].end(); ++It1) {
977 It2 = It1;
978 for (++It2; It2 != EqualVNs[ParentVNI->id].end(); ++It2) {
979 if (DominatedVNIs.count(*It1) || DominatedVNIs.count(*It2))
980 continue;
981
982 MachineBasicBlock *MBB1 = LIS.getMBBFromIndex((*It1)->def);
983 MachineBasicBlock *MBB2 = LIS.getMBBFromIndex((*It2)->def);
984 if (MBB1 == MBB2) {
985 DominatedVNIs.insert((*It1)->def < (*It2)->def ? (*It2) : (*It1));
986 } else if (MDT.dominates(MBB1, MBB2)) {
987 DominatedVNIs.insert(*It2);
988 } else if (MDT.dominates(MBB2, MBB1)) {
989 DominatedVNIs.insert(*It1);
990 }
991 }
992 }
993 if (!DominatedVNIs.empty()) {
994 forceRecompute(0, *ParentVNI);
995 append_range(BackCopies, DominatedVNIs);
996 DominatedVNIs.clear();
997 }
998 }
999}
1000
1001/// For SM_Size mode, find a common dominator for all the back-copies for
1002/// the same ParentVNI and hoist the backcopies to the dominator BB.
1003/// For SM_Speed mode, if the common dominator is hot and it is not beneficial
1004/// to do the hoisting, simply remove the dominated backcopies for the same
1005/// ParentVNI.
1006void SplitEditor::hoistCopies() {
1007 // Get the complement interval, always RegIdx 0.
1008 LiveInterval *LI = &LIS.getInterval(Edit->get(0));
1009 LiveInterval *Parent = &Edit->getParent();
1010
1011 // Track the nearest common dominator for all back-copies for each ParentVNI,
1012 // indexed by ParentVNI->id.
1013 using DomPair = std::pair<MachineBasicBlock *, SlotIndex>;
1014 SmallVector<DomPair, 8> NearestDom(Parent->getNumValNums());
1015 // The total cost of all the back-copies for each ParentVNI.
1016 SmallVector<BlockFrequency, 8> Costs(Parent->getNumValNums());
1017 // The ParentVNI->id set for which hoisting back-copies are not beneficial
1018 // for Speed.
1019 DenseSet<unsigned> NotToHoistSet;
1020
1021 // Find the nearest common dominator for parent values with multiple
1022 // back-copies. If a single back-copy dominates, put it in DomPair.second.
1023 for (VNInfo *VNI : LI->valnos) {
4
Assuming '__begin1' is not equal to '__end1'
1024 if (VNI->isUnused())
5
Taking false branch
1025 continue;
1026 VNInfo *ParentVNI = Edit->getParent().getVNInfoAt(VNI->def);
1027 assert(ParentVNI && "Parent not live at complement def")((void)0);
1028
1029 // Don't hoist remats. The complement is probably going to disappear
1030 // completely anyway.
1031 if (Edit->didRematerialize(ParentVNI))
6
Assuming the condition is false
7
Taking false branch
1032 continue;
1033
1034 MachineBasicBlock *ValMBB = LIS.getMBBFromIndex(VNI->def);
1035
1036 DomPair &Dom = NearestDom[ParentVNI->id];
1037
1038 // Keep directly defined parent values. This is either a PHI or an
1039 // instruction in the complement range. All other copies of ParentVNI
1040 // should be eliminated.
1041 if (VNI->def == ParentVNI->def) {
8
Taking false branch
1042 LLVM_DEBUG(dbgs() << "Direct complement def at " << VNI->def << '\n')do { } while (false);
1043 Dom = DomPair(ValMBB, VNI->def);
1044 continue;
1045 }
1046 // Skip the singly mapped values. There is nothing to gain from hoisting a
1047 // single back-copy.
1048 if (Values.lookup(std::make_pair(0, ParentVNI->id)).getPointer()) {
9
Assuming the condition is false
10
Taking false branch
1049 LLVM_DEBUG(dbgs() << "Single complement def at " << VNI->def << '\n')do { } while (false);
1050 continue;
1051 }
1052
1053 if (!Dom.first) {
11
Assuming field 'first' is non-null
12
Taking false branch
1054 // First time we see ParentVNI. VNI dominates itself.
1055 Dom = DomPair(ValMBB, VNI->def);
1056 } else if (Dom.first == ValMBB) {
13
Assuming 'ValMBB' is not equal to field 'first'
14
Taking false branch
1057 // Two defs in the same block. Pick the earlier def.
1058 if (!Dom.second.isValid() || VNI->def < Dom.second)
1059 Dom.second = VNI->def;
1060 } else {
1061 // Different basic blocks. Check if one dominates.
1062 MachineBasicBlock *Near =
1063 MDT.findNearestCommonDominator(Dom.first, ValMBB);
15
Calling 'MachineDominatorTree::findNearestCommonDominator'
1064 if (Near == ValMBB)
1065 // Def ValMBB dominates.
1066 Dom = DomPair(ValMBB, VNI->def);
1067 else if (Near != Dom.first)
1068 // None dominate. Hoist to common dominator, need new def.
1069 Dom = DomPair(Near, SlotIndex());
1070 Costs[ParentVNI->id] += MBFI.getBlockFreq(ValMBB);
1071 }
1072
1073 LLVM_DEBUG(dbgs() << "Multi-mapped complement " << VNI->id << '@'do { } while (false)
1074 << VNI->def << " for parent " << ParentVNI->id << '@'do { } while (false)
1075 << ParentVNI->def << " hoist to "do { } while (false)
1076 << printMBBReference(*Dom.first) << ' ' << Dom.seconddo { } while (false)
1077 << '\n')do { } while (false);
1078 }
1079
1080 // Insert the hoisted copies.
1081 for (unsigned i = 0, e = Parent->getNumValNums(); i != e; ++i) {
1082 DomPair &Dom = NearestDom[i];
1083 if (!Dom.first || Dom.second.isValid())
1084 continue;
1085 // This value needs a hoisted copy inserted at the end of Dom.first.
1086 VNInfo *ParentVNI = Parent->getValNumInfo(i);
1087 MachineBasicBlock *DefMBB = LIS.getMBBFromIndex(ParentVNI->def);
1088 // Get a less loopy dominator than Dom.first.
1089 Dom.first = findShallowDominator(Dom.first, DefMBB);
1090 if (SpillMode == SM_Speed &&
1091 MBFI.getBlockFreq(Dom.first) > Costs[ParentVNI->id]) {
1092 NotToHoistSet.insert(ParentVNI->id);
1093 continue;
1094 }
1095 SlotIndex LSP = SA.getLastSplitPoint(Dom.first);
1096 if (LSP <= ParentVNI->def) {
1097 NotToHoistSet.insert(ParentVNI->id);
1098 continue;
1099 }
1100 Dom.second = defFromParent(0, ParentVNI, LSP, *Dom.first,
1101 SA.getLastSplitPointIter(Dom.first))->def;
1102 }
1103
1104 // Remove redundant back-copies that are now known to be dominated by another
1105 // def with the same value.
1106 SmallVector<VNInfo*, 8> BackCopies;
1107 for (VNInfo *VNI : LI->valnos) {
1108 if (VNI->isUnused())
1109 continue;
1110 VNInfo *ParentVNI = Edit->getParent().getVNInfoAt(VNI->def);
1111 const DomPair &Dom = NearestDom[ParentVNI->id];
1112 if (!Dom.first || Dom.second == VNI->def ||
1113 NotToHoistSet.count(ParentVNI->id))
1114 continue;
1115 BackCopies.push_back(VNI);
1116 forceRecompute(0, *ParentVNI);
1117 }
1118
1119 // If it is not beneficial to hoist all the BackCopies, simply remove
1120 // redundant BackCopies in speed mode.
1121 if (SpillMode == SM_Speed && !NotToHoistSet.empty())
1122 computeRedundantBackCopies(NotToHoistSet, BackCopies);
1123
1124 removeBackCopies(BackCopies);
1125}
1126
1127/// transferValues - Transfer all possible values to the new live ranges.
1128/// Values that were rematerialized are left alone, they need LICalc.extend().
1129bool SplitEditor::transferValues() {
1130 bool Skipped = false;
1131 RegAssignMap::const_iterator AssignI = RegAssign.begin();
1132 for (const LiveRange::Segment &S : Edit->getParent()) {
1133 LLVM_DEBUG(dbgs() << " blit " << S << ':')do { } while (false);
1134 VNInfo *ParentVNI = S.valno;
1135 // RegAssign has holes where RegIdx 0 should be used.
1136 SlotIndex Start = S.start;
1137 AssignI.advanceTo(Start);
1138 do {
1139 unsigned RegIdx;
1140 SlotIndex End = S.end;
1141 if (!AssignI.valid()) {
1142 RegIdx = 0;
1143 } else if (AssignI.start() <= Start) {
1144 RegIdx = AssignI.value();
1145 if (AssignI.stop() < End) {
1146 End = AssignI.stop();
1147 ++AssignI;
1148 }
1149 } else {
1150 RegIdx = 0;
1151 End = std::min(End, AssignI.start());
1152 }
1153
1154 // The interval [Start;End) is continuously mapped to RegIdx, ParentVNI.
1155 LLVM_DEBUG(dbgs() << " [" << Start << ';' << End << ")=" << RegIdx << '('do { } while (false)
1156 << printReg(Edit->get(RegIdx)) << ')')do { } while (false);
1157 LiveInterval &LI = LIS.getInterval(Edit->get(RegIdx));
1158
1159 // Check for a simply defined value that can be blitted directly.
1160 ValueForcePair VFP = Values.lookup(std::make_pair(RegIdx, ParentVNI->id));
1161 if (VNInfo *VNI = VFP.getPointer()) {
1162 LLVM_DEBUG(dbgs() << ':' << VNI->id)do { } while (false);
1163 LI.addSegment(LiveInterval::Segment(Start, End, VNI));
1164 Start = End;
1165 continue;
1166 }
1167
1168 // Skip values with forced recomputation.
1169 if (VFP.getInt()) {
1170 LLVM_DEBUG(dbgs() << "(recalc)")do { } while (false);
1171 Skipped = true;
1172 Start = End;
1173 continue;
1174 }
1175
1176 LiveIntervalCalc &LIC = getLICalc(RegIdx);
1177
1178 // This value has multiple defs in RegIdx, but it wasn't rematerialized,
1179 // so the live range is accurate. Add live-in blocks in [Start;End) to the
1180 // LiveInBlocks.
1181 MachineFunction::iterator MBB = LIS.getMBBFromIndex(Start)->getIterator();
1182 SlotIndex BlockStart, BlockEnd;
1183 std::tie(BlockStart, BlockEnd) = LIS.getSlotIndexes()->getMBBRange(&*MBB);
1184
1185 // The first block may be live-in, or it may have its own def.
1186 if (Start != BlockStart) {
1187 VNInfo *VNI = LI.extendInBlock(BlockStart, std::min(BlockEnd, End));
1188 assert(VNI && "Missing def for complex mapped value")((void)0);
1189 LLVM_DEBUG(dbgs() << ':' << VNI->id << "*" << printMBBReference(*MBB))do { } while (false);
1190 // MBB has its own def. Is it also live-out?
1191 if (BlockEnd <= End)
1192 LIC.setLiveOutValue(&*MBB, VNI);
1193
1194 // Skip to the next block for live-in.
1195 ++MBB;
1196 BlockStart = BlockEnd;
1197 }
1198
1199 // Handle the live-in blocks covered by [Start;End).
1200 assert(Start <= BlockStart && "Expected live-in block")((void)0);
1201 while (BlockStart < End) {
1202 LLVM_DEBUG(dbgs() << ">" << printMBBReference(*MBB))do { } while (false);
1203 BlockEnd = LIS.getMBBEndIdx(&*MBB);
1204 if (BlockStart == ParentVNI->def) {
1205 // This block has the def of a parent PHI, so it isn't live-in.
1206 assert(ParentVNI->isPHIDef() && "Non-phi defined at block start?")((void)0);
1207 VNInfo *VNI = LI.extendInBlock(BlockStart, std::min(BlockEnd, End));
1208 assert(VNI && "Missing def for complex mapped parent PHI")((void)0);
1209 if (End >= BlockEnd)
1210 LIC.setLiveOutValue(&*MBB, VNI); // Live-out as well.
1211 } else {
1212 // This block needs a live-in value. The last block covered may not
1213 // be live-out.
1214 if (End < BlockEnd)
1215 LIC.addLiveInBlock(LI, MDT[&*MBB], End);
1216 else {
1217 // Live-through, and we don't know the value.
1218 LIC.addLiveInBlock(LI, MDT[&*MBB]);
1219 LIC.setLiveOutValue(&*MBB, nullptr);
1220 }
1221 }
1222 BlockStart = BlockEnd;
1223 ++MBB;
1224 }
1225 Start = End;
1226 } while (Start != S.end);
1227 LLVM_DEBUG(dbgs() << '\n')do { } while (false);
1228 }
1229
1230 LICalc[0].calculateValues();
1231 if (SpillMode)
1232 LICalc[1].calculateValues();
1233
1234 return Skipped;
1235}
1236
1237static bool removeDeadSegment(SlotIndex Def, LiveRange &LR) {
1238 const LiveRange::Segment *Seg = LR.getSegmentContaining(Def);
1239 if (Seg == nullptr)
1240 return true;
1241 if (Seg->end != Def.getDeadSlot())
1242 return false;
1243 // This is a dead PHI. Remove it.
1244 LR.removeSegment(*Seg, true);
1245 return true;
1246}
1247
1248void SplitEditor::extendPHIRange(MachineBasicBlock &B, LiveIntervalCalc &LIC,
1249 LiveRange &LR, LaneBitmask LM,
1250 ArrayRef<SlotIndex> Undefs) {
1251 for (MachineBasicBlock *P : B.predecessors()) {
1252 SlotIndex End = LIS.getMBBEndIdx(P);
1253 SlotIndex LastUse = End.getPrevSlot();
1254 // The predecessor may not have a live-out value. That is OK, like an
1255 // undef PHI operand.
1256 LiveInterval &PLI = Edit->getParent();
1257 // Need the cast because the inputs to ?: would otherwise be deemed
1258 // "incompatible": SubRange vs LiveInterval.
1259 LiveRange &PSR = !LM.all() ? getSubRangeForMaskExact(LM, PLI)
1260 : static_cast<LiveRange &>(PLI);
1261 if (PSR.liveAt(LastUse))
1262 LIC.extend(LR, End, /*PhysReg=*/0, Undefs);
1263 }
1264}
1265
1266void SplitEditor::extendPHIKillRanges() {
1267 // Extend live ranges to be live-out for successor PHI values.
1268
1269 // Visit each PHI def slot in the parent live interval. If the def is dead,
1270 // remove it. Otherwise, extend the live interval to reach the end indexes
1271 // of all predecessor blocks.
1272
1273 LiveInterval &ParentLI = Edit->getParent();
1274 for (const VNInfo *V : ParentLI.valnos) {
1275 if (V->isUnused() || !V->isPHIDef())
1276 continue;
1277
1278 unsigned RegIdx = RegAssign.lookup(V->def);
1279 LiveInterval &LI = LIS.getInterval(Edit->get(RegIdx));
1280 LiveIntervalCalc &LIC = getLICalc(RegIdx);
1281 MachineBasicBlock &B = *LIS.getMBBFromIndex(V->def);
1282 if (!removeDeadSegment(V->def, LI))
1283 extendPHIRange(B, LIC, LI, LaneBitmask::getAll(), /*Undefs=*/{});
1284 }
1285
1286 SmallVector<SlotIndex, 4> Undefs;
1287 LiveIntervalCalc SubLIC;
1288
1289 for (LiveInterval::SubRange &PS : ParentLI.subranges()) {
1290 for (const VNInfo *V : PS.valnos) {
1291 if (V->isUnused() || !V->isPHIDef())
1292 continue;
1293 unsigned RegIdx = RegAssign.lookup(V->def);
1294 LiveInterval &LI = LIS.getInterval(Edit->get(RegIdx));
1295 LiveInterval::SubRange &S = getSubRangeForMaskExact(PS.LaneMask, LI);
1296 if (removeDeadSegment(V->def, S))
1297 continue;
1298
1299 MachineBasicBlock &B = *LIS.getMBBFromIndex(V->def);
1300 SubLIC.reset(&VRM.getMachineFunction(), LIS.getSlotIndexes(), &MDT,
1301 &LIS.getVNInfoAllocator());
1302 Undefs.clear();
1303 LI.computeSubRangeUndefs(Undefs, PS.LaneMask, MRI, *LIS.getSlotIndexes());
1304 extendPHIRange(B, SubLIC, S, PS.LaneMask, Undefs);
1305 }
1306 }
1307}
1308
1309/// rewriteAssigned - Rewrite all uses of Edit->getReg().
1310void SplitEditor::rewriteAssigned(bool ExtendRanges) {
1311 struct ExtPoint {
1312 ExtPoint(const MachineOperand &O, unsigned R, SlotIndex N)
1313 : MO(O), RegIdx(R), Next(N) {}
1314
1315 MachineOperand MO;
1316 unsigned RegIdx;
1317 SlotIndex Next;
1318 };
1319
1320 SmallVector<ExtPoint,4> ExtPoints;
1321
1322 for (MachineOperand &MO :
1323 llvm::make_early_inc_range(MRI.reg_operands(Edit->getReg()))) {
1324 MachineInstr *MI = MO.getParent();
1325 // LiveDebugVariables should have handled all DBG_VALUE instructions.
1326 if (MI->isDebugValue()) {
1327 LLVM_DEBUG(dbgs() << "Zapping " << *MI)do { } while (false);
1328 MO.setReg(0);
1329 continue;
1330 }
1331
1332 // <undef> operands don't really read the register, so it doesn't matter
1333 // which register we choose. When the use operand is tied to a def, we must
1334 // use the same register as the def, so just do that always.
1335 SlotIndex Idx = LIS.getInstructionIndex(*MI);
1336 if (MO.isDef() || MO.isUndef())
1337 Idx = Idx.getRegSlot(MO.isEarlyClobber());
1338
1339 // Rewrite to the mapped register at Idx.
1340 unsigned RegIdx = RegAssign.lookup(Idx);
1341 LiveInterval &LI = LIS.getInterval(Edit->get(RegIdx));
1342 MO.setReg(LI.reg());
1343 LLVM_DEBUG(dbgs() << " rewr " << printMBBReference(*MI->getParent())do { } while (false)
1344 << '\t' << Idx << ':' << RegIdx << '\t' << *MI)do { } while (false);
1345
1346 // Extend liveness to Idx if the instruction reads reg.
1347 if (!ExtendRanges || MO.isUndef())
1348 continue;
1349
1350 // Skip instructions that don't read Reg.
1351 if (MO.isDef()) {
1352 if (!MO.getSubReg() && !MO.isEarlyClobber())
1353 continue;
1354 // We may want to extend a live range for a partial redef, or for a use
1355 // tied to an early clobber.
1356 Idx = Idx.getPrevSlot();
1357 if (!Edit->getParent().liveAt(Idx))
1358 continue;
1359 } else
1360 Idx = Idx.getRegSlot(true);
1361
1362 SlotIndex Next = Idx.getNextSlot();
1363 if (LI.hasSubRanges()) {
1364 // We have to delay extending subranges until we have seen all operands
1365 // defining the register. This is because a <def,read-undef> operand
1366 // will create an "undef" point, and we cannot extend any subranges
1367 // until all of them have been accounted for.
1368 if (MO.isUse())
1369 ExtPoints.push_back(ExtPoint(MO, RegIdx, Next));
1370 } else {
1371 LiveIntervalCalc &LIC = getLICalc(RegIdx);
1372 LIC.extend(LI, Next, 0, ArrayRef<SlotIndex>());
1373 }
1374 }
1375
1376 for (ExtPoint &EP : ExtPoints) {
1377 LiveInterval &LI = LIS.getInterval(Edit->get(EP.RegIdx));
1378 assert(LI.hasSubRanges())((void)0);
1379
1380 LiveIntervalCalc SubLIC;
1381 Register Reg = EP.MO.getReg(), Sub = EP.MO.getSubReg();
1382 LaneBitmask LM = Sub != 0 ? TRI.getSubRegIndexLaneMask(Sub)
1383 : MRI.getMaxLaneMaskForVReg(Reg);
1384 for (LiveInterval::SubRange &S : LI.subranges()) {
1385 if ((S.LaneMask & LM).none())
1386 continue;
1387 // The problem here can be that the new register may have been created
1388 // for a partially defined original register. For example:
1389 // %0:subreg_hireg<def,read-undef> = ...
1390 // ...
1391 // %1 = COPY %0
1392 if (S.empty())
1393 continue;
1394 SubLIC.reset(&VRM.getMachineFunction(), LIS.getSlotIndexes(), &MDT,
1395 &LIS.getVNInfoAllocator());
1396 SmallVector<SlotIndex, 4> Undefs;
1397 LI.computeSubRangeUndefs(Undefs, S.LaneMask, MRI, *LIS.getSlotIndexes());
1398 SubLIC.extend(S, EP.Next, 0, Undefs);
1399 }
1400 }
1401
1402 for (Register R : *Edit) {
1403 LiveInterval &LI = LIS.getInterval(R);
1404 if (!LI.hasSubRanges())
1405 continue;
1406 LI.clear();
1407 LI.removeEmptySubRanges();
1408 LIS.constructMainRangeFromSubranges(LI);
1409 }
1410}
1411
1412void SplitEditor::deleteRematVictims() {
1413 SmallVector<MachineInstr*, 8> Dead;
1414 for (const Register &R : *Edit) {
1415 LiveInterval *LI = &LIS.getInterval(R);
1416 for (const LiveRange::Segment &S : LI->segments) {
1417 // Dead defs end at the dead slot.
1418 if (S.end != S.valno->def.getDeadSlot())
1419 continue;
1420 if (S.valno->isPHIDef())
1421 continue;
1422 MachineInstr *MI = LIS.getInstructionFromIndex(S.valno->def);
1423 assert(MI && "Missing instruction for dead def")((void)0);
1424 MI->addRegisterDead(LI->reg(), &TRI);
1425
1426 if (!MI->allDefsAreDead())
1427 continue;
1428
1429 LLVM_DEBUG(dbgs() << "All defs dead: " << *MI)do { } while (false);
1430 Dead.push_back(MI);
1431 }
1432 }
1433
1434 if (Dead.empty())
1435 return;
1436
1437 Edit->eliminateDeadDefs(Dead, None, &AA);
1438}
1439
1440void SplitEditor::forceRecomputeVNI(const VNInfo &ParentVNI) {
1441 // Fast-path for common case.
1442 if (!ParentVNI.isPHIDef()) {
1443 for (unsigned I = 0, E = Edit->size(); I != E; ++I)
1444 forceRecompute(I, ParentVNI);
1445 return;
1446 }
1447
1448 // Trace value through phis.
1449 SmallPtrSet<const VNInfo *, 8> Visited; ///< whether VNI was/is in worklist.
1450 SmallVector<const VNInfo *, 4> WorkList;
1451 Visited.insert(&ParentVNI);
1452 WorkList.push_back(&ParentVNI);
1453
1454 const LiveInterval &ParentLI = Edit->getParent();
1455 const SlotIndexes &Indexes = *LIS.getSlotIndexes();
1456 do {
1457 const VNInfo &VNI = *WorkList.back();
1458 WorkList.pop_back();
1459 for (unsigned I = 0, E = Edit->size(); I != E; ++I)
1460 forceRecompute(I, VNI);
1461 if (!VNI.isPHIDef())
1462 continue;
1463
1464 MachineBasicBlock &MBB = *Indexes.getMBBFromIndex(VNI.def);
1465 for (const MachineBasicBlock *Pred : MBB.predecessors()) {
1466 SlotIndex PredEnd = Indexes.getMBBEndIdx(Pred);
1467 VNInfo *PredVNI = ParentLI.getVNInfoBefore(PredEnd);
1468 assert(PredVNI && "Value available in PhiVNI predecessor")((void)0);
1469 if (Visited.insert(PredVNI).second)
1470 WorkList.push_back(PredVNI);
1471 }
1472 } while(!WorkList.empty());
1473}
1474
1475void SplitEditor::finish(SmallVectorImpl<unsigned> *LRMap) {
1476 ++NumFinished;
1477
1478 // At this point, the live intervals in Edit contain VNInfos corresponding to
1479 // the inserted copies.
1480
1481 // Add the original defs from the parent interval.
1482 for (const VNInfo *ParentVNI : Edit->getParent().valnos) {
1
Assuming '__begin1' is equal to '__end1'
1483 if (ParentVNI->isUnused())
1484 continue;
1485 unsigned RegIdx = RegAssign.lookup(ParentVNI->def);
1486 defValue(RegIdx, ParentVNI, ParentVNI->def, true);
1487
1488 // Force rematted values to be recomputed everywhere.
1489 // The new live ranges may be truncated.
1490 if (Edit->didRematerialize(ParentVNI))
1491 forceRecomputeVNI(*ParentVNI);
1492 }
1493
1494 // Hoist back-copies to the complement interval when in spill mode.
1495 switch (SpillMode) {
2
Control jumps to 'case SM_Size:' at line 1499
1496 case SM_Partition:
1497 // Leave all back-copies as is.
1498 break;
1499 case SM_Size:
1500 case SM_Speed:
1501 // hoistCopies will behave differently between size and speed.
1502 hoistCopies();
3
Calling 'SplitEditor::hoistCopies'
1503 }
1504
1505 // Transfer the simply mapped values, check if any are skipped.
1506 bool Skipped = transferValues();
1507
1508 // Rewrite virtual registers, possibly extending ranges.
1509 rewriteAssigned(Skipped);
1510
1511 if (Skipped)
1512 extendPHIKillRanges();
1513 else
1514 ++NumSimple;
1515
1516 // Delete defs that were rematted everywhere.
1517 if (Skipped)
1518 deleteRematVictims();
1519
1520 // Get rid of unused values and set phi-kill flags.
1521 for (Register Reg : *Edit) {
1522 LiveInterval &LI = LIS.getInterval(Reg);
1523 LI.removeEmptySubRanges();
1524 LI.RenumberValues();
1525 }
1526
1527 // Provide a reverse mapping from original indices to Edit ranges.
1528 if (LRMap) {
1529 LRMap->clear();
1530 for (unsigned i = 0, e = Edit->size(); i != e; ++i)
1531 LRMap->push_back(i);
1532 }
1533
1534 // Now check if any registers were separated into multiple components.
1535 ConnectedVNInfoEqClasses ConEQ(LIS);
1536 for (unsigned i = 0, e = Edit->size(); i != e; ++i) {
1537 // Don't use iterators, they are invalidated by create() below.
1538 Register VReg = Edit->get(i);
1539 LiveInterval &LI = LIS.getInterval(VReg);
1540 SmallVector<LiveInterval*, 8> SplitLIs;
1541 LIS.splitSeparateComponents(LI, SplitLIs);
1542 Register Original = VRM.getOriginal(VReg);
1543 for (LiveInterval *SplitLI : SplitLIs)
1544 VRM.setIsSplitFromReg(SplitLI->reg(), Original);
1545
1546 // The new intervals all map back to i.
1547 if (LRMap)
1548 LRMap->resize(Edit->size(), i);
1549 }
1550
1551 // Calculate spill weight and allocation hints for new intervals.
1552 Edit->calculateRegClassAndHint(VRM.getMachineFunction(), VRAI);
1553
1554 assert(!LRMap || LRMap->size() == Edit->size())((void)0);
1555}
1556
1557//===----------------------------------------------------------------------===//
1558// Single Block Splitting
1559//===----------------------------------------------------------------------===//
1560
1561bool SplitAnalysis::shouldSplitSingleBlock(const BlockInfo &BI,
1562 bool SingleInstrs) const {
1563 // Always split for multiple instructions.
1564 if (!BI.isOneInstr())
1565 return true;
1566 // Don't split for single instructions unless explicitly requested.
1567 if (!SingleInstrs)
1568 return false;
1569 // Splitting a live-through range always makes progress.
1570 if (BI.LiveIn && BI.LiveOut)
1571 return true;
1572 // No point in isolating a copy. It has no register class constraints.
1573 if (LIS.getInstructionFromIndex(BI.FirstInstr)->isCopyLike())
1574 return false;
1575 // Finally, don't isolate an end point that was created by earlier splits.
1576 return isOriginalEndpoint(BI.FirstInstr);
1577}
1578
1579void SplitEditor::splitSingleBlock(const SplitAnalysis::BlockInfo &BI) {
1580 openIntv();
1581 SlotIndex LastSplitPoint = SA.getLastSplitPoint(BI.MBB);
1582 SlotIndex SegStart = enterIntvBefore(std::min(BI.FirstInstr,
1583 LastSplitPoint));
1584 if (!BI.LiveOut || BI.LastInstr < LastSplitPoint) {
1585 useIntv(SegStart, leaveIntvAfter(BI.LastInstr));
1586 } else {
1587 // The last use is after the last valid split point.
1588 SlotIndex SegStop = leaveIntvBefore(LastSplitPoint);
1589 useIntv(SegStart, SegStop);
1590 overlapIntv(SegStop, BI.LastInstr);
1591 }
1592}
1593
1594//===----------------------------------------------------------------------===//
1595// Global Live Range Splitting Support
1596//===----------------------------------------------------------------------===//
1597
1598// These methods support a method of global live range splitting that uses a
1599// global algorithm to decide intervals for CFG edges. They will insert split
1600// points and color intervals in basic blocks while avoiding interference.
1601//
1602// Note that splitSingleBlock is also useful for blocks where both CFG edges
1603// are on the stack.
1604
1605void SplitEditor::splitLiveThroughBlock(unsigned MBBNum,
1606 unsigned IntvIn, SlotIndex LeaveBefore,
1607 unsigned IntvOut, SlotIndex EnterAfter){
1608 SlotIndex Start, Stop;
1609 std::tie(Start, Stop) = LIS.getSlotIndexes()->getMBBRange(MBBNum);
1610
1611 LLVM_DEBUG(dbgs() << "%bb." << MBBNum << " [" << Start << ';' << Stopdo { } while (false)
1612 << ") intf " << LeaveBefore << '-' << EnterAfterdo { } while (false)
1613 << ", live-through " << IntvIn << " -> " << IntvOut)do { } while (false);
1614
1615 assert((IntvIn || IntvOut) && "Use splitSingleBlock for isolated blocks")((void)0);
1616
1617 assert((!LeaveBefore || LeaveBefore < Stop) && "Interference after block")((void)0);
1618 assert((!IntvIn || !LeaveBefore || LeaveBefore > Start) && "Impossible intf")((void)0);
1619 assert((!EnterAfter || EnterAfter >= Start) && "Interference before block")((void)0);
1620
1621 MachineBasicBlock *MBB = VRM.getMachineFunction().getBlockNumbered(MBBNum);
1622
1623 if (!IntvOut) {
1624 LLVM_DEBUG(dbgs() << ", spill on entry.\n")do { } while (false);
1625 //
1626 // <<<<<<<<< Possible LeaveBefore interference.
1627 // |-----------| Live through.
1628 // -____________ Spill on entry.
1629 //
1630 selectIntv(IntvIn);
1631 SlotIndex Idx = leaveIntvAtTop(*MBB);
1632 assert((!LeaveBefore || Idx <= LeaveBefore) && "Interference")((void)0);
1633 (void)Idx;
1634 return;
1635 }
1636
1637 if (!IntvIn) {
1638 LLVM_DEBUG(dbgs() << ", reload on exit.\n")do { } while (false);
1639 //
1640 // >>>>>>> Possible EnterAfter interference.
1641 // |-----------| Live through.
1642 // ___________-- Reload on exit.
1643 //
1644 selectIntv(IntvOut);
1645 SlotIndex Idx = enterIntvAtEnd(*MBB);
1646 assert((!EnterAfter || Idx >= EnterAfter) && "Interference")((void)0);
1647 (void)Idx;
1648 return;
1649 }
1650
1651 if (IntvIn == IntvOut && !LeaveBefore && !EnterAfter) {
1652 LLVM_DEBUG(dbgs() << ", straight through.\n")do { } while (false);
1653 //
1654 // |-----------| Live through.
1655 // ------------- Straight through, same intv, no interference.
1656 //
1657 selectIntv(IntvOut);
1658 useIntv(Start, Stop);
1659 return;
1660 }
1661
1662 // We cannot legally insert splits after LSP.
1663 SlotIndex LSP = SA.getLastSplitPoint(MBBNum);
1664 assert((!IntvOut || !EnterAfter || EnterAfter < LSP) && "Impossible intf")((void)0);
1665
1666 if (IntvIn != IntvOut && (!LeaveBefore || !EnterAfter ||
1667 LeaveBefore.getBaseIndex() > EnterAfter.getBoundaryIndex())) {
1668 LLVM_DEBUG(dbgs() << ", switch avoiding interference.\n")do { } while (false);
1669 //
1670 // >>>> <<<< Non-overlapping EnterAfter/LeaveBefore interference.
1671 // |-----------| Live through.
1672 // ------======= Switch intervals between interference.
1673 //
1674 selectIntv(IntvOut);
1675 SlotIndex Idx;
1676 if (LeaveBefore && LeaveBefore < LSP) {
1677 Idx = enterIntvBefore(LeaveBefore);
1678 useIntv(Idx, Stop);
1679 } else {
1680 Idx = enterIntvAtEnd(*MBB);
1681 }
1682 selectIntv(IntvIn);
1683 useIntv(Start, Idx);
1684 assert((!LeaveBefore || Idx <= LeaveBefore) && "Interference")((void)0);
1685 assert((!EnterAfter || Idx >= EnterAfter) && "Interference")((void)0);
1686 return;
1687 }
1688
1689 LLVM_DEBUG(dbgs() << ", create local intv for interference.\n")do { } while (false);
1690 //
1691 // >>><><><><<<< Overlapping EnterAfter/LeaveBefore interference.
1692 // |-----------| Live through.
1693 // ==---------== Switch intervals before/after interference.
1694 //
1695 assert(LeaveBefore <= EnterAfter && "Missed case")((void)0);
1696
1697 selectIntv(IntvOut);
1698 SlotIndex Idx = enterIntvAfter(EnterAfter);
1699 useIntv(Idx, Stop);
1700 assert((!EnterAfter || Idx >= EnterAfter) && "Interference")((void)0);
1701
1702 selectIntv(IntvIn);
1703 Idx = leaveIntvBefore(LeaveBefore);
1704 useIntv(Start, Idx);
1705 assert((!LeaveBefore || Idx <= LeaveBefore) && "Interference")((void)0);
1706}
1707
1708void SplitEditor::splitRegInBlock(const SplitAnalysis::BlockInfo &BI,
1709 unsigned IntvIn, SlotIndex LeaveBefore) {
1710 SlotIndex Start, Stop;
1711 std::tie(Start, Stop) = LIS.getSlotIndexes()->getMBBRange(BI.MBB);
1712
1713 LLVM_DEBUG(dbgs() << printMBBReference(*BI.MBB) << " [" << Start << ';'do { } while (false)
1714 << Stop << "), uses " << BI.FirstInstr << '-'do { } while (false)
1715 << BI.LastInstr << ", reg-in " << IntvIndo { } while (false)
1716 << ", leave before " << LeaveBeforedo { } while (false)
1717 << (BI.LiveOut ? ", stack-out" : ", killed in block"))do { } while (false);
1718
1719 assert(IntvIn && "Must have register in")((void)0);
1720 assert(BI.LiveIn && "Must be live-in")((void)0);
1721 assert((!LeaveBefore || LeaveBefore > Start) && "Bad interference")((void)0);
1722
1723 if (!BI.LiveOut && (!LeaveBefore || LeaveBefore >= BI.LastInstr)) {
1724 LLVM_DEBUG(dbgs() << " before interference.\n")do { } while (false);
1725 //
1726 // <<< Interference after kill.
1727 // |---o---x | Killed in block.
1728 // ========= Use IntvIn everywhere.
1729 //
1730 selectIntv(IntvIn);
1731 useIntv(Start, BI.LastInstr);
1732 return;
1733 }
1734
1735 SlotIndex LSP = SA.getLastSplitPoint(BI.MBB);
1736
1737 if (!LeaveBefore || LeaveBefore > BI.LastInstr.getBoundaryIndex()) {
1738 //
1739 // <<< Possible interference after last use.
1740 // |---o---o---| Live-out on stack.
1741 // =========____ Leave IntvIn after last use.
1742 //
1743 // < Interference after last use.
1744 // |---o---o--o| Live-out on stack, late last use.
1745 // ============ Copy to stack after LSP, overlap IntvIn.
1746 // \_____ Stack interval is live-out.
1747 //
1748 if (BI.LastInstr < LSP) {
1749 LLVM_DEBUG(dbgs() << ", spill after last use before interference.\n")do { } while (false);
1750 selectIntv(IntvIn);
1751 SlotIndex Idx = leaveIntvAfter(BI.LastInstr);
1752 useIntv(Start, Idx);
1753 assert((!LeaveBefore || Idx <= LeaveBefore) && "Interference")((void)0);
1754 } else {
1755 LLVM_DEBUG(dbgs() << ", spill before last split point.\n")do { } while (false);
1756 selectIntv(IntvIn);
1757 SlotIndex Idx = leaveIntvBefore(LSP);
1758 overlapIntv(Idx, BI.LastInstr);
1759 useIntv(Start, Idx);
1760 assert((!LeaveBefore || Idx <= LeaveBefore) && "Interference")((void)0);
1761 }
1762 return;
1763 }
1764
1765 // The interference is overlapping somewhere we wanted to use IntvIn. That
1766 // means we need to create a local interval that can be allocated a
1767 // different register.
1768 unsigned LocalIntv = openIntv();
1769 (void)LocalIntv;
1770 LLVM_DEBUG(dbgs() << ", creating local interval " << LocalIntv << ".\n")do { } while (false);
1771
1772 if (!BI.LiveOut || BI.LastInstr < LSP) {
1773 //
1774 // <<<<<<< Interference overlapping uses.
1775 // |---o---o---| Live-out on stack.
1776 // =====----____ Leave IntvIn before interference, then spill.
1777 //
1778 SlotIndex To = leaveIntvAfter(BI.LastInstr);
1779 SlotIndex From = enterIntvBefore(LeaveBefore);
1780 useIntv(From, To);
1781 selectIntv(IntvIn);
1782 useIntv(Start, From);
1783 assert((!LeaveBefore || From <= LeaveBefore) && "Interference")((void)0);
1784 return;
1785 }
1786
1787 // <<<<<<< Interference overlapping uses.
1788 // |---o---o--o| Live-out on stack, late last use.
1789 // =====------- Copy to stack before LSP, overlap LocalIntv.
1790 // \_____ Stack interval is live-out.
1791 //
1792 SlotIndex To = leaveIntvBefore(LSP);
1793 overlapIntv(To, BI.LastInstr);
1794 SlotIndex From = enterIntvBefore(std::min(To, LeaveBefore));
1795 useIntv(From, To);
1796 selectIntv(IntvIn);
1797 useIntv(Start, From);
1798 assert((!LeaveBefore || From <= LeaveBefore) && "Interference")((void)0);
1799}
1800
1801void SplitEditor::splitRegOutBlock(const SplitAnalysis::BlockInfo &BI,
1802 unsigned IntvOut, SlotIndex EnterAfter) {
1803 SlotIndex Start, Stop;
1804 std::tie(Start, Stop) = LIS.getSlotIndexes()->getMBBRange(BI.MBB);
1805
1806 LLVM_DEBUG(dbgs() << printMBBReference(*BI.MBB) << " [" << Start << ';'do { } while (false)
1807 << Stop << "), uses " << BI.FirstInstr << '-'do { } while (false)
1808 << BI.LastInstr << ", reg-out " << IntvOutdo { } while (false)
1809 << ", enter after " << EnterAfterdo { } while (false)
1810 << (BI.LiveIn ? ", stack-in" : ", defined in block"))do { } while (false);
1811
1812 SlotIndex LSP = SA.getLastSplitPoint(BI.MBB);
1813
1814 assert(IntvOut && "Must have register out")((void)0);
1815 assert(BI.LiveOut && "Must be live-out")((void)0);
1816 assert((!EnterAfter || EnterAfter < LSP) && "Bad interference")((void)0);
1817
1818 if (!BI.LiveIn && (!EnterAfter || EnterAfter <= BI.FirstInstr)) {
1819 LLVM_DEBUG(dbgs() << " after interference.\n")do { } while (false);
1820 //
1821 // >>>> Interference before def.
1822 // | o---o---| Defined in block.
1823 // ========= Use IntvOut everywhere.
1824 //
1825 selectIntv(IntvOut);
1826 useIntv(BI.FirstInstr, Stop);
1827 return;
1828 }
1829
1830 if (!EnterAfter || EnterAfter < BI.FirstInstr.getBaseIndex()) {
1831 LLVM_DEBUG(dbgs() << ", reload after interference.\n")do { } while (false);
1832 //
1833 // >>>> Interference before def.
1834 // |---o---o---| Live-through, stack-in.
1835 // ____========= Enter IntvOut before first use.
1836 //
1837 selectIntv(IntvOut);
1838 SlotIndex Idx = enterIntvBefore(std::min(LSP, BI.FirstInstr));
1839 useIntv(Idx, Stop);
1840 assert((!EnterAfter || Idx >= EnterAfter) && "Interference")((void)0);
1841 return;
1842 }
1843
1844 // The interference is overlapping somewhere we wanted to use IntvOut. That
1845 // means we need to create a local interval that can be allocated a
1846 // different register.
1847 LLVM_DEBUG(dbgs() << ", interference overlaps uses.\n")do { } while (false);
1848 //
1849 // >>>>>>> Interference overlapping uses.
1850 // |---o---o---| Live-through, stack-in.
1851 // ____---====== Create local interval for interference range.
1852 //
1853 selectIntv(IntvOut);
1854 SlotIndex Idx = enterIntvAfter(EnterAfter);
1855 useIntv(Idx, Stop);
1856 assert((!EnterAfter || Idx >= EnterAfter) && "Interference")((void)0);
1857
1858 openIntv();
1859 SlotIndex From = enterIntvBefore(std::min(Idx, BI.FirstInstr));
1860 useIntv(From, Idx);
1861}
1862
1863void SplitAnalysis::BlockInfo::print(raw_ostream &OS) const {
1864 OS << "{" << printMBBReference(*MBB) << ", "
1865 << "uses " << FirstInstr << " to " << LastInstr << ", "
1866 << "1st def " << FirstDef << ", "
1867 << (LiveIn ? "live in" : "dead in") << ", "
1868 << (LiveOut ? "live out" : "dead out") << "}";
1869}
1870
1871void SplitAnalysis::BlockInfo::dump() const {
1872 print(dbgs());
1873 dbgs() << "\n";
1874}

/usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/CodeGen/MachineDominators.h

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
27namespace llvm {
28
29template <>
30inline void DominatorTreeBase<MachineBasicBlock, false>::addRoot(
31 MachineBasicBlock *MBB) {
32 this->Roots.push_back(MBB);
33}
34
35extern template class DomTreeNodeBase<MachineBasicBlock>;
36extern template class DominatorTreeBase<MachineBasicBlock, false>; // DomTree
37extern template class DominatorTreeBase<MachineBasicBlock, true>; // PostDomTree
38
39using MachineDomTreeNode = DomTreeNodeBase<MachineBasicBlock>;
40
41//===-------------------------------------
42/// DominatorTree Class - Concrete subclass of DominatorTreeBase that is used to
43/// compute a normal dominator tree.
44///
45class 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
79public:
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);
16
Calling 'DominatorTreeBase::findNearestCommonDominator'
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
248template <class Node, class ChildIterator>
249struct 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
258template <class T> struct GraphTraits;
259
260template <>
261struct GraphTraits<MachineDomTreeNode *>
262 : public MachineDomTreeGraphTraitsBase<MachineDomTreeNode,
263 MachineDomTreeNode::const_iterator> {
264};
265
266template <>
267struct GraphTraits<const MachineDomTreeNode *>
268 : public MachineDomTreeGraphTraitsBase<const MachineDomTreeNode,
269 MachineDomTreeNode::const_iterator> {
270};
271
272template <> 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

/usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Support/GenericDomTree.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
42namespace llvm {
43
44template <typename NodeT, bool IsPostDom>
45class DominatorTreeBase;
46
47namespace DomTreeBuilder {
48template <typename DomTreeT>
49struct SemiNCAInfo;
50} // namespace DomTreeBuilder
51
52/// Base class for the actual dominator tree node.
53template <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
146private:
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
172template <class NodeT>
173raw_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
185template <class NodeT>
186void 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
195namespace DomTreeBuilder {
196// The routines below are provided in a separate header but referenced here.
197template <typename DomTreeT>
198void Calculate(DomTreeT &DT);
199
200template <typename DomTreeT>
201void CalculateWithUpdates(DomTreeT &DT,
202 ArrayRef<typename DomTreeT::UpdateType> Updates);
203
204template <typename DomTreeT>
205void InsertEdge(DomTreeT &DT, typename DomTreeT::NodePtr From,
206 typename DomTreeT::NodePtr To);
207
208template <typename DomTreeT>
209void DeleteEdge(DomTreeT &DT, typename DomTreeT::NodePtr From,
210 typename DomTreeT::NodePtr To);
211
212template <typename DomTreeT>
213void ApplyUpdates(DomTreeT &DT,
214 GraphDiff<typename DomTreeT::NodePtr,
215 DomTreeT::IsPostDominator> &PreViewCFG,
216 GraphDiff<typename DomTreeT::NodePtr,
217 DomTreeT::IsPostDominator> *PostViewCFG);
218
219template <typename DomTreeT>
220bool 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.
227template <typename NodeT, bool IsPostDom>
228class 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
247protected:
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; }
18
Returning zero (loaded from 'IsPostDominator'), which participates in a condition later
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())
25
Calling 'operator!='
31
Returning from 'operator!='
32
Taking true branch
354 return I->second.get();
33
Returning pointer
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()) {
17
Calling 'DominatorTreeBase::isPostDominator'
19
Returning from 'DominatorTreeBase::isPostDominator'
20
Taking true branch
476 NodeT &Entry = A->getParent()->front();
477 if (A == &Entry || B == &Entry)
21
Assuming the condition is false
22
Assuming the condition is false
23
Taking false branch
478 return &Entry;
479 }
480
481 DomTreeNodeBase<NodeT> *NodeA = getNode(A);
24
Calling 'DominatorTreeBase::getNode'
34
Returning from 'DominatorTreeBase::getNode'
35
'NodeA' initialized here
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) {
36
Assuming 'NodeA' is equal to 'NodeB'
37
Assuming pointer value is null
38
Loop condition is false. Execution continues on line 494
489 if (NodeA->getLevel() < NodeB->getLevel()) std::swap(NodeA, NodeB);
490
491 NodeA = NodeA->IDom;
492 }
493
494 return NodeA->getBlock();
39
Called C++ object pointer is null
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
729public:
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
815protected:
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
914template <typename T>
915using DomTreeBase = DominatorTreeBase<T, false>;
916
917template <typename T>
918using 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.
922template <typename NodeT, bool IsPostDom>
923bool 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}
934template <typename NodeT, bool IsPostDom>
935bool 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

/usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ADT/DenseMap.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
34namespace llvm {
35
36namespace detail {
37
38// We extend a pair to allow users to override the bucket type with their own
39// implementation without requiring two members.
40template <typename KeyT, typename ValueT>
41struct 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
52template <typename KeyT, typename ValueT,
53 typename KeyInfoT = DenseMapInfo<KeyT>,
54 typename Bucket = llvm::detail::DenseMapPair<KeyT, ValueT>,
55 bool IsConst = false>
56class DenseMapIterator;
57
58template <typename DerivedT, typename KeyT, typename ValueT, typename KeyInfoT,
59 typename BucketT>
60class DenseMapBase : public DebugEpochBase {
61 template <typename T>
62 using const_arg_type_t = typename const_pointer_or_const_ref<T>::type;
63
64public:
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
357protected:
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
463private:
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
667public:
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).
683template <typename DerivedT, typename KeyT, typename ValueT, typename KeyInfoT,
684 typename BucketT>
685bool 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.
703template <typename DerivedT, typename KeyT, typename ValueT, typename KeyInfoT,
704 typename BucketT>
705bool 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
711template <typename KeyT, typename ValueT,
712 typename KeyInfoT = DenseMapInfo<KeyT>,
713 typename BucketT = llvm::detail::DenseMapPair<KeyT, ValueT>>
714class 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
727public:
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
839private:
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
877template <typename KeyT, typename ValueT, unsigned InlineBuckets = 4,
878 typename KeyInfoT = DenseMapInfo<KeyT>,
879 typename BucketT = llvm::detail::DenseMapPair<KeyT, ValueT>>
880class 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
906public:
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
1115private:
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
1190template <typename KeyT, typename ValueT, typename KeyInfoT, typename Bucket,
1191 bool IsConst>
1192class DenseMapIterator : DebugEpochBase::HandleBase {
1193 friend class DenseMapIterator<KeyT, ValueT, KeyInfoT, Bucket, true>;
1194 friend class DenseMapIterator<KeyT, ValueT, KeyInfoT, Bucket, false>;
1195
1196public:
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
1204private:
1205 pointer Ptr = nullptr;
1206 pointer End = nullptr;
1207
1208public:
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;
27
Assuming 'LHS.Ptr' is not equal to 'RHS.Ptr'
28
Returning zero, which participates in a condition later
1255 }
1256
1257 friend bool operator!=(const DenseMapIterator &LHS,
1258 const DenseMapIterator &RHS) {
1259 return !(LHS == RHS);
26
Calling 'operator=='
29
Returning from 'operator=='
30
Returning the value 1, which participates in a condition later
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
1279private:
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
1301template <typename KeyT, typename ValueT, typename KeyInfoT>
1302inline 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