LLVM 19.0.0git
CoroElide.cpp
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1//===- CoroElide.cpp - Coroutine Frame Allocation Elision Pass ------------===//
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
10#include "CoroInternal.h"
11#include "llvm/ADT/DenseMap.h"
12#include "llvm/ADT/Statistic.h"
16#include "llvm/IR/Dominators.h"
20#include <optional>
21
22using namespace llvm;
23
24#define DEBUG_TYPE "coro-elide"
25
26STATISTIC(NumOfCoroElided, "The # of coroutine get elided.");
27
28#ifndef NDEBUG
30 "coro-elide-info-output-file", cl::value_desc("filename"),
31 cl::desc("File to record the coroutines got elided"), cl::Hidden);
32#endif
33
34namespace {
35// Created on demand if the coro-elide pass has work to do.
36struct Lowerer : coro::LowererBase {
42 SmallPtrSet<const SwitchInst *, 4> CoroSuspendSwitches;
43
44 Lowerer(Module &M) : LowererBase(M) {}
45
46 void elideHeapAllocations(Function *F, uint64_t FrameSize, Align FrameAlign,
47 AAResults &AA);
48 bool shouldElide(Function *F, DominatorTree &DT) const;
49 void collectPostSplitCoroIds(Function *F);
50 bool processCoroId(CoroIdInst *, AAResults &AA, DominatorTree &DT,
52 bool hasEscapePath(const CoroBeginInst *,
53 const SmallPtrSetImpl<BasicBlock *> &) const;
54};
55} // end anonymous namespace
56
57// Go through the list of coro.subfn.addr intrinsics and replace them with the
58// provided constant.
61 if (Users.empty())
62 return;
63
64 // See if we need to bitcast the constant to match the type of the intrinsic
65 // being replaced. Note: All coro.subfn.addr intrinsics return the same type,
66 // so we only need to examine the type of the first one in the list.
67 Type *IntrTy = Users.front()->getType();
68 Type *ValueTy = Value->getType();
69 if (ValueTy != IntrTy) {
70 // May need to tweak the function type to match the type expected at the
71 // use site.
72 assert(ValueTy->isPointerTy() && IntrTy->isPointerTy());
74 }
75
76 // Now the value type matches the type of the intrinsic. Replace them all!
77 for (CoroSubFnInst *I : Users)
79}
80
81// See if any operand of the call instruction references the coroutine frame.
82static bool operandReferences(CallInst *CI, AllocaInst *Frame, AAResults &AA) {
83 for (Value *Op : CI->operand_values())
84 if (!AA.isNoAlias(Op, Frame))
85 return true;
86 return false;
87}
88
89// Look for any tail calls referencing the coroutine frame and remove tail
90// attribute from them, since now coroutine frame resides on the stack and tail
91// call implies that the function does not references anything on the stack.
92// However if it's a musttail call, we cannot remove the tailcall attribute.
93// It's safe to keep it there as the musttail call is for symmetric transfer,
94// and by that point the frame should have been destroyed and hence not
95// interfering with operands.
97 Function &F = *Frame->getFunction();
98 for (Instruction &I : instructions(F))
99 if (auto *Call = dyn_cast<CallInst>(&I))
100 if (Call->isTailCall() && operandReferences(Call, Frame, AA) &&
101 !Call->isMustTailCall())
102 Call->setTailCall(false);
103}
104
105// Given a resume function @f.resume(%f.frame* %frame), returns the size
106// and expected alignment of %f.frame type.
107static std::optional<std::pair<uint64_t, Align>>
109 // Pull information from the function attributes.
110 auto Size = Resume->getParamDereferenceableBytes(0);
111 if (!Size)
112 return std::nullopt;
113 return std::make_pair(Size, Resume->getParamAlign(0).valueOrOne());
114}
115
116// Finds first non alloca instruction in the entry block of a function.
118 for (Instruction &I : F->getEntryBlock())
119 if (!isa<AllocaInst>(&I))
120 return &I;
121 llvm_unreachable("no terminator in the entry block");
122}
123
124#ifndef NDEBUG
125static std::unique_ptr<raw_fd_ostream> getOrCreateLogFile() {
127 "coro-elide-info-output-file shouldn't be empty");
128 std::error_code EC;
129 auto Result = std::make_unique<raw_fd_ostream>(CoroElideInfoOutputFilename,
131 if (!EC)
132 return Result;
133 llvm::errs() << "Error opening coro-elide-info-output-file '"
134 << CoroElideInfoOutputFilename << " for appending!\n";
135 return std::make_unique<raw_fd_ostream>(2, false); // stderr.
136}
137#endif
138
139// To elide heap allocations we need to suppress code blocks guarded by
140// llvm.coro.alloc and llvm.coro.free instructions.
141void Lowerer::elideHeapAllocations(Function *F, uint64_t FrameSize,
142 Align FrameAlign, AAResults &AA) {
143 LLVMContext &C = F->getContext();
144 auto *InsertPt =
145 getFirstNonAllocaInTheEntryBlock(CoroIds.front()->getFunction());
146
147 // Replacing llvm.coro.alloc with false will suppress dynamic
148 // allocation as it is expected for the frontend to generate the code that
149 // looks like:
150 // id = coro.id(...)
151 // mem = coro.alloc(id) ? malloc(coro.size()) : 0;
152 // coro.begin(id, mem)
153 auto *False = ConstantInt::getFalse(C);
154 for (auto *CA : CoroAllocs) {
155 CA->replaceAllUsesWith(False);
156 CA->eraseFromParent();
157 }
158
159 // FIXME: Design how to transmit alignment information for every alloca that
160 // is spilled into the coroutine frame and recreate the alignment information
161 // here. Possibly we will need to do a mini SROA here and break the coroutine
162 // frame into individual AllocaInst recreating the original alignment.
163 const DataLayout &DL = F->getParent()->getDataLayout();
164 auto FrameTy = ArrayType::get(Type::getInt8Ty(C), FrameSize);
165 auto *Frame = new AllocaInst(FrameTy, DL.getAllocaAddrSpace(), "", InsertPt);
166 Frame->setAlignment(FrameAlign);
167 auto *FrameVoidPtr =
168 new BitCastInst(Frame, PointerType::getUnqual(C), "vFrame", InsertPt);
169
170 for (auto *CB : CoroBegins) {
171 CB->replaceAllUsesWith(FrameVoidPtr);
172 CB->eraseFromParent();
173 }
174
175 // Since now coroutine frame lives on the stack we need to make sure that
176 // any tail call referencing it, must be made non-tail call.
177 removeTailCallAttribute(Frame, AA);
178}
179
180bool Lowerer::hasEscapePath(const CoroBeginInst *CB,
181 const SmallPtrSetImpl<BasicBlock *> &TIs) const {
182 const auto &It = DestroyAddr.find(CB);
183 assert(It != DestroyAddr.end());
184
185 // Limit the number of blocks we visit.
186 unsigned Limit = 32 * (1 + It->second.size());
187
189 Worklist.push_back(CB->getParent());
190
192 // Consider basicblock of coro.destroy as visited one, so that we
193 // skip the path pass through coro.destroy.
194 for (auto *DA : It->second)
195 Visited.insert(DA->getParent());
196
198 for (auto *U : CB->users()) {
199 // The use from coroutine intrinsics are not a problem.
200 if (isa<CoroFreeInst, CoroSubFnInst, CoroSaveInst>(U))
201 continue;
202
203 // Think all other usages may be an escaping candidate conservatively.
204 //
205 // Note that the major user of switch ABI coroutine (the C++) will store
206 // resume.fn, destroy.fn and the index to the coroutine frame immediately.
207 // So the parent of the coro.begin in C++ will be always escaping.
208 // Then we can't get any performance benefits for C++ by improving the
209 // precision of the method.
210 //
211 // The reason why we still judge it is we want to make LLVM Coroutine in
212 // switch ABIs to be self contained as much as possible instead of a
213 // by-product of C++20 Coroutines.
214 EscapingBBs.insert(cast<Instruction>(U)->getParent());
215 }
216
217 bool PotentiallyEscaped = false;
218
219 do {
220 const auto *BB = Worklist.pop_back_val();
221 if (!Visited.insert(BB).second)
222 continue;
223
224 // A Path insensitive marker to test whether the coro.begin escapes.
225 // It is intentional to make it path insensitive while it may not be
226 // precise since we don't want the process to be too slow.
227 PotentiallyEscaped |= EscapingBBs.count(BB);
228
229 if (TIs.count(BB)) {
230 if (isa<ReturnInst>(BB->getTerminator()) || PotentiallyEscaped)
231 return true;
232
233 // If the function ends with the exceptional terminator, the memory used
234 // by the coroutine frame can be released by stack unwinding
235 // automatically. So we can think the coro.begin doesn't escape if it
236 // exits the function by exceptional terminator.
237
238 continue;
239 }
240
241 // Conservatively say that there is potentially a path.
242 if (!--Limit)
243 return true;
244
245 auto TI = BB->getTerminator();
246 // Although the default dest of coro.suspend switches is suspend pointer
247 // which means a escape path to normal terminator, it is reasonable to skip
248 // it since coroutine frame doesn't change outside the coroutine body.
249 if (isa<SwitchInst>(TI) &&
250 CoroSuspendSwitches.count(cast<SwitchInst>(TI))) {
251 Worklist.push_back(cast<SwitchInst>(TI)->getSuccessor(1));
252 Worklist.push_back(cast<SwitchInst>(TI)->getSuccessor(2));
253 } else
254 Worklist.append(succ_begin(BB), succ_end(BB));
255
256 } while (!Worklist.empty());
257
258 // We have exhausted all possible paths and are certain that coro.begin can
259 // not reach to any of terminators.
260 return false;
261}
262
263bool Lowerer::shouldElide(Function *F, DominatorTree &DT) const {
264 // If no CoroAllocs, we cannot suppress allocation, so elision is not
265 // possible.
266 if (CoroAllocs.empty())
267 return false;
268
269 // Check that for every coro.begin there is at least one coro.destroy directly
270 // referencing the SSA value of that coro.begin along each
271 // non-exceptional path.
272 // If the value escaped, then coro.destroy would have been referencing a
273 // memory location storing that value and not the virtual register.
274
276 // First gather all of the terminators for the function.
277 // Consider the final coro.suspend as the real terminator when the current
278 // function is a coroutine.
279 for (BasicBlock &B : *F) {
280 auto *TI = B.getTerminator();
281
282 if (TI->getNumSuccessors() != 0 || isa<UnreachableInst>(TI))
283 continue;
284
285 Terminators.insert(&B);
286 }
287
288 // Filter out the coro.destroy that lie along exceptional paths.
289 SmallPtrSet<CoroBeginInst *, 8> ReferencedCoroBegins;
290 for (const auto &It : DestroyAddr) {
291 // If every terminators is dominated by coro.destroy, we could know the
292 // corresponding coro.begin wouldn't escape.
293 //
294 // Otherwise hasEscapePath would decide whether there is any paths from
295 // coro.begin to Terminators which not pass through any of the
296 // coro.destroys.
297 //
298 // hasEscapePath is relatively slow, so we avoid to run it as much as
299 // possible.
300 if (llvm::all_of(Terminators,
301 [&](auto *TI) {
302 return llvm::any_of(It.second, [&](auto *DA) {
303 return DT.dominates(DA, TI->getTerminator());
304 });
305 }) ||
306 !hasEscapePath(It.first, Terminators))
307 ReferencedCoroBegins.insert(It.first);
308 }
309
310 // If size of the set is the same as total number of coro.begin, that means we
311 // found a coro.free or coro.destroy referencing each coro.begin, so we can
312 // perform heap elision.
313 return ReferencedCoroBegins.size() == CoroBegins.size();
314}
315
316void Lowerer::collectPostSplitCoroIds(Function *F) {
317 CoroIds.clear();
318 CoroSuspendSwitches.clear();
319 for (auto &I : instructions(F)) {
320 if (auto *CII = dyn_cast<CoroIdInst>(&I))
321 if (CII->getInfo().isPostSplit())
322 // If it is the coroutine itself, don't touch it.
323 if (CII->getCoroutine() != CII->getFunction())
324 CoroIds.push_back(CII);
325
326 // Consider case like:
327 // %0 = call i8 @llvm.coro.suspend(...)
328 // switch i8 %0, label %suspend [i8 0, label %resume
329 // i8 1, label %cleanup]
330 // and collect the SwitchInsts which are used by escape analysis later.
331 if (auto *CSI = dyn_cast<CoroSuspendInst>(&I))
332 if (CSI->hasOneUse() && isa<SwitchInst>(CSI->use_begin()->getUser())) {
333 SwitchInst *SWI = cast<SwitchInst>(CSI->use_begin()->getUser());
334 if (SWI->getNumCases() == 2)
335 CoroSuspendSwitches.insert(SWI);
336 }
337 }
338}
339
340bool Lowerer::processCoroId(CoroIdInst *CoroId, AAResults &AA,
342 CoroBegins.clear();
343 CoroAllocs.clear();
344 ResumeAddr.clear();
345 DestroyAddr.clear();
346
347 // Collect all coro.begin and coro.allocs associated with this coro.id.
348 for (User *U : CoroId->users()) {
349 if (auto *CB = dyn_cast<CoroBeginInst>(U))
350 CoroBegins.push_back(CB);
351 else if (auto *CA = dyn_cast<CoroAllocInst>(U))
352 CoroAllocs.push_back(CA);
353 }
354
355 // Collect all coro.subfn.addrs associated with coro.begin.
356 // Note, we only devirtualize the calls if their coro.subfn.addr refers to
357 // coro.begin directly. If we run into cases where this check is too
358 // conservative, we can consider relaxing the check.
359 for (CoroBeginInst *CB : CoroBegins) {
360 for (User *U : CB->users())
361 if (auto *II = dyn_cast<CoroSubFnInst>(U))
362 switch (II->getIndex()) {
364 ResumeAddr.push_back(II);
365 break;
367 DestroyAddr[CB].push_back(II);
368 break;
369 default:
370 llvm_unreachable("unexpected coro.subfn.addr constant");
371 }
372 }
373
374 // PostSplit coro.id refers to an array of subfunctions in its Info
375 // argument.
376 ConstantArray *Resumers = CoroId->getInfo().Resumers;
377 assert(Resumers && "PostSplit coro.id Info argument must refer to an array"
378 "of coroutine subfunctions");
379 auto *ResumeAddrConstant =
381
382 replaceWithConstant(ResumeAddrConstant, ResumeAddr);
383
384 bool ShouldElide = shouldElide(CoroId->getFunction(), DT);
385 if (!ShouldElide)
386 ORE.emit([&]() {
387 if (auto FrameSizeAndAlign =
388 getFrameLayout(cast<Function>(ResumeAddrConstant)))
389 return OptimizationRemarkMissed(DEBUG_TYPE, "CoroElide", CoroId)
390 << "'" << ore::NV("callee", CoroId->getCoroutine()->getName())
391 << "' not elided in '"
392 << ore::NV("caller", CoroId->getFunction()->getName())
393 << "' (frame_size="
394 << ore::NV("frame_size", FrameSizeAndAlign->first) << ", align="
395 << ore::NV("align", FrameSizeAndAlign->second.value()) << ")";
396 else
397 return OptimizationRemarkMissed(DEBUG_TYPE, "CoroElide", CoroId)
398 << "'" << ore::NV("callee", CoroId->getCoroutine()->getName())
399 << "' not elided in '"
400 << ore::NV("caller", CoroId->getFunction()->getName())
401 << "' (frame_size=unknown, align=unknown)";
402 });
403
404 auto *DestroyAddrConstant = Resumers->getAggregateElement(
406
407 for (auto &It : DestroyAddr)
408 replaceWithConstant(DestroyAddrConstant, It.second);
409
410 if (ShouldElide) {
411 if (auto FrameSizeAndAlign =
412 getFrameLayout(cast<Function>(ResumeAddrConstant))) {
413 elideHeapAllocations(CoroId->getFunction(), FrameSizeAndAlign->first,
414 FrameSizeAndAlign->second, AA);
415 coro::replaceCoroFree(CoroId, /*Elide=*/true);
416 NumOfCoroElided++;
417#ifndef NDEBUG
418 if (!CoroElideInfoOutputFilename.empty())
420 << "Elide " << CoroId->getCoroutine()->getName() << " in "
421 << CoroId->getFunction()->getName() << "\n";
422#endif
423 ORE.emit([&]() {
424 return OptimizationRemark(DEBUG_TYPE, "CoroElide", CoroId)
425 << "'" << ore::NV("callee", CoroId->getCoroutine()->getName())
426 << "' elided in '"
427 << ore::NV("caller", CoroId->getFunction()->getName())
428 << "' (frame_size="
429 << ore::NV("frame_size", FrameSizeAndAlign->first) << ", align="
430 << ore::NV("align", FrameSizeAndAlign->second.value()) << ")";
431 });
432 } else {
433 ORE.emit([&]() {
434 return OptimizationRemarkMissed(DEBUG_TYPE, "CoroElide", CoroId)
435 << "'" << ore::NV("callee", CoroId->getCoroutine()->getName())
436 << "' not elided in '"
437 << ore::NV("caller", CoroId->getFunction()->getName())
438 << "' (frame_size=unknown, align=unknown)";
439 });
440 }
441 }
442
443 return true;
444}
445
447 return coro::declaresIntrinsics(M, {"llvm.coro.id", "llvm.coro.id.async"});
448}
449
451 auto &M = *F.getParent();
453 return PreservedAnalyses::all();
454
455 Lowerer L(M);
456 L.CoroIds.clear();
457 L.collectPostSplitCoroIds(&F);
458 // If we did not find any coro.id, there is nothing to do.
459 if (L.CoroIds.empty())
460 return PreservedAnalyses::all();
461
462 AAResults &AA = AM.getResult<AAManager>(F);
465
466 bool Changed = false;
467 for (auto *CII : L.CoroIds)
468 Changed |= L.processCoroId(CII, AA, DT, ORE);
469
470 return Changed ? PreservedAnalyses::none() : PreservedAnalyses::all();
471}
MachineBasicBlock MachineBasicBlock::iterator DebugLoc DL
static GCRegistry::Add< OcamlGC > B("ocaml", "ocaml 3.10-compatible GC")
static void replaceWithConstant(Constant *Value, SmallVectorImpl< CoroSubFnInst * > &Users)
Definition: CoroElide.cpp:59
static Instruction * getFirstNonAllocaInTheEntryBlock(Function *F)
Definition: CoroElide.cpp:117
static cl::opt< std::string > CoroElideInfoOutputFilename("coro-elide-info-output-file", cl::value_desc("filename"), cl::desc("File to record the coroutines got elided"), cl::Hidden)
static void removeTailCallAttribute(AllocaInst *Frame, AAResults &AA)
Definition: CoroElide.cpp:96
static std::optional< std::pair< uint64_t, Align > > getFrameLayout(Function *Resume)
Definition: CoroElide.cpp:108
static bool declaresCoroElideIntrinsics(Module &M)
Definition: CoroElide.cpp:446
#define DEBUG_TYPE
Definition: CoroElide.cpp:24
static std::unique_ptr< raw_fd_ostream > getOrCreateLogFile()
Definition: CoroElide.cpp:125
static bool operandReferences(CallInst *CI, AllocaInst *Frame, AAResults &AA)
Definition: CoroElide.cpp:82
This file defines the DenseMap class.
uint64_t Size
iv Induction Variable Users
Definition: IVUsers.cpp:48
Select target instructions out of generic instructions
#define F(x, y, z)
Definition: MD5.cpp:55
#define I(x, y, z)
Definition: MD5.cpp:58
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
This file defines the 'Statistic' class, which is designed to be an easy way to expose various metric...
#define STATISTIC(VARNAME, DESC)
Definition: Statistic.h:167
A manager for alias analyses.
bool isNoAlias(const MemoryLocation &LocA, const MemoryLocation &LocB)
A trivial helper function to check to see if the specified pointers are no-alias.
an instruction to allocate memory on the stack
Definition: Instructions.h:59
A container for analyses that lazily runs them and caches their results.
Definition: PassManager.h:348
PassT::Result & getResult(IRUnitT &IR, ExtraArgTs... ExtraArgs)
Get the result of an analysis pass for a given IR unit.
Definition: PassManager.h:500
LLVM Basic Block Representation.
Definition: BasicBlock.h:60
This class represents a no-op cast from one type to another.
This class represents a function call, abstracting a target machine's calling convention.
ConstantArray - Constant Array Declarations.
Definition: Constants.h:422
static Constant * getBitCast(Constant *C, Type *Ty, bool OnlyIfReduced=false)
Definition: Constants.cpp:2140
static ConstantInt * getFalse(LLVMContext &Context)
Definition: Constants.cpp:856
This is an important base class in LLVM.
Definition: Constant.h:41
Constant * getAggregateElement(unsigned Elt) const
For aggregates (struct/array/vector) return the constant that corresponds to the specified element if...
Definition: Constants.cpp:432
This class represents the llvm.coro.begin instruction.
Definition: CoroInstr.h:418
This represents the llvm.coro.id instruction.
Definition: CoroInstr.h:113
Info getInfo() const
Definition: CoroInstr.h:162
Function * getCoroutine() const
Definition: CoroInstr.h:182
This class represents the llvm.coro.subfn.addr instruction.
Definition: CoroInstr.h:35
This class represents an Operation in the Expression.
A parsed version of the target data layout string in and methods for querying it.
Definition: DataLayout.h:110
Analysis pass which computes a DominatorTree.
Definition: Dominators.h:275
Concrete subclass of DominatorTreeBase that is used to compute a normal dominator tree.
Definition: Dominators.h:162
uint64_t getParamDereferenceableBytes(unsigned ArgNo) const
Extract the number of dereferenceable bytes for a parameter.
Definition: Function.h:496
MaybeAlign getParamAlign(unsigned ArgNo) const
Definition: Function.h:461
const BasicBlock * getParent() const
Definition: Instruction.h:150
const Function * getFunction() const
Return the function this instruction belongs to.
Definition: Instruction.cpp:75
This is an important class for using LLVM in a threaded context.
Definition: LLVMContext.h:67
A Module instance is used to store all the information related to an LLVM module.
Definition: Module.h:65
The optimization diagnostic interface.
void emit(DiagnosticInfoOptimizationBase &OptDiag)
Output the remark via the diagnostic handler and to the optimization record file.
Diagnostic information for missed-optimization remarks.
Diagnostic information for applied optimization remarks.
A set of analyses that are preserved following a run of a transformation pass.
Definition: Analysis.h:109
static PreservedAnalyses none()
Convenience factory function for the empty preserved set.
Definition: Analysis.h:112
static PreservedAnalyses all()
Construct a special preserved set that preserves all passes.
Definition: Analysis.h:115
size_type size() const
Definition: SmallPtrSet.h:94
A templated base class for SmallPtrSet which provides the typesafe interface that is common across al...
Definition: SmallPtrSet.h:321
size_type count(ConstPtrType Ptr) const
count - Return 1 if the specified pointer is in the set, 0 otherwise.
Definition: SmallPtrSet.h:360
std::pair< iterator, bool > insert(PtrType Ptr)
Inserts Ptr if and only if there is no element in the container equal to Ptr.
Definition: SmallPtrSet.h:342
SmallPtrSet - This class implements a set which is optimized for holding SmallSize or less elements.
Definition: SmallPtrSet.h:427
bool empty() const
Definition: SmallVector.h:94
This class consists of common code factored out of the SmallVector class to reduce code duplication b...
Definition: SmallVector.h:586
void append(ItTy in_start, ItTy in_end)
Add the specified range to the end of the SmallVector.
Definition: SmallVector.h:696
void push_back(const T &Elt)
Definition: SmallVector.h:426
This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small.
Definition: SmallVector.h:1209
Multiway switch.
unsigned getNumCases() const
Return the number of 'cases' in this switch instruction, excluding the default case.
The instances of the Type class are immutable: once they are created, they are never changed.
Definition: Type.h:45
bool isPointerTy() const
True if this is an instance of PointerType.
Definition: Type.h:255
static IntegerType * getInt8Ty(LLVMContext &C)
iterator_range< value_op_iterator > operand_values()
Definition: User.h:266
LLVM Value Representation.
Definition: Value.h:74
Type * getType() const
All values are typed, get the type of this value.
Definition: Value.h:255
iterator_range< user_iterator > users()
Definition: Value.h:421
StringRef getName() const
Return a constant reference to the value's name.
Definition: Value.cpp:309
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
@ C
The default llvm calling convention, compatible with C.
Definition: CallingConv.h:34
bool declaresIntrinsics(const Module &M, const std::initializer_list< StringRef >)
Definition: Coroutines.cpp:112
void replaceCoroFree(CoroIdInst *CoroId, bool Elide)
Definition: Coroutines.cpp:125
DiagnosticInfoOptimizationBase::Argument NV
@ OF_Append
The file should be opened in append mode.
Definition: FileSystem.h:771
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
Interval::succ_iterator succ_end(Interval *I)
Definition: Interval.h:102
bool all_of(R &&range, UnaryPredicate P)
Provide wrappers to std::all_of which take ranges instead of having to pass begin/end explicitly.
Definition: STLExtras.h:1731
Interval::succ_iterator succ_begin(Interval *I)
succ_begin/succ_end - define methods so that Intervals may be used just like BasicBlocks can with the...
Definition: Interval.h:99
bool any_of(R &&range, UnaryPredicate P)
Provide wrappers to std::any_of which take ranges instead of having to pass begin/end explicitly.
Definition: STLExtras.h:1738
bool replaceAndRecursivelySimplify(Instruction *I, Value *SimpleV, const TargetLibraryInfo *TLI=nullptr, const DominatorTree *DT=nullptr, AssumptionCache *AC=nullptr, SmallSetVector< Instruction *, 8 > *UnsimplifiedUsers=nullptr)
Replace all uses of 'I' with 'SimpleV' and simplify the uses recursively.
raw_fd_ostream & errs()
This returns a reference to a raw_ostream for standard error.
This struct is a compact representation of a valid (non-zero power of two) alignment.
Definition: Alignment.h:39
PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM)
Definition: CoroElide.cpp:450
ConstantArray * Resumers
Definition: CoroInstr.h:156
Used in the streaming interface as the general argument type.
Align valueOrOne() const
For convenience, returns a valid alignment or 1 if undefined.
Definition: Alignment.h:141