LLVM 17.0.0git
CallPromotionUtils.cpp
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1//===- CallPromotionUtils.cpp - Utilities for call promotion ----*- 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 implements utilities useful for promoting indirect call sites to
10// direct call sites.
11//
12//===----------------------------------------------------------------------===//
13
15#include "llvm/Analysis/Loads.h"
17#include "llvm/IR/IRBuilder.h"
20
21using namespace llvm;
22
23#define DEBUG_TYPE "call-promotion-utils"
24
25/// Fix-up phi nodes in an invoke instruction's normal destination.
26///
27/// After versioning an invoke instruction, values coming from the original
28/// block will now be coming from the "merge" block. For example, in the code
29/// below:
30///
31/// then_bb:
32/// %t0 = invoke i32 %ptr() to label %merge_bb unwind label %unwind_dst
33///
34/// else_bb:
35/// %t1 = invoke i32 %ptr() to label %merge_bb unwind label %unwind_dst
36///
37/// merge_bb:
38/// %t2 = phi i32 [ %t0, %then_bb ], [ %t1, %else_bb ]
39/// br %normal_dst
40///
41/// normal_dst:
42/// %t3 = phi i32 [ %x, %orig_bb ], ...
43///
44/// "orig_bb" is no longer a predecessor of "normal_dst", so the phi nodes in
45/// "normal_dst" must be fixed to refer to "merge_bb":
46///
47/// normal_dst:
48/// %t3 = phi i32 [ %x, %merge_bb ], ...
49///
50static void fixupPHINodeForNormalDest(InvokeInst *Invoke, BasicBlock *OrigBlock,
51 BasicBlock *MergeBlock) {
52 for (PHINode &Phi : Invoke->getNormalDest()->phis()) {
53 int Idx = Phi.getBasicBlockIndex(OrigBlock);
54 if (Idx == -1)
55 continue;
56 Phi.setIncomingBlock(Idx, MergeBlock);
57 }
58}
59
60/// Fix-up phi nodes in an invoke instruction's unwind destination.
61///
62/// After versioning an invoke instruction, values coming from the original
63/// block will now be coming from either the "then" block or the "else" block.
64/// For example, in the code below:
65///
66/// then_bb:
67/// %t0 = invoke i32 %ptr() to label %merge_bb unwind label %unwind_dst
68///
69/// else_bb:
70/// %t1 = invoke i32 %ptr() to label %merge_bb unwind label %unwind_dst
71///
72/// unwind_dst:
73/// %t3 = phi i32 [ %x, %orig_bb ], ...
74///
75/// "orig_bb" is no longer a predecessor of "unwind_dst", so the phi nodes in
76/// "unwind_dst" must be fixed to refer to "then_bb" and "else_bb":
77///
78/// unwind_dst:
79/// %t3 = phi i32 [ %x, %then_bb ], [ %x, %else_bb ], ...
80///
81static void fixupPHINodeForUnwindDest(InvokeInst *Invoke, BasicBlock *OrigBlock,
82 BasicBlock *ThenBlock,
83 BasicBlock *ElseBlock) {
84 for (PHINode &Phi : Invoke->getUnwindDest()->phis()) {
85 int Idx = Phi.getBasicBlockIndex(OrigBlock);
86 if (Idx == -1)
87 continue;
88 auto *V = Phi.getIncomingValue(Idx);
89 Phi.setIncomingBlock(Idx, ThenBlock);
90 Phi.addIncoming(V, ElseBlock);
91 }
92}
93
94/// Create a phi node for the returned value of a call or invoke instruction.
95///
96/// After versioning a call or invoke instruction that returns a value, we have
97/// to merge the value of the original and new instructions. We do this by
98/// creating a phi node and replacing uses of the original instruction with this
99/// phi node.
100///
101/// For example, if \p OrigInst is defined in "else_bb" and \p NewInst is
102/// defined in "then_bb", we create the following phi node:
103///
104/// ; Uses of the original instruction are replaced by uses of the phi node.
105/// %t0 = phi i32 [ %orig_inst, %else_bb ], [ %new_inst, %then_bb ],
106///
107static void createRetPHINode(Instruction *OrigInst, Instruction *NewInst,
108 BasicBlock *MergeBlock, IRBuilder<> &Builder) {
109
110 if (OrigInst->getType()->isVoidTy() || OrigInst->use_empty())
111 return;
112
113 Builder.SetInsertPoint(&MergeBlock->front());
114 PHINode *Phi = Builder.CreatePHI(OrigInst->getType(), 0);
115 SmallVector<User *, 16> UsersToUpdate(OrigInst->users());
116 for (User *U : UsersToUpdate)
117 U->replaceUsesOfWith(OrigInst, Phi);
118 Phi->addIncoming(OrigInst, OrigInst->getParent());
119 Phi->addIncoming(NewInst, NewInst->getParent());
120}
121
122/// Cast a call or invoke instruction to the given type.
123///
124/// When promoting a call site, the return type of the call site might not match
125/// that of the callee. If this is the case, we have to cast the returned value
126/// to the correct type. The location of the cast depends on if we have a call
127/// or invoke instruction.
128///
129/// For example, if the call instruction below requires a bitcast after
130/// promotion:
131///
132/// orig_bb:
133/// %t0 = call i32 @func()
134/// ...
135///
136/// The bitcast is placed after the call instruction:
137///
138/// orig_bb:
139/// ; Uses of the original return value are replaced by uses of the bitcast.
140/// %t0 = call i32 @func()
141/// %t1 = bitcast i32 %t0 to ...
142/// ...
143///
144/// A similar transformation is performed for invoke instructions. However,
145/// since invokes are terminating, a new block is created for the bitcast. For
146/// example, if the invoke instruction below requires a bitcast after promotion:
147///
148/// orig_bb:
149/// %t0 = invoke i32 @func() to label %normal_dst unwind label %unwind_dst
150///
151/// The edge between the original block and the invoke's normal destination is
152/// split, and the bitcast is placed there:
153///
154/// orig_bb:
155/// %t0 = invoke i32 @func() to label %split_bb unwind label %unwind_dst
156///
157/// split_bb:
158/// ; Uses of the original return value are replaced by uses of the bitcast.
159/// %t1 = bitcast i32 %t0 to ...
160/// br label %normal_dst
161///
162static void createRetBitCast(CallBase &CB, Type *RetTy, CastInst **RetBitCast) {
163
164 // Save the users of the calling instruction. These uses will be changed to
165 // use the bitcast after we create it.
166 SmallVector<User *, 16> UsersToUpdate(CB.users());
167
168 // Determine an appropriate location to create the bitcast for the return
169 // value. The location depends on if we have a call or invoke instruction.
170 Instruction *InsertBefore = nullptr;
171 if (auto *Invoke = dyn_cast<InvokeInst>(&CB))
172 InsertBefore =
173 &SplitEdge(Invoke->getParent(), Invoke->getNormalDest())->front();
174 else
175 InsertBefore = &*std::next(CB.getIterator());
176
177 // Bitcast the return value to the correct type.
178 auto *Cast = CastInst::CreateBitOrPointerCast(&CB, RetTy, "", InsertBefore);
179 if (RetBitCast)
180 *RetBitCast = Cast;
181
182 // Replace all the original uses of the calling instruction with the bitcast.
183 for (User *U : UsersToUpdate)
184 U->replaceUsesOfWith(&CB, Cast);
185}
186
187/// Predicate and clone the given call site.
188///
189/// This function creates an if-then-else structure at the location of the call
190/// site. The "if" condition compares the call site's called value to the given
191/// callee. The original call site is moved into the "else" block, and a clone
192/// of the call site is placed in the "then" block. The cloned instruction is
193/// returned.
194///
195/// For example, the call instruction below:
196///
197/// orig_bb:
198/// %t0 = call i32 %ptr()
199/// ...
200///
201/// Is replace by the following:
202///
203/// orig_bb:
204/// %cond = icmp eq i32 ()* %ptr, @func
205/// br i1 %cond, %then_bb, %else_bb
206///
207/// then_bb:
208/// ; The clone of the original call instruction is placed in the "then"
209/// ; block. It is not yet promoted.
210/// %t1 = call i32 %ptr()
211/// br merge_bb
212///
213/// else_bb:
214/// ; The original call instruction is moved to the "else" block.
215/// %t0 = call i32 %ptr()
216/// br merge_bb
217///
218/// merge_bb:
219/// ; Uses of the original call instruction are replaced by uses of the phi
220/// ; node.
221/// %t2 = phi i32 [ %t0, %else_bb ], [ %t1, %then_bb ]
222/// ...
223///
224/// A similar transformation is performed for invoke instructions. However,
225/// since invokes are terminating, more work is required. For example, the
226/// invoke instruction below:
227///
228/// orig_bb:
229/// %t0 = invoke %ptr() to label %normal_dst unwind label %unwind_dst
230///
231/// Is replace by the following:
232///
233/// orig_bb:
234/// %cond = icmp eq i32 ()* %ptr, @func
235/// br i1 %cond, %then_bb, %else_bb
236///
237/// then_bb:
238/// ; The clone of the original invoke instruction is placed in the "then"
239/// ; block, and its normal destination is set to the "merge" block. It is
240/// ; not yet promoted.
241/// %t1 = invoke i32 %ptr() to label %merge_bb unwind label %unwind_dst
242///
243/// else_bb:
244/// ; The original invoke instruction is moved into the "else" block, and
245/// ; its normal destination is set to the "merge" block.
246/// %t0 = invoke i32 %ptr() to label %merge_bb unwind label %unwind_dst
247///
248/// merge_bb:
249/// ; Uses of the original invoke instruction are replaced by uses of the
250/// ; phi node, and the merge block branches to the normal destination.
251/// %t2 = phi i32 [ %t0, %else_bb ], [ %t1, %then_bb ]
252/// br %normal_dst
253///
254/// An indirect musttail call is processed slightly differently in that:
255/// 1. No merge block needed for the orginal and the cloned callsite, since
256/// either one ends the flow. No phi node is needed either.
257/// 2. The return statement following the original call site is duplicated too
258/// and placed immediately after the cloned call site per the IR convention.
259///
260/// For example, the musttail call instruction below:
261///
262/// orig_bb:
263/// %t0 = musttail call i32 %ptr()
264/// ...
265///
266/// Is replaced by the following:
267///
268/// cond_bb:
269/// %cond = icmp eq i32 ()* %ptr, @func
270/// br i1 %cond, %then_bb, %orig_bb
271///
272/// then_bb:
273/// ; The clone of the original call instruction is placed in the "then"
274/// ; block. It is not yet promoted.
275/// %t1 = musttail call i32 %ptr()
276/// ret %t1
277///
278/// orig_bb:
279/// ; The original call instruction stays in its original block.
280/// %t0 = musttail call i32 %ptr()
281/// ret %t0
283 MDNode *BranchWeights) {
284
285 IRBuilder<> Builder(&CB);
286 CallBase *OrigInst = &CB;
287 BasicBlock *OrigBlock = OrigInst->getParent();
288
289 // Create the compare. The called value and callee must have the same type to
290 // be compared.
291 if (CB.getCalledOperand()->getType() != Callee->getType())
292 Callee = Builder.CreateBitCast(Callee, CB.getCalledOperand()->getType());
293 auto *Cond = Builder.CreateICmpEQ(CB.getCalledOperand(), Callee);
294
295 if (OrigInst->isMustTailCall()) {
296 // Create an if-then structure. The original instruction stays in its block,
297 // and a clone of the original instruction is placed in the "then" block.
298 Instruction *ThenTerm =
299 SplitBlockAndInsertIfThen(Cond, &CB, false, BranchWeights);
300 BasicBlock *ThenBlock = ThenTerm->getParent();
301 ThenBlock->setName("if.true.direct_targ");
302 CallBase *NewInst = cast<CallBase>(OrigInst->clone());
303 NewInst->insertBefore(ThenTerm);
304
305 // Place a clone of the optional bitcast after the new call site.
306 Value *NewRetVal = NewInst;
307 auto Next = OrigInst->getNextNode();
308 if (auto *BitCast = dyn_cast_or_null<BitCastInst>(Next)) {
309 assert(BitCast->getOperand(0) == OrigInst &&
310 "bitcast following musttail call must use the call");
311 auto NewBitCast = BitCast->clone();
312 NewBitCast->replaceUsesOfWith(OrigInst, NewInst);
313 NewBitCast->insertBefore(ThenTerm);
314 NewRetVal = NewBitCast;
315 Next = BitCast->getNextNode();
316 }
317
318 // Place a clone of the return instruction after the new call site.
319 ReturnInst *Ret = dyn_cast_or_null<ReturnInst>(Next);
320 assert(Ret && "musttail call must precede a ret with an optional bitcast");
321 auto NewRet = Ret->clone();
322 if (Ret->getReturnValue())
323 NewRet->replaceUsesOfWith(Ret->getReturnValue(), NewRetVal);
324 NewRet->insertBefore(ThenTerm);
325
326 // A return instructions is terminating, so we don't need the terminator
327 // instruction just created.
328 ThenTerm->eraseFromParent();
329
330 return *NewInst;
331 }
332
333 // Create an if-then-else structure. The original instruction is moved into
334 // the "else" block, and a clone of the original instruction is placed in the
335 // "then" block.
336 Instruction *ThenTerm = nullptr;
337 Instruction *ElseTerm = nullptr;
338 SplitBlockAndInsertIfThenElse(Cond, &CB, &ThenTerm, &ElseTerm, BranchWeights);
339 BasicBlock *ThenBlock = ThenTerm->getParent();
340 BasicBlock *ElseBlock = ElseTerm->getParent();
341 BasicBlock *MergeBlock = OrigInst->getParent();
342
343 ThenBlock->setName("if.true.direct_targ");
344 ElseBlock->setName("if.false.orig_indirect");
345 MergeBlock->setName("if.end.icp");
346
347 CallBase *NewInst = cast<CallBase>(OrigInst->clone());
348 OrigInst->moveBefore(ElseTerm);
349 NewInst->insertBefore(ThenTerm);
350
351 // If the original call site is an invoke instruction, we have extra work to
352 // do since invoke instructions are terminating. We have to fix-up phi nodes
353 // in the invoke's normal and unwind destinations.
354 if (auto *OrigInvoke = dyn_cast<InvokeInst>(OrigInst)) {
355 auto *NewInvoke = cast<InvokeInst>(NewInst);
356
357 // Invoke instructions are terminating, so we don't need the terminator
358 // instructions that were just created.
359 ThenTerm->eraseFromParent();
360 ElseTerm->eraseFromParent();
361
362 // Branch from the "merge" block to the original normal destination.
363 Builder.SetInsertPoint(MergeBlock);
364 Builder.CreateBr(OrigInvoke->getNormalDest());
365
366 // Fix-up phi nodes in the original invoke's normal and unwind destinations.
367 fixupPHINodeForNormalDest(OrigInvoke, OrigBlock, MergeBlock);
368 fixupPHINodeForUnwindDest(OrigInvoke, MergeBlock, ThenBlock, ElseBlock);
369
370 // Now set the normal destinations of the invoke instructions to be the
371 // "merge" block.
372 OrigInvoke->setNormalDest(MergeBlock);
373 NewInvoke->setNormalDest(MergeBlock);
374 }
375
376 // Create a phi node for the returned value of the call site.
377 createRetPHINode(OrigInst, NewInst, MergeBlock, Builder);
378
379 return *NewInst;
380}
381
383 const char **FailureReason) {
384 assert(!CB.getCalledFunction() && "Only indirect call sites can be promoted");
385
386 auto &DL = Callee->getParent()->getDataLayout();
387
388 // Check the return type. The callee's return value type must be bitcast
389 // compatible with the call site's type.
390 Type *CallRetTy = CB.getType();
391 Type *FuncRetTy = Callee->getReturnType();
392 if (CallRetTy != FuncRetTy)
393 if (!CastInst::isBitOrNoopPointerCastable(FuncRetTy, CallRetTy, DL)) {
394 if (FailureReason)
395 *FailureReason = "Return type mismatch";
396 return false;
397 }
398
399 // The number of formal arguments of the callee.
400 unsigned NumParams = Callee->getFunctionType()->getNumParams();
401
402 // The number of actual arguments in the call.
403 unsigned NumArgs = CB.arg_size();
404
405 // Check the number of arguments. The callee and call site must agree on the
406 // number of arguments.
407 if (NumArgs != NumParams && !Callee->isVarArg()) {
408 if (FailureReason)
409 *FailureReason = "The number of arguments mismatch";
410 return false;
411 }
412
413 // Check the argument types. The callee's formal argument types must be
414 // bitcast compatible with the corresponding actual argument types of the call
415 // site.
416 unsigned I = 0;
417 for (; I < NumParams; ++I) {
418 // Make sure that the callee and call agree on byval/inalloca. The types do
419 // not have to match.
420 if (Callee->hasParamAttribute(I, Attribute::ByVal) !=
421 CB.getAttributes().hasParamAttr(I, Attribute::ByVal)) {
422 if (FailureReason)
423 *FailureReason = "byval mismatch";
424 return false;
425 }
426 if (Callee->hasParamAttribute(I, Attribute::InAlloca) !=
427 CB.getAttributes().hasParamAttr(I, Attribute::InAlloca)) {
428 if (FailureReason)
429 *FailureReason = "inalloca mismatch";
430 return false;
431 }
432
434 Type *ActualTy = CB.getArgOperand(I)->getType();
435 if (FormalTy == ActualTy)
436 continue;
437 if (!CastInst::isBitOrNoopPointerCastable(ActualTy, FormalTy, DL)) {
438 if (FailureReason)
439 *FailureReason = "Argument type mismatch";
440 return false;
441 }
442
443 // MustTail call needs stricter type match. See
444 // Verifier::verifyMustTailCall().
445 if (CB.isMustTailCall()) {
446 PointerType *PF = dyn_cast<PointerType>(FormalTy);
447 PointerType *PA = dyn_cast<PointerType>(ActualTy);
448 if (!PF || !PA || PF->getAddressSpace() != PA->getAddressSpace()) {
449 if (FailureReason)
450 *FailureReason = "Musttail call Argument type mismatch";
451 return false;
452 }
453 }
454 }
455 for (; I < NumArgs; I++) {
456 // Vararg functions can have more arguments than parameters.
457 assert(Callee->isVarArg());
458 if (CB.paramHasAttr(I, Attribute::StructRet)) {
459 if (FailureReason)
460 *FailureReason = "SRet arg to vararg function";
461 return false;
462 }
463 }
464
465 return true;
466}
467
469 CastInst **RetBitCast) {
470 assert(!CB.getCalledFunction() && "Only indirect call sites can be promoted");
471
472 // Set the called function of the call site to be the given callee (but don't
473 // change the type).
475
476 // Since the call site will no longer be direct, we must clear metadata that
477 // is only appropriate for indirect calls. This includes !prof and !callees
478 // metadata.
479 CB.setMetadata(LLVMContext::MD_prof, nullptr);
480 CB.setMetadata(LLVMContext::MD_callees, nullptr);
481
482 // If the function type of the call site matches that of the callee, no
483 // additional work is required.
485 return CB;
486
487 // Save the return types of the call site and callee.
488 Type *CallSiteRetTy = CB.getType();
489 Type *CalleeRetTy = Callee->getReturnType();
490
491 // Change the function type of the call site the match that of the callee.
493
494 // Inspect the arguments of the call site. If an argument's type doesn't
495 // match the corresponding formal argument's type in the callee, bitcast it
496 // to the correct type.
497 auto CalleeType = Callee->getFunctionType();
498 auto CalleeParamNum = CalleeType->getNumParams();
499
500 LLVMContext &Ctx = Callee->getContext();
501 const AttributeList &CallerPAL = CB.getAttributes();
502 // The new list of argument attributes.
504 bool AttributeChanged = false;
505
506 for (unsigned ArgNo = 0; ArgNo < CalleeParamNum; ++ArgNo) {
507 auto *Arg = CB.getArgOperand(ArgNo);
508 Type *FormalTy = CalleeType->getParamType(ArgNo);
509 Type *ActualTy = Arg->getType();
510 if (FormalTy != ActualTy) {
511 auto *Cast = CastInst::CreateBitOrPointerCast(Arg, FormalTy, "", &CB);
512 CB.setArgOperand(ArgNo, Cast);
513
514 // Remove any incompatible attributes for the argument.
515 AttrBuilder ArgAttrs(Ctx, CallerPAL.getParamAttrs(ArgNo));
516 ArgAttrs.remove(AttributeFuncs::typeIncompatible(FormalTy));
517
518 // We may have a different byval/inalloca type.
519 if (ArgAttrs.getByValType())
520 ArgAttrs.addByValAttr(Callee->getParamByValType(ArgNo));
521 if (ArgAttrs.getInAllocaType())
522 ArgAttrs.addInAllocaAttr(Callee->getParamInAllocaType(ArgNo));
523
524 NewArgAttrs.push_back(AttributeSet::get(Ctx, ArgAttrs));
525 AttributeChanged = true;
526 } else
527 NewArgAttrs.push_back(CallerPAL.getParamAttrs(ArgNo));
528 }
529
530 // If the return type of the call site doesn't match that of the callee, cast
531 // the returned value to the appropriate type.
532 // Remove any incompatible return value attribute.
533 AttrBuilder RAttrs(Ctx, CallerPAL.getRetAttrs());
534 if (!CallSiteRetTy->isVoidTy() && CallSiteRetTy != CalleeRetTy) {
535 createRetBitCast(CB, CallSiteRetTy, RetBitCast);
536 RAttrs.remove(AttributeFuncs::typeIncompatible(CalleeRetTy));
537 AttributeChanged = true;
538 }
539
540 // Set the new callsite attribute.
541 if (AttributeChanged)
542 CB.setAttributes(AttributeList::get(Ctx, CallerPAL.getFnAttrs(),
543 AttributeSet::get(Ctx, RAttrs),
544 NewArgAttrs));
545
546 return CB;
547}
548
550 MDNode *BranchWeights) {
551
552 // Version the indirect call site. If the called value is equal to the given
553 // callee, 'NewInst' will be executed, otherwise the original call site will
554 // be executed.
555 CallBase &NewInst = versionCallSite(CB, Callee, BranchWeights);
556
557 // Promote 'NewInst' so that it directly calls the desired function.
558 return promoteCall(NewInst, Callee);
559}
560
563 Module *M = CB.getCaller()->getParent();
564 const DataLayout &DL = M->getDataLayout();
566
567 LoadInst *VTableEntryLoad = dyn_cast<LoadInst>(Callee);
568 if (!VTableEntryLoad)
569 return false; // Not a vtable entry load.
570 Value *VTableEntryPtr = VTableEntryLoad->getPointerOperand();
571 APInt VTableOffset(DL.getTypeSizeInBits(VTableEntryPtr->getType()), 0);
572 Value *VTableBasePtr = VTableEntryPtr->stripAndAccumulateConstantOffsets(
573 DL, VTableOffset, /* AllowNonInbounds */ true);
574 LoadInst *VTablePtrLoad = dyn_cast<LoadInst>(VTableBasePtr);
575 if (!VTablePtrLoad)
576 return false; // Not a vtable load.
577 Value *Object = VTablePtrLoad->getPointerOperand();
578 APInt ObjectOffset(DL.getTypeSizeInBits(Object->getType()), 0);
579 Value *ObjectBase = Object->stripAndAccumulateConstantOffsets(
580 DL, ObjectOffset, /* AllowNonInbounds */ true);
581 if (!(isa<AllocaInst>(ObjectBase) && ObjectOffset == 0))
582 // Not an Alloca or the offset isn't zero.
583 return false;
584
585 // Look for the vtable pointer store into the object by the ctor.
586 BasicBlock::iterator BBI(VTablePtrLoad);
587 Value *VTablePtr = FindAvailableLoadedValue(
588 VTablePtrLoad, VTablePtrLoad->getParent(), BBI, 0, nullptr, nullptr);
589 if (!VTablePtr)
590 return false; // No vtable found.
591 APInt VTableOffsetGVBase(DL.getTypeSizeInBits(VTablePtr->getType()), 0);
592 Value *VTableGVBase = VTablePtr->stripAndAccumulateConstantOffsets(
593 DL, VTableOffsetGVBase, /* AllowNonInbounds */ true);
594 GlobalVariable *GV = dyn_cast<GlobalVariable>(VTableGVBase);
595 if (!(GV && GV->isConstant() && GV->hasDefinitiveInitializer()))
596 // Not in the form of a global constant variable with an initializer.
597 return false;
598
599 Constant *VTableGVInitializer = GV->getInitializer();
600 APInt VTableGVOffset = VTableOffsetGVBase + VTableOffset;
601 if (!(VTableGVOffset.getActiveBits() <= 64))
602 return false; // Out of range.
603 Constant *Ptr = getPointerAtOffset(VTableGVInitializer,
604 VTableGVOffset.getZExtValue(),
605 *M);
606 if (!Ptr)
607 return false; // No constant (function) pointer found.
608 Function *DirectCallee = dyn_cast<Function>(Ptr->stripPointerCasts());
609 if (!DirectCallee)
610 return false; // No function pointer found.
611
612 if (!isLegalToPromote(CB, DirectCallee))
613 return false;
614
615 // Success.
616 promoteCall(CB, DirectCallee);
617 return true;
618}
619
620#undef DEBUG_TYPE
MachineBasicBlock MachineBasicBlock::iterator DebugLoc DL
amdgpu Simplify well known AMD library false FunctionCallee Callee
amdgpu Simplify well known AMD library false FunctionCallee Value * Arg
assume Assume Builder
SmallVector< MachineOperand, 4 > Cond
static void fixupPHINodeForNormalDest(InvokeInst *Invoke, BasicBlock *OrigBlock, BasicBlock *MergeBlock)
Fix-up phi nodes in an invoke instruction's normal destination.
static void fixupPHINodeForUnwindDest(InvokeInst *Invoke, BasicBlock *OrigBlock, BasicBlock *ThenBlock, BasicBlock *ElseBlock)
Fix-up phi nodes in an invoke instruction's unwind destination.
static void createRetBitCast(CallBase &CB, Type *RetTy, CastInst **RetBitCast)
Cast a call or invoke instruction to the given type.
static void createRetPHINode(Instruction *OrigInst, Instruction *NewInst, BasicBlock *MergeBlock, IRBuilder<> &Builder)
Create a phi node for the returned value of a call or invoke instruction.
return RetTy
Returns the sub type a function will return at a given Idx Should correspond to the result type of an ExtractValue instruction executed with just that one unsigned Idx
#define I(x, y, z)
Definition: MD5.cpp:58
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
Class for arbitrary precision integers.
Definition: APInt.h:75
uint64_t getZExtValue() const
Get zero extended value.
Definition: APInt.h:1494
unsigned getActiveBits() const
Compute the number of active bits in the value.
Definition: APInt.h:1463
Type * getByValType() const
Retrieve the byval type.
Definition: Attributes.h:1139
AttrBuilder & addByValAttr(Type *Ty)
This turns a byval type into the form used internally in Attribute.
Type * getInAllocaType() const
Retrieve the inalloca type.
Definition: Attributes.h:1153
AttrBuilder & addInAllocaAttr(Type *Ty)
This turns an inalloca type into the form used internally in Attribute.
AttrBuilder & remove(const AttributeMask &AM)
Remove the attributes from the builder.
AttributeSet getFnAttrs() const
The function attributes are returned.
static AttributeList get(LLVMContext &C, ArrayRef< std::pair< unsigned, Attribute > > Attrs)
Create an AttributeList with the specified parameters in it.
AttributeSet getRetAttrs() const
The attributes for the ret value are returned.
bool hasParamAttr(unsigned ArgNo, Attribute::AttrKind Kind) const
Return true if the attribute exists for the given argument.
Definition: Attributes.h:764
AttributeSet getParamAttrs(unsigned ArgNo) const
The attributes for the argument or parameter at the given index are returned.
static AttributeSet get(LLVMContext &C, const AttrBuilder &B)
Definition: Attributes.cpp:693
LLVM Basic Block Representation.
Definition: BasicBlock.h:56
iterator_range< const_phi_iterator > phis() const
Returns a range that iterates over the phis in the basic block.
Definition: BasicBlock.h:372
const Instruction & front() const
Definition: BasicBlock.h:326
InstListType::iterator iterator
Instruction iterators...
Definition: BasicBlock.h:87
Base class for all callable instructions (InvokeInst and CallInst) Holds everything related to callin...
Definition: InstrTypes.h:1184
Function * getCalledFunction() const
Returns the function called, or null if this is an indirect function invocation or the function signa...
Definition: InstrTypes.h:1406
bool paramHasAttr(unsigned ArgNo, Attribute::AttrKind Kind) const
Determine whether the argument or parameter has the given attribute.
bool isMustTailCall() const
Tests if this call site must be tail call optimized.
Value * getCalledOperand() const
Definition: InstrTypes.h:1399
void setAttributes(AttributeList A)
Set the parameter attributes for this call.
Definition: InstrTypes.h:1488
Value * getArgOperand(unsigned i) const
Definition: InstrTypes.h:1351
void mutateFunctionType(FunctionType *FTy)
Definition: InstrTypes.h:1266
void setArgOperand(unsigned i, Value *v)
Definition: InstrTypes.h:1356
FunctionType * getFunctionType() const
Definition: InstrTypes.h:1264
void setCalledOperand(Value *V)
Definition: InstrTypes.h:1442
unsigned arg_size() const
Definition: InstrTypes.h:1349
AttributeList getAttributes() const
Return the parameter attributes for this call.
Definition: InstrTypes.h:1484
Function * getCaller()
Helper to get the caller (the parent function).
This is the base class for all instructions that perform data casts.
Definition: InstrTypes.h:428
static CastInst * CreateBitOrPointerCast(Value *S, Type *Ty, const Twine &Name="", Instruction *InsertBefore=nullptr)
Create a BitCast, a PtrToInt, or an IntToPTr cast instruction.
static bool isBitOrNoopPointerCastable(Type *SrcTy, Type *DestTy, const DataLayout &DL)
Check whether a bitcast, inttoptr, or ptrtoint cast between these types is valid and a no-op.
This is an important base class in LLVM.
Definition: Constant.h:41
A parsed version of the target data layout string in and methods for querying it.
Definition: DataLayout.h:114
FunctionType * getFunctionType()
Definition: DerivedTypes.h:182
unsigned getNumParams() const
Return the number of fixed parameters this function type requires.
Definition: DerivedTypes.h:139
Module * getParent()
Get the module that this global value is contained inside of...
Definition: GlobalValue.h:652
const Constant * getInitializer() const
getInitializer - Return the initializer for this global variable.
bool isConstant() const
If the value is a global constant, its value is immutable throughout the runtime execution of the pro...
bool hasDefinitiveInitializer() const
hasDefinitiveInitializer - Whether the global variable has an initializer, and any other instances of...
This provides a uniform API for creating instructions and inserting them into a basic block: either a...
Definition: IRBuilder.h:2550
Instruction * clone() const
Create a copy of 'this' instruction that is identical in all ways except the following:
void insertBefore(Instruction *InsertPos)
Insert an unlinked instruction into a basic block immediately before the specified instruction.
Definition: Instruction.cpp:88
const BasicBlock * getParent() const
Definition: Instruction.h:90
void setMetadata(unsigned KindID, MDNode *Node)
Set the metadata of the specified kind to the specified node.
Definition: Metadata.cpp:1455
SymbolTableList< Instruction >::iterator eraseFromParent()
This method unlinks 'this' from the containing basic block and deletes it.
Definition: Instruction.cpp:82
void moveBefore(Instruction *MovePos)
Unlink this instruction from its current basic block and insert it into the basic block that MovePos ...
Invoke instruction.
BasicBlock * getUnwindDest() const
BasicBlock * getNormalDest() const
This is an important class for using LLVM in a threaded context.
Definition: LLVMContext.h:67
An instruction for reading from memory.
Definition: Instructions.h:177
Value * getPointerOperand()
Definition: Instructions.h:264
Metadata node.
Definition: Metadata.h:943
A Module instance is used to store all the information related to an LLVM module.
Definition: Module.h:65
void addIncoming(Value *V, BasicBlock *BB)
Add an incoming value to the end of the PHI list.
Class to represent pointers.
Definition: DerivedTypes.h:632
unsigned getAddressSpace() const
Return the address space of the Pointer type.
Definition: DerivedTypes.h:682
Return a value (possibly void), from a function.
void push_back(const T &Elt)
Definition: SmallVector.h:416
This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small.
Definition: SmallVector.h:1200
The instances of the Type class are immutable: once they are created, they are never changed.
Definition: Type.h:45
Type * getFunctionParamType(unsigned i) const
bool isVoidTy() const
Return true if this is 'void'.
Definition: Type.h:140
bool replaceUsesOfWith(Value *From, Value *To)
Replace uses of one Value with another.
Definition: User.cpp:21
LLVM Value Representation.
Definition: Value.h:74
Type * getType() const
All values are typed, get the type of this value.
Definition: Value.h:255
const Value * stripAndAccumulateConstantOffsets(const DataLayout &DL, APInt &Offset, bool AllowNonInbounds, bool AllowInvariantGroup=false, function_ref< bool(Value &Value, APInt &Offset)> ExternalAnalysis=nullptr) const
Accumulate the constant offset this value has compared to a base pointer.
void setName(const Twine &Name)
Change the name of the value.
Definition: Value.cpp:375
iterator_range< user_iterator > users()
Definition: Value.h:421
bool use_empty() const
Definition: Value.h:344
self_iterator getIterator()
Definition: ilist_node.h:82
NodeTy * getNextNode()
Get the next node, or nullptr for the list tail.
Definition: ilist_node.h:289
AttributeMask typeIncompatible(Type *Ty, AttributeSafetyKind ASK=ASK_ALL)
Which attributes cannot be applied to a type.
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
bool isLegalToPromote(const CallBase &CB, Function *Callee, const char **FailureReason=nullptr)
Return true if the given indirect call site can be made to call Callee.
CallBase & promoteCallWithIfThenElse(CallBase &CB, Function *Callee, MDNode *BranchWeights=nullptr)
Promote the given indirect call site to conditionally call Callee.
Value * FindAvailableLoadedValue(LoadInst *Load, BasicBlock *ScanBB, BasicBlock::iterator &ScanFrom, unsigned MaxInstsToScan=DefMaxInstsToScan, AAResults *AA=nullptr, bool *IsLoadCSE=nullptr, unsigned *NumScanedInst=nullptr)
Scan backwards to see if we have the value of the given load available locally within a small number ...
Definition: Loads.cpp:428
void SplitBlockAndInsertIfThenElse(Value *Cond, Instruction *SplitBefore, Instruction **ThenTerm, Instruction **ElseTerm, MDNode *BranchWeights=nullptr, DomTreeUpdater *DTU=nullptr)
SplitBlockAndInsertIfThenElse is similar to SplitBlockAndInsertIfThen, but also creates the ElseBlock...
CallBase & versionCallSite(CallBase &CB, Value *Callee, MDNode *BranchWeights)
Predicate and clone the given call site.
CallBase & promoteCall(CallBase &CB, Function *Callee, CastInst **RetBitCast=nullptr)
Promote the given indirect call site to unconditionally call Callee.
bool tryPromoteCall(CallBase &CB)
Try to promote (devirtualize) a virtual call on an Alloca.
BasicBlock * SplitEdge(BasicBlock *From, BasicBlock *To, DominatorTree *DT=nullptr, LoopInfo *LI=nullptr, MemorySSAUpdater *MSSAU=nullptr, const Twine &BBName="")
Split the edge connecting the specified blocks, and return the newly created basic block between From...
Instruction * SplitBlockAndInsertIfThen(Value *Cond, Instruction *SplitBefore, bool Unreachable, MDNode *BranchWeights, DominatorTree *DT, LoopInfo *LI=nullptr, BasicBlock *ThenBlock=nullptr)
Split the containing block at the specified instruction - everything before SplitBefore stays in the ...
Constant * getPointerAtOffset(Constant *I, uint64_t Offset, Module &M, Constant *TopLevelGlobal=nullptr)
Processes a Constant recursively looking into elements of arrays, structs and expressions to find a t...