1 //===- InstCombineCalls.cpp -----------------------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the visitCall and visitInvoke functions.
12 //===----------------------------------------------------------------------===//
14 #include "InstCombine.h"
15 #include "llvm/IntrinsicInst.h"
16 #include "llvm/Support/CallSite.h"
17 #include "llvm/Target/TargetData.h"
18 #include "llvm/Analysis/MemoryBuiltins.h"
21 /// getPromotedType - Return the specified type promoted as it would be to pass
22 /// though a va_arg area.
23 static const Type *getPromotedType(const Type *Ty) {
24 if (const IntegerType* ITy = dyn_cast<IntegerType>(Ty)) {
25 if (ITy->getBitWidth() < 32)
26 return Type::getInt32Ty(Ty->getContext());
31 /// EnforceKnownAlignment - If the specified pointer points to an object that
32 /// we control, modify the object's alignment to PrefAlign. This isn't
33 /// often possible though. If alignment is important, a more reliable approach
34 /// is to simply align all global variables and allocation instructions to
35 /// their preferred alignment from the beginning.
37 static unsigned EnforceKnownAlignment(Value *V,
38 unsigned Align, unsigned PrefAlign) {
40 User *U = dyn_cast<User>(V);
43 switch (Operator::getOpcode(U)) {
45 case Instruction::BitCast:
46 return EnforceKnownAlignment(U->getOperand(0), Align, PrefAlign);
47 case Instruction::GetElementPtr: {
48 // If all indexes are zero, it is just the alignment of the base pointer.
49 bool AllZeroOperands = true;
50 for (User::op_iterator i = U->op_begin() + 1, e = U->op_end(); i != e; ++i)
51 if (!isa<Constant>(*i) ||
52 !cast<Constant>(*i)->isNullValue()) {
53 AllZeroOperands = false;
57 if (AllZeroOperands) {
58 // Treat this like a bitcast.
59 return EnforceKnownAlignment(U->getOperand(0), Align, PrefAlign);
65 if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
66 // If there is a large requested alignment and we can, bump up the alignment
68 if (!GV->isDeclaration()) {
69 if (GV->getAlignment() >= PrefAlign)
70 Align = GV->getAlignment();
72 GV->setAlignment(PrefAlign);
76 } else if (AllocaInst *AI = dyn_cast<AllocaInst>(V)) {
77 // If there is a requested alignment and if this is an alloca, round up.
78 if (AI->getAlignment() >= PrefAlign)
79 Align = AI->getAlignment();
81 AI->setAlignment(PrefAlign);
89 /// GetOrEnforceKnownAlignment - If the specified pointer has an alignment that
90 /// we can determine, return it, otherwise return 0. If PrefAlign is specified,
91 /// and it is more than the alignment of the ultimate object, see if we can
92 /// increase the alignment of the ultimate object, making this check succeed.
93 unsigned InstCombiner::GetOrEnforceKnownAlignment(Value *V,
95 unsigned BitWidth = TD ? TD->getTypeSizeInBits(V->getType()) :
96 sizeof(PrefAlign) * CHAR_BIT;
97 APInt Mask = APInt::getAllOnesValue(BitWidth);
98 APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0);
99 ComputeMaskedBits(V, Mask, KnownZero, KnownOne);
100 unsigned TrailZ = KnownZero.countTrailingOnes();
101 unsigned Align = 1u << std::min(BitWidth - 1, TrailZ);
103 if (PrefAlign > Align)
104 Align = EnforceKnownAlignment(V, Align, PrefAlign);
106 // We don't need to make any adjustment.
110 Instruction *InstCombiner::SimplifyMemTransfer(MemIntrinsic *MI) {
111 unsigned DstAlign = GetOrEnforceKnownAlignment(MI->getOperand(1));
112 unsigned SrcAlign = GetOrEnforceKnownAlignment(MI->getOperand(2));
113 unsigned MinAlign = std::min(DstAlign, SrcAlign);
114 unsigned CopyAlign = MI->getAlignment();
116 if (CopyAlign < MinAlign) {
117 MI->setAlignment(ConstantInt::get(MI->getAlignmentType(),
122 // If MemCpyInst length is 1/2/4/8 bytes then replace memcpy with
124 ConstantInt *MemOpLength = dyn_cast<ConstantInt>(MI->getOperand(3));
125 if (MemOpLength == 0) return 0;
127 // Source and destination pointer types are always "i8*" for intrinsic. See
128 // if the size is something we can handle with a single primitive load/store.
129 // A single load+store correctly handles overlapping memory in the memmove
131 unsigned Size = MemOpLength->getZExtValue();
132 if (Size == 0) return MI; // Delete this mem transfer.
134 if (Size > 8 || (Size&(Size-1)))
135 return 0; // If not 1/2/4/8 bytes, exit.
137 // Use an integer load+store unless we can find something better.
139 PointerType::getUnqual(IntegerType::get(MI->getContext(), Size<<3));
141 // Memcpy forces the use of i8* for the source and destination. That means
142 // that if you're using memcpy to move one double around, you'll get a cast
143 // from double* to i8*. We'd much rather use a double load+store rather than
144 // an i64 load+store, here because this improves the odds that the source or
145 // dest address will be promotable. See if we can find a better type than the
147 Value *StrippedDest = MI->getOperand(1)->stripPointerCasts();
148 if (StrippedDest != MI->getOperand(1)) {
149 const Type *SrcETy = cast<PointerType>(StrippedDest->getType())
151 if (TD && SrcETy->isSized() && TD->getTypeStoreSize(SrcETy) == Size) {
152 // The SrcETy might be something like {{{double}}} or [1 x double]. Rip
153 // down through these levels if so.
154 while (!SrcETy->isSingleValueType()) {
155 if (const StructType *STy = dyn_cast<StructType>(SrcETy)) {
156 if (STy->getNumElements() == 1)
157 SrcETy = STy->getElementType(0);
160 } else if (const ArrayType *ATy = dyn_cast<ArrayType>(SrcETy)) {
161 if (ATy->getNumElements() == 1)
162 SrcETy = ATy->getElementType();
169 if (SrcETy->isSingleValueType())
170 NewPtrTy = PointerType::getUnqual(SrcETy);
175 // If the memcpy/memmove provides better alignment info than we can
177 SrcAlign = std::max(SrcAlign, CopyAlign);
178 DstAlign = std::max(DstAlign, CopyAlign);
180 Value *Src = Builder->CreateBitCast(MI->getOperand(2), NewPtrTy);
181 Value *Dest = Builder->CreateBitCast(MI->getOperand(1), NewPtrTy);
182 Instruction *L = new LoadInst(Src, "tmp", false, SrcAlign);
183 InsertNewInstBefore(L, *MI);
184 InsertNewInstBefore(new StoreInst(L, Dest, false, DstAlign), *MI);
186 // Set the size of the copy to 0, it will be deleted on the next iteration.
187 MI->setOperand(3, Constant::getNullValue(MemOpLength->getType()));
191 Instruction *InstCombiner::SimplifyMemSet(MemSetInst *MI) {
192 unsigned Alignment = GetOrEnforceKnownAlignment(MI->getDest());
193 if (MI->getAlignment() < Alignment) {
194 MI->setAlignment(ConstantInt::get(MI->getAlignmentType(),
199 // Extract the length and alignment and fill if they are constant.
200 ConstantInt *LenC = dyn_cast<ConstantInt>(MI->getLength());
201 ConstantInt *FillC = dyn_cast<ConstantInt>(MI->getValue());
202 if (!LenC || !FillC || !FillC->getType()->isIntegerTy(8))
204 uint64_t Len = LenC->getZExtValue();
205 Alignment = MI->getAlignment();
207 // If the length is zero, this is a no-op
208 if (Len == 0) return MI; // memset(d,c,0,a) -> noop
210 // memset(s,c,n) -> store s, c (for n=1,2,4,8)
211 if (Len <= 8 && isPowerOf2_32((uint32_t)Len)) {
212 const Type *ITy = IntegerType::get(MI->getContext(), Len*8); // n=1 -> i8.
214 Value *Dest = MI->getDest();
215 Dest = Builder->CreateBitCast(Dest, PointerType::getUnqual(ITy));
217 // Alignment 0 is identity for alignment 1 for memset, but not store.
218 if (Alignment == 0) Alignment = 1;
220 // Extract the fill value and store.
221 uint64_t Fill = FillC->getZExtValue()*0x0101010101010101ULL;
222 InsertNewInstBefore(new StoreInst(ConstantInt::get(ITy, Fill),
223 Dest, false, Alignment), *MI);
225 // Set the size of the copy to 0, it will be deleted on the next iteration.
226 MI->setLength(Constant::getNullValue(LenC->getType()));
233 /// visitCallInst - CallInst simplification. This mostly only handles folding
234 /// of intrinsic instructions. For normal calls, it allows visitCallSite to do
235 /// the heavy lifting.
237 Instruction *InstCombiner::visitCallInst(CallInst &CI) {
239 return visitFree(CI);
241 // If the caller function is nounwind, mark the call as nounwind, even if the
243 if (CI.getParent()->getParent()->doesNotThrow() &&
244 !CI.doesNotThrow()) {
245 CI.setDoesNotThrow();
249 IntrinsicInst *II = dyn_cast<IntrinsicInst>(&CI);
250 if (!II) return visitCallSite(&CI);
252 // Intrinsics cannot occur in an invoke, so handle them here instead of in
254 if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(II)) {
255 bool Changed = false;
257 // memmove/cpy/set of zero bytes is a noop.
258 if (Constant *NumBytes = dyn_cast<Constant>(MI->getLength())) {
259 if (NumBytes->isNullValue()) return EraseInstFromFunction(CI);
261 if (ConstantInt *CI = dyn_cast<ConstantInt>(NumBytes))
262 if (CI->getZExtValue() == 1) {
263 // Replace the instruction with just byte operations. We would
264 // transform other cases to loads/stores, but we don't know if
265 // alignment is sufficient.
269 // If we have a memmove and the source operation is a constant global,
270 // then the source and dest pointers can't alias, so we can change this
271 // into a call to memcpy.
272 if (MemMoveInst *MMI = dyn_cast<MemMoveInst>(MI)) {
273 if (GlobalVariable *GVSrc = dyn_cast<GlobalVariable>(MMI->getSource()))
274 if (GVSrc->isConstant()) {
275 Module *M = CI.getParent()->getParent()->getParent();
276 Intrinsic::ID MemCpyID = Intrinsic::memcpy;
278 Tys[0] = CI.getOperand(3)->getType();
280 Intrinsic::getDeclaration(M, MemCpyID, Tys, 1));
285 if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(MI)) {
286 // memmove(x,x,size) -> noop.
287 if (MTI->getSource() == MTI->getDest())
288 return EraseInstFromFunction(CI);
291 // If we can determine a pointer alignment that is bigger than currently
292 // set, update the alignment.
293 if (isa<MemTransferInst>(MI)) {
294 if (Instruction *I = SimplifyMemTransfer(MI))
296 } else if (MemSetInst *MSI = dyn_cast<MemSetInst>(MI)) {
297 if (Instruction *I = SimplifyMemSet(MSI))
301 if (Changed) return II;
304 switch (II->getIntrinsicID()) {
306 case Intrinsic::objectsize: {
307 // We need target data for just about everything so depend on it.
310 const Type *ReturnTy = CI.getType();
311 bool Min = (cast<ConstantInt>(II->getOperand(2))->getZExtValue() == 1);
313 // Get to the real allocated thing and offset as fast as possible.
314 Value *Op1 = II->getOperand(1)->stripPointerCasts();
316 // If we've stripped down to a single global variable that we
317 // can know the size of then just return that.
318 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Op1)) {
319 if (GV->hasDefinitiveInitializer()) {
320 Constant *C = GV->getInitializer();
321 uint64_t GlobalSize = TD->getTypeAllocSize(C->getType());
322 return ReplaceInstUsesWith(CI, ConstantInt::get(ReturnTy, GlobalSize));
324 // Can't determine size of the GV.
325 Constant *RetVal = ConstantInt::get(ReturnTy, Min ? 0 : -1ULL);
326 return ReplaceInstUsesWith(CI, RetVal);
328 } else if (AllocaInst *AI = dyn_cast<AllocaInst>(Op1)) {
330 if (AI->getAllocatedType()->isSized()) {
331 uint64_t AllocaSize = TD->getTypeAllocSize(AI->getAllocatedType());
332 if (AI->isArrayAllocation()) {
333 const ConstantInt *C = dyn_cast<ConstantInt>(AI->getArraySize());
335 AllocaSize *= C->getZExtValue();
337 return ReplaceInstUsesWith(CI, ConstantInt::get(ReturnTy, AllocaSize));
339 } else if (CallInst *MI = extractMallocCall(Op1)) {
340 const Type* MallocType = getMallocAllocatedType(MI);
342 if (MallocType->isSized()) {
343 if (Value *NElems = getMallocArraySize(MI, TD, true)) {
344 if (ConstantInt *NElements = dyn_cast<ConstantInt>(NElems))
345 return ReplaceInstUsesWith(CI, ConstantInt::get(ReturnTy,
346 (NElements->getZExtValue() * TD->getTypeAllocSize(MallocType))));
349 } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Op1)) {
350 // Only handle constant GEPs here.
351 if (CE->getOpcode() != Instruction::GetElementPtr) break;
352 GEPOperator *GEP = cast<GEPOperator>(CE);
354 // Make sure we're not a constant offset from an external
356 Value *Operand = GEP->getPointerOperand();
357 Operand = Operand->stripPointerCasts();
358 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Operand))
359 if (!GV->hasDefinitiveInitializer()) break;
361 // Get what we're pointing to and its size.
362 const PointerType *BaseType =
363 cast<PointerType>(Operand->getType());
364 uint64_t Size = TD->getTypeAllocSize(BaseType->getElementType());
366 // Get the current byte offset into the thing. Use the original
367 // operand in case we're looking through a bitcast.
368 SmallVector<Value*, 8> Ops(CE->op_begin()+1, CE->op_end());
369 const PointerType *OffsetType =
370 cast<PointerType>(GEP->getPointerOperand()->getType());
371 uint64_t Offset = TD->getIndexedOffset(OffsetType, &Ops[0], Ops.size());
374 // Out of bound reference? Negative index normalized to large
375 // index? Just return "I don't know".
376 Constant *RetVal = ConstantInt::get(ReturnTy, Min ? 0 : -1ULL);
377 return ReplaceInstUsesWith(CI, RetVal);
380 Constant *RetVal = ConstantInt::get(ReturnTy, Size-Offset);
381 return ReplaceInstUsesWith(CI, RetVal);
385 // Do not return "I don't know" here. Later optimization passes could
386 // make it possible to evaluate objectsize to a constant.
389 case Intrinsic::bswap:
390 // bswap(bswap(x)) -> x
391 if (IntrinsicInst *Operand = dyn_cast<IntrinsicInst>(II->getOperand(1)))
392 if (Operand->getIntrinsicID() == Intrinsic::bswap)
393 return ReplaceInstUsesWith(CI, Operand->getOperand(1));
395 // bswap(trunc(bswap(x))) -> trunc(lshr(x, c))
396 if (TruncInst *TI = dyn_cast<TruncInst>(II->getOperand(1))) {
397 if (IntrinsicInst *Operand = dyn_cast<IntrinsicInst>(TI->getOperand(0)))
398 if (Operand->getIntrinsicID() == Intrinsic::bswap) {
399 unsigned C = Operand->getType()->getPrimitiveSizeInBits() -
400 TI->getType()->getPrimitiveSizeInBits();
401 Value *CV = ConstantInt::get(Operand->getType(), C);
402 Value *V = Builder->CreateLShr(Operand->getOperand(1), CV);
403 return new TruncInst(V, TI->getType());
408 case Intrinsic::powi:
409 if (ConstantInt *Power = dyn_cast<ConstantInt>(II->getOperand(2))) {
412 return ReplaceInstUsesWith(CI, ConstantFP::get(CI.getType(), 1.0));
415 return ReplaceInstUsesWith(CI, II->getOperand(1));
416 // powi(x, -1) -> 1/x
417 if (Power->isAllOnesValue())
418 return BinaryOperator::CreateFDiv(ConstantFP::get(CI.getType(), 1.0),
422 case Intrinsic::cttz: {
423 // If all bits below the first known one are known zero,
424 // this value is constant.
425 const IntegerType *IT = cast<IntegerType>(II->getOperand(1)->getType());
426 uint32_t BitWidth = IT->getBitWidth();
427 APInt KnownZero(BitWidth, 0);
428 APInt KnownOne(BitWidth, 0);
429 ComputeMaskedBits(II->getOperand(1), APInt::getAllOnesValue(BitWidth),
430 KnownZero, KnownOne);
431 unsigned TrailingZeros = KnownOne.countTrailingZeros();
432 APInt Mask(APInt::getLowBitsSet(BitWidth, TrailingZeros));
433 if ((Mask & KnownZero) == Mask)
434 return ReplaceInstUsesWith(CI, ConstantInt::get(IT,
435 APInt(BitWidth, TrailingZeros)));
439 case Intrinsic::ctlz: {
440 // If all bits above the first known one are known zero,
441 // this value is constant.
442 const IntegerType *IT = cast<IntegerType>(II->getOperand(1)->getType());
443 uint32_t BitWidth = IT->getBitWidth();
444 APInt KnownZero(BitWidth, 0);
445 APInt KnownOne(BitWidth, 0);
446 ComputeMaskedBits(II->getOperand(1), APInt::getAllOnesValue(BitWidth),
447 KnownZero, KnownOne);
448 unsigned LeadingZeros = KnownOne.countLeadingZeros();
449 APInt Mask(APInt::getHighBitsSet(BitWidth, LeadingZeros));
450 if ((Mask & KnownZero) == Mask)
451 return ReplaceInstUsesWith(CI, ConstantInt::get(IT,
452 APInt(BitWidth, LeadingZeros)));
456 case Intrinsic::uadd_with_overflow: {
457 Value *LHS = II->getOperand(1), *RHS = II->getOperand(2);
458 const IntegerType *IT = cast<IntegerType>(II->getOperand(1)->getType());
459 uint32_t BitWidth = IT->getBitWidth();
460 APInt Mask = APInt::getSignBit(BitWidth);
461 APInt LHSKnownZero(BitWidth, 0);
462 APInt LHSKnownOne(BitWidth, 0);
463 ComputeMaskedBits(LHS, Mask, LHSKnownZero, LHSKnownOne);
464 bool LHSKnownNegative = LHSKnownOne[BitWidth - 1];
465 bool LHSKnownPositive = LHSKnownZero[BitWidth - 1];
467 if (LHSKnownNegative || LHSKnownPositive) {
468 APInt RHSKnownZero(BitWidth, 0);
469 APInt RHSKnownOne(BitWidth, 0);
470 ComputeMaskedBits(RHS, Mask, RHSKnownZero, RHSKnownOne);
471 bool RHSKnownNegative = RHSKnownOne[BitWidth - 1];
472 bool RHSKnownPositive = RHSKnownZero[BitWidth - 1];
473 if (LHSKnownNegative && RHSKnownNegative) {
474 // The sign bit is set in both cases: this MUST overflow.
475 // Create a simple add instruction, and insert it into the struct.
476 Instruction *Add = BinaryOperator::CreateAdd(LHS, RHS, "", &CI);
479 UndefValue::get(LHS->getType()),ConstantInt::getTrue(II->getContext())
481 Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false);
482 return InsertValueInst::Create(Struct, Add, 0);
485 if (LHSKnownPositive && RHSKnownPositive) {
486 // The sign bit is clear in both cases: this CANNOT overflow.
487 // Create a simple add instruction, and insert it into the struct.
488 Instruction *Add = BinaryOperator::CreateNUWAdd(LHS, RHS, "", &CI);
491 UndefValue::get(LHS->getType()),
492 ConstantInt::getFalse(II->getContext())
494 Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false);
495 return InsertValueInst::Create(Struct, Add, 0);
499 // FALL THROUGH uadd into sadd
500 case Intrinsic::sadd_with_overflow:
501 // Canonicalize constants into the RHS.
502 if (isa<Constant>(II->getOperand(1)) &&
503 !isa<Constant>(II->getOperand(2))) {
504 Value *LHS = II->getOperand(1);
505 II->setOperand(1, II->getOperand(2));
506 II->setOperand(2, LHS);
510 // X + undef -> undef
511 if (isa<UndefValue>(II->getOperand(2)))
512 return ReplaceInstUsesWith(CI, UndefValue::get(II->getType()));
514 if (ConstantInt *RHS = dyn_cast<ConstantInt>(II->getOperand(2))) {
515 // X + 0 -> {X, false}
518 UndefValue::get(II->getOperand(0)->getType()),
519 ConstantInt::getFalse(II->getContext())
521 Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false);
522 return InsertValueInst::Create(Struct, II->getOperand(1), 0);
526 case Intrinsic::usub_with_overflow:
527 case Intrinsic::ssub_with_overflow:
528 // undef - X -> undef
529 // X - undef -> undef
530 if (isa<UndefValue>(II->getOperand(1)) ||
531 isa<UndefValue>(II->getOperand(2)))
532 return ReplaceInstUsesWith(CI, UndefValue::get(II->getType()));
534 if (ConstantInt *RHS = dyn_cast<ConstantInt>(II->getOperand(2))) {
535 // X - 0 -> {X, false}
538 UndefValue::get(II->getOperand(1)->getType()),
539 ConstantInt::getFalse(II->getContext())
541 Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false);
542 return InsertValueInst::Create(Struct, II->getOperand(1), 0);
546 case Intrinsic::umul_with_overflow:
547 case Intrinsic::smul_with_overflow:
548 // Canonicalize constants into the RHS.
549 if (isa<Constant>(II->getOperand(1)) &&
550 !isa<Constant>(II->getOperand(2))) {
551 Value *LHS = II->getOperand(1);
552 II->setOperand(1, II->getOperand(2));
553 II->setOperand(2, LHS);
557 // X * undef -> undef
558 if (isa<UndefValue>(II->getOperand(2)))
559 return ReplaceInstUsesWith(CI, UndefValue::get(II->getType()));
561 if (ConstantInt *RHSI = dyn_cast<ConstantInt>(II->getOperand(2))) {
564 return ReplaceInstUsesWith(CI, Constant::getNullValue(II->getType()));
566 // X * 1 -> {X, false}
567 if (RHSI->equalsInt(1)) {
569 UndefValue::get(II->getOperand(1)->getType()),
570 ConstantInt::getFalse(II->getContext())
572 Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false);
573 return InsertValueInst::Create(Struct, II->getOperand(1), 0);
577 case Intrinsic::ppc_altivec_lvx:
578 case Intrinsic::ppc_altivec_lvxl:
579 case Intrinsic::x86_sse_loadu_ps:
580 case Intrinsic::x86_sse2_loadu_pd:
581 case Intrinsic::x86_sse2_loadu_dq:
582 // Turn PPC lvx -> load if the pointer is known aligned.
583 // Turn X86 loadups -> load if the pointer is known aligned.
584 if (GetOrEnforceKnownAlignment(II->getOperand(1), 16) >= 16) {
585 Value *Ptr = Builder->CreateBitCast(II->getOperand(1),
586 PointerType::getUnqual(II->getType()));
587 return new LoadInst(Ptr);
590 case Intrinsic::ppc_altivec_stvx:
591 case Intrinsic::ppc_altivec_stvxl:
592 // Turn stvx -> store if the pointer is known aligned.
593 if (GetOrEnforceKnownAlignment(II->getOperand(2), 16) >= 16) {
594 const Type *OpPtrTy =
595 PointerType::getUnqual(II->getOperand(1)->getType());
596 Value *Ptr = Builder->CreateBitCast(II->getOperand(2), OpPtrTy);
597 return new StoreInst(II->getOperand(1), Ptr);
600 case Intrinsic::x86_sse_storeu_ps:
601 case Intrinsic::x86_sse2_storeu_pd:
602 case Intrinsic::x86_sse2_storeu_dq:
603 // Turn X86 storeu -> store if the pointer is known aligned.
604 if (GetOrEnforceKnownAlignment(II->getOperand(1), 16) >= 16) {
605 const Type *OpPtrTy =
606 PointerType::getUnqual(II->getOperand(2)->getType());
607 Value *Ptr = Builder->CreateBitCast(II->getOperand(1), OpPtrTy);
608 return new StoreInst(II->getOperand(2), Ptr);
612 case Intrinsic::x86_sse_cvttss2si: {
613 // These intrinsics only demands the 0th element of its input vector. If
614 // we can simplify the input based on that, do so now.
616 cast<VectorType>(II->getOperand(1)->getType())->getNumElements();
617 APInt DemandedElts(VWidth, 1);
618 APInt UndefElts(VWidth, 0);
619 if (Value *V = SimplifyDemandedVectorElts(II->getOperand(1), DemandedElts,
621 II->setOperand(1, V);
627 case Intrinsic::ppc_altivec_vperm:
628 // Turn vperm(V1,V2,mask) -> shuffle(V1,V2,mask) if mask is a constant.
629 if (ConstantVector *Mask = dyn_cast<ConstantVector>(II->getOperand(3))) {
630 assert(Mask->getNumOperands() == 16 && "Bad type for intrinsic!");
632 // Check that all of the elements are integer constants or undefs.
633 bool AllEltsOk = true;
634 for (unsigned i = 0; i != 16; ++i) {
635 if (!isa<ConstantInt>(Mask->getOperand(i)) &&
636 !isa<UndefValue>(Mask->getOperand(i))) {
643 // Cast the input vectors to byte vectors.
644 Value *Op0 = Builder->CreateBitCast(II->getOperand(1), Mask->getType());
645 Value *Op1 = Builder->CreateBitCast(II->getOperand(2), Mask->getType());
646 Value *Result = UndefValue::get(Op0->getType());
648 // Only extract each element once.
649 Value *ExtractedElts[32];
650 memset(ExtractedElts, 0, sizeof(ExtractedElts));
652 for (unsigned i = 0; i != 16; ++i) {
653 if (isa<UndefValue>(Mask->getOperand(i)))
655 unsigned Idx=cast<ConstantInt>(Mask->getOperand(i))->getZExtValue();
656 Idx &= 31; // Match the hardware behavior.
658 if (ExtractedElts[Idx] == 0) {
660 Builder->CreateExtractElement(Idx < 16 ? Op0 : Op1,
661 ConstantInt::get(Type::getInt32Ty(II->getContext()),
662 Idx&15, false), "tmp");
665 // Insert this value into the result vector.
666 Result = Builder->CreateInsertElement(Result, ExtractedElts[Idx],
667 ConstantInt::get(Type::getInt32Ty(II->getContext()),
670 return CastInst::Create(Instruction::BitCast, Result, CI.getType());
675 case Intrinsic::stackrestore: {
676 // If the save is right next to the restore, remove the restore. This can
677 // happen when variable allocas are DCE'd.
678 if (IntrinsicInst *SS = dyn_cast<IntrinsicInst>(II->getOperand(1))) {
679 if (SS->getIntrinsicID() == Intrinsic::stacksave) {
680 BasicBlock::iterator BI = SS;
682 return EraseInstFromFunction(CI);
686 // Scan down this block to see if there is another stack restore in the
687 // same block without an intervening call/alloca.
688 BasicBlock::iterator BI = II;
689 TerminatorInst *TI = II->getParent()->getTerminator();
690 bool CannotRemove = false;
691 for (++BI; &*BI != TI; ++BI) {
692 if (isa<AllocaInst>(BI) || isMalloc(BI)) {
696 if (CallInst *BCI = dyn_cast<CallInst>(BI)) {
697 if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(BCI)) {
698 // If there is a stackrestore below this one, remove this one.
699 if (II->getIntrinsicID() == Intrinsic::stackrestore)
700 return EraseInstFromFunction(CI);
701 // Otherwise, ignore the intrinsic.
703 // If we found a non-intrinsic call, we can't remove the stack
711 // If the stack restore is in a return/unwind block and if there are no
712 // allocas or calls between the restore and the return, nuke the restore.
713 if (!CannotRemove && (isa<ReturnInst>(TI) || isa<UnwindInst>(TI)))
714 return EraseInstFromFunction(CI);
719 return visitCallSite(II);
722 // InvokeInst simplification
724 Instruction *InstCombiner::visitInvokeInst(InvokeInst &II) {
725 return visitCallSite(&II);
728 /// isSafeToEliminateVarargsCast - If this cast does not affect the value
729 /// passed through the varargs area, we can eliminate the use of the cast.
730 static bool isSafeToEliminateVarargsCast(const CallSite CS,
731 const CastInst * const CI,
732 const TargetData * const TD,
734 if (!CI->isLosslessCast())
737 // The size of ByVal arguments is derived from the type, so we
738 // can't change to a type with a different size. If the size were
739 // passed explicitly we could avoid this check.
740 if (!CS.paramHasAttr(ix, Attribute::ByVal))
744 cast<PointerType>(CI->getOperand(0)->getType())->getElementType();
745 const Type* DstTy = cast<PointerType>(CI->getType())->getElementType();
746 if (!SrcTy->isSized() || !DstTy->isSized())
748 if (!TD || TD->getTypeAllocSize(SrcTy) != TD->getTypeAllocSize(DstTy))
753 // visitCallSite - Improvements for call and invoke instructions.
755 Instruction *InstCombiner::visitCallSite(CallSite CS) {
756 bool Changed = false;
758 // If the callee is a constexpr cast of a function, attempt to move the cast
759 // to the arguments of the call/invoke.
760 if (transformConstExprCastCall(CS)) return 0;
762 Value *Callee = CS.getCalledValue();
764 if (Function *CalleeF = dyn_cast<Function>(Callee))
765 // If the call and callee calling conventions don't match, this call must
766 // be unreachable, as the call is undefined.
767 if (CalleeF->getCallingConv() != CS.getCallingConv() &&
768 // Only do this for calls to a function with a body. A prototype may
769 // not actually end up matching the implementation's calling conv for a
770 // variety of reasons (e.g. it may be written in assembly).
771 !CalleeF->isDeclaration()) {
772 Instruction *OldCall = CS.getInstruction();
773 new StoreInst(ConstantInt::getTrue(Callee->getContext()),
774 UndefValue::get(Type::getInt1PtrTy(Callee->getContext())),
776 // If OldCall dues not return void then replaceAllUsesWith undef.
777 // This allows ValueHandlers and custom metadata to adjust itself.
778 if (!OldCall->getType()->isVoidTy())
779 OldCall->replaceAllUsesWith(UndefValue::get(OldCall->getType()));
780 if (isa<CallInst>(OldCall))
781 return EraseInstFromFunction(*OldCall);
783 // We cannot remove an invoke, because it would change the CFG, just
784 // change the callee to a null pointer.
785 cast<InvokeInst>(OldCall)->setOperand(0,
786 Constant::getNullValue(CalleeF->getType()));
790 if (isa<ConstantPointerNull>(Callee) || isa<UndefValue>(Callee)) {
791 // This instruction is not reachable, just remove it. We insert a store to
792 // undef so that we know that this code is not reachable, despite the fact
793 // that we can't modify the CFG here.
794 new StoreInst(ConstantInt::getTrue(Callee->getContext()),
795 UndefValue::get(Type::getInt1PtrTy(Callee->getContext())),
796 CS.getInstruction());
798 // If CS dues not return void then replaceAllUsesWith undef.
799 // This allows ValueHandlers and custom metadata to adjust itself.
800 if (!CS.getInstruction()->getType()->isVoidTy())
801 CS.getInstruction()->
802 replaceAllUsesWith(UndefValue::get(CS.getInstruction()->getType()));
804 if (InvokeInst *II = dyn_cast<InvokeInst>(CS.getInstruction())) {
805 // Don't break the CFG, insert a dummy cond branch.
806 BranchInst::Create(II->getNormalDest(), II->getUnwindDest(),
807 ConstantInt::getTrue(Callee->getContext()), II);
809 return EraseInstFromFunction(*CS.getInstruction());
812 if (BitCastInst *BC = dyn_cast<BitCastInst>(Callee))
813 if (IntrinsicInst *In = dyn_cast<IntrinsicInst>(BC->getOperand(0)))
814 if (In->getIntrinsicID() == Intrinsic::init_trampoline)
815 return transformCallThroughTrampoline(CS);
817 const PointerType *PTy = cast<PointerType>(Callee->getType());
818 const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
819 if (FTy->isVarArg()) {
820 int ix = FTy->getNumParams() + (isa<InvokeInst>(Callee) ? 3 : 1);
821 // See if we can optimize any arguments passed through the varargs area of
823 for (CallSite::arg_iterator I = CS.arg_begin()+FTy->getNumParams(),
824 E = CS.arg_end(); I != E; ++I, ++ix) {
825 CastInst *CI = dyn_cast<CastInst>(*I);
826 if (CI && isSafeToEliminateVarargsCast(CS, CI, TD, ix)) {
827 *I = CI->getOperand(0);
833 if (isa<InlineAsm>(Callee) && !CS.doesNotThrow()) {
834 // Inline asm calls cannot throw - mark them 'nounwind'.
835 CS.setDoesNotThrow();
839 return Changed ? CS.getInstruction() : 0;
842 // transformConstExprCastCall - If the callee is a constexpr cast of a function,
843 // attempt to move the cast to the arguments of the call/invoke.
845 bool InstCombiner::transformConstExprCastCall(CallSite CS) {
846 if (!isa<ConstantExpr>(CS.getCalledValue())) return false;
847 ConstantExpr *CE = cast<ConstantExpr>(CS.getCalledValue());
848 if (CE->getOpcode() != Instruction::BitCast ||
849 !isa<Function>(CE->getOperand(0)))
851 Function *Callee = cast<Function>(CE->getOperand(0));
852 Instruction *Caller = CS.getInstruction();
853 const AttrListPtr &CallerPAL = CS.getAttributes();
855 // Okay, this is a cast from a function to a different type. Unless doing so
856 // would cause a type conversion of one of our arguments, change this call to
857 // be a direct call with arguments casted to the appropriate types.
859 const FunctionType *FT = Callee->getFunctionType();
860 const Type *OldRetTy = Caller->getType();
861 const Type *NewRetTy = FT->getReturnType();
863 if (NewRetTy->isStructTy())
864 return false; // TODO: Handle multiple return values.
866 // Check to see if we are changing the return type...
867 if (OldRetTy != NewRetTy) {
868 if (Callee->isDeclaration() &&
869 // Conversion is ok if changing from one pointer type to another or from
870 // a pointer to an integer of the same size.
871 !((OldRetTy->isPointerTy() || !TD ||
872 OldRetTy == TD->getIntPtrType(Caller->getContext())) &&
873 (NewRetTy->isPointerTy() || !TD ||
874 NewRetTy == TD->getIntPtrType(Caller->getContext()))))
875 return false; // Cannot transform this return value.
877 if (!Caller->use_empty() &&
878 // void -> non-void is handled specially
879 !NewRetTy->isVoidTy() && !CastInst::isCastable(NewRetTy, OldRetTy))
880 return false; // Cannot transform this return value.
882 if (!CallerPAL.isEmpty() && !Caller->use_empty()) {
883 Attributes RAttrs = CallerPAL.getRetAttributes();
884 if (RAttrs & Attribute::typeIncompatible(NewRetTy))
885 return false; // Attribute not compatible with transformed value.
888 // If the callsite is an invoke instruction, and the return value is used by
889 // a PHI node in a successor, we cannot change the return type of the call
890 // because there is no place to put the cast instruction (without breaking
891 // the critical edge). Bail out in this case.
892 if (!Caller->use_empty())
893 if (InvokeInst *II = dyn_cast<InvokeInst>(Caller))
894 for (Value::use_iterator UI = II->use_begin(), E = II->use_end();
896 if (PHINode *PN = dyn_cast<PHINode>(*UI))
897 if (PN->getParent() == II->getNormalDest() ||
898 PN->getParent() == II->getUnwindDest())
902 unsigned NumActualArgs = unsigned(CS.arg_end()-CS.arg_begin());
903 unsigned NumCommonArgs = std::min(FT->getNumParams(), NumActualArgs);
905 CallSite::arg_iterator AI = CS.arg_begin();
906 for (unsigned i = 0, e = NumCommonArgs; i != e; ++i, ++AI) {
907 const Type *ParamTy = FT->getParamType(i);
908 const Type *ActTy = (*AI)->getType();
910 if (!CastInst::isCastable(ActTy, ParamTy))
911 return false; // Cannot transform this parameter value.
913 if (CallerPAL.getParamAttributes(i + 1)
914 & Attribute::typeIncompatible(ParamTy))
915 return false; // Attribute not compatible with transformed value.
917 // Converting from one pointer type to another or between a pointer and an
918 // integer of the same size is safe even if we do not have a body.
919 bool isConvertible = ActTy == ParamTy ||
920 (TD && ((ParamTy->isPointerTy() ||
921 ParamTy == TD->getIntPtrType(Caller->getContext())) &&
922 (ActTy->isPointerTy() ||
923 ActTy == TD->getIntPtrType(Caller->getContext()))));
924 if (Callee->isDeclaration() && !isConvertible) return false;
927 if (FT->getNumParams() < NumActualArgs && !FT->isVarArg() &&
928 Callee->isDeclaration())
929 return false; // Do not delete arguments unless we have a function body.
931 if (FT->getNumParams() < NumActualArgs && FT->isVarArg() &&
932 !CallerPAL.isEmpty())
933 // In this case we have more arguments than the new function type, but we
934 // won't be dropping them. Check that these extra arguments have attributes
935 // that are compatible with being a vararg call argument.
936 for (unsigned i = CallerPAL.getNumSlots(); i; --i) {
937 if (CallerPAL.getSlot(i - 1).Index <= FT->getNumParams())
939 Attributes PAttrs = CallerPAL.getSlot(i - 1).Attrs;
940 if (PAttrs & Attribute::VarArgsIncompatible)
944 // Okay, we decided that this is a safe thing to do: go ahead and start
945 // inserting cast instructions as necessary...
946 std::vector<Value*> Args;
947 Args.reserve(NumActualArgs);
948 SmallVector<AttributeWithIndex, 8> attrVec;
949 attrVec.reserve(NumCommonArgs);
951 // Get any return attributes.
952 Attributes RAttrs = CallerPAL.getRetAttributes();
954 // If the return value is not being used, the type may not be compatible
955 // with the existing attributes. Wipe out any problematic attributes.
956 RAttrs &= ~Attribute::typeIncompatible(NewRetTy);
958 // Add the new return attributes.
960 attrVec.push_back(AttributeWithIndex::get(0, RAttrs));
963 for (unsigned i = 0; i != NumCommonArgs; ++i, ++AI) {
964 const Type *ParamTy = FT->getParamType(i);
965 if ((*AI)->getType() == ParamTy) {
968 Instruction::CastOps opcode = CastInst::getCastOpcode(*AI,
969 false, ParamTy, false);
970 Args.push_back(Builder->CreateCast(opcode, *AI, ParamTy, "tmp"));
973 // Add any parameter attributes.
974 if (Attributes PAttrs = CallerPAL.getParamAttributes(i + 1))
975 attrVec.push_back(AttributeWithIndex::get(i + 1, PAttrs));
978 // If the function takes more arguments than the call was taking, add them
980 for (unsigned i = NumCommonArgs; i != FT->getNumParams(); ++i)
981 Args.push_back(Constant::getNullValue(FT->getParamType(i)));
983 // If we are removing arguments to the function, emit an obnoxious warning.
984 if (FT->getNumParams() < NumActualArgs) {
985 if (!FT->isVarArg()) {
986 errs() << "WARNING: While resolving call to function '"
987 << Callee->getName() << "' arguments were dropped!\n";
989 // Add all of the arguments in their promoted form to the arg list.
990 for (unsigned i = FT->getNumParams(); i != NumActualArgs; ++i, ++AI) {
991 const Type *PTy = getPromotedType((*AI)->getType());
992 if (PTy != (*AI)->getType()) {
993 // Must promote to pass through va_arg area!
994 Instruction::CastOps opcode =
995 CastInst::getCastOpcode(*AI, false, PTy, false);
996 Args.push_back(Builder->CreateCast(opcode, *AI, PTy, "tmp"));
1001 // Add any parameter attributes.
1002 if (Attributes PAttrs = CallerPAL.getParamAttributes(i + 1))
1003 attrVec.push_back(AttributeWithIndex::get(i + 1, PAttrs));
1008 if (Attributes FnAttrs = CallerPAL.getFnAttributes())
1009 attrVec.push_back(AttributeWithIndex::get(~0, FnAttrs));
1011 if (NewRetTy->isVoidTy())
1012 Caller->setName(""); // Void type should not have a name.
1014 const AttrListPtr &NewCallerPAL = AttrListPtr::get(attrVec.begin(),
1018 if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) {
1019 NC = InvokeInst::Create(Callee, II->getNormalDest(), II->getUnwindDest(),
1020 Args.begin(), Args.end(),
1021 Caller->getName(), Caller);
1022 cast<InvokeInst>(NC)->setCallingConv(II->getCallingConv());
1023 cast<InvokeInst>(NC)->setAttributes(NewCallerPAL);
1025 NC = CallInst::Create(Callee, Args.begin(), Args.end(),
1026 Caller->getName(), Caller);
1027 CallInst *CI = cast<CallInst>(Caller);
1028 if (CI->isTailCall())
1029 cast<CallInst>(NC)->setTailCall();
1030 cast<CallInst>(NC)->setCallingConv(CI->getCallingConv());
1031 cast<CallInst>(NC)->setAttributes(NewCallerPAL);
1034 // Insert a cast of the return type as necessary.
1036 if (OldRetTy != NV->getType() && !Caller->use_empty()) {
1037 if (!NV->getType()->isVoidTy()) {
1038 Instruction::CastOps opcode = CastInst::getCastOpcode(NC, false,
1040 NV = NC = CastInst::Create(opcode, NC, OldRetTy, "tmp");
1042 // If this is an invoke instruction, we should insert it after the first
1043 // non-phi, instruction in the normal successor block.
1044 if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) {
1045 BasicBlock::iterator I = II->getNormalDest()->getFirstNonPHI();
1046 InsertNewInstBefore(NC, *I);
1048 // Otherwise, it's a call, just insert cast right after the call instr
1049 InsertNewInstBefore(NC, *Caller);
1051 Worklist.AddUsersToWorkList(*Caller);
1053 NV = UndefValue::get(Caller->getType());
1058 if (!Caller->use_empty())
1059 Caller->replaceAllUsesWith(NV);
1061 EraseInstFromFunction(*Caller);
1065 // transformCallThroughTrampoline - Turn a call to a function created by the
1066 // init_trampoline intrinsic into a direct call to the underlying function.
1068 Instruction *InstCombiner::transformCallThroughTrampoline(CallSite CS) {
1069 Value *Callee = CS.getCalledValue();
1070 const PointerType *PTy = cast<PointerType>(Callee->getType());
1071 const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1072 const AttrListPtr &Attrs = CS.getAttributes();
1074 // If the call already has the 'nest' attribute somewhere then give up -
1075 // otherwise 'nest' would occur twice after splicing in the chain.
1076 if (Attrs.hasAttrSomewhere(Attribute::Nest))
1079 IntrinsicInst *Tramp =
1080 cast<IntrinsicInst>(cast<BitCastInst>(Callee)->getOperand(0));
1082 Function *NestF = cast<Function>(Tramp->getOperand(2)->stripPointerCasts());
1083 const PointerType *NestFPTy = cast<PointerType>(NestF->getType());
1084 const FunctionType *NestFTy = cast<FunctionType>(NestFPTy->getElementType());
1086 const AttrListPtr &NestAttrs = NestF->getAttributes();
1087 if (!NestAttrs.isEmpty()) {
1088 unsigned NestIdx = 1;
1089 const Type *NestTy = 0;
1090 Attributes NestAttr = Attribute::None;
1092 // Look for a parameter marked with the 'nest' attribute.
1093 for (FunctionType::param_iterator I = NestFTy->param_begin(),
1094 E = NestFTy->param_end(); I != E; ++NestIdx, ++I)
1095 if (NestAttrs.paramHasAttr(NestIdx, Attribute::Nest)) {
1096 // Record the parameter type and any other attributes.
1098 NestAttr = NestAttrs.getParamAttributes(NestIdx);
1103 Instruction *Caller = CS.getInstruction();
1104 std::vector<Value*> NewArgs;
1105 NewArgs.reserve(unsigned(CS.arg_end()-CS.arg_begin())+1);
1107 SmallVector<AttributeWithIndex, 8> NewAttrs;
1108 NewAttrs.reserve(Attrs.getNumSlots() + 1);
1110 // Insert the nest argument into the call argument list, which may
1111 // mean appending it. Likewise for attributes.
1113 // Add any result attributes.
1114 if (Attributes Attr = Attrs.getRetAttributes())
1115 NewAttrs.push_back(AttributeWithIndex::get(0, Attr));
1119 CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end();
1121 if (Idx == NestIdx) {
1122 // Add the chain argument and attributes.
1123 Value *NestVal = Tramp->getOperand(3);
1124 if (NestVal->getType() != NestTy)
1125 NestVal = new BitCastInst(NestVal, NestTy, "nest", Caller);
1126 NewArgs.push_back(NestVal);
1127 NewAttrs.push_back(AttributeWithIndex::get(NestIdx, NestAttr));
1133 // Add the original argument and attributes.
1134 NewArgs.push_back(*I);
1135 if (Attributes Attr = Attrs.getParamAttributes(Idx))
1137 (AttributeWithIndex::get(Idx + (Idx >= NestIdx), Attr));
1143 // Add any function attributes.
1144 if (Attributes Attr = Attrs.getFnAttributes())
1145 NewAttrs.push_back(AttributeWithIndex::get(~0, Attr));
1147 // The trampoline may have been bitcast to a bogus type (FTy).
1148 // Handle this by synthesizing a new function type, equal to FTy
1149 // with the chain parameter inserted.
1151 std::vector<const Type*> NewTypes;
1152 NewTypes.reserve(FTy->getNumParams()+1);
1154 // Insert the chain's type into the list of parameter types, which may
1155 // mean appending it.
1158 FunctionType::param_iterator I = FTy->param_begin(),
1159 E = FTy->param_end();
1163 // Add the chain's type.
1164 NewTypes.push_back(NestTy);
1169 // Add the original type.
1170 NewTypes.push_back(*I);
1176 // Replace the trampoline call with a direct call. Let the generic
1177 // code sort out any function type mismatches.
1178 FunctionType *NewFTy = FunctionType::get(FTy->getReturnType(), NewTypes,
1180 Constant *NewCallee =
1181 NestF->getType() == PointerType::getUnqual(NewFTy) ?
1182 NestF : ConstantExpr::getBitCast(NestF,
1183 PointerType::getUnqual(NewFTy));
1184 const AttrListPtr &NewPAL = AttrListPtr::get(NewAttrs.begin(),
1187 Instruction *NewCaller;
1188 if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) {
1189 NewCaller = InvokeInst::Create(NewCallee,
1190 II->getNormalDest(), II->getUnwindDest(),
1191 NewArgs.begin(), NewArgs.end(),
1192 Caller->getName(), Caller);
1193 cast<InvokeInst>(NewCaller)->setCallingConv(II->getCallingConv());
1194 cast<InvokeInst>(NewCaller)->setAttributes(NewPAL);
1196 NewCaller = CallInst::Create(NewCallee, NewArgs.begin(), NewArgs.end(),
1197 Caller->getName(), Caller);
1198 if (cast<CallInst>(Caller)->isTailCall())
1199 cast<CallInst>(NewCaller)->setTailCall();
1200 cast<CallInst>(NewCaller)->
1201 setCallingConv(cast<CallInst>(Caller)->getCallingConv());
1202 cast<CallInst>(NewCaller)->setAttributes(NewPAL);
1204 if (!Caller->getType()->isVoidTy())
1205 Caller->replaceAllUsesWith(NewCaller);
1206 Caller->eraseFromParent();
1207 Worklist.Remove(Caller);
1212 // Replace the trampoline call with a direct call. Since there is no 'nest'
1213 // parameter, there is no need to adjust the argument list. Let the generic
1214 // code sort out any function type mismatches.
1215 Constant *NewCallee =
1216 NestF->getType() == PTy ? NestF :
1217 ConstantExpr::getBitCast(NestF, PTy);
1218 CS.setCalledFunction(NewCallee);
1219 return CS.getInstruction();