1 //===-- ConstantFolding.cpp - Fold instructions into constants ------------===//
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 defines routines for folding instructions into constants.
12 // Also, to supplement the basic VMCore ConstantExpr simplifications,
13 // this file defines some additional folding routines that can make use of
14 // TargetData information. These functions cannot go in VMCore due to library
17 //===----------------------------------------------------------------------===//
19 #include "llvm/Analysis/ConstantFolding.h"
20 #include "llvm/Constants.h"
21 #include "llvm/DerivedTypes.h"
22 #include "llvm/Function.h"
23 #include "llvm/GlobalVariable.h"
24 #include "llvm/Instructions.h"
25 #include "llvm/Intrinsics.h"
26 #include "llvm/Analysis/ValueTracking.h"
27 #include "llvm/Target/TargetData.h"
28 #include "llvm/ADT/SmallVector.h"
29 #include "llvm/ADT/StringMap.h"
30 #include "llvm/Support/ErrorHandling.h"
31 #include "llvm/Support/GetElementPtrTypeIterator.h"
32 #include "llvm/Support/MathExtras.h"
33 #include "llvm/Support/FEnv.h"
38 //===----------------------------------------------------------------------===//
39 // Constant Folding internal helper functions
40 //===----------------------------------------------------------------------===//
42 /// FoldBitCast - Constant fold bitcast, symbolically evaluating it with
43 /// TargetData. This always returns a non-null constant, but it may be a
44 /// ConstantExpr if unfoldable.
45 static Constant *FoldBitCast(Constant *C, const Type *DestTy,
46 const TargetData &TD) {
48 // This only handles casts to vectors currently.
49 const VectorType *DestVTy = dyn_cast<VectorType>(DestTy);
51 return ConstantExpr::getBitCast(C, DestTy);
53 // If this is a scalar -> vector cast, convert the input into a <1 x scalar>
54 // vector so the code below can handle it uniformly.
55 if (isa<ConstantFP>(C) || isa<ConstantInt>(C)) {
56 Constant *Ops = C; // don't take the address of C!
57 return FoldBitCast(ConstantVector::get(&Ops, 1), DestTy, TD);
60 // If this is a bitcast from constant vector -> vector, fold it.
61 ConstantVector *CV = dyn_cast<ConstantVector>(C);
63 return ConstantExpr::getBitCast(C, DestTy);
65 // If the element types match, VMCore can fold it.
66 unsigned NumDstElt = DestVTy->getNumElements();
67 unsigned NumSrcElt = CV->getNumOperands();
68 if (NumDstElt == NumSrcElt)
69 return ConstantExpr::getBitCast(C, DestTy);
71 const Type *SrcEltTy = CV->getType()->getElementType();
72 const Type *DstEltTy = DestVTy->getElementType();
74 // Otherwise, we're changing the number of elements in a vector, which
75 // requires endianness information to do the right thing. For example,
76 // bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>)
77 // folds to (little endian):
78 // <4 x i32> <i32 0, i32 0, i32 1, i32 0>
79 // and to (big endian):
80 // <4 x i32> <i32 0, i32 0, i32 0, i32 1>
82 // First thing is first. We only want to think about integer here, so if
83 // we have something in FP form, recast it as integer.
84 if (DstEltTy->isFloatingPointTy()) {
85 // Fold to an vector of integers with same size as our FP type.
86 unsigned FPWidth = DstEltTy->getPrimitiveSizeInBits();
87 const Type *DestIVTy =
88 VectorType::get(IntegerType::get(C->getContext(), FPWidth), NumDstElt);
89 // Recursively handle this integer conversion, if possible.
90 C = FoldBitCast(C, DestIVTy, TD);
91 if (!C) return ConstantExpr::getBitCast(C, DestTy);
93 // Finally, VMCore can handle this now that #elts line up.
94 return ConstantExpr::getBitCast(C, DestTy);
97 // Okay, we know the destination is integer, if the input is FP, convert
98 // it to integer first.
99 if (SrcEltTy->isFloatingPointTy()) {
100 unsigned FPWidth = SrcEltTy->getPrimitiveSizeInBits();
101 const Type *SrcIVTy =
102 VectorType::get(IntegerType::get(C->getContext(), FPWidth), NumSrcElt);
103 // Ask VMCore to do the conversion now that #elts line up.
104 C = ConstantExpr::getBitCast(C, SrcIVTy);
105 CV = dyn_cast<ConstantVector>(C);
106 if (!CV) // If VMCore wasn't able to fold it, bail out.
110 // Now we know that the input and output vectors are both integer vectors
111 // of the same size, and that their #elements is not the same. Do the
112 // conversion here, which depends on whether the input or output has
114 bool isLittleEndian = TD.isLittleEndian();
116 SmallVector<Constant*, 32> Result;
117 if (NumDstElt < NumSrcElt) {
118 // Handle: bitcast (<4 x i32> <i32 0, i32 1, i32 2, i32 3> to <2 x i64>)
119 Constant *Zero = Constant::getNullValue(DstEltTy);
120 unsigned Ratio = NumSrcElt/NumDstElt;
121 unsigned SrcBitSize = SrcEltTy->getPrimitiveSizeInBits();
123 for (unsigned i = 0; i != NumDstElt; ++i) {
124 // Build each element of the result.
125 Constant *Elt = Zero;
126 unsigned ShiftAmt = isLittleEndian ? 0 : SrcBitSize*(Ratio-1);
127 for (unsigned j = 0; j != Ratio; ++j) {
128 Constant *Src = dyn_cast<ConstantInt>(CV->getOperand(SrcElt++));
129 if (!Src) // Reject constantexpr elements.
130 return ConstantExpr::getBitCast(C, DestTy);
132 // Zero extend the element to the right size.
133 Src = ConstantExpr::getZExt(Src, Elt->getType());
135 // Shift it to the right place, depending on endianness.
136 Src = ConstantExpr::getShl(Src,
137 ConstantInt::get(Src->getType(), ShiftAmt));
138 ShiftAmt += isLittleEndian ? SrcBitSize : -SrcBitSize;
141 Elt = ConstantExpr::getOr(Elt, Src);
143 Result.push_back(Elt);
146 // Handle: bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>)
147 unsigned Ratio = NumDstElt/NumSrcElt;
148 unsigned DstBitSize = DstEltTy->getPrimitiveSizeInBits();
150 // Loop over each source value, expanding into multiple results.
151 for (unsigned i = 0; i != NumSrcElt; ++i) {
152 Constant *Src = dyn_cast<ConstantInt>(CV->getOperand(i));
153 if (!Src) // Reject constantexpr elements.
154 return ConstantExpr::getBitCast(C, DestTy);
156 unsigned ShiftAmt = isLittleEndian ? 0 : DstBitSize*(Ratio-1);
157 for (unsigned j = 0; j != Ratio; ++j) {
158 // Shift the piece of the value into the right place, depending on
160 Constant *Elt = ConstantExpr::getLShr(Src,
161 ConstantInt::get(Src->getType(), ShiftAmt));
162 ShiftAmt += isLittleEndian ? DstBitSize : -DstBitSize;
164 // Truncate and remember this piece.
165 Result.push_back(ConstantExpr::getTrunc(Elt, DstEltTy));
170 return ConstantVector::get(Result.data(), Result.size());
174 /// IsConstantOffsetFromGlobal - If this constant is actually a constant offset
175 /// from a global, return the global and the constant. Because of
176 /// constantexprs, this function is recursive.
177 static bool IsConstantOffsetFromGlobal(Constant *C, GlobalValue *&GV,
178 int64_t &Offset, const TargetData &TD) {
179 // Trivial case, constant is the global.
180 if ((GV = dyn_cast<GlobalValue>(C))) {
185 // Otherwise, if this isn't a constant expr, bail out.
186 ConstantExpr *CE = dyn_cast<ConstantExpr>(C);
187 if (!CE) return false;
189 // Look through ptr->int and ptr->ptr casts.
190 if (CE->getOpcode() == Instruction::PtrToInt ||
191 CE->getOpcode() == Instruction::BitCast)
192 return IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, TD);
194 // i32* getelementptr ([5 x i32]* @a, i32 0, i32 5)
195 if (CE->getOpcode() == Instruction::GetElementPtr) {
196 // Cannot compute this if the element type of the pointer is missing size
198 if (!cast<PointerType>(CE->getOperand(0)->getType())
199 ->getElementType()->isSized())
202 // If the base isn't a global+constant, we aren't either.
203 if (!IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, TD))
206 // Otherwise, add any offset that our operands provide.
207 gep_type_iterator GTI = gep_type_begin(CE);
208 for (User::const_op_iterator i = CE->op_begin() + 1, e = CE->op_end();
209 i != e; ++i, ++GTI) {
210 ConstantInt *CI = dyn_cast<ConstantInt>(*i);
211 if (!CI) return false; // Index isn't a simple constant?
212 if (CI->isZero()) continue; // Not adding anything.
214 if (const StructType *ST = dyn_cast<StructType>(*GTI)) {
216 Offset += TD.getStructLayout(ST)->getElementOffset(CI->getZExtValue());
218 const SequentialType *SQT = cast<SequentialType>(*GTI);
219 Offset += TD.getTypeAllocSize(SQT->getElementType())*CI->getSExtValue();
228 /// ReadDataFromGlobal - Recursive helper to read bits out of global. C is the
229 /// constant being copied out of. ByteOffset is an offset into C. CurPtr is the
230 /// pointer to copy results into and BytesLeft is the number of bytes left in
231 /// the CurPtr buffer. TD is the target data.
232 static bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset,
233 unsigned char *CurPtr, unsigned BytesLeft,
234 const TargetData &TD) {
235 assert(ByteOffset <= TD.getTypeAllocSize(C->getType()) &&
236 "Out of range access");
238 // If this element is zero or undefined, we can just return since *CurPtr is
240 if (isa<ConstantAggregateZero>(C) || isa<UndefValue>(C))
243 if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) {
244 if (CI->getBitWidth() > 64 ||
245 (CI->getBitWidth() & 7) != 0)
248 uint64_t Val = CI->getZExtValue();
249 unsigned IntBytes = unsigned(CI->getBitWidth()/8);
251 for (unsigned i = 0; i != BytesLeft && ByteOffset != IntBytes; ++i) {
252 CurPtr[i] = (unsigned char)(Val >> (ByteOffset * 8));
258 if (ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
259 if (CFP->getType()->isDoubleTy()) {
260 C = FoldBitCast(C, Type::getInt64Ty(C->getContext()), TD);
261 return ReadDataFromGlobal(C, ByteOffset, CurPtr, BytesLeft, TD);
263 if (CFP->getType()->isFloatTy()){
264 C = FoldBitCast(C, Type::getInt32Ty(C->getContext()), TD);
265 return ReadDataFromGlobal(C, ByteOffset, CurPtr, BytesLeft, TD);
270 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(C)) {
271 const StructLayout *SL = TD.getStructLayout(CS->getType());
272 unsigned Index = SL->getElementContainingOffset(ByteOffset);
273 uint64_t CurEltOffset = SL->getElementOffset(Index);
274 ByteOffset -= CurEltOffset;
277 // If the element access is to the element itself and not to tail padding,
278 // read the bytes from the element.
279 uint64_t EltSize = TD.getTypeAllocSize(CS->getOperand(Index)->getType());
281 if (ByteOffset < EltSize &&
282 !ReadDataFromGlobal(CS->getOperand(Index), ByteOffset, CurPtr,
288 // Check to see if we read from the last struct element, if so we're done.
289 if (Index == CS->getType()->getNumElements())
292 // If we read all of the bytes we needed from this element we're done.
293 uint64_t NextEltOffset = SL->getElementOffset(Index);
295 if (BytesLeft <= NextEltOffset-CurEltOffset-ByteOffset)
298 // Move to the next element of the struct.
299 CurPtr += NextEltOffset-CurEltOffset-ByteOffset;
300 BytesLeft -= NextEltOffset-CurEltOffset-ByteOffset;
302 CurEltOffset = NextEltOffset;
307 if (ConstantArray *CA = dyn_cast<ConstantArray>(C)) {
308 uint64_t EltSize = TD.getTypeAllocSize(CA->getType()->getElementType());
309 uint64_t Index = ByteOffset / EltSize;
310 uint64_t Offset = ByteOffset - Index * EltSize;
311 for (; Index != CA->getType()->getNumElements(); ++Index) {
312 if (!ReadDataFromGlobal(CA->getOperand(Index), Offset, CurPtr,
315 if (EltSize >= BytesLeft)
319 BytesLeft -= EltSize;
325 if (ConstantVector *CV = dyn_cast<ConstantVector>(C)) {
326 uint64_t EltSize = TD.getTypeAllocSize(CV->getType()->getElementType());
327 uint64_t Index = ByteOffset / EltSize;
328 uint64_t Offset = ByteOffset - Index * EltSize;
329 for (; Index != CV->getType()->getNumElements(); ++Index) {
330 if (!ReadDataFromGlobal(CV->getOperand(Index), Offset, CurPtr,
333 if (EltSize >= BytesLeft)
337 BytesLeft -= EltSize;
343 // Otherwise, unknown initializer type.
347 static Constant *FoldReinterpretLoadFromConstPtr(Constant *C,
348 const TargetData &TD) {
349 const Type *LoadTy = cast<PointerType>(C->getType())->getElementType();
350 const IntegerType *IntType = dyn_cast<IntegerType>(LoadTy);
352 // If this isn't an integer load we can't fold it directly.
354 // If this is a float/double load, we can try folding it as an int32/64 load
355 // and then bitcast the result. This can be useful for union cases. Note
356 // that address spaces don't matter here since we're not going to result in
357 // an actual new load.
359 if (LoadTy->isFloatTy())
360 MapTy = Type::getInt32PtrTy(C->getContext());
361 else if (LoadTy->isDoubleTy())
362 MapTy = Type::getInt64PtrTy(C->getContext());
363 else if (LoadTy->isVectorTy()) {
364 MapTy = IntegerType::get(C->getContext(),
365 TD.getTypeAllocSizeInBits(LoadTy));
366 MapTy = PointerType::getUnqual(MapTy);
370 C = FoldBitCast(C, MapTy, TD);
371 if (Constant *Res = FoldReinterpretLoadFromConstPtr(C, TD))
372 return FoldBitCast(Res, LoadTy, TD);
376 unsigned BytesLoaded = (IntType->getBitWidth() + 7) / 8;
377 if (BytesLoaded > 32 || BytesLoaded == 0) return 0;
381 if (!IsConstantOffsetFromGlobal(C, GVal, Offset, TD))
384 GlobalVariable *GV = dyn_cast<GlobalVariable>(GVal);
385 if (!GV || !GV->isConstant() || !GV->hasDefinitiveInitializer() ||
386 !GV->getInitializer()->getType()->isSized())
389 // If we're loading off the beginning of the global, some bytes may be valid,
390 // but we don't try to handle this.
391 if (Offset < 0) return 0;
393 // If we're not accessing anything in this constant, the result is undefined.
394 if (uint64_t(Offset) >= TD.getTypeAllocSize(GV->getInitializer()->getType()))
395 return UndefValue::get(IntType);
397 unsigned char RawBytes[32] = {0};
398 if (!ReadDataFromGlobal(GV->getInitializer(), Offset, RawBytes,
402 APInt ResultVal = APInt(IntType->getBitWidth(), RawBytes[BytesLoaded-1]);
403 for (unsigned i = 1; i != BytesLoaded; ++i) {
405 ResultVal |= RawBytes[BytesLoaded-1-i];
408 return ConstantInt::get(IntType->getContext(), ResultVal);
411 /// ConstantFoldLoadFromConstPtr - Return the value that a load from C would
412 /// produce if it is constant and determinable. If this is not determinable,
414 Constant *llvm::ConstantFoldLoadFromConstPtr(Constant *C,
415 const TargetData *TD) {
416 // First, try the easy cases:
417 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(C))
418 if (GV->isConstant() && GV->hasDefinitiveInitializer())
419 return GV->getInitializer();
421 // If the loaded value isn't a constant expr, we can't handle it.
422 ConstantExpr *CE = dyn_cast<ConstantExpr>(C);
425 if (CE->getOpcode() == Instruction::GetElementPtr) {
426 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(CE->getOperand(0)))
427 if (GV->isConstant() && GV->hasDefinitiveInitializer())
429 ConstantFoldLoadThroughGEPConstantExpr(GV->getInitializer(), CE))
433 // Instead of loading constant c string, use corresponding integer value
434 // directly if string length is small enough.
436 if (TD && GetConstantStringInfo(CE, Str) && !Str.empty()) {
437 unsigned StrLen = Str.length();
438 const Type *Ty = cast<PointerType>(CE->getType())->getElementType();
439 unsigned NumBits = Ty->getPrimitiveSizeInBits();
440 // Replace load with immediate integer if the result is an integer or fp
442 if ((NumBits >> 3) == StrLen + 1 && (NumBits & 7) == 0 &&
443 (isa<IntegerType>(Ty) || Ty->isFloatingPointTy())) {
444 APInt StrVal(NumBits, 0);
445 APInt SingleChar(NumBits, 0);
446 if (TD->isLittleEndian()) {
447 for (signed i = StrLen-1; i >= 0; i--) {
448 SingleChar = (uint64_t) Str[i] & UCHAR_MAX;
449 StrVal = (StrVal << 8) | SingleChar;
452 for (unsigned i = 0; i < StrLen; i++) {
453 SingleChar = (uint64_t) Str[i] & UCHAR_MAX;
454 StrVal = (StrVal << 8) | SingleChar;
456 // Append NULL at the end.
458 StrVal = (StrVal << 8) | SingleChar;
461 Constant *Res = ConstantInt::get(CE->getContext(), StrVal);
462 if (Ty->isFloatingPointTy())
463 Res = ConstantExpr::getBitCast(Res, Ty);
468 // If this load comes from anywhere in a constant global, and if the global
469 // is all undef or zero, we know what it loads.
470 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(CE->getUnderlyingObject())){
471 if (GV->isConstant() && GV->hasDefinitiveInitializer()) {
472 const Type *ResTy = cast<PointerType>(C->getType())->getElementType();
473 if (GV->getInitializer()->isNullValue())
474 return Constant::getNullValue(ResTy);
475 if (isa<UndefValue>(GV->getInitializer()))
476 return UndefValue::get(ResTy);
480 // Try hard to fold loads from bitcasted strange and non-type-safe things. We
481 // currently don't do any of this for big endian systems. It can be
482 // generalized in the future if someone is interested.
483 if (TD && TD->isLittleEndian())
484 return FoldReinterpretLoadFromConstPtr(CE, *TD);
488 static Constant *ConstantFoldLoadInst(const LoadInst *LI, const TargetData *TD){
489 if (LI->isVolatile()) return 0;
491 if (Constant *C = dyn_cast<Constant>(LI->getOperand(0)))
492 return ConstantFoldLoadFromConstPtr(C, TD);
497 /// SymbolicallyEvaluateBinop - One of Op0/Op1 is a constant expression.
498 /// Attempt to symbolically evaluate the result of a binary operator merging
499 /// these together. If target data info is available, it is provided as TD,
500 /// otherwise TD is null.
501 static Constant *SymbolicallyEvaluateBinop(unsigned Opc, Constant *Op0,
502 Constant *Op1, const TargetData *TD){
505 // Fold (and 0xffffffff00000000, (shl x, 32)) -> shl.
506 // Fold (lshr (or X, Y), 32) -> (lshr [X/Y], 32) if one doesn't contribute
510 // If the constant expr is something like &A[123] - &A[4].f, fold this into a
511 // constant. This happens frequently when iterating over a global array.
512 if (Opc == Instruction::Sub && TD) {
513 GlobalValue *GV1, *GV2;
514 int64_t Offs1, Offs2;
516 if (IsConstantOffsetFromGlobal(Op0, GV1, Offs1, *TD))
517 if (IsConstantOffsetFromGlobal(Op1, GV2, Offs2, *TD) &&
519 // (&GV+C1) - (&GV+C2) -> C1-C2, pointer arithmetic cannot overflow.
520 return ConstantInt::get(Op0->getType(), Offs1-Offs2);
527 /// CastGEPIndices - If array indices are not pointer-sized integers,
528 /// explicitly cast them so that they aren't implicitly casted by the
530 static Constant *CastGEPIndices(Constant *const *Ops, unsigned NumOps,
531 const Type *ResultTy,
532 const TargetData *TD) {
534 const Type *IntPtrTy = TD->getIntPtrType(ResultTy->getContext());
537 SmallVector<Constant*, 32> NewIdxs;
538 for (unsigned i = 1; i != NumOps; ++i) {
540 !isa<StructType>(GetElementPtrInst::getIndexedType(Ops[0]->getType(),
541 reinterpret_cast<Value *const *>(Ops+1),
543 Ops[i]->getType() != IntPtrTy) {
545 NewIdxs.push_back(ConstantExpr::getCast(CastInst::getCastOpcode(Ops[i],
551 NewIdxs.push_back(Ops[i]);
556 ConstantExpr::getGetElementPtr(Ops[0], &NewIdxs[0], NewIdxs.size());
557 if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
558 if (Constant *Folded = ConstantFoldConstantExpression(CE, TD))
563 /// SymbolicallyEvaluateGEP - If we can symbolically evaluate the specified GEP
564 /// constant expression, do so.
565 static Constant *SymbolicallyEvaluateGEP(Constant *const *Ops, unsigned NumOps,
566 const Type *ResultTy,
567 const TargetData *TD) {
568 Constant *Ptr = Ops[0];
569 if (!TD || !cast<PointerType>(Ptr->getType())->getElementType()->isSized())
573 TD->getTypeSizeInBits(TD->getIntPtrType(Ptr->getContext()));
575 // If this is a constant expr gep that is effectively computing an
576 // "offsetof", fold it into 'cast int Size to T*' instead of 'gep 0, 0, 12'
577 for (unsigned i = 1; i != NumOps; ++i)
578 if (!isa<ConstantInt>(Ops[i]))
581 APInt Offset = APInt(BitWidth,
582 TD->getIndexedOffset(Ptr->getType(),
583 (Value**)Ops+1, NumOps-1));
584 Ptr = cast<Constant>(Ptr->stripPointerCasts());
586 // If this is a GEP of a GEP, fold it all into a single GEP.
587 while (GEPOperator *GEP = dyn_cast<GEPOperator>(Ptr)) {
588 SmallVector<Value *, 4> NestedOps(GEP->op_begin()+1, GEP->op_end());
590 // Do not try the incorporate the sub-GEP if some index is not a number.
591 bool AllConstantInt = true;
592 for (unsigned i = 0, e = NestedOps.size(); i != e; ++i)
593 if (!isa<ConstantInt>(NestedOps[i])) {
594 AllConstantInt = false;
600 Ptr = cast<Constant>(GEP->getOperand(0));
601 Offset += APInt(BitWidth,
602 TD->getIndexedOffset(Ptr->getType(),
603 (Value**)NestedOps.data(),
605 Ptr = cast<Constant>(Ptr->stripPointerCasts());
608 // If the base value for this address is a literal integer value, fold the
609 // getelementptr to the resulting integer value casted to the pointer type.
610 APInt BasePtr(BitWidth, 0);
611 if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr))
612 if (CE->getOpcode() == Instruction::IntToPtr)
613 if (ConstantInt *Base = dyn_cast<ConstantInt>(CE->getOperand(0))) {
614 BasePtr = Base->getValue();
615 BasePtr.zextOrTrunc(BitWidth);
617 if (Ptr->isNullValue() || BasePtr != 0) {
618 Constant *C = ConstantInt::get(Ptr->getContext(), Offset+BasePtr);
619 return ConstantExpr::getIntToPtr(C, ResultTy);
622 // Otherwise form a regular getelementptr. Recompute the indices so that
623 // we eliminate over-indexing of the notional static type array bounds.
624 // This makes it easy to determine if the getelementptr is "inbounds".
625 // Also, this helps GlobalOpt do SROA on GlobalVariables.
626 const Type *Ty = Ptr->getType();
627 SmallVector<Constant*, 32> NewIdxs;
629 if (const SequentialType *ATy = dyn_cast<SequentialType>(Ty)) {
630 if (ATy->isPointerTy()) {
631 // The only pointer indexing we'll do is on the first index of the GEP.
632 if (!NewIdxs.empty())
635 // Only handle pointers to sized types, not pointers to functions.
636 if (!ATy->getElementType()->isSized())
640 // Determine which element of the array the offset points into.
641 APInt ElemSize(BitWidth, TD->getTypeAllocSize(ATy->getElementType()));
642 const IntegerType *IntPtrTy = TD->getIntPtrType(Ty->getContext());
644 // The element size is 0. This may be [0 x Ty]*, so just use a zero
645 // index for this level and proceed to the next level to see if it can
646 // accommodate the offset.
647 NewIdxs.push_back(ConstantInt::get(IntPtrTy, 0));
649 // The element size is non-zero divide the offset by the element
650 // size (rounding down), to compute the index at this level.
651 APInt NewIdx = Offset.udiv(ElemSize);
652 Offset -= NewIdx * ElemSize;
653 NewIdxs.push_back(ConstantInt::get(IntPtrTy, NewIdx));
655 Ty = ATy->getElementType();
656 } else if (const StructType *STy = dyn_cast<StructType>(Ty)) {
657 // Determine which field of the struct the offset points into. The
658 // getZExtValue is at least as safe as the StructLayout API because we
659 // know the offset is within the struct at this point.
660 const StructLayout &SL = *TD->getStructLayout(STy);
661 unsigned ElIdx = SL.getElementContainingOffset(Offset.getZExtValue());
662 NewIdxs.push_back(ConstantInt::get(Type::getInt32Ty(Ty->getContext()),
664 Offset -= APInt(BitWidth, SL.getElementOffset(ElIdx));
665 Ty = STy->getTypeAtIndex(ElIdx);
667 // We've reached some non-indexable type.
670 } while (Ty != cast<PointerType>(ResultTy)->getElementType());
672 // If we haven't used up the entire offset by descending the static
673 // type, then the offset is pointing into the middle of an indivisible
674 // member, so we can't simplify it.
680 ConstantExpr::getGetElementPtr(Ptr, &NewIdxs[0], NewIdxs.size());
681 assert(cast<PointerType>(C->getType())->getElementType() == Ty &&
682 "Computed GetElementPtr has unexpected type!");
684 // If we ended up indexing a member with a type that doesn't match
685 // the type of what the original indices indexed, add a cast.
686 if (Ty != cast<PointerType>(ResultTy)->getElementType())
687 C = FoldBitCast(C, ResultTy, *TD);
694 //===----------------------------------------------------------------------===//
695 // Constant Folding public APIs
696 //===----------------------------------------------------------------------===//
698 /// ConstantFoldInstruction - Try to constant fold the specified instruction.
699 /// If successful, the constant result is returned, if not, null is returned.
700 /// Note that this fails if not all of the operands are constant. Otherwise,
701 /// this function can only fail when attempting to fold instructions like loads
702 /// and stores, which have no constant expression form.
703 Constant *llvm::ConstantFoldInstruction(Instruction *I, const TargetData *TD) {
704 // Handle PHI nodes quickly here...
705 if (PHINode *PN = dyn_cast<PHINode>(I)) {
706 Constant *CommonValue = 0;
708 for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
709 Value *Incoming = PN->getIncomingValue(i);
710 // If the incoming value is undef then skip it. Note that while we could
711 // skip the value if it is equal to the phi node itself we choose not to
712 // because that would break the rule that constant folding only applies if
713 // all operands are constants.
714 if (isa<UndefValue>(Incoming))
716 // If the incoming value is not a constant, or is a different constant to
717 // the one we saw previously, then give up.
718 Constant *C = dyn_cast<Constant>(Incoming);
719 if (!C || (CommonValue && C != CommonValue))
724 // If we reach here, all incoming values are the same constant or undef.
725 return CommonValue ? CommonValue : UndefValue::get(PN->getType());
728 // Scan the operand list, checking to see if they are all constants, if so,
729 // hand off to ConstantFoldInstOperands.
730 SmallVector<Constant*, 8> Ops;
731 for (User::op_iterator i = I->op_begin(), e = I->op_end(); i != e; ++i)
732 if (Constant *Op = dyn_cast<Constant>(*i))
735 return 0; // All operands not constant!
737 if (const CmpInst *CI = dyn_cast<CmpInst>(I))
738 return ConstantFoldCompareInstOperands(CI->getPredicate(), Ops[0], Ops[1],
741 if (const LoadInst *LI = dyn_cast<LoadInst>(I))
742 return ConstantFoldLoadInst(LI, TD);
744 if (InsertValueInst *IVI = dyn_cast<InsertValueInst>(I))
745 return ConstantExpr::getInsertValue(
746 cast<Constant>(IVI->getAggregateOperand()),
747 cast<Constant>(IVI->getInsertedValueOperand()),
748 IVI->idx_begin(), IVI->getNumIndices());
750 if (ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(I))
751 return ConstantExpr::getExtractValue(
752 cast<Constant>(EVI->getAggregateOperand()),
753 EVI->idx_begin(), EVI->getNumIndices());
755 return ConstantFoldInstOperands(I->getOpcode(), I->getType(),
756 Ops.data(), Ops.size(), TD);
759 /// ConstantFoldConstantExpression - Attempt to fold the constant expression
760 /// using the specified TargetData. If successful, the constant result is
761 /// result is returned, if not, null is returned.
762 Constant *llvm::ConstantFoldConstantExpression(const ConstantExpr *CE,
763 const TargetData *TD) {
764 SmallVector<Constant*, 8> Ops;
765 for (User::const_op_iterator i = CE->op_begin(), e = CE->op_end();
767 Constant *NewC = cast<Constant>(*i);
768 // Recursively fold the ConstantExpr's operands.
769 if (ConstantExpr *NewCE = dyn_cast<ConstantExpr>(NewC))
770 NewC = ConstantFoldConstantExpression(NewCE, TD);
775 return ConstantFoldCompareInstOperands(CE->getPredicate(), Ops[0], Ops[1],
777 return ConstantFoldInstOperands(CE->getOpcode(), CE->getType(),
778 Ops.data(), Ops.size(), TD);
781 /// ConstantFoldInstOperands - Attempt to constant fold an instruction with the
782 /// specified opcode and operands. If successful, the constant result is
783 /// returned, if not, null is returned. Note that this function can fail when
784 /// attempting to fold instructions like loads and stores, which have no
785 /// constant expression form.
787 /// TODO: This function neither utilizes nor preserves nsw/nuw/inbounds/etc
788 /// information, due to only being passed an opcode and operands. Constant
789 /// folding using this function strips this information.
791 Constant *llvm::ConstantFoldInstOperands(unsigned Opcode, const Type *DestTy,
792 Constant* const* Ops, unsigned NumOps,
793 const TargetData *TD) {
794 // Handle easy binops first.
795 if (Instruction::isBinaryOp(Opcode)) {
796 if (isa<ConstantExpr>(Ops[0]) || isa<ConstantExpr>(Ops[1]))
797 if (Constant *C = SymbolicallyEvaluateBinop(Opcode, Ops[0], Ops[1], TD))
800 return ConstantExpr::get(Opcode, Ops[0], Ops[1]);
805 case Instruction::ICmp:
806 case Instruction::FCmp: assert(0 && "Invalid for compares");
807 case Instruction::Call:
808 if (Function *F = dyn_cast<Function>(Ops[NumOps - 1]))
809 if (canConstantFoldCallTo(F))
810 return ConstantFoldCall(F, Ops, NumOps - 1);
812 case Instruction::PtrToInt:
813 // If the input is a inttoptr, eliminate the pair. This requires knowing
814 // the width of a pointer, so it can't be done in ConstantExpr::getCast.
815 if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[0])) {
816 if (TD && CE->getOpcode() == Instruction::IntToPtr) {
817 Constant *Input = CE->getOperand(0);
818 unsigned InWidth = Input->getType()->getScalarSizeInBits();
819 if (TD->getPointerSizeInBits() < InWidth) {
821 ConstantInt::get(CE->getContext(), APInt::getLowBitsSet(InWidth,
822 TD->getPointerSizeInBits()));
823 Input = ConstantExpr::getAnd(Input, Mask);
825 // Do a zext or trunc to get to the dest size.
826 return ConstantExpr::getIntegerCast(Input, DestTy, false);
829 return ConstantExpr::getCast(Opcode, Ops[0], DestTy);
830 case Instruction::IntToPtr:
831 // If the input is a ptrtoint, turn the pair into a ptr to ptr bitcast if
832 // the int size is >= the ptr size. This requires knowing the width of a
833 // pointer, so it can't be done in ConstantExpr::getCast.
834 if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[0]))
836 TD->getPointerSizeInBits() <= CE->getType()->getScalarSizeInBits() &&
837 CE->getOpcode() == Instruction::PtrToInt)
838 return FoldBitCast(CE->getOperand(0), DestTy, *TD);
840 return ConstantExpr::getCast(Opcode, Ops[0], DestTy);
841 case Instruction::Trunc:
842 case Instruction::ZExt:
843 case Instruction::SExt:
844 case Instruction::FPTrunc:
845 case Instruction::FPExt:
846 case Instruction::UIToFP:
847 case Instruction::SIToFP:
848 case Instruction::FPToUI:
849 case Instruction::FPToSI:
850 return ConstantExpr::getCast(Opcode, Ops[0], DestTy);
851 case Instruction::BitCast:
853 return FoldBitCast(Ops[0], DestTy, *TD);
854 return ConstantExpr::getBitCast(Ops[0], DestTy);
855 case Instruction::Select:
856 return ConstantExpr::getSelect(Ops[0], Ops[1], Ops[2]);
857 case Instruction::ExtractElement:
858 return ConstantExpr::getExtractElement(Ops[0], Ops[1]);
859 case Instruction::InsertElement:
860 return ConstantExpr::getInsertElement(Ops[0], Ops[1], Ops[2]);
861 case Instruction::ShuffleVector:
862 return ConstantExpr::getShuffleVector(Ops[0], Ops[1], Ops[2]);
863 case Instruction::GetElementPtr:
864 if (Constant *C = CastGEPIndices(Ops, NumOps, DestTy, TD))
866 if (Constant *C = SymbolicallyEvaluateGEP(Ops, NumOps, DestTy, TD))
869 return ConstantExpr::getGetElementPtr(Ops[0], Ops+1, NumOps-1);
873 /// ConstantFoldCompareInstOperands - Attempt to constant fold a compare
874 /// instruction (icmp/fcmp) with the specified operands. If it fails, it
875 /// returns a constant expression of the specified operands.
877 Constant *llvm::ConstantFoldCompareInstOperands(unsigned Predicate,
878 Constant *Ops0, Constant *Ops1,
879 const TargetData *TD) {
880 // fold: icmp (inttoptr x), null -> icmp x, 0
881 // fold: icmp (ptrtoint x), 0 -> icmp x, null
882 // fold: icmp (inttoptr x), (inttoptr y) -> icmp trunc/zext x, trunc/zext y
883 // fold: icmp (ptrtoint x), (ptrtoint y) -> icmp x, y
885 // ConstantExpr::getCompare cannot do this, because it doesn't have TD
886 // around to know if bit truncation is happening.
887 if (ConstantExpr *CE0 = dyn_cast<ConstantExpr>(Ops0)) {
888 if (TD && Ops1->isNullValue()) {
889 const Type *IntPtrTy = TD->getIntPtrType(CE0->getContext());
890 if (CE0->getOpcode() == Instruction::IntToPtr) {
891 // Convert the integer value to the right size to ensure we get the
892 // proper extension or truncation.
893 Constant *C = ConstantExpr::getIntegerCast(CE0->getOperand(0),
895 Constant *Null = Constant::getNullValue(C->getType());
896 return ConstantFoldCompareInstOperands(Predicate, C, Null, TD);
899 // Only do this transformation if the int is intptrty in size, otherwise
900 // there is a truncation or extension that we aren't modeling.
901 if (CE0->getOpcode() == Instruction::PtrToInt &&
902 CE0->getType() == IntPtrTy) {
903 Constant *C = CE0->getOperand(0);
904 Constant *Null = Constant::getNullValue(C->getType());
905 return ConstantFoldCompareInstOperands(Predicate, C, Null, TD);
909 if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(Ops1)) {
910 if (TD && CE0->getOpcode() == CE1->getOpcode()) {
911 const Type *IntPtrTy = TD->getIntPtrType(CE0->getContext());
913 if (CE0->getOpcode() == Instruction::IntToPtr) {
914 // Convert the integer value to the right size to ensure we get the
915 // proper extension or truncation.
916 Constant *C0 = ConstantExpr::getIntegerCast(CE0->getOperand(0),
918 Constant *C1 = ConstantExpr::getIntegerCast(CE1->getOperand(0),
920 return ConstantFoldCompareInstOperands(Predicate, C0, C1, TD);
923 // Only do this transformation if the int is intptrty in size, otherwise
924 // there is a truncation or extension that we aren't modeling.
925 if ((CE0->getOpcode() == Instruction::PtrToInt &&
926 CE0->getType() == IntPtrTy &&
927 CE0->getOperand(0)->getType() == CE1->getOperand(0)->getType()))
928 return ConstantFoldCompareInstOperands(Predicate, CE0->getOperand(0),
929 CE1->getOperand(0), TD);
933 // icmp eq (or x, y), 0 -> (icmp eq x, 0) & (icmp eq y, 0)
934 // icmp ne (or x, y), 0 -> (icmp ne x, 0) | (icmp ne y, 0)
935 if ((Predicate == ICmpInst::ICMP_EQ || Predicate == ICmpInst::ICMP_NE) &&
936 CE0->getOpcode() == Instruction::Or && Ops1->isNullValue()) {
938 ConstantFoldCompareInstOperands(Predicate, CE0->getOperand(0), Ops1,TD);
940 ConstantFoldCompareInstOperands(Predicate, CE0->getOperand(1), Ops1,TD);
942 Predicate == ICmpInst::ICMP_EQ ? Instruction::And : Instruction::Or;
943 Constant *Ops[] = { LHS, RHS };
944 return ConstantFoldInstOperands(OpC, LHS->getType(), Ops, 2, TD);
948 return ConstantExpr::getCompare(Predicate, Ops0, Ops1);
952 /// ConstantFoldLoadThroughGEPConstantExpr - Given a constant and a
953 /// getelementptr constantexpr, return the constant value being addressed by the
954 /// constant expression, or null if something is funny and we can't decide.
955 Constant *llvm::ConstantFoldLoadThroughGEPConstantExpr(Constant *C,
957 if (CE->getOperand(1) != Constant::getNullValue(CE->getOperand(1)->getType()))
958 return 0; // Do not allow stepping over the value!
960 // Loop over all of the operands, tracking down which value we are
962 gep_type_iterator I = gep_type_begin(CE), E = gep_type_end(CE);
963 for (++I; I != E; ++I)
964 if (const StructType *STy = dyn_cast<StructType>(*I)) {
965 ConstantInt *CU = cast<ConstantInt>(I.getOperand());
966 assert(CU->getZExtValue() < STy->getNumElements() &&
967 "Struct index out of range!");
968 unsigned El = (unsigned)CU->getZExtValue();
969 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(C)) {
970 C = CS->getOperand(El);
971 } else if (isa<ConstantAggregateZero>(C)) {
972 C = Constant::getNullValue(STy->getElementType(El));
973 } else if (isa<UndefValue>(C)) {
974 C = UndefValue::get(STy->getElementType(El));
978 } else if (ConstantInt *CI = dyn_cast<ConstantInt>(I.getOperand())) {
979 if (const ArrayType *ATy = dyn_cast<ArrayType>(*I)) {
980 if (CI->getZExtValue() >= ATy->getNumElements())
982 if (ConstantArray *CA = dyn_cast<ConstantArray>(C))
983 C = CA->getOperand(CI->getZExtValue());
984 else if (isa<ConstantAggregateZero>(C))
985 C = Constant::getNullValue(ATy->getElementType());
986 else if (isa<UndefValue>(C))
987 C = UndefValue::get(ATy->getElementType());
990 } else if (const VectorType *VTy = dyn_cast<VectorType>(*I)) {
991 if (CI->getZExtValue() >= VTy->getNumElements())
993 if (ConstantVector *CP = dyn_cast<ConstantVector>(C))
994 C = CP->getOperand(CI->getZExtValue());
995 else if (isa<ConstantAggregateZero>(C))
996 C = Constant::getNullValue(VTy->getElementType());
997 else if (isa<UndefValue>(C))
998 C = UndefValue::get(VTy->getElementType());
1011 //===----------------------------------------------------------------------===//
1012 // Constant Folding for Calls
1015 /// canConstantFoldCallTo - Return true if its even possible to fold a call to
1016 /// the specified function.
1018 llvm::canConstantFoldCallTo(const Function *F) {
1019 switch (F->getIntrinsicID()) {
1020 case Intrinsic::sqrt:
1021 case Intrinsic::powi:
1022 case Intrinsic::bswap:
1023 case Intrinsic::ctpop:
1024 case Intrinsic::ctlz:
1025 case Intrinsic::cttz:
1026 case Intrinsic::uadd_with_overflow:
1027 case Intrinsic::usub_with_overflow:
1028 case Intrinsic::sadd_with_overflow:
1029 case Intrinsic::ssub_with_overflow:
1030 case Intrinsic::smul_with_overflow:
1031 case Intrinsic::convert_from_fp16:
1032 case Intrinsic::convert_to_fp16:
1039 if (!F->hasName()) return false;
1040 StringRef Name = F->getName();
1042 // In these cases, the check of the length is required. We don't want to
1043 // return true for a name like "cos\0blah" which strcmp would return equal to
1044 // "cos", but has length 8.
1046 default: return false;
1048 return Name == "acos" || Name == "asin" ||
1049 Name == "atan" || Name == "atan2";
1051 return Name == "cos" || Name == "ceil" || Name == "cosf" || Name == "cosh";
1053 return Name == "exp";
1055 return Name == "fabs" || Name == "fmod" || Name == "floor";
1057 return Name == "log" || Name == "log10";
1059 return Name == "pow";
1061 return Name == "sin" || Name == "sinh" || Name == "sqrt" ||
1062 Name == "sinf" || Name == "sqrtf";
1064 return Name == "tan" || Name == "tanh";
1068 static Constant *ConstantFoldFP(double (*NativeFP)(double), double V,
1070 sys::llvm_fenv_clearexcept();
1072 if (sys::llvm_fenv_testexcept()) {
1073 sys::llvm_fenv_clearexcept();
1077 if (Ty->isFloatTy())
1078 return ConstantFP::get(Ty->getContext(), APFloat((float)V));
1079 if (Ty->isDoubleTy())
1080 return ConstantFP::get(Ty->getContext(), APFloat(V));
1081 llvm_unreachable("Can only constant fold float/double");
1082 return 0; // dummy return to suppress warning
1085 static Constant *ConstantFoldBinaryFP(double (*NativeFP)(double, double),
1086 double V, double W, const Type *Ty) {
1087 sys::llvm_fenv_clearexcept();
1089 if (sys::llvm_fenv_testexcept()) {
1090 sys::llvm_fenv_clearexcept();
1094 if (Ty->isFloatTy())
1095 return ConstantFP::get(Ty->getContext(), APFloat((float)V));
1096 if (Ty->isDoubleTy())
1097 return ConstantFP::get(Ty->getContext(), APFloat(V));
1098 llvm_unreachable("Can only constant fold float/double");
1099 return 0; // dummy return to suppress warning
1102 /// ConstantFoldCall - Attempt to constant fold a call to the specified function
1103 /// with the specified arguments, returning null if unsuccessful.
1105 llvm::ConstantFoldCall(Function *F,
1106 Constant *const *Operands, unsigned NumOperands) {
1107 if (!F->hasName()) return 0;
1108 StringRef Name = F->getName();
1110 const Type *Ty = F->getReturnType();
1111 if (NumOperands == 1) {
1112 if (ConstantFP *Op = dyn_cast<ConstantFP>(Operands[0])) {
1113 if (Name == "llvm.convert.to.fp16") {
1114 APFloat Val(Op->getValueAPF());
1117 Val.convert(APFloat::IEEEhalf, APFloat::rmNearestTiesToEven, &lost);
1119 return ConstantInt::get(F->getContext(), Val.bitcastToAPInt());
1122 if (!Ty->isFloatTy() && !Ty->isDoubleTy())
1125 /// We only fold functions with finite arguments. Folding NaN and inf is
1126 /// likely to be aborted with an exception anyway, and some host libms
1127 /// have known errors raising exceptions.
1128 if (Op->getValueAPF().isNaN() || Op->getValueAPF().isInfinity())
1131 /// Currently APFloat versions of these functions do not exist, so we use
1132 /// the host native double versions. Float versions are not called
1133 /// directly but for all these it is true (float)(f((double)arg)) ==
1134 /// f(arg). Long double not supported yet.
1135 double V = Ty->isFloatTy() ? (double)Op->getValueAPF().convertToFloat() :
1136 Op->getValueAPF().convertToDouble();
1140 return ConstantFoldFP(acos, V, Ty);
1141 else if (Name == "asin")
1142 return ConstantFoldFP(asin, V, Ty);
1143 else if (Name == "atan")
1144 return ConstantFoldFP(atan, V, Ty);
1148 return ConstantFoldFP(ceil, V, Ty);
1149 else if (Name == "cos")
1150 return ConstantFoldFP(cos, V, Ty);
1151 else if (Name == "cosh")
1152 return ConstantFoldFP(cosh, V, Ty);
1153 else if (Name == "cosf")
1154 return ConstantFoldFP(cos, V, Ty);
1158 return ConstantFoldFP(exp, V, Ty);
1162 return ConstantFoldFP(fabs, V, Ty);
1163 else if (Name == "floor")
1164 return ConstantFoldFP(floor, V, Ty);
1167 if (Name == "log" && V > 0)
1168 return ConstantFoldFP(log, V, Ty);
1169 else if (Name == "log10" && V > 0)
1170 return ConstantFoldFP(log10, V, Ty);
1171 else if (Name == "llvm.sqrt.f32" ||
1172 Name == "llvm.sqrt.f64") {
1174 return ConstantFoldFP(sqrt, V, Ty);
1176 return Constant::getNullValue(Ty);
1181 return ConstantFoldFP(sin, V, Ty);
1182 else if (Name == "sinh")
1183 return ConstantFoldFP(sinh, V, Ty);
1184 else if (Name == "sqrt" && V >= 0)
1185 return ConstantFoldFP(sqrt, V, Ty);
1186 else if (Name == "sqrtf" && V >= 0)
1187 return ConstantFoldFP(sqrt, V, Ty);
1188 else if (Name == "sinf")
1189 return ConstantFoldFP(sin, V, Ty);
1193 return ConstantFoldFP(tan, V, Ty);
1194 else if (Name == "tanh")
1195 return ConstantFoldFP(tanh, V, Ty);
1204 if (ConstantInt *Op = dyn_cast<ConstantInt>(Operands[0])) {
1205 if (Name.startswith("llvm.bswap"))
1206 return ConstantInt::get(F->getContext(), Op->getValue().byteSwap());
1207 else if (Name.startswith("llvm.ctpop"))
1208 return ConstantInt::get(Ty, Op->getValue().countPopulation());
1209 else if (Name.startswith("llvm.cttz"))
1210 return ConstantInt::get(Ty, Op->getValue().countTrailingZeros());
1211 else if (Name.startswith("llvm.ctlz"))
1212 return ConstantInt::get(Ty, Op->getValue().countLeadingZeros());
1213 else if (Name == "llvm.convert.from.fp16") {
1214 APFloat Val(Op->getValue());
1217 APFloat::opStatus status =
1218 Val.convert(APFloat::IEEEsingle, APFloat::rmNearestTiesToEven, &lost);
1220 // Conversion is always precise.
1222 assert(status == APFloat::opOK && !lost &&
1223 "Precision lost during fp16 constfolding");
1225 return ConstantFP::get(F->getContext(), Val);
1230 if (isa<UndefValue>(Operands[0])) {
1231 if (Name.startswith("llvm.bswap"))
1239 if (NumOperands == 2) {
1240 if (ConstantFP *Op1 = dyn_cast<ConstantFP>(Operands[0])) {
1241 if (!Ty->isFloatTy() && !Ty->isDoubleTy())
1243 double Op1V = Ty->isFloatTy() ?
1244 (double)Op1->getValueAPF().convertToFloat() :
1245 Op1->getValueAPF().convertToDouble();
1246 if (ConstantFP *Op2 = dyn_cast<ConstantFP>(Operands[1])) {
1247 if (Op2->getType() != Op1->getType())
1250 double Op2V = Ty->isFloatTy() ?
1251 (double)Op2->getValueAPF().convertToFloat():
1252 Op2->getValueAPF().convertToDouble();
1255 return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty);
1257 return ConstantFoldBinaryFP(fmod, Op1V, Op2V, Ty);
1258 if (Name == "atan2")
1259 return ConstantFoldBinaryFP(atan2, Op1V, Op2V, Ty);
1260 } else if (ConstantInt *Op2C = dyn_cast<ConstantInt>(Operands[1])) {
1261 if (Name == "llvm.powi.f32")
1262 return ConstantFP::get(F->getContext(),
1263 APFloat((float)std::pow((float)Op1V,
1264 (int)Op2C->getZExtValue())));
1265 if (Name == "llvm.powi.f64")
1266 return ConstantFP::get(F->getContext(),
1267 APFloat((double)std::pow((double)Op1V,
1268 (int)Op2C->getZExtValue())));
1274 if (ConstantInt *Op1 = dyn_cast<ConstantInt>(Operands[0])) {
1275 if (ConstantInt *Op2 = dyn_cast<ConstantInt>(Operands[1])) {
1276 switch (F->getIntrinsicID()) {
1278 case Intrinsic::sadd_with_overflow:
1279 case Intrinsic::uadd_with_overflow:
1280 case Intrinsic::ssub_with_overflow:
1281 case Intrinsic::usub_with_overflow:
1282 case Intrinsic::smul_with_overflow: {
1285 switch (F->getIntrinsicID()) {
1286 default: assert(0 && "Invalid case");
1287 case Intrinsic::sadd_with_overflow:
1288 Res = Op1->getValue().sadd_ov(Op2->getValue(), Overflow);
1290 case Intrinsic::uadd_with_overflow:
1291 Res = Op1->getValue().uadd_ov(Op2->getValue(), Overflow);
1293 case Intrinsic::ssub_with_overflow:
1294 Res = Op1->getValue().ssub_ov(Op2->getValue(), Overflow);
1296 case Intrinsic::usub_with_overflow:
1297 Res = Op1->getValue().usub_ov(Op2->getValue(), Overflow);
1299 case Intrinsic::smul_with_overflow:
1300 Res = Op1->getValue().smul_ov(Op2->getValue(), Overflow);
1304 ConstantInt::get(F->getContext(), Res),
1305 ConstantInt::get(Type::getInt1Ty(F->getContext()), Overflow)
1307 return ConstantStruct::get(F->getContext(), Ops, 2, false);