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-rw-r--r--lib/Analysis/ConstantFolding.cpp736
1 files changed, 415 insertions, 321 deletions
diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp
index ccb56631b846..6c471ab45048 100644
--- a/lib/Analysis/ConstantFolding.cpp
+++ b/lib/Analysis/ConstantFolding.cpp
@@ -17,6 +17,7 @@
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/ConstantFolding.h"
+#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringMap.h"
@@ -34,15 +35,16 @@
#include "llvm/IR/Operator.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
+#include <cassert>
#include <cerrno>
+#include <cfenv>
#include <cmath>
-
-#ifdef HAVE_FENV_H
-#include <fenv.h>
-#endif
+#include <limits>
using namespace llvm;
+namespace {
+
//===----------------------------------------------------------------------===//
// Constant Folding internal helper functions
//===----------------------------------------------------------------------===//
@@ -50,7 +52,7 @@ using namespace llvm;
/// Constant fold bitcast, symbolically evaluating it with DataLayout.
/// This always returns a non-null constant, but it may be a
/// ConstantExpr if unfoldable.
-static Constant *FoldBitCast(Constant *C, Type *DestTy, const DataLayout &DL) {
+Constant *FoldBitCast(Constant *C, Type *DestTy, const DataLayout &DL) {
// Catch the obvious splat cases.
if (C->isNullValue() && !DestTy->isX86_MMXTy())
return Constant::getNullValue(DestTy);
@@ -59,8 +61,8 @@ static Constant *FoldBitCast(Constant *C, Type *DestTy, const DataLayout &DL) {
return Constant::getAllOnesValue(DestTy);
// Handle a vector->integer cast.
- if (IntegerType *IT = dyn_cast<IntegerType>(DestTy)) {
- VectorType *VTy = dyn_cast<VectorType>(C->getType());
+ if (auto *IT = dyn_cast<IntegerType>(DestTy)) {
+ auto *VTy = dyn_cast<VectorType>(C->getType());
if (!VTy)
return ConstantExpr::getBitCast(C, DestTy);
@@ -77,27 +79,30 @@ static Constant *FoldBitCast(Constant *C, Type *DestTy, const DataLayout &DL) {
C = ConstantExpr::getBitCast(C, SrcIVTy);
}
- ConstantDataVector *CDV = dyn_cast<ConstantDataVector>(C);
- if (!CDV)
- return ConstantExpr::getBitCast(C, DestTy);
-
// Now that we know that the input value is a vector of integers, just shift
// and insert them into our result.
- unsigned BitShift = DL.getTypeAllocSizeInBits(SrcEltTy);
+ unsigned BitShift = DL.getTypeSizeInBits(SrcEltTy);
APInt Result(IT->getBitWidth(), 0);
for (unsigned i = 0; i != NumSrcElts; ++i) {
- Result <<= BitShift;
+ Constant *Element;
if (DL.isLittleEndian())
- Result |= CDV->getElementAsInteger(NumSrcElts-i-1);
+ Element = C->getAggregateElement(NumSrcElts-i-1);
else
- Result |= CDV->getElementAsInteger(i);
+ Element = C->getAggregateElement(i);
+
+ auto *ElementCI = dyn_cast_or_null<ConstantInt>(Element);
+ if (!ElementCI)
+ return ConstantExpr::getBitCast(C, DestTy);
+
+ Result <<= BitShift;
+ Result |= ElementCI->getValue().zextOrSelf(IT->getBitWidth());
}
return ConstantInt::get(IT, Result);
}
// The code below only handles casts to vectors currently.
- VectorType *DestVTy = dyn_cast<VectorType>(DestTy);
+ auto *DestVTy = dyn_cast<VectorType>(DestTy);
if (!DestVTy)
return ConstantExpr::getBitCast(C, DestTy);
@@ -175,7 +180,7 @@ static Constant *FoldBitCast(Constant *C, Type *DestTy, const DataLayout &DL) {
Constant *Elt = Zero;
unsigned ShiftAmt = isLittleEndian ? 0 : SrcBitSize*(Ratio-1);
for (unsigned j = 0; j != Ratio; ++j) {
- Constant *Src =dyn_cast<ConstantInt>(C->getAggregateElement(SrcElt++));
+ Constant *Src = dyn_cast<ConstantInt>(C->getAggregateElement(SrcElt++));
if (!Src) // Reject constantexpr elements.
return ConstantExpr::getBitCast(C, DestTy);
@@ -201,7 +206,7 @@ static Constant *FoldBitCast(Constant *C, Type *DestTy, const DataLayout &DL) {
// Loop over each source value, expanding into multiple results.
for (unsigned i = 0; i != NumSrcElt; ++i) {
- Constant *Src = dyn_cast<ConstantInt>(C->getAggregateElement(i));
+ auto *Src = dyn_cast<ConstantInt>(C->getAggregateElement(i));
if (!Src) // Reject constantexpr elements.
return ConstantExpr::getBitCast(C, DestTy);
@@ -230,11 +235,12 @@ static Constant *FoldBitCast(Constant *C, Type *DestTy, const DataLayout &DL) {
return ConstantVector::get(Result);
}
+} // end anonymous namespace
/// If this constant is a constant offset from a global, return the global and
/// the constant. Because of constantexprs, this function is recursive.
-static bool IsConstantOffsetFromGlobal(Constant *C, GlobalValue *&GV,
- APInt &Offset, const DataLayout &DL) {
+bool llvm::IsConstantOffsetFromGlobal(Constant *C, GlobalValue *&GV,
+ APInt &Offset, const DataLayout &DL) {
// Trivial case, constant is the global.
if ((GV = dyn_cast<GlobalValue>(C))) {
unsigned BitWidth = DL.getPointerTypeSizeInBits(GV->getType());
@@ -243,7 +249,7 @@ static bool IsConstantOffsetFromGlobal(Constant *C, GlobalValue *&GV,
}
// Otherwise, if this isn't a constant expr, bail out.
- ConstantExpr *CE = dyn_cast<ConstantExpr>(C);
+ auto *CE = dyn_cast<ConstantExpr>(C);
if (!CE) return false;
// Look through ptr->int and ptr->ptr casts.
@@ -252,7 +258,7 @@ static bool IsConstantOffsetFromGlobal(Constant *C, GlobalValue *&GV,
return IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, DL);
// i32* getelementptr ([5 x i32]* @a, i32 0, i32 5)
- GEPOperator *GEP = dyn_cast<GEPOperator>(CE);
+ auto *GEP = dyn_cast<GEPOperator>(CE);
if (!GEP)
return false;
@@ -271,13 +277,14 @@ static bool IsConstantOffsetFromGlobal(Constant *C, GlobalValue *&GV,
return true;
}
+namespace {
+
/// Recursive helper to read bits out of global. C is the constant being copied
/// out of. ByteOffset is an offset into C. CurPtr is the pointer to copy
/// results into and BytesLeft is the number of bytes left in
/// the CurPtr buffer. DL is the DataLayout.
-static bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset,
- unsigned char *CurPtr, unsigned BytesLeft,
- const DataLayout &DL) {
+bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset, unsigned char *CurPtr,
+ unsigned BytesLeft, const DataLayout &DL) {
assert(ByteOffset <= DL.getTypeAllocSize(C->getType()) &&
"Out of range access");
@@ -286,7 +293,7 @@ static bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset,
if (isa<ConstantAggregateZero>(C) || isa<UndefValue>(C))
return true;
- if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) {
+ if (auto *CI = dyn_cast<ConstantInt>(C)) {
if (CI->getBitWidth() > 64 ||
(CI->getBitWidth() & 7) != 0)
return false;
@@ -304,7 +311,7 @@ static bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset,
return true;
}
- if (ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
+ if (auto *CFP = dyn_cast<ConstantFP>(C)) {
if (CFP->getType()->isDoubleTy()) {
C = FoldBitCast(C, Type::getInt64Ty(C->getContext()), DL);
return ReadDataFromGlobal(C, ByteOffset, CurPtr, BytesLeft, DL);
@@ -320,7 +327,7 @@ static bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset,
return false;
}
- if (ConstantStruct *CS = dyn_cast<ConstantStruct>(C)) {
+ if (auto *CS = dyn_cast<ConstantStruct>(C)) {
const StructLayout *SL = DL.getStructLayout(CS->getType());
unsigned Index = SL->getElementContainingOffset(ByteOffset);
uint64_t CurEltOffset = SL->getElementOffset(Index);
@@ -364,7 +371,7 @@ static bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset,
uint64_t Index = ByteOffset / EltSize;
uint64_t Offset = ByteOffset - Index * EltSize;
uint64_t NumElts;
- if (ArrayType *AT = dyn_cast<ArrayType>(C->getType()))
+ if (auto *AT = dyn_cast<ArrayType>(C->getType()))
NumElts = AT->getNumElements();
else
NumElts = C->getType()->getVectorNumElements();
@@ -386,7 +393,7 @@ static bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset,
return true;
}
- if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
+ if (auto *CE = dyn_cast<ConstantExpr>(C)) {
if (CE->getOpcode() == Instruction::IntToPtr &&
CE->getOperand(0)->getType() == DL.getIntPtrType(CE->getType())) {
return ReadDataFromGlobal(CE->getOperand(0), ByteOffset, CurPtr,
@@ -398,11 +405,10 @@ static bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset,
return false;
}
-static Constant *FoldReinterpretLoadFromConstPtr(Constant *C,
- const DataLayout &DL) {
- PointerType *PTy = cast<PointerType>(C->getType());
- Type *LoadTy = PTy->getElementType();
- IntegerType *IntType = dyn_cast<IntegerType>(LoadTy);
+Constant *FoldReinterpretLoadFromConstPtr(Constant *C, Type *LoadTy,
+ const DataLayout &DL) {
+ auto *PTy = cast<PointerType>(C->getType());
+ auto *IntType = dyn_cast<IntegerType>(LoadTy);
// If this isn't an integer load we can't fold it directly.
if (!IntType) {
@@ -414,19 +420,19 @@ static Constant *FoldReinterpretLoadFromConstPtr(Constant *C,
// an actual new load.
Type *MapTy;
if (LoadTy->isHalfTy())
- MapTy = Type::getInt16PtrTy(C->getContext(), AS);
+ MapTy = Type::getInt16Ty(C->getContext());
else if (LoadTy->isFloatTy())
- MapTy = Type::getInt32PtrTy(C->getContext(), AS);
+ MapTy = Type::getInt32Ty(C->getContext());
else if (LoadTy->isDoubleTy())
- MapTy = Type::getInt64PtrTy(C->getContext(), AS);
+ MapTy = Type::getInt64Ty(C->getContext());
else if (LoadTy->isVectorTy()) {
- MapTy = PointerType::getIntNPtrTy(C->getContext(),
- DL.getTypeAllocSizeInBits(LoadTy), AS);
+ MapTy = PointerType::getIntNTy(C->getContext(),
+ DL.getTypeAllocSizeInBits(LoadTy));
} else
return nullptr;
- C = FoldBitCast(C, MapTy, DL);
- if (Constant *Res = FoldReinterpretLoadFromConstPtr(C, DL))
+ C = FoldBitCast(C, MapTy->getPointerTo(AS), DL);
+ if (Constant *Res = FoldReinterpretLoadFromConstPtr(C, MapTy, DL))
return FoldBitCast(Res, LoadTy, DL);
return nullptr;
}
@@ -436,28 +442,38 @@ static Constant *FoldReinterpretLoadFromConstPtr(Constant *C,
return nullptr;
GlobalValue *GVal;
- APInt Offset;
- if (!IsConstantOffsetFromGlobal(C, GVal, Offset, DL))
+ APInt OffsetAI;
+ if (!IsConstantOffsetFromGlobal(C, GVal, OffsetAI, DL))
return nullptr;
- GlobalVariable *GV = dyn_cast<GlobalVariable>(GVal);
+ auto *GV = dyn_cast<GlobalVariable>(GVal);
if (!GV || !GV->isConstant() || !GV->hasDefinitiveInitializer() ||
!GV->getInitializer()->getType()->isSized())
return nullptr;
- // If we're loading off the beginning of the global, some bytes may be valid,
- // but we don't try to handle this.
- if (Offset.isNegative())
- return nullptr;
+ int64_t Offset = OffsetAI.getSExtValue();
+ int64_t InitializerSize = DL.getTypeAllocSize(GV->getInitializer()->getType());
+
+ // If we're not accessing anything in this constant, the result is undefined.
+ if (Offset + BytesLoaded <= 0)
+ return UndefValue::get(IntType);
// If we're not accessing anything in this constant, the result is undefined.
- if (Offset.getZExtValue() >=
- DL.getTypeAllocSize(GV->getInitializer()->getType()))
+ if (Offset >= InitializerSize)
return UndefValue::get(IntType);
unsigned char RawBytes[32] = {0};
- if (!ReadDataFromGlobal(GV->getInitializer(), Offset.getZExtValue(), RawBytes,
- BytesLoaded, DL))
+ unsigned char *CurPtr = RawBytes;
+ unsigned BytesLeft = BytesLoaded;
+
+ // If we're loading off the beginning of the global, some bytes may be valid.
+ if (Offset < 0) {
+ CurPtr += -Offset;
+ BytesLeft += Offset;
+ Offset = 0;
+ }
+
+ if (!ReadDataFromGlobal(GV->getInitializer(), Offset, CurPtr, BytesLeft, DL))
return nullptr;
APInt ResultVal = APInt(IntType->getBitWidth(), 0);
@@ -478,14 +494,15 @@ static Constant *FoldReinterpretLoadFromConstPtr(Constant *C,
return ConstantInt::get(IntType->getContext(), ResultVal);
}
-static Constant *ConstantFoldLoadThroughBitcast(ConstantExpr *CE,
- const DataLayout &DL) {
- auto *DestPtrTy = dyn_cast<PointerType>(CE->getType());
- if (!DestPtrTy)
+Constant *ConstantFoldLoadThroughBitcast(ConstantExpr *CE, Type *DestTy,
+ const DataLayout &DL) {
+ auto *SrcPtr = CE->getOperand(0);
+ auto *SrcPtrTy = dyn_cast<PointerType>(SrcPtr->getType());
+ if (!SrcPtrTy)
return nullptr;
- Type *DestTy = DestPtrTy->getElementType();
+ Type *SrcTy = SrcPtrTy->getPointerElementType();
- Constant *C = ConstantFoldLoadFromConstPtr(CE->getOperand(0), DL);
+ Constant *C = ConstantFoldLoadFromConstPtr(SrcPtr, SrcTy, DL);
if (!C)
return nullptr;
@@ -522,26 +539,26 @@ static Constant *ConstantFoldLoadThroughBitcast(ConstantExpr *CE,
return nullptr;
}
-/// Return the value that a load from C would produce if it is constant and
-/// determinable. If this is not determinable, return null.
-Constant *llvm::ConstantFoldLoadFromConstPtr(Constant *C,
+} // end anonymous namespace
+
+Constant *llvm::ConstantFoldLoadFromConstPtr(Constant *C, Type *Ty,
const DataLayout &DL) {
// First, try the easy cases:
- if (GlobalVariable *GV = dyn_cast<GlobalVariable>(C))
+ if (auto *GV = dyn_cast<GlobalVariable>(C))
if (GV->isConstant() && GV->hasDefinitiveInitializer())
return GV->getInitializer();
if (auto *GA = dyn_cast<GlobalAlias>(C))
- if (GA->getAliasee() && !GA->mayBeOverridden())
- return ConstantFoldLoadFromConstPtr(GA->getAliasee(), DL);
+ if (GA->getAliasee() && !GA->isInterposable())
+ return ConstantFoldLoadFromConstPtr(GA->getAliasee(), Ty, DL);
// If the loaded value isn't a constant expr, we can't handle it.
- ConstantExpr *CE = dyn_cast<ConstantExpr>(C);
+ auto *CE = dyn_cast<ConstantExpr>(C);
if (!CE)
return nullptr;
if (CE->getOpcode() == Instruction::GetElementPtr) {
- if (GlobalVariable *GV = dyn_cast<GlobalVariable>(CE->getOperand(0))) {
+ if (auto *GV = dyn_cast<GlobalVariable>(CE->getOperand(0))) {
if (GV->isConstant() && GV->hasDefinitiveInitializer()) {
if (Constant *V =
ConstantFoldLoadThroughGEPConstantExpr(GV->getInitializer(), CE))
@@ -551,15 +568,14 @@ Constant *llvm::ConstantFoldLoadFromConstPtr(Constant *C,
}
if (CE->getOpcode() == Instruction::BitCast)
- if (Constant *LoadedC = ConstantFoldLoadThroughBitcast(CE, DL))
+ if (Constant *LoadedC = ConstantFoldLoadThroughBitcast(CE, Ty, DL))
return LoadedC;
// Instead of loading constant c string, use corresponding integer value
// directly if string length is small enough.
StringRef Str;
if (getConstantStringInfo(CE, Str) && !Str.empty()) {
- unsigned StrLen = Str.size();
- Type *Ty = cast<PointerType>(CE->getType())->getElementType();
+ size_t StrLen = Str.size();
unsigned NumBits = Ty->getPrimitiveSizeInBits();
// Replace load with immediate integer if the result is an integer or fp
// value.
@@ -568,13 +584,13 @@ Constant *llvm::ConstantFoldLoadFromConstPtr(Constant *C,
APInt StrVal(NumBits, 0);
APInt SingleChar(NumBits, 0);
if (DL.isLittleEndian()) {
- for (signed i = StrLen-1; i >= 0; i--) {
- SingleChar = (uint64_t) Str[i] & UCHAR_MAX;
+ for (unsigned char C : reverse(Str.bytes())) {
+ SingleChar = static_cast<uint64_t>(C);
StrVal = (StrVal << 8) | SingleChar;
}
} else {
- for (unsigned i = 0; i < StrLen; i++) {
- SingleChar = (uint64_t) Str[i] & UCHAR_MAX;
+ for (unsigned char C : Str.bytes()) {
+ SingleChar = static_cast<uint64_t>(C);
StrVal = (StrVal << 8) | SingleChar;
}
// Append NULL at the end.
@@ -591,27 +607,26 @@ Constant *llvm::ConstantFoldLoadFromConstPtr(Constant *C,
// If this load comes from anywhere in a constant global, and if the global
// is all undef or zero, we know what it loads.
- if (GlobalVariable *GV =
- dyn_cast<GlobalVariable>(GetUnderlyingObject(CE, DL))) {
+ if (auto *GV = dyn_cast<GlobalVariable>(GetUnderlyingObject(CE, DL))) {
if (GV->isConstant() && GV->hasDefinitiveInitializer()) {
- Type *ResTy = cast<PointerType>(C->getType())->getElementType();
if (GV->getInitializer()->isNullValue())
- return Constant::getNullValue(ResTy);
+ return Constant::getNullValue(Ty);
if (isa<UndefValue>(GV->getInitializer()))
- return UndefValue::get(ResTy);
+ return UndefValue::get(Ty);
}
}
// Try hard to fold loads from bitcasted strange and non-type-safe things.
- return FoldReinterpretLoadFromConstPtr(CE, DL);
+ return FoldReinterpretLoadFromConstPtr(CE, Ty, DL);
}
-static Constant *ConstantFoldLoadInst(const LoadInst *LI,
- const DataLayout &DL) {
+namespace {
+
+Constant *ConstantFoldLoadInst(const LoadInst *LI, const DataLayout &DL) {
if (LI->isVolatile()) return nullptr;
- if (Constant *C = dyn_cast<Constant>(LI->getOperand(0)))
- return ConstantFoldLoadFromConstPtr(C, DL);
+ if (auto *C = dyn_cast<Constant>(LI->getOperand(0)))
+ return ConstantFoldLoadFromConstPtr(C, LI->getType(), DL);
return nullptr;
}
@@ -620,9 +635,8 @@ static Constant *ConstantFoldLoadInst(const LoadInst *LI,
/// Attempt to symbolically evaluate the result of a binary operator merging
/// these together. If target data info is available, it is provided as DL,
/// otherwise DL is null.
-static Constant *SymbolicallyEvaluateBinop(unsigned Opc, Constant *Op0,
- Constant *Op1,
- const DataLayout &DL) {
+Constant *SymbolicallyEvaluateBinop(unsigned Opc, Constant *Op0, Constant *Op1,
+ const DataLayout &DL) {
// SROA
// Fold (and 0xffffffff00000000, (shl x, 32)) -> shl.
@@ -674,18 +688,16 @@ static Constant *SymbolicallyEvaluateBinop(unsigned Opc, Constant *Op0,
/// If array indices are not pointer-sized integers, explicitly cast them so
/// that they aren't implicitly casted by the getelementptr.
-static Constant *CastGEPIndices(Type *SrcTy, ArrayRef<Constant *> Ops,
- Type *ResultTy, const DataLayout &DL,
- const TargetLibraryInfo *TLI) {
+Constant *CastGEPIndices(Type *SrcElemTy, ArrayRef<Constant *> Ops,
+ Type *ResultTy, const DataLayout &DL,
+ const TargetLibraryInfo *TLI) {
Type *IntPtrTy = DL.getIntPtrType(ResultTy);
bool Any = false;
SmallVector<Constant*, 32> NewIdxs;
for (unsigned i = 1, e = Ops.size(); i != e; ++i) {
if ((i == 1 ||
- !isa<StructType>(GetElementPtrInst::getIndexedType(
- cast<PointerType>(Ops[0]->getType()->getScalarType())
- ->getElementType(),
+ !isa<StructType>(GetElementPtrInst::getIndexedType(SrcElemTy,
Ops.slice(1, i - 1)))) &&
Ops[i]->getType() != IntPtrTy) {
Any = true;
@@ -701,8 +713,8 @@ static Constant *CastGEPIndices(Type *SrcTy, ArrayRef<Constant *> Ops,
if (!Any)
return nullptr;
- Constant *C = ConstantExpr::getGetElementPtr(SrcTy, Ops[0], NewIdxs);
- if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
+ Constant *C = ConstantExpr::getGetElementPtr(SrcElemTy, Ops[0], NewIdxs);
+ if (auto *CE = dyn_cast<ConstantExpr>(C)) {
if (Constant *Folded = ConstantFoldConstantExpression(CE, DL, TLI))
C = Folded;
}
@@ -711,32 +723,41 @@ static Constant *CastGEPIndices(Type *SrcTy, ArrayRef<Constant *> Ops,
}
/// Strip the pointer casts, but preserve the address space information.
-static Constant* StripPtrCastKeepAS(Constant* Ptr) {
+Constant* StripPtrCastKeepAS(Constant* Ptr, Type *&ElemTy) {
assert(Ptr->getType()->isPointerTy() && "Not a pointer type");
- PointerType *OldPtrTy = cast<PointerType>(Ptr->getType());
+ auto *OldPtrTy = cast<PointerType>(Ptr->getType());
Ptr = Ptr->stripPointerCasts();
- PointerType *NewPtrTy = cast<PointerType>(Ptr->getType());
+ auto *NewPtrTy = cast<PointerType>(Ptr->getType());
+
+ ElemTy = NewPtrTy->getPointerElementType();
// Preserve the address space number of the pointer.
if (NewPtrTy->getAddressSpace() != OldPtrTy->getAddressSpace()) {
- NewPtrTy = NewPtrTy->getElementType()->getPointerTo(
- OldPtrTy->getAddressSpace());
+ NewPtrTy = ElemTy->getPointerTo(OldPtrTy->getAddressSpace());
Ptr = ConstantExpr::getPointerCast(Ptr, NewPtrTy);
}
return Ptr;
}
/// If we can symbolically evaluate the GEP constant expression, do so.
-static Constant *SymbolicallyEvaluateGEP(Type *SrcTy, ArrayRef<Constant *> Ops,
- Type *ResultTy, const DataLayout &DL,
- const TargetLibraryInfo *TLI) {
+Constant *SymbolicallyEvaluateGEP(const GEPOperator *GEP,
+ ArrayRef<Constant *> Ops,
+ const DataLayout &DL,
+ const TargetLibraryInfo *TLI) {
+ Type *SrcElemTy = GEP->getSourceElementType();
+ Type *ResElemTy = GEP->getResultElementType();
+ Type *ResTy = GEP->getType();
+ if (!SrcElemTy->isSized())
+ return nullptr;
+
+ if (Constant *C = CastGEPIndices(SrcElemTy, Ops, ResTy, DL, TLI))
+ return C;
+
Constant *Ptr = Ops[0];
- if (!Ptr->getType()->getPointerElementType()->isSized() ||
- !Ptr->getType()->isPointerTy())
+ if (!Ptr->getType()->isPointerTy())
return nullptr;
Type *IntPtrTy = DL.getIntPtrType(Ptr->getType());
- Type *ResultElementTy = ResultTy->getPointerElementType();
// If this is a constant expr gep that is effectively computing an
// "offsetof", fold it into 'cast int Size to T*' instead of 'gep 0, 0, 12'
@@ -745,16 +766,16 @@ static Constant *SymbolicallyEvaluateGEP(Type *SrcTy, ArrayRef<Constant *> Ops,
// If this is "gep i8* Ptr, (sub 0, V)", fold this as:
// "inttoptr (sub (ptrtoint Ptr), V)"
- if (Ops.size() == 2 && ResultElementTy->isIntegerTy(8)) {
- ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[1]);
+ if (Ops.size() == 2 && ResElemTy->isIntegerTy(8)) {
+ auto *CE = dyn_cast<ConstantExpr>(Ops[1]);
assert((!CE || CE->getType() == IntPtrTy) &&
"CastGEPIndices didn't canonicalize index types!");
if (CE && CE->getOpcode() == Instruction::Sub &&
CE->getOperand(0)->isNullValue()) {
Constant *Res = ConstantExpr::getPtrToInt(Ptr, CE->getType());
Res = ConstantExpr::getSub(Res, CE->getOperand(1));
- Res = ConstantExpr::getIntToPtr(Res, ResultTy);
- if (ConstantExpr *ResCE = dyn_cast<ConstantExpr>(Res))
+ Res = ConstantExpr::getIntToPtr(Res, ResTy);
+ if (auto *ResCE = dyn_cast<ConstantExpr>(Res))
Res = ConstantFoldConstantExpression(ResCE, DL, TLI);
return Res;
}
@@ -765,19 +786,19 @@ static Constant *SymbolicallyEvaluateGEP(Type *SrcTy, ArrayRef<Constant *> Ops,
unsigned BitWidth = DL.getTypeSizeInBits(IntPtrTy);
APInt Offset =
APInt(BitWidth,
- DL.getIndexedOffset(
- Ptr->getType(),
+ DL.getIndexedOffsetInType(
+ SrcElemTy,
makeArrayRef((Value * const *)Ops.data() + 1, Ops.size() - 1)));
- Ptr = StripPtrCastKeepAS(Ptr);
+ Ptr = StripPtrCastKeepAS(Ptr, SrcElemTy);
// If this is a GEP of a GEP, fold it all into a single GEP.
- while (GEPOperator *GEP = dyn_cast<GEPOperator>(Ptr)) {
+ while (auto *GEP = dyn_cast<GEPOperator>(Ptr)) {
SmallVector<Value *, 4> NestedOps(GEP->op_begin() + 1, GEP->op_end());
// Do not try the incorporate the sub-GEP if some index is not a number.
bool AllConstantInt = true;
- for (unsigned i = 0, e = NestedOps.size(); i != e; ++i)
- if (!isa<ConstantInt>(NestedOps[i])) {
+ for (Value *NestedOp : NestedOps)
+ if (!isa<ConstantInt>(NestedOp)) {
AllConstantInt = false;
break;
}
@@ -785,23 +806,24 @@ static Constant *SymbolicallyEvaluateGEP(Type *SrcTy, ArrayRef<Constant *> Ops,
break;
Ptr = cast<Constant>(GEP->getOperand(0));
- Offset += APInt(BitWidth, DL.getIndexedOffset(Ptr->getType(), NestedOps));
- Ptr = StripPtrCastKeepAS(Ptr);
+ SrcElemTy = GEP->getSourceElementType();
+ Offset += APInt(BitWidth, DL.getIndexedOffsetInType(SrcElemTy, NestedOps));
+ Ptr = StripPtrCastKeepAS(Ptr, SrcElemTy);
}
// If the base value for this address is a literal integer value, fold the
// getelementptr to the resulting integer value casted to the pointer type.
APInt BasePtr(BitWidth, 0);
- if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr)) {
+ if (auto *CE = dyn_cast<ConstantExpr>(Ptr)) {
if (CE->getOpcode() == Instruction::IntToPtr) {
- if (ConstantInt *Base = dyn_cast<ConstantInt>(CE->getOperand(0)))
+ if (auto *Base = dyn_cast<ConstantInt>(CE->getOperand(0)))
BasePtr = Base->getValue().zextOrTrunc(BitWidth);
}
}
if (Ptr->isNullValue() || BasePtr != 0) {
Constant *C = ConstantInt::get(Ptr->getContext(), Offset + BasePtr);
- return ConstantExpr::getIntToPtr(C, ResultTy);
+ return ConstantExpr::getIntToPtr(C, ResTy);
}
// Otherwise form a regular getelementptr. Recompute the indices so that
@@ -813,39 +835,49 @@ static Constant *SymbolicallyEvaluateGEP(Type *SrcTy, ArrayRef<Constant *> Ops,
SmallVector<Constant *, 32> NewIdxs;
do {
- if (SequentialType *ATy = dyn_cast<SequentialType>(Ty)) {
- if (ATy->isPointerTy()) {
+ if (!Ty->isStructTy()) {
+ if (Ty->isPointerTy()) {
// The only pointer indexing we'll do is on the first index of the GEP.
if (!NewIdxs.empty())
break;
+ Ty = SrcElemTy;
+
// Only handle pointers to sized types, not pointers to functions.
- if (!ATy->getElementType()->isSized())
+ if (!Ty->isSized())
return nullptr;
+ } else if (auto *ATy = dyn_cast<SequentialType>(Ty)) {
+ Ty = ATy->getElementType();
+ } else {
+ // We've reached some non-indexable type.
+ break;
}
// Determine which element of the array the offset points into.
- APInt ElemSize(BitWidth, DL.getTypeAllocSize(ATy->getElementType()));
- if (ElemSize == 0)
+ APInt ElemSize(BitWidth, DL.getTypeAllocSize(Ty));
+ if (ElemSize == 0) {
// The element size is 0. This may be [0 x Ty]*, so just use a zero
// index for this level and proceed to the next level to see if it can
// accommodate the offset.
NewIdxs.push_back(ConstantInt::get(IntPtrTy, 0));
- else {
+ } else {
// The element size is non-zero divide the offset by the element
// size (rounding down), to compute the index at this level.
- APInt NewIdx = Offset.udiv(ElemSize);
+ bool Overflow;
+ APInt NewIdx = Offset.sdiv_ov(ElemSize, Overflow);
+ if (Overflow)
+ break;
Offset -= NewIdx * ElemSize;
NewIdxs.push_back(ConstantInt::get(IntPtrTy, NewIdx));
}
- Ty = ATy->getElementType();
- } else if (StructType *STy = dyn_cast<StructType>(Ty)) {
+ } else {
+ auto *STy = cast<StructType>(Ty);
// If we end up with an offset that isn't valid for this struct type, we
// can't re-form this GEP in a regular form, so bail out. The pointer
// operand likely went through casts that are necessary to make the GEP
// sensible.
const StructLayout &SL = *DL.getStructLayout(STy);
- if (Offset.uge(SL.getSizeInBytes()))
+ if (Offset.isNegative() || Offset.uge(SL.getSizeInBytes()))
break;
// Determine which field of the struct the offset points into. The
@@ -856,11 +888,8 @@ static Constant *SymbolicallyEvaluateGEP(Type *SrcTy, ArrayRef<Constant *> Ops,
ElIdx));
Offset -= APInt(BitWidth, SL.getElementOffset(ElIdx));
Ty = STy->getTypeAtIndex(ElIdx);
- } else {
- // We've reached some non-indexable type.
- break;
}
- } while (Ty != ResultElementTy);
+ } while (Ty != ResElemTy);
// If we haven't used up the entire offset by descending the static
// type, then the offset is pointing into the middle of an indivisible
@@ -869,33 +898,78 @@ static Constant *SymbolicallyEvaluateGEP(Type *SrcTy, ArrayRef<Constant *> Ops,
return nullptr;
// Create a GEP.
- Constant *C = ConstantExpr::getGetElementPtr(SrcTy, Ptr, NewIdxs);
+ Constant *C = ConstantExpr::getGetElementPtr(SrcElemTy, Ptr, NewIdxs);
assert(C->getType()->getPointerElementType() == Ty &&
"Computed GetElementPtr has unexpected type!");
// If we ended up indexing a member with a type that doesn't match
// the type of what the original indices indexed, add a cast.
- if (Ty != ResultElementTy)
- C = FoldBitCast(C, ResultTy, DL);
+ if (Ty != ResElemTy)
+ C = FoldBitCast(C, ResTy, DL);
return C;
}
+/// Attempt to constant fold an instruction with the
+/// specified opcode and operands. If successful, the constant result is
+/// returned, if not, null is returned. Note that this function can fail when
+/// attempting to fold instructions like loads and stores, which have no
+/// constant expression form.
+///
+/// TODO: This function neither utilizes nor preserves nsw/nuw/inbounds/etc
+/// information, due to only being passed an opcode and operands. Constant
+/// folding using this function strips this information.
+///
+Constant *ConstantFoldInstOperandsImpl(const Value *InstOrCE, Type *DestTy,
+ unsigned Opcode,
+ ArrayRef<Constant *> Ops,
+ const DataLayout &DL,
+ const TargetLibraryInfo *TLI) {
+ // Handle easy binops first.
+ if (Instruction::isBinaryOp(Opcode))
+ return ConstantFoldBinaryOpOperands(Opcode, Ops[0], Ops[1], DL);
+
+ if (Instruction::isCast(Opcode))
+ return ConstantFoldCastOperand(Opcode, Ops[0], DestTy, DL);
+
+ if (auto *GEP = dyn_cast<GEPOperator>(InstOrCE)) {
+ if (Constant *C = SymbolicallyEvaluateGEP(GEP, Ops, DL, TLI))
+ return C;
+
+ return ConstantExpr::getGetElementPtr(GEP->getSourceElementType(),
+ Ops[0], Ops.slice(1));
+ }
+
+ switch (Opcode) {
+ default: return nullptr;
+ case Instruction::ICmp:
+ case Instruction::FCmp: llvm_unreachable("Invalid for compares");
+ case Instruction::Call:
+ if (auto *F = dyn_cast<Function>(Ops.back()))
+ if (canConstantFoldCallTo(F))
+ return ConstantFoldCall(F, Ops.slice(0, Ops.size() - 1), TLI);
+ return nullptr;
+ case Instruction::Select:
+ return ConstantExpr::getSelect(Ops[0], Ops[1], Ops[2]);
+ case Instruction::ExtractElement:
+ return ConstantExpr::getExtractElement(Ops[0], Ops[1]);
+ case Instruction::InsertElement:
+ return ConstantExpr::getInsertElement(Ops[0], Ops[1], Ops[2]);
+ case Instruction::ShuffleVector:
+ return ConstantExpr::getShuffleVector(Ops[0], Ops[1], Ops[2]);
+ }
+}
+} // end anonymous namespace
//===----------------------------------------------------------------------===//
// Constant Folding public APIs
//===----------------------------------------------------------------------===//
-/// Try to constant fold the specified instruction.
-/// If successful, the constant result is returned, if not, null is returned.
-/// Note that this fails if not all of the operands are constant. Otherwise,
-/// this function can only fail when attempting to fold instructions like loads
-/// and stores, which have no constant expression form.
Constant *llvm::ConstantFoldInstruction(Instruction *I, const DataLayout &DL,
const TargetLibraryInfo *TLI) {
// Handle PHI nodes quickly here...
- if (PHINode *PN = dyn_cast<PHINode>(I)) {
+ if (auto *PN = dyn_cast<PHINode>(I)) {
Constant *CommonValue = nullptr;
for (Value *Incoming : PN->incoming_values()) {
@@ -906,11 +980,11 @@ Constant *llvm::ConstantFoldInstruction(Instruction *I, const DataLayout &DL,
if (isa<UndefValue>(Incoming))
continue;
// If the incoming value is not a constant, then give up.
- Constant *C = dyn_cast<Constant>(Incoming);
+ auto *C = dyn_cast<Constant>(Incoming);
if (!C)
return nullptr;
// Fold the PHI's operands.
- if (ConstantExpr *NewC = dyn_cast<ConstantExpr>(C))
+ if (auto *NewC = dyn_cast<ConstantExpr>(C))
C = ConstantFoldConstantExpression(NewC, DL, TLI);
// If the incoming value is a different constant to
// the one we saw previously, then give up.
@@ -925,54 +999,55 @@ Constant *llvm::ConstantFoldInstruction(Instruction *I, const DataLayout &DL,
}
// Scan the operand list, checking to see if they are all constants, if so,
- // hand off to ConstantFoldInstOperands.
- SmallVector<Constant*, 8> Ops;
- for (User::op_iterator i = I->op_begin(), e = I->op_end(); i != e; ++i) {
- Constant *Op = dyn_cast<Constant>(*i);
- if (!Op)
- return nullptr; // All operands not constant!
+ // hand off to ConstantFoldInstOperandsImpl.
+ if (!all_of(I->operands(), [](Use &U) { return isa<Constant>(U); }))
+ return nullptr;
+ SmallVector<Constant *, 8> Ops;
+ for (const Use &OpU : I->operands()) {
+ auto *Op = cast<Constant>(&OpU);
// Fold the Instruction's operands.
- if (ConstantExpr *NewCE = dyn_cast<ConstantExpr>(Op))
+ if (auto *NewCE = dyn_cast<ConstantExpr>(Op))
Op = ConstantFoldConstantExpression(NewCE, DL, TLI);
Ops.push_back(Op);
}
- if (const CmpInst *CI = dyn_cast<CmpInst>(I))
+ if (const auto *CI = dyn_cast<CmpInst>(I))
return ConstantFoldCompareInstOperands(CI->getPredicate(), Ops[0], Ops[1],
DL, TLI);
- if (const LoadInst *LI = dyn_cast<LoadInst>(I))
+ if (const auto *LI = dyn_cast<LoadInst>(I))
return ConstantFoldLoadInst(LI, DL);
- if (InsertValueInst *IVI = dyn_cast<InsertValueInst>(I)) {
+ if (auto *IVI = dyn_cast<InsertValueInst>(I)) {
return ConstantExpr::getInsertValue(
cast<Constant>(IVI->getAggregateOperand()),
cast<Constant>(IVI->getInsertedValueOperand()),
IVI->getIndices());
}
- if (ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(I)) {
+ if (auto *EVI = dyn_cast<ExtractValueInst>(I)) {
return ConstantExpr::getExtractValue(
cast<Constant>(EVI->getAggregateOperand()),
EVI->getIndices());
}
- return ConstantFoldInstOperands(I->getOpcode(), I->getType(), Ops, DL, TLI);
+ return ConstantFoldInstOperands(I, Ops, DL, TLI);
}
-static Constant *
+namespace {
+
+Constant *
ConstantFoldConstantExpressionImpl(const ConstantExpr *CE, const DataLayout &DL,
const TargetLibraryInfo *TLI,
SmallPtrSetImpl<ConstantExpr *> &FoldedOps) {
SmallVector<Constant *, 8> Ops;
- for (User::const_op_iterator i = CE->op_begin(), e = CE->op_end(); i != e;
- ++i) {
- Constant *NewC = cast<Constant>(*i);
+ for (const Use &NewU : CE->operands()) {
+ auto *NewC = cast<Constant>(&NewU);
// Recursively fold the ConstantExpr's operands. If we have already folded
// a ConstantExpr, we don't have to process it again.
- if (ConstantExpr *NewCE = dyn_cast<ConstantExpr>(NewC)) {
+ if (auto *NewCE = dyn_cast<ConstantExpr>(NewC)) {
if (FoldedOps.insert(NewCE).second)
NewC = ConstantFoldConstantExpressionImpl(NewCE, DL, TLI, FoldedOps);
}
@@ -982,12 +1057,13 @@ ConstantFoldConstantExpressionImpl(const ConstantExpr *CE, const DataLayout &DL,
if (CE->isCompare())
return ConstantFoldCompareInstOperands(CE->getPredicate(), Ops[0], Ops[1],
DL, TLI);
- return ConstantFoldInstOperands(CE->getOpcode(), CE->getType(), Ops, DL, TLI);
+
+ return ConstantFoldInstOperandsImpl(CE, CE->getType(), CE->getOpcode(), Ops,
+ DL, TLI);
}
-/// Attempt to fold the constant expression
-/// using the specified DataLayout. If successful, the constant result is
-/// result is returned, if not, null is returned.
+} // end anonymous namespace
+
Constant *llvm::ConstantFoldConstantExpression(const ConstantExpr *CE,
const DataLayout &DL,
const TargetLibraryInfo *TLI) {
@@ -995,114 +1071,22 @@ Constant *llvm::ConstantFoldConstantExpression(const ConstantExpr *CE,
return ConstantFoldConstantExpressionImpl(CE, DL, TLI, FoldedOps);
}
-/// Attempt to constant fold an instruction with the
-/// specified opcode and operands. If successful, the constant result is
-/// returned, if not, null is returned. Note that this function can fail when
-/// attempting to fold instructions like loads and stores, which have no
-/// constant expression form.
-///
-/// TODO: This function neither utilizes nor preserves nsw/nuw/inbounds/etc
-/// information, due to only being passed an opcode and operands. Constant
-/// folding using this function strips this information.
-///
-Constant *llvm::ConstantFoldInstOperands(unsigned Opcode, Type *DestTy,
+Constant *llvm::ConstantFoldInstOperands(Instruction *I,
ArrayRef<Constant *> Ops,
const DataLayout &DL,
const TargetLibraryInfo *TLI) {
- // Handle easy binops first.
- if (Instruction::isBinaryOp(Opcode)) {
- if (isa<ConstantExpr>(Ops[0]) || isa<ConstantExpr>(Ops[1])) {
- if (Constant *C = SymbolicallyEvaluateBinop(Opcode, Ops[0], Ops[1], DL))
- return C;
- }
-
- return ConstantExpr::get(Opcode, Ops[0], Ops[1]);
- }
-
- switch (Opcode) {
- default: return nullptr;
- case Instruction::ICmp:
- case Instruction::FCmp: llvm_unreachable("Invalid for compares");
- case Instruction::Call:
- if (Function *F = dyn_cast<Function>(Ops.back()))
- if (canConstantFoldCallTo(F))
- return ConstantFoldCall(F, Ops.slice(0, Ops.size() - 1), TLI);
- return nullptr;
- case Instruction::PtrToInt:
- // If the input is a inttoptr, eliminate the pair. This requires knowing
- // the width of a pointer, so it can't be done in ConstantExpr::getCast.
- if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[0])) {
- if (CE->getOpcode() == Instruction::IntToPtr) {
- Constant *Input = CE->getOperand(0);
- unsigned InWidth = Input->getType()->getScalarSizeInBits();
- unsigned PtrWidth = DL.getPointerTypeSizeInBits(CE->getType());
- if (PtrWidth < InWidth) {
- Constant *Mask =
- ConstantInt::get(CE->getContext(),
- APInt::getLowBitsSet(InWidth, PtrWidth));
- Input = ConstantExpr::getAnd(Input, Mask);
- }
- // Do a zext or trunc to get to the dest size.
- return ConstantExpr::getIntegerCast(Input, DestTy, false);
- }
- }
- return ConstantExpr::getCast(Opcode, Ops[0], DestTy);
- case Instruction::IntToPtr:
- // If the input is a ptrtoint, turn the pair into a ptr to ptr bitcast if
- // the int size is >= the ptr size and the address spaces are the same.
- // This requires knowing the width of a pointer, so it can't be done in
- // ConstantExpr::getCast.
- if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[0])) {
- if (CE->getOpcode() == Instruction::PtrToInt) {
- Constant *SrcPtr = CE->getOperand(0);
- unsigned SrcPtrSize = DL.getPointerTypeSizeInBits(SrcPtr->getType());
- unsigned MidIntSize = CE->getType()->getScalarSizeInBits();
-
- if (MidIntSize >= SrcPtrSize) {
- unsigned SrcAS = SrcPtr->getType()->getPointerAddressSpace();
- if (SrcAS == DestTy->getPointerAddressSpace())
- return FoldBitCast(CE->getOperand(0), DestTy, DL);
- }
- }
- }
-
- return ConstantExpr::getCast(Opcode, Ops[0], DestTy);
- case Instruction::Trunc:
- case Instruction::ZExt:
- case Instruction::SExt:
- case Instruction::FPTrunc:
- case Instruction::FPExt:
- case Instruction::UIToFP:
- case Instruction::SIToFP:
- case Instruction::FPToUI:
- case Instruction::FPToSI:
- case Instruction::AddrSpaceCast:
- return ConstantExpr::getCast(Opcode, Ops[0], DestTy);
- case Instruction::BitCast:
- return FoldBitCast(Ops[0], DestTy, DL);
- case Instruction::Select:
- return ConstantExpr::getSelect(Ops[0], Ops[1], Ops[2]);
- case Instruction::ExtractElement:
- return ConstantExpr::getExtractElement(Ops[0], Ops[1]);
- case Instruction::InsertElement:
- return ConstantExpr::getInsertElement(Ops[0], Ops[1], Ops[2]);
- case Instruction::ShuffleVector:
- return ConstantExpr::getShuffleVector(Ops[0], Ops[1], Ops[2]);
- case Instruction::GetElementPtr: {
- Type *SrcTy = nullptr;
- if (Constant *C = CastGEPIndices(SrcTy, Ops, DestTy, DL, TLI))
- return C;
- if (Constant *C = SymbolicallyEvaluateGEP(SrcTy, Ops, DestTy, DL, TLI))
- return C;
+ return ConstantFoldInstOperandsImpl(I, I->getType(), I->getOpcode(), Ops, DL,
+ TLI);
+}
- return ConstantExpr::getGetElementPtr(SrcTy, Ops[0], Ops.slice(1));
- }
- }
+Constant *llvm::ConstantFoldInstOperands(unsigned Opcode, Type *DestTy,
+ ArrayRef<Constant *> Ops,
+ const DataLayout &DL,
+ const TargetLibraryInfo *TLI) {
+ assert(Opcode != Instruction::GetElementPtr && "Invalid for GEPs");
+ return ConstantFoldInstOperandsImpl(nullptr, DestTy, Opcode, Ops, DL, TLI);
}
-/// Attempt to constant fold a compare
-/// instruction (icmp/fcmp) with the specified operands. If it fails, it
-/// returns a constant expression of the specified operands.
Constant *llvm::ConstantFoldCompareInstOperands(unsigned Predicate,
Constant *Ops0, Constant *Ops1,
const DataLayout &DL,
@@ -1115,7 +1099,7 @@ Constant *llvm::ConstantFoldCompareInstOperands(unsigned Predicate,
// FIXME: The following comment is out of data and the DataLayout is here now.
// ConstantExpr::getCompare cannot do this, because it doesn't have DL
// around to know if bit truncation is happening.
- if (ConstantExpr *CE0 = dyn_cast<ConstantExpr>(Ops0)) {
+ if (auto *CE0 = dyn_cast<ConstantExpr>(Ops0)) {
if (Ops1->isNullValue()) {
if (CE0->getOpcode() == Instruction::IntToPtr) {
Type *IntPtrTy = DL.getIntPtrType(CE0->getType());
@@ -1139,7 +1123,7 @@ Constant *llvm::ConstantFoldCompareInstOperands(unsigned Predicate,
}
}
- if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(Ops1)) {
+ if (auto *CE1 = dyn_cast<ConstantExpr>(Ops1)) {
if (CE0->getOpcode() == CE1->getOpcode()) {
if (CE0->getOpcode() == Instruction::IntToPtr) {
Type *IntPtrTy = DL.getIntPtrType(CE0->getType());
@@ -1176,18 +1160,85 @@ Constant *llvm::ConstantFoldCompareInstOperands(unsigned Predicate,
Predicate, CE0->getOperand(1), Ops1, DL, TLI);
unsigned OpC =
Predicate == ICmpInst::ICMP_EQ ? Instruction::And : Instruction::Or;
- Constant *Ops[] = { LHS, RHS };
- return ConstantFoldInstOperands(OpC, LHS->getType(), Ops, DL, TLI);
+ return ConstantFoldBinaryOpOperands(OpC, LHS, RHS, DL);
}
}
return ConstantExpr::getCompare(Predicate, Ops0, Ops1);
}
+Constant *llvm::ConstantFoldBinaryOpOperands(unsigned Opcode, Constant *LHS,
+ Constant *RHS,
+ const DataLayout &DL) {
+ assert(Instruction::isBinaryOp(Opcode));
+ if (isa<ConstantExpr>(LHS) || isa<ConstantExpr>(RHS))
+ if (Constant *C = SymbolicallyEvaluateBinop(Opcode, LHS, RHS, DL))
+ return C;
+
+ return ConstantExpr::get(Opcode, LHS, RHS);
+}
+
+Constant *llvm::ConstantFoldCastOperand(unsigned Opcode, Constant *C,
+ Type *DestTy, const DataLayout &DL) {
+ assert(Instruction::isCast(Opcode));
+ switch (Opcode) {
+ default:
+ llvm_unreachable("Missing case");
+ case Instruction::PtrToInt:
+ // If the input is a inttoptr, eliminate the pair. This requires knowing
+ // the width of a pointer, so it can't be done in ConstantExpr::getCast.
+ if (auto *CE = dyn_cast<ConstantExpr>(C)) {
+ if (CE->getOpcode() == Instruction::IntToPtr) {
+ Constant *Input = CE->getOperand(0);
+ unsigned InWidth = Input->getType()->getScalarSizeInBits();
+ unsigned PtrWidth = DL.getPointerTypeSizeInBits(CE->getType());
+ if (PtrWidth < InWidth) {
+ Constant *Mask =
+ ConstantInt::get(CE->getContext(),
+ APInt::getLowBitsSet(InWidth, PtrWidth));
+ Input = ConstantExpr::getAnd(Input, Mask);
+ }
+ // Do a zext or trunc to get to the dest size.
+ return ConstantExpr::getIntegerCast(Input, DestTy, false);
+ }
+ }
+ return ConstantExpr::getCast(Opcode, C, DestTy);
+ case Instruction::IntToPtr:
+ // If the input is a ptrtoint, turn the pair into a ptr to ptr bitcast if
+ // the int size is >= the ptr size and the address spaces are the same.
+ // This requires knowing the width of a pointer, so it can't be done in
+ // ConstantExpr::getCast.
+ if (auto *CE = dyn_cast<ConstantExpr>(C)) {
+ if (CE->getOpcode() == Instruction::PtrToInt) {
+ Constant *SrcPtr = CE->getOperand(0);
+ unsigned SrcPtrSize = DL.getPointerTypeSizeInBits(SrcPtr->getType());
+ unsigned MidIntSize = CE->getType()->getScalarSizeInBits();
+
+ if (MidIntSize >= SrcPtrSize) {
+ unsigned SrcAS = SrcPtr->getType()->getPointerAddressSpace();
+ if (SrcAS == DestTy->getPointerAddressSpace())
+ return FoldBitCast(CE->getOperand(0), DestTy, DL);
+ }
+ }
+ }
+
+ return ConstantExpr::getCast(Opcode, C, DestTy);
+ case Instruction::Trunc:
+ case Instruction::ZExt:
+ case Instruction::SExt:
+ case Instruction::FPTrunc:
+ case Instruction::FPExt:
+ case Instruction::UIToFP:
+ case Instruction::SIToFP:
+ case Instruction::FPToUI:
+ case Instruction::FPToSI:
+ case Instruction::AddrSpaceCast:
+ return ConstantExpr::getCast(Opcode, C, DestTy);
+ case Instruction::BitCast:
+ return FoldBitCast(C, DestTy, DL);
+ }
+}
-/// Given a constant and a getelementptr constantexpr, return the constant value
-/// being addressed by the constant expression, or null if something is funny
-/// and we can't decide.
Constant *llvm::ConstantFoldLoadThroughGEPConstantExpr(Constant *C,
ConstantExpr *CE) {
if (!CE->getOperand(1)->isNullValue())
@@ -1203,27 +1254,23 @@ Constant *llvm::ConstantFoldLoadThroughGEPConstantExpr(Constant *C,
return C;
}
-/// Given a constant and getelementptr indices (with an *implied* zero pointer
-/// index that is not in the list), return the constant value being addressed by
-/// a virtual load, or null if something is funny and we can't decide.
-Constant *llvm::ConstantFoldLoadThroughGEPIndices(Constant *C,
- ArrayRef<Constant*> Indices) {
+Constant *
+llvm::ConstantFoldLoadThroughGEPIndices(Constant *C,
+ ArrayRef<Constant *> Indices) {
// Loop over all of the operands, tracking down which value we are
// addressing.
- for (unsigned i = 0, e = Indices.size(); i != e; ++i) {
- C = C->getAggregateElement(Indices[i]);
+ for (Constant *Index : Indices) {
+ C = C->getAggregateElement(Index);
if (!C)
return nullptr;
}
return C;
}
-
//===----------------------------------------------------------------------===//
// Constant Folding for Calls
//
-/// Return true if it's even possible to fold a call to the specified function.
bool llvm::canConstantFoldCallTo(const Function *F) {
switch (F->getIntrinsicID()) {
case Intrinsic::fabs:
@@ -1252,6 +1299,7 @@ bool llvm::canConstantFoldCallTo(const Function *F) {
case Intrinsic::fmuladd:
case Intrinsic::copysign:
case Intrinsic::round:
+ case Intrinsic::masked_load:
case Intrinsic::sadd_with_overflow:
case Intrinsic::uadd_with_overflow:
case Intrinsic::ssub_with_overflow:
@@ -1260,6 +1308,7 @@ bool llvm::canConstantFoldCallTo(const Function *F) {
case Intrinsic::umul_with_overflow:
case Intrinsic::convert_from_fp16:
case Intrinsic::convert_to_fp16:
+ case Intrinsic::bitreverse:
case Intrinsic::x86_sse_cvtss2si:
case Intrinsic::x86_sse_cvtss2si64:
case Intrinsic::x86_sse_cvttss2si:
@@ -1309,7 +1358,9 @@ bool llvm::canConstantFoldCallTo(const Function *F) {
}
}
-static Constant *GetConstantFoldFPValue(double V, Type *Ty) {
+namespace {
+
+Constant *GetConstantFoldFPValue(double V, Type *Ty) {
if (Ty->isHalfTy()) {
APFloat APF(V);
bool unused;
@@ -1321,12 +1372,10 @@ static Constant *GetConstantFoldFPValue(double V, Type *Ty) {
if (Ty->isDoubleTy())
return ConstantFP::get(Ty->getContext(), APFloat(V));
llvm_unreachable("Can only constant fold half/float/double");
-
}
-namespace {
/// Clear the floating-point exception state.
-static inline void llvm_fenv_clearexcept() {
+inline void llvm_fenv_clearexcept() {
#if defined(HAVE_FENV_H) && HAVE_DECL_FE_ALL_EXCEPT
feclearexcept(FE_ALL_EXCEPT);
#endif
@@ -1334,7 +1383,7 @@ static inline void llvm_fenv_clearexcept() {
}
/// Test if a floating-point exception was raised.
-static inline bool llvm_fenv_testexcept() {
+inline bool llvm_fenv_testexcept() {
int errno_val = errno;
if (errno_val == ERANGE || errno_val == EDOM)
return true;
@@ -1344,10 +1393,8 @@ static inline bool llvm_fenv_testexcept() {
#endif
return false;
}
-} // End namespace
-static Constant *ConstantFoldFP(double (*NativeFP)(double), double V,
- Type *Ty) {
+Constant *ConstantFoldFP(double (*NativeFP)(double), double V, Type *Ty) {
llvm_fenv_clearexcept();
V = NativeFP(V);
if (llvm_fenv_testexcept()) {
@@ -1358,8 +1405,8 @@ static Constant *ConstantFoldFP(double (*NativeFP)(double), double V,
return GetConstantFoldFPValue(V, Ty);
}
-static Constant *ConstantFoldBinaryFP(double (*NativeFP)(double, double),
- double V, double W, Type *Ty) {
+Constant *ConstantFoldBinaryFP(double (*NativeFP)(double, double), double V,
+ double W, Type *Ty) {
llvm_fenv_clearexcept();
V = NativeFP(V, W);
if (llvm_fenv_testexcept()) {
@@ -1377,8 +1424,8 @@ static Constant *ConstantFoldBinaryFP(double (*NativeFP)(double, double),
/// integer type Ty is used to select how many bits are available for the
/// result. Returns null if the conversion cannot be performed, otherwise
/// returns the Constant value resulting from the conversion.
-static Constant *ConstantFoldConvertToInt(const APFloat &Val,
- bool roundTowardZero, Type *Ty) {
+Constant *ConstantFoldConvertToInt(const APFloat &Val, bool roundTowardZero,
+ Type *Ty) {
// All of these conversion intrinsics form an integer of at most 64bits.
unsigned ResultWidth = Ty->getIntegerBitWidth();
assert(ResultWidth <= 64 &&
@@ -1396,7 +1443,7 @@ static Constant *ConstantFoldConvertToInt(const APFloat &Val,
return ConstantInt::get(Ty, UIntVal, /*isSigned=*/true);
}
-static double getValueAsDouble(ConstantFP *Op) {
+double getValueAsDouble(ConstantFP *Op) {
Type *Ty = Op->getType();
if (Ty->isFloatTy())
@@ -1411,11 +1458,16 @@ static double getValueAsDouble(ConstantFP *Op) {
return APF.convertToDouble();
}
-static Constant *ConstantFoldScalarCall(StringRef Name, unsigned IntrinsicID,
- Type *Ty, ArrayRef<Constant *> Operands,
- const TargetLibraryInfo *TLI) {
+Constant *ConstantFoldScalarCall(StringRef Name, unsigned IntrinsicID, Type *Ty,
+ ArrayRef<Constant *> Operands,
+ const TargetLibraryInfo *TLI) {
if (Operands.size() == 1) {
- if (ConstantFP *Op = dyn_cast<ConstantFP>(Operands[0])) {
+ if (isa<UndefValue>(Operands[0])) {
+ // cosine(arg) is between -1 and 1. cosine(invalid arg) is NaN
+ if (IntrinsicID == Intrinsic::cos)
+ return Constant::getNullValue(Ty);
+ }
+ if (auto *Op = dyn_cast<ConstantFP>(Operands[0])) {
if (IntrinsicID == Intrinsic::convert_to_fp16) {
APFloat Val(Op->getValueAPF());
@@ -1586,12 +1638,14 @@ static Constant *ConstantFoldScalarCall(StringRef Name, unsigned IntrinsicID,
return nullptr;
}
- if (ConstantInt *Op = dyn_cast<ConstantInt>(Operands[0])) {
+ if (auto *Op = dyn_cast<ConstantInt>(Operands[0])) {
switch (IntrinsicID) {
case Intrinsic::bswap:
return ConstantInt::get(Ty->getContext(), Op->getValue().byteSwap());
case Intrinsic::ctpop:
return ConstantInt::get(Ty, Op->getValue().countPopulation());
+ case Intrinsic::bitreverse:
+ return ConstantInt::get(Ty->getContext(), Op->getValue().reverseBits());
case Intrinsic::convert_from_fp16: {
APFloat Val(APFloat::IEEEhalf, Op->getValue());
@@ -1614,7 +1668,7 @@ static Constant *ConstantFoldScalarCall(StringRef Name, unsigned IntrinsicID,
// Support ConstantVector in case we have an Undef in the top.
if (isa<ConstantVector>(Operands[0]) ||
isa<ConstantDataVector>(Operands[0])) {
- Constant *Op = cast<Constant>(Operands[0]);
+ auto *Op = cast<Constant>(Operands[0]);
switch (IntrinsicID) {
default: break;
case Intrinsic::x86_sse_cvtss2si:
@@ -1646,12 +1700,12 @@ static Constant *ConstantFoldScalarCall(StringRef Name, unsigned IntrinsicID,
}
if (Operands.size() == 2) {
- if (ConstantFP *Op1 = dyn_cast<ConstantFP>(Operands[0])) {
+ if (auto *Op1 = dyn_cast<ConstantFP>(Operands[0])) {
if (!Ty->isHalfTy() && !Ty->isFloatTy() && !Ty->isDoubleTy())
return nullptr;
double Op1V = getValueAsDouble(Op1);
- if (ConstantFP *Op2 = dyn_cast<ConstantFP>(Operands[1])) {
+ if (auto *Op2 = dyn_cast<ConstantFP>(Operands[1])) {
if (Op2->getType() != Op1->getType())
return nullptr;
@@ -1661,7 +1715,7 @@ static Constant *ConstantFoldScalarCall(StringRef Name, unsigned IntrinsicID,
}
if (IntrinsicID == Intrinsic::copysign) {
APFloat V1 = Op1->getValueAPF();
- APFloat V2 = Op2->getValueAPF();
+ const APFloat &V2 = Op2->getValueAPF();
V1.copySign(V2);
return ConstantFP::get(Ty->getContext(), V1);
}
@@ -1689,7 +1743,7 @@ static Constant *ConstantFoldScalarCall(StringRef Name, unsigned IntrinsicID,
if ((Name == "atan2" && TLI->has(LibFunc::atan2)) ||
(Name == "atan2f" && TLI->has(LibFunc::atan2f)))
return ConstantFoldBinaryFP(atan2, Op1V, Op2V, Ty);
- } else if (ConstantInt *Op2C = dyn_cast<ConstantInt>(Operands[1])) {
+ } else if (auto *Op2C = dyn_cast<ConstantInt>(Operands[1])) {
if (IntrinsicID == Intrinsic::powi && Ty->isHalfTy())
return ConstantFP::get(Ty->getContext(),
APFloat((float)std::pow((float)Op1V,
@@ -1706,8 +1760,8 @@ static Constant *ConstantFoldScalarCall(StringRef Name, unsigned IntrinsicID,
return nullptr;
}
- if (ConstantInt *Op1 = dyn_cast<ConstantInt>(Operands[0])) {
- if (ConstantInt *Op2 = dyn_cast<ConstantInt>(Operands[1])) {
+ if (auto *Op1 = dyn_cast<ConstantInt>(Operands[0])) {
+ if (auto *Op2 = dyn_cast<ConstantInt>(Operands[1])) {
switch (IntrinsicID) {
default: break;
case Intrinsic::sadd_with_overflow:
@@ -1764,9 +1818,9 @@ static Constant *ConstantFoldScalarCall(StringRef Name, unsigned IntrinsicID,
if (Operands.size() != 3)
return nullptr;
- if (const ConstantFP *Op1 = dyn_cast<ConstantFP>(Operands[0])) {
- if (const ConstantFP *Op2 = dyn_cast<ConstantFP>(Operands[1])) {
- if (const ConstantFP *Op3 = dyn_cast<ConstantFP>(Operands[2])) {
+ if (const auto *Op1 = dyn_cast<ConstantFP>(Operands[0])) {
+ if (const auto *Op2 = dyn_cast<ConstantFP>(Operands[1])) {
+ if (const auto *Op3 = dyn_cast<ConstantFP>(Operands[2])) {
switch (IntrinsicID) {
default: break;
case Intrinsic::fma:
@@ -1788,14 +1842,53 @@ static Constant *ConstantFoldScalarCall(StringRef Name, unsigned IntrinsicID,
return nullptr;
}
-static Constant *ConstantFoldVectorCall(StringRef Name, unsigned IntrinsicID,
- VectorType *VTy,
- ArrayRef<Constant *> Operands,
- const TargetLibraryInfo *TLI) {
+Constant *ConstantFoldVectorCall(StringRef Name, unsigned IntrinsicID,
+ VectorType *VTy, ArrayRef<Constant *> Operands,
+ const DataLayout &DL,
+ const TargetLibraryInfo *TLI) {
SmallVector<Constant *, 4> Result(VTy->getNumElements());
SmallVector<Constant *, 4> Lane(Operands.size());
Type *Ty = VTy->getElementType();
+ if (IntrinsicID == Intrinsic::masked_load) {
+ auto *SrcPtr = Operands[0];
+ auto *Mask = Operands[2];
+ auto *Passthru = Operands[3];
+
+ Constant *VecData = ConstantFoldLoadFromConstPtr(SrcPtr, VTy, DL);
+
+ SmallVector<Constant *, 32> NewElements;
+ for (unsigned I = 0, E = VTy->getNumElements(); I != E; ++I) {
+ auto *MaskElt = Mask->getAggregateElement(I);
+ if (!MaskElt)
+ break;
+ auto *PassthruElt = Passthru->getAggregateElement(I);
+ auto *VecElt = VecData ? VecData->getAggregateElement(I) : nullptr;
+ if (isa<UndefValue>(MaskElt)) {
+ if (PassthruElt)
+ NewElements.push_back(PassthruElt);
+ else if (VecElt)
+ NewElements.push_back(VecElt);
+ else
+ return nullptr;
+ }
+ if (MaskElt->isNullValue()) {
+ if (!PassthruElt)
+ return nullptr;
+ NewElements.push_back(PassthruElt);
+ } else if (MaskElt->isOneValue()) {
+ if (!VecElt)
+ return nullptr;
+ NewElements.push_back(VecElt);
+ } else {
+ return nullptr;
+ }
+ }
+ if (NewElements.size() != VTy->getNumElements())
+ return nullptr;
+ return ConstantVector::get(NewElements);
+ }
+
for (unsigned I = 0, E = VTy->getNumElements(); I != E; ++I) {
// Gather a column of constants.
for (unsigned J = 0, JE = Operands.size(); J != JE; ++J) {
@@ -1816,8 +1909,8 @@ static Constant *ConstantFoldVectorCall(StringRef Name, unsigned IntrinsicID,
return ConstantVector::get(Result);
}
-/// Attempt to constant fold a call to the specified function
-/// with the specified arguments, returning null if unsuccessful.
+} // end anonymous namespace
+
Constant *
llvm::ConstantFoldCall(Function *F, ArrayRef<Constant *> Operands,
const TargetLibraryInfo *TLI) {
@@ -1827,8 +1920,9 @@ llvm::ConstantFoldCall(Function *F, ArrayRef<Constant *> Operands,
Type *Ty = F->getReturnType();
- if (VectorType *VTy = dyn_cast<VectorType>(Ty))
- return ConstantFoldVectorCall(Name, F->getIntrinsicID(), VTy, Operands, TLI);
+ if (auto *VTy = dyn_cast<VectorType>(Ty))
+ return ConstantFoldVectorCall(Name, F->getIntrinsicID(), VTy, Operands,
+ F->getParent()->getDataLayout(), TLI);
return ConstantFoldScalarCall(Name, F->getIntrinsicID(), Ty, Operands, TLI);
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-09-21 08:01:22 +0000