#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/Analysis/ValueTracking.h"
+#include "llvm/Config/config.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Function.h"
+#include "llvm/IR/GetElementPtrTypeIterator.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/Operator.h"
#include "llvm/Support/ErrorHandling.h"
-#include "llvm/Support/FEnv.h"
-#include "llvm/Support/GetElementPtrTypeIterator.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Target/TargetLibraryInfo.h"
#include <cerrno>
#include <cmath>
+
+#ifdef HAVE_FENV_H
+#include <fenv.h>
+#endif
+
using namespace llvm;
//===----------------------------------------------------------------------===//
// Constant Folding internal helper functions
//===----------------------------------------------------------------------===//
-/// FoldBitCast - Constant fold bitcast, symbolically evaluating it with
-/// DataLayout. This always returns a non-null constant, but it may be a
+/// 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 &TD) {
// Handle a vector->integer cast.
if (IntegerType *IT = dyn_cast<IntegerType>(DestTy)) {
VectorType *VTy = dyn_cast<VectorType>(C->getType());
- if (VTy == 0)
+ if (!VTy)
return ConstantExpr::getBitCast(C, DestTy);
unsigned NumSrcElts = VTy->getNumElements();
}
ConstantDataVector *CDV = dyn_cast<ConstantDataVector>(C);
- if (CDV == 0)
+ if (!CDV)
return ConstantExpr::getBitCast(C, DestTy);
// Now that we know that the input value is a vector of integers, just shift
// The code below only handles casts to vectors currently.
VectorType *DestVTy = dyn_cast<VectorType>(DestTy);
- if (DestVTy == 0)
+ if (!DestVTy)
return ConstantExpr::getBitCast(C, DestTy);
// If this is a scalar -> vector cast, convert the input into a <1 x scalar>
}
-/// IsConstantOffsetFromGlobal - If this constant is actually a constant offset
-/// from a global, return the global and the constant. Because of
-/// constantexprs, this function is recursive.
+/// 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 &TD) {
// Trivial case, constant is the global.
if ((GV = dyn_cast<GlobalValue>(C))) {
- Offset.clearAllBits();
+ unsigned BitWidth = TD.getPointerTypeSizeInBits(GV->getType());
+ Offset = APInt(BitWidth, 0);
return true;
}
// Look through ptr->int and ptr->ptr casts.
if (CE->getOpcode() == Instruction::PtrToInt ||
- CE->getOpcode() == Instruction::BitCast)
+ CE->getOpcode() == Instruction::BitCast ||
+ CE->getOpcode() == Instruction::AddrSpaceCast)
return IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, TD);
// i32* getelementptr ([5 x i32]* @a, i32 0, i32 5)
- if (GEPOperator *GEP = dyn_cast<GEPOperator>(CE)) {
- // If the base isn't a global+constant, we aren't either.
- if (!IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, TD))
- return false;
+ GEPOperator *GEP = dyn_cast<GEPOperator>(CE);
+ if (!GEP)
+ return false;
- // Otherwise, add any offset that our operands provide.
- return GEP->accumulateConstantOffset(TD, Offset);
- }
+ unsigned BitWidth = TD.getPointerTypeSizeInBits(GEP->getType());
+ APInt TmpOffset(BitWidth, 0);
- return false;
+ // If the base isn't a global+constant, we aren't either.
+ if (!IsConstantOffsetFromGlobal(CE->getOperand(0), GV, TmpOffset, TD))
+ return false;
+
+ // Otherwise, add any offset that our operands provide.
+ if (!GEP->accumulateConstantOffset(TD, TmpOffset))
+ return false;
+
+ Offset = TmpOffset;
+ return true;
}
-/// ReadDataFromGlobal - 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. TD is the target data.
+/// 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. TD is the target data.
static bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset,
unsigned char *CurPtr, unsigned BytesLeft,
const DataLayout &TD) {
TD.getTypeAllocSizeInBits(LoadTy),
AS);
} else
- return 0;
+ return nullptr;
C = FoldBitCast(C, MapTy, TD);
if (Constant *Res = FoldReinterpretLoadFromConstPtr(C, TD))
return FoldBitCast(Res, LoadTy, TD);
- return 0;
+ return nullptr;
}
unsigned BytesLoaded = (IntType->getBitWidth() + 7) / 8;
if (BytesLoaded > 32 || BytesLoaded == 0)
- return 0;
+ return nullptr;
GlobalValue *GVal;
- APInt Offset(TD.getPointerTypeSizeInBits(PTy), 0);
+ APInt Offset;
if (!IsConstantOffsetFromGlobal(C, GVal, Offset, TD))
- return 0;
+ return nullptr;
GlobalVariable *GV = dyn_cast<GlobalVariable>(GVal);
if (!GV || !GV->isConstant() || !GV->hasDefinitiveInitializer() ||
!GV->getInitializer()->getType()->isSized())
- return 0;
+ 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 0;
+ return nullptr;
// If we're not accessing anything in this constant, the result is undefined.
if (Offset.getZExtValue() >=
unsigned char RawBytes[32] = {0};
if (!ReadDataFromGlobal(GV->getInitializer(), Offset.getZExtValue(), RawBytes,
BytesLoaded, TD))
- return 0;
+ return nullptr;
APInt ResultVal = APInt(IntType->getBitWidth(), 0);
if (TD.isLittleEndian()) {
return ConstantInt::get(IntType->getContext(), ResultVal);
}
-/// ConstantFoldLoadFromConstPtr - Return the value that a load from C would
-/// produce if it is constant and determinable. If this is not determinable,
-/// return null.
+static Constant *ConstantFoldLoadThroughBitcast(ConstantExpr *CE,
+ const DataLayout *DL) {
+ if (!DL)
+ return nullptr;
+ auto *DestPtrTy = dyn_cast<PointerType>(CE->getType());
+ if (!DestPtrTy)
+ return nullptr;
+ Type *DestTy = DestPtrTy->getElementType();
+
+ Constant *C = ConstantFoldLoadFromConstPtr(CE->getOperand(0), DL);
+ if (!C)
+ return nullptr;
+
+ do {
+ Type *SrcTy = C->getType();
+
+ // If the type sizes are the same and a cast is legal, just directly
+ // cast the constant.
+ if (DL->getTypeSizeInBits(DestTy) == DL->getTypeSizeInBits(SrcTy)) {
+ Instruction::CastOps Cast = Instruction::BitCast;
+ // If we are going from a pointer to int or vice versa, we spell the cast
+ // differently.
+ if (SrcTy->isIntegerTy() && DestTy->isPointerTy())
+ Cast = Instruction::IntToPtr;
+ else if (SrcTy->isPointerTy() && DestTy->isIntegerTy())
+ Cast = Instruction::PtrToInt;
+
+ if (CastInst::castIsValid(Cast, C, DestTy))
+ return ConstantExpr::getCast(Cast, C, DestTy);
+ }
+
+ // If this isn't an aggregate type, there is nothing we can do to drill down
+ // and find a bitcastable constant.
+ if (!SrcTy->isAggregateType())
+ return nullptr;
+
+ // We're simulating a load through a pointer that was bitcast to point to
+ // a different type, so we can try to walk down through the initial
+ // elements of an aggregate to see if some part of th e aggregate is
+ // castable to implement the "load" semantic model.
+ C = C->getAggregateElement(0u);
+ } while (C);
+
+ 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,
const DataLayout *TD) {
// First, try the easy cases:
// If the loaded value isn't a constant expr, we can't handle it.
ConstantExpr *CE = dyn_cast<ConstantExpr>(C);
if (!CE)
- return 0;
+ return nullptr;
if (CE->getOpcode() == Instruction::GetElementPtr) {
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(CE->getOperand(0))) {
}
}
+ if (CE->getOpcode() == Instruction::BitCast)
+ if (Constant *LoadedC = ConstantFoldLoadThroughBitcast(CE, TD))
+ return LoadedC;
+
// Instead of loading constant c string, use corresponding integer value
// directly if string length is small enough.
StringRef Str;
// Try hard to fold loads from bitcasted strange and non-type-safe things.
if (TD)
return FoldReinterpretLoadFromConstPtr(CE, *TD);
- return 0;
+ return nullptr;
}
static Constant *ConstantFoldLoadInst(const LoadInst *LI, const DataLayout *TD){
- if (LI->isVolatile()) return 0;
+ if (LI->isVolatile()) return nullptr;
if (Constant *C = dyn_cast<Constant>(LI->getOperand(0)))
return ConstantFoldLoadFromConstPtr(C, TD);
- return 0;
+ return nullptr;
}
-/// SymbolicallyEvaluateBinop - One of Op0/Op1 is a constant expression.
+/// One of Op0/Op1 is a constant expression.
/// 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.
unsigned BitWidth = DL->getTypeSizeInBits(Op0->getType()->getScalarType());
APInt KnownZero0(BitWidth, 0), KnownOne0(BitWidth, 0);
APInt KnownZero1(BitWidth, 0), KnownOne1(BitWidth, 0);
- ComputeMaskedBits(Op0, KnownZero0, KnownOne0, DL);
- ComputeMaskedBits(Op1, KnownZero1, KnownOne1, DL);
+ computeKnownBits(Op0, KnownZero0, KnownOne0, DL);
+ computeKnownBits(Op1, KnownZero1, KnownOne1, DL);
if ((KnownOne1 | KnownZero0).isAllOnesValue()) {
// All the bits of Op0 that the 'and' could be masking are already zero.
return Op0;
// constant. This happens frequently when iterating over a global array.
if (Opc == Instruction::Sub && DL) {
GlobalValue *GV1, *GV2;
- unsigned PtrSize = DL->getPointerSizeInBits();
- APInt Offs1(PtrSize, 0), Offs2(PtrSize, 0);
+ APInt Offs1, Offs2;
if (IsConstantOffsetFromGlobal(Op0, GV1, Offs1, *DL))
if (IsConstantOffsetFromGlobal(Op1, GV2, Offs2, *DL) &&
}
}
- return 0;
+ return nullptr;
}
-/// CastGEPIndices - If array indices are not pointer-sized integers,
-/// explicitly cast them so that they aren't implicitly casted by the
-/// getelementptr.
+/// If array indices are not pointer-sized integers, explicitly cast them so
+/// that they aren't implicitly casted by the getelementptr.
static Constant *CastGEPIndices(ArrayRef<Constant *> Ops,
Type *ResultTy, const DataLayout *TD,
const TargetLibraryInfo *TLI) {
if (!TD)
- return 0;
+ return nullptr;
Type *IntPtrTy = TD->getIntPtrType(ResultTy);
}
if (!Any)
- return 0;
+ return nullptr;
Constant *C = ConstantExpr::getGetElementPtr(Ops[0], NewIdxs);
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
static Constant* StripPtrCastKeepAS(Constant* Ptr) {
assert(Ptr->getType()->isPointerTy() && "Not a pointer type");
PointerType *OldPtrTy = cast<PointerType>(Ptr->getType());
- Ptr = cast<Constant>(Ptr->stripPointerCasts());
+ Ptr = Ptr->stripPointerCasts();
PointerType *NewPtrTy = cast<PointerType>(Ptr->getType());
// Preserve the address space number of the pointer.
if (NewPtrTy->getAddressSpace() != OldPtrTy->getAddressSpace()) {
NewPtrTy = NewPtrTy->getElementType()->getPointerTo(
OldPtrTy->getAddressSpace());
- Ptr = ConstantExpr::getBitCast(Ptr, NewPtrTy);
+ Ptr = ConstantExpr::getPointerCast(Ptr, NewPtrTy);
}
return Ptr;
}
-/// SymbolicallyEvaluateGEP - If we can symbolically evaluate the specified GEP
-/// constant expression, do so.
+/// If we can symbolically evaluate the GEP constant expression, do so.
static Constant *SymbolicallyEvaluateGEP(ArrayRef<Constant *> Ops,
Type *ResultTy, const DataLayout *TD,
const TargetLibraryInfo *TLI) {
Constant *Ptr = Ops[0];
if (!TD || !Ptr->getType()->getPointerElementType()->isSized() ||
!Ptr->getType()->isPointerTy())
- return 0;
+ return nullptr;
Type *IntPtrTy = TD->getIntPtrType(Ptr->getType());
Type *ResultElementTy = ResultTy->getPointerElementType();
// "inttoptr (sub (ptrtoint Ptr), V)"
if (Ops.size() == 2 && ResultElementTy->isIntegerTy(8)) {
ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[1]);
- assert((CE == 0 || CE->getType() == IntPtrTy) &&
+ assert((!CE || CE->getType() == IntPtrTy) &&
"CastGEPIndices didn't canonicalize index types!");
if (CE && CE->getOpcode() == Instruction::Sub &&
CE->getOperand(0)->isNullValue()) {
return Res;
}
}
- return 0;
+ return nullptr;
}
unsigned BitWidth = TD->getTypeSizeInBits(IntPtrTy);
// Only handle pointers to sized types, not pointers to functions.
if (!ATy->getElementType()->isSized())
- return 0;
+ return nullptr;
}
// Determine which element of the array the offset points into.
// type, then the offset is pointing into the middle of an indivisible
// member, so we can't simplify it.
if (Offset != 0)
- return 0;
+ return nullptr;
// Create a GEP.
Constant *C = ConstantExpr::getGetElementPtr(Ptr, NewIdxs);
// Constant Folding public APIs
//===----------------------------------------------------------------------===//
-/// ConstantFoldInstruction - Try to constant fold the specified instruction.
+/// 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
const TargetLibraryInfo *TLI) {
// Handle PHI nodes quickly here...
if (PHINode *PN = dyn_cast<PHINode>(I)) {
- Constant *CommonValue = 0;
+ Constant *CommonValue = nullptr;
for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
Value *Incoming = PN->getIncomingValue(i);
// If the incoming value is not a constant, then give up.
Constant *C = dyn_cast<Constant>(Incoming);
if (!C)
- return 0;
+ return nullptr;
// Fold the PHI's operands.
if (ConstantExpr *NewC = dyn_cast<ConstantExpr>(C))
C = ConstantFoldConstantExpression(NewC, TD, TLI);
// If the incoming value is a different constant to
// the one we saw previously, then give up.
if (CommonValue && C != CommonValue)
- return 0;
+ return nullptr;
CommonValue = C;
}
for (User::op_iterator i = I->op_begin(), e = I->op_end(); i != e; ++i) {
Constant *Op = dyn_cast<Constant>(*i);
if (!Op)
- return 0; // All operands not constant!
+ return nullptr; // All operands not constant!
// Fold the Instruction's operands.
if (ConstantExpr *NewCE = dyn_cast<ConstantExpr>(Op))
static Constant *
ConstantFoldConstantExpressionImpl(const ConstantExpr *CE, const DataLayout *TD,
const TargetLibraryInfo *TLI,
- SmallPtrSet<ConstantExpr *, 4> &FoldedOps) {
+ SmallPtrSetImpl<ConstantExpr *> &FoldedOps) {
SmallVector<Constant *, 8> Ops;
for (User::const_op_iterator i = CE->op_begin(), e = CE->op_end(); i != e;
++i) {
return ConstantFoldInstOperands(CE->getOpcode(), CE->getType(), Ops, TD, TLI);
}
-/// ConstantFoldConstantExpression - Attempt to fold the constant expression
+/// Attempt to fold the constant expression
/// using the specified DataLayout. If successful, the constant result is
/// result is returned, if not, null is returned.
Constant *llvm::ConstantFoldConstantExpression(const ConstantExpr *CE,
return ConstantFoldConstantExpressionImpl(CE, TD, TLI, FoldedOps);
}
-/// ConstantFoldInstOperands - Attempt to constant fold an instruction with the
+/// 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
}
switch (Opcode) {
- default: return 0;
+ 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 0;
+ 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 (TD && CE->getOpcode() == Instruction::IntToPtr) {
Constant *Input = CE->getOperand(0);
unsigned InWidth = Input->getType()->getScalarSizeInBits();
- if (TD->getPointerTypeSizeInBits(CE->getType()) < InWidth) {
+ unsigned PtrWidth = TD->getPointerTypeSizeInBits(CE->getType());
+ if (PtrWidth < InWidth) {
Constant *Mask =
- ConstantInt::get(CE->getContext(), APInt::getLowBitsSet(InWidth,
- TD->getPointerSizeInBits()));
+ 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::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. This requires knowing the width of a
- // pointer, so it can't be done in ConstantExpr::getCast.
+ // 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 (TD && CE->getOpcode() == Instruction::PtrToInt) {
Constant *SrcPtr = CE->getOperand(0);
unsigned MidIntSize = CE->getType()->getScalarSizeInBits();
if (MidIntSize >= SrcPtrSize) {
- unsigned DestPtrSize = TD->getPointerTypeSizeInBits(DestTy);
- if (SrcPtrSize == DestPtrSize)
+ unsigned SrcAS = SrcPtr->getType()->getPointerAddressSpace();
+ if (SrcAS == DestTy->getPointerAddressSpace())
return FoldBitCast(CE->getOperand(0), DestTy, *TD);
}
}
case Instruction::SIToFP:
case Instruction::FPToUI:
case Instruction::FPToSI:
+ case Instruction::AddrSpaceCast:
return ConstantExpr::getCast(Opcode, Ops[0], DestTy);
case Instruction::BitCast:
if (TD)
}
}
-/// ConstantFoldCompareInstOperands - Attempt to constant fold a compare
+/// 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 *TD,
}
-/// ConstantFoldLoadThroughGEPConstantExpr - 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.
+/// 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())
- return 0; // Do not allow stepping over the value!
+ return nullptr; // Do not allow stepping over the value!
// Loop over all of the operands, tracking down which value we are
// addressing.
for (unsigned i = 2, e = CE->getNumOperands(); i != e; ++i) {
C = C->getAggregateElement(CE->getOperand(i));
- if (C == 0)
- return 0;
+ if (!C)
+ return nullptr;
}
return C;
}
-/// ConstantFoldLoadThroughGEPIndices - 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.
+/// 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) {
// 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]);
- if (C == 0)
- return 0;
+ if (!C)
+ return nullptr;
}
return C;
}
// Constant Folding for Calls
//
-/// canConstantFoldCallTo - Return true if its even possible to fold a call to
-/// the specified function.
+/// 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:
case Intrinsic::exp:
case Intrinsic::exp2:
case Intrinsic::floor:
+ case Intrinsic::ceil:
case Intrinsic::sqrt:
case Intrinsic::pow:
case Intrinsic::powi:
case Intrinsic::ctpop:
case Intrinsic::ctlz:
case Intrinsic::cttz:
+ case Intrinsic::fma:
+ case Intrinsic::fmuladd:
+ case Intrinsic::copysign:
+ case Intrinsic::round:
case Intrinsic::sadd_with_overflow:
case Intrinsic::uadd_with_overflow:
case Intrinsic::ssub_with_overflow:
}
}
-static Constant *ConstantFoldFP(double (*NativeFP)(double), double V,
- Type *Ty) {
- sys::llvm_fenv_clearexcept();
- V = NativeFP(V);
- if (sys::llvm_fenv_testexcept()) {
- sys::llvm_fenv_clearexcept();
- return 0;
- }
-
+static Constant *GetConstantFoldFPValue(double V, Type *Ty) {
if (Ty->isHalfTy()) {
APFloat APF(V);
bool unused;
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() {
+#if defined(HAVE_FENV_H) && HAVE_DECL_FE_ALL_EXCEPT
+ feclearexcept(FE_ALL_EXCEPT);
+#endif
+ errno = 0;
+}
+
+/// Test if a floating-point exception was raised.
+static inline bool llvm_fenv_testexcept() {
+ int errno_val = errno;
+ if (errno_val == ERANGE || errno_val == EDOM)
+ return true;
+#if defined(HAVE_FENV_H) && HAVE_DECL_FE_ALL_EXCEPT && HAVE_DECL_FE_INEXACT
+ if (fetestexcept(FE_ALL_EXCEPT & ~FE_INEXACT))
+ return true;
+#endif
+ return false;
+}
+} // End namespace
+
+static Constant *ConstantFoldFP(double (*NativeFP)(double), double V,
+ Type *Ty) {
+ llvm_fenv_clearexcept();
+ V = NativeFP(V);
+ if (llvm_fenv_testexcept()) {
+ llvm_fenv_clearexcept();
+ return nullptr;
+ }
+
+ return GetConstantFoldFPValue(V, Ty);
}
static Constant *ConstantFoldBinaryFP(double (*NativeFP)(double, double),
double V, double W, Type *Ty) {
- sys::llvm_fenv_clearexcept();
+ llvm_fenv_clearexcept();
V = NativeFP(V, W);
- if (sys::llvm_fenv_testexcept()) {
- sys::llvm_fenv_clearexcept();
- return 0;
+ if (llvm_fenv_testexcept()) {
+ llvm_fenv_clearexcept();
+ return nullptr;
}
- if (Ty->isHalfTy()) {
- APFloat APF(V);
- bool unused;
- APF.convert(APFloat::IEEEhalf, APFloat::rmNearestTiesToEven, &unused);
- return ConstantFP::get(Ty->getContext(), APF);
- }
- if (Ty->isFloatTy())
- return ConstantFP::get(Ty->getContext(), APFloat((float)V));
- if (Ty->isDoubleTy())
- return ConstantFP::get(Ty->getContext(), APFloat(V));
- llvm_unreachable("Can only constant fold half/float/double");
+ return GetConstantFoldFPValue(V, Ty);
}
-/// ConstantFoldConvertToInt - Attempt to an SSE floating point to integer
-/// conversion of a constant floating point. If roundTowardZero is false, the
-/// default IEEE rounding is used (toward nearest, ties to even). This matches
-/// the behavior of the non-truncating SSE instructions in the default rounding
-/// mode. The desired 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.
+/// Attempt to fold an SSE floating point to integer conversion of a constant
+/// floating point. If roundTowardZero is false, the default IEEE rounding is
+/// used (toward nearest, ties to even). This matches the behavior of the
+/// non-truncating SSE instructions in the default rounding mode. The desired
+/// 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) {
// All of these conversion intrinsics form an integer of at most 64bits.
/*isSigned=*/true, mode,
&isExact);
if (status != APFloat::opOK && status != APFloat::opInexact)
- return 0;
+ return nullptr;
return ConstantInt::get(Ty, UIntVal, /*isSigned=*/true);
}
-/// ConstantFoldCall - Attempt to constant fold a call to the specified function
-/// with the specified arguments, returning null if unsuccessful.
-Constant *
-llvm::ConstantFoldCall(Function *F, ArrayRef<Constant *> Operands,
- const TargetLibraryInfo *TLI) {
- if (!F->hasName())
- return 0;
- StringRef Name = F->getName();
+static double getValueAsDouble(ConstantFP *Op) {
+ Type *Ty = Op->getType();
- Type *Ty = F->getReturnType();
+ if (Ty->isFloatTy())
+ return Op->getValueAPF().convertToFloat();
+
+ if (Ty->isDoubleTy())
+ return Op->getValueAPF().convertToDouble();
+
+ bool unused;
+ APFloat APF = Op->getValueAPF();
+ APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, &unused);
+ return APF.convertToDouble();
+}
+
+static 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 (F->getIntrinsicID() == Intrinsic::convert_to_fp16) {
+ if (IntrinsicID == Intrinsic::convert_to_fp16) {
APFloat Val(Op->getValueAPF());
bool lost = false;
Val.convert(APFloat::IEEEhalf, APFloat::rmNearestTiesToEven, &lost);
- return ConstantInt::get(F->getContext(), Val.bitcastToAPInt());
+ return ConstantInt::get(Ty->getContext(), Val.bitcastToAPInt());
}
- if (!TLI)
- return 0;
if (!Ty->isHalfTy() && !Ty->isFloatTy() && !Ty->isDoubleTy())
- return 0;
+ return nullptr;
+
+ if (IntrinsicID == Intrinsic::round) {
+ APFloat V = Op->getValueAPF();
+ V.roundToIntegral(APFloat::rmNearestTiesToAway);
+ return ConstantFP::get(Ty->getContext(), V);
+ }
/// We only fold functions with finite arguments. Folding NaN and inf is
/// likely to be aborted with an exception anyway, and some host libms
/// have known errors raising exceptions.
if (Op->getValueAPF().isNaN() || Op->getValueAPF().isInfinity())
- return 0;
+ return nullptr;
/// Currently APFloat versions of these functions do not exist, so we use
/// the host native double versions. Float versions are not called
/// directly but for all these it is true (float)(f((double)arg)) ==
/// f(arg). Long double not supported yet.
- double V;
- if (Ty->isFloatTy())
- V = Op->getValueAPF().convertToFloat();
- else if (Ty->isDoubleTy())
- V = Op->getValueAPF().convertToDouble();
- else {
- bool unused;
- APFloat APF = Op->getValueAPF();
- APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, &unused);
- V = APF.convertToDouble();
- }
+ double V = getValueAsDouble(Op);
- switch (F->getIntrinsicID()) {
+ switch (IntrinsicID) {
default: break;
case Intrinsic::fabs:
return ConstantFoldFP(fabs, V, Ty);
#endif
case Intrinsic::floor:
return ConstantFoldFP(floor, V, Ty);
+ case Intrinsic::ceil:
+ return ConstantFoldFP(ceil, V, Ty);
}
+ if (!TLI)
+ return nullptr;
+
switch (Name[0]) {
case 'a':
if (Name == "acos" && TLI->has(LibFunc::acos))
return ConstantFoldFP(log, V, Ty);
else if (Name == "log10" && V > 0 && TLI->has(LibFunc::log10))
return ConstantFoldFP(log10, V, Ty);
- else if (F->getIntrinsicID() == Intrinsic::sqrt &&
+ else if (IntrinsicID == Intrinsic::sqrt &&
(Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy())) {
if (V >= -0.0)
return ConstantFoldFP(sqrt, V, Ty);
- else // Undefined
- return Constant::getNullValue(Ty);
+ else {
+ // Unlike the sqrt definitions in C/C++, POSIX, and IEEE-754 - which
+ // all guarantee or favor returning NaN - the square root of a
+ // negative number is not defined for the LLVM sqrt intrinsic.
+ // This is because the intrinsic should only be emitted in place of
+ // libm's sqrt function when using "no-nans-fp-math".
+ return UndefValue::get(Ty);
+ }
}
break;
case 's':
default:
break;
}
- return 0;
+ return nullptr;
}
if (ConstantInt *Op = dyn_cast<ConstantInt>(Operands[0])) {
- switch (F->getIntrinsicID()) {
+ switch (IntrinsicID) {
case Intrinsic::bswap:
- return ConstantInt::get(F->getContext(), Op->getValue().byteSwap());
+ return ConstantInt::get(Ty->getContext(), Op->getValue().byteSwap());
case Intrinsic::ctpop:
return ConstantInt::get(Ty, Op->getValue().countPopulation());
case Intrinsic::convert_from_fp16: {
assert(status == APFloat::opOK && !lost &&
"Precision lost during fp16 constfolding");
- return ConstantFP::get(F->getContext(), Val);
+ return ConstantFP::get(Ty->getContext(), Val);
}
default:
- return 0;
+ return nullptr;
}
}
if (isa<ConstantVector>(Operands[0]) ||
isa<ConstantDataVector>(Operands[0])) {
Constant *Op = cast<Constant>(Operands[0]);
- switch (F->getIntrinsicID()) {
+ switch (IntrinsicID) {
default: break;
case Intrinsic::x86_sse_cvtss2si:
case Intrinsic::x86_sse_cvtss2si64:
}
if (isa<UndefValue>(Operands[0])) {
- if (F->getIntrinsicID() == Intrinsic::bswap)
+ if (IntrinsicID == Intrinsic::bswap)
return Operands[0];
- return 0;
+ return nullptr;
}
- return 0;
+ return nullptr;
}
if (Operands.size() == 2) {
if (ConstantFP *Op1 = dyn_cast<ConstantFP>(Operands[0])) {
if (!Ty->isHalfTy() && !Ty->isFloatTy() && !Ty->isDoubleTy())
- return 0;
- double Op1V;
- if (Ty->isFloatTy())
- Op1V = Op1->getValueAPF().convertToFloat();
- else if (Ty->isDoubleTy())
- Op1V = Op1->getValueAPF().convertToDouble();
- else {
- bool unused;
- APFloat APF = Op1->getValueAPF();
- APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, &unused);
- Op1V = APF.convertToDouble();
- }
+ return nullptr;
+ double Op1V = getValueAsDouble(Op1);
if (ConstantFP *Op2 = dyn_cast<ConstantFP>(Operands[1])) {
if (Op2->getType() != Op1->getType())
- return 0;
-
- double Op2V;
- if (Ty->isFloatTy())
- Op2V = Op2->getValueAPF().convertToFloat();
- else if (Ty->isDoubleTy())
- Op2V = Op2->getValueAPF().convertToDouble();
- else {
- bool unused;
- APFloat APF = Op2->getValueAPF();
- APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, &unused);
- Op2V = APF.convertToDouble();
- }
+ return nullptr;
- if (F->getIntrinsicID() == Intrinsic::pow) {
+ double Op2V = getValueAsDouble(Op2);
+ if (IntrinsicID == Intrinsic::pow) {
return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty);
}
+ if (IntrinsicID == Intrinsic::copysign) {
+ APFloat V1 = Op1->getValueAPF();
+ APFloat V2 = Op2->getValueAPF();
+ V1.copySign(V2);
+ return ConstantFP::get(Ty->getContext(), V1);
+ }
if (!TLI)
- return 0;
+ return nullptr;
if (Name == "pow" && TLI->has(LibFunc::pow))
return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty);
if (Name == "fmod" && TLI->has(LibFunc::fmod))
if (Name == "atan2" && TLI->has(LibFunc::atan2))
return ConstantFoldBinaryFP(atan2, Op1V, Op2V, Ty);
} else if (ConstantInt *Op2C = dyn_cast<ConstantInt>(Operands[1])) {
- if (F->getIntrinsicID() == Intrinsic::powi && Ty->isHalfTy())
- return ConstantFP::get(F->getContext(),
+ if (IntrinsicID == Intrinsic::powi && Ty->isHalfTy())
+ return ConstantFP::get(Ty->getContext(),
APFloat((float)std::pow((float)Op1V,
(int)Op2C->getZExtValue())));
- if (F->getIntrinsicID() == Intrinsic::powi && Ty->isFloatTy())
- return ConstantFP::get(F->getContext(),
+ if (IntrinsicID == Intrinsic::powi && Ty->isFloatTy())
+ return ConstantFP::get(Ty->getContext(),
APFloat((float)std::pow((float)Op1V,
(int)Op2C->getZExtValue())));
- if (F->getIntrinsicID() == Intrinsic::powi && Ty->isDoubleTy())
- return ConstantFP::get(F->getContext(),
+ if (IntrinsicID == Intrinsic::powi && Ty->isDoubleTy())
+ return ConstantFP::get(Ty->getContext(),
APFloat((double)std::pow((double)Op1V,
(int)Op2C->getZExtValue())));
}
- return 0;
+ return nullptr;
}
if (ConstantInt *Op1 = dyn_cast<ConstantInt>(Operands[0])) {
if (ConstantInt *Op2 = dyn_cast<ConstantInt>(Operands[1])) {
- switch (F->getIntrinsicID()) {
+ switch (IntrinsicID) {
default: break;
case Intrinsic::sadd_with_overflow:
case Intrinsic::uadd_with_overflow:
case Intrinsic::umul_with_overflow: {
APInt Res;
bool Overflow;
- switch (F->getIntrinsicID()) {
+ switch (IntrinsicID) {
default: llvm_unreachable("Invalid case");
case Intrinsic::sadd_with_overflow:
Res = Op1->getValue().sadd_ov(Op2->getValue(), Overflow);
break;
}
Constant *Ops[] = {
- ConstantInt::get(F->getContext(), Res),
- ConstantInt::get(Type::getInt1Ty(F->getContext()), Overflow)
+ ConstantInt::get(Ty->getContext(), Res),
+ ConstantInt::get(Type::getInt1Ty(Ty->getContext()), Overflow)
};
- return ConstantStruct::get(cast<StructType>(F->getReturnType()), Ops);
+ return ConstantStruct::get(cast<StructType>(Ty), Ops);
}
case Intrinsic::cttz:
if (Op2->isOne() && Op1->isZero()) // cttz(0, 1) is undef.
}
}
- return 0;
+ return nullptr;
+ }
+ return nullptr;
+ }
+
+ 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])) {
+ switch (IntrinsicID) {
+ default: break;
+ case Intrinsic::fma:
+ case Intrinsic::fmuladd: {
+ APFloat V = Op1->getValueAPF();
+ APFloat::opStatus s = V.fusedMultiplyAdd(Op2->getValueAPF(),
+ Op3->getValueAPF(),
+ APFloat::rmNearestTiesToEven);
+ if (s != APFloat::opInvalidOp)
+ return ConstantFP::get(Ty->getContext(), V);
+
+ return nullptr;
+ }
+ }
+ }
+ }
+ }
+
+ return nullptr;
+}
+
+static Constant *ConstantFoldVectorCall(StringRef Name, unsigned IntrinsicID,
+ VectorType *VTy,
+ ArrayRef<Constant *> Operands,
+ const TargetLibraryInfo *TLI) {
+ SmallVector<Constant *, 4> Result(VTy->getNumElements());
+ SmallVector<Constant *, 4> Lane(Operands.size());
+ Type *Ty = VTy->getElementType();
+
+ 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) {
+ Constant *Agg = Operands[J]->getAggregateElement(I);
+ if (!Agg)
+ return nullptr;
+
+ Lane[J] = Agg;
}
- return 0;
+
+ // Use the regular scalar folding to simplify this column.
+ Constant *Folded = ConstantFoldScalarCall(Name, IntrinsicID, Ty, Lane, TLI);
+ if (!Folded)
+ return nullptr;
+ Result[I] = Folded;
}
- return 0;
+
+ return ConstantVector::get(Result);
+}
+
+/// Attempt to constant fold a call to the specified function
+/// with the specified arguments, returning null if unsuccessful.
+Constant *
+llvm::ConstantFoldCall(Function *F, ArrayRef<Constant *> Operands,
+ const TargetLibraryInfo *TLI) {
+ if (!F->hasName())
+ return nullptr;
+ StringRef Name = F->getName();
+
+ Type *Ty = F->getReturnType();
+
+ if (VectorType *VTy = dyn_cast<VectorType>(Ty))
+ return ConstantFoldVectorCall(Name, F->getIntrinsicID(), VTy, Operands, TLI);
+
+ return ConstantFoldScalarCall(Name, F->getIntrinsicID(), Ty, Operands, TLI);
}