// ConstantExpr::get* methods to automatically fold constants when possible.
//
// The current constant folding implementation is implemented in two pieces: the
-// template-based folder for simple primitive constants like ConstantInt, and
-// the special case hackery that we use to symbolically evaluate expressions
-// that use ConstantExprs.
+// pieces that don't need TargetData, and the pieces that do. This is to avoid
+// a dependence in VMCore on Target.
//
//===----------------------------------------------------------------------===//
#include "llvm/DerivedTypes.h"
#include "llvm/Function.h"
#include "llvm/GlobalAlias.h"
+#include "llvm/GlobalVariable.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Support/Compiler.h"
+#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/GetElementPtrTypeIterator.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/MathExtras.h"
unsigned NumElts = DstTy->getNumElements();
if (NumElts != CV->getNumOperands())
return 0;
-
+
// Check to verify that all elements of the input are simple.
for (unsigned i = 0; i != NumElts; ++i) {
if (!isa<ConstantInt>(CV->getOperand(i)) &&
std::vector<Constant*> Result;
const Type *DstEltTy = DstTy->getElementType();
for (unsigned i = 0; i != NumElts; ++i)
- Result.push_back(ConstantExpr::getBitCast(CV->getOperand(i), DstEltTy));
+ Result.push_back(ConstantExpr::getBitCast(CV->getOperand(i),
+ DstEltTy));
return ConstantVector::get(Result);
}
static unsigned
foldConstantCastPair(
unsigned opc, ///< opcode of the second cast constant expression
- const ConstantExpr*Op, ///< the first cast constant expression
+ ConstantExpr *Op, ///< the first cast constant expression
const Type *DstTy ///< desintation type of the first cast
) {
assert(Op && Op->isCast() && "Can't fold cast of cast without a cast!");
assert(DstTy && DstTy->isFirstClassType() && "Invalid cast destination type");
assert(CastInst::isCast(opc) && "Invalid cast opcode");
-
+
// The the types and opcodes for the two Cast constant expressions
const Type *SrcTy = Op->getOperand(0)->getType();
const Type *MidTy = Op->getType();
// Let CastInst::isEliminableCastPair do the heavy lifting.
return CastInst::isEliminableCastPair(firstOp, secondOp, SrcTy, MidTy, DstTy,
- Type::Int64Ty);
+ Type::getInt64Ty(DstTy->getContext()));
}
static Constant *FoldBitCast(Constant *V, const Type *DestTy) {
const Type *SrcTy = V->getType();
if (SrcTy == DestTy)
return V; // no-op cast
-
+
// Check to see if we are casting a pointer to an aggregate to a pointer to
// the first element. If so, return the appropriate GEP instruction.
if (const PointerType *PTy = dyn_cast<PointerType>(V->getType()))
if (const PointerType *DPTy = dyn_cast<PointerType>(DestTy))
if (PTy->getAddressSpace() == DPTy->getAddressSpace()) {
SmallVector<Value*, 8> IdxList;
- IdxList.push_back(Constant::getNullValue(Type::Int32Ty));
+ Value *Zero =
+ Constant::getNullValue(Type::getInt32Ty(DPTy->getContext()));
+ IdxList.push_back(Zero);
const Type *ElTy = PTy->getElementType();
while (ElTy != DPTy->getElementType()) {
if (const StructType *STy = dyn_cast<StructType>(ElTy)) {
if (STy->getNumElements() == 0) break;
ElTy = STy->getElementType(0);
- IdxList.push_back(Constant::getNullValue(Type::Int32Ty));
+ IdxList.push_back(Zero);
} else if (const SequentialType *STy =
dyn_cast<SequentialType>(ElTy)) {
- if (isa<PointerType>(ElTy)) break; // Can't index into pointers!
+ if (ElTy->isPointerTy()) break; // Can't index into pointers!
ElTy = STy->getElementType();
- IdxList.push_back(IdxList[0]);
+ IdxList.push_back(Zero);
} else {
break;
}
}
-
+
if (ElTy == DPTy->getElementType())
- return ConstantExpr::getGetElementPtr(V, &IdxList[0], IdxList.size());
+ // This GEP is inbounds because all indices are zero.
+ return ConstantExpr::getInBoundsGetElementPtr(V, &IdxList[0],
+ IdxList.size());
}
-
+
// Handle casts from one vector constant to another. We know that the src
// and dest type have the same size (otherwise its an illegal cast).
if (const VectorType *DestPTy = dyn_cast<VectorType>(DestTy)) {
if (const VectorType *SrcTy = dyn_cast<VectorType>(V->getType())) {
assert(DestPTy->getBitWidth() == SrcTy->getBitWidth() &&
"Not cast between same sized vectors!");
+ SrcTy = NULL;
// First, check for null. Undef is already handled.
if (isa<ConstantAggregateZero>(V))
return Constant::getNullValue(DestTy);
-
+
if (ConstantVector *CV = dyn_cast<ConstantVector>(V))
return BitCastConstantVector(CV, DestPTy);
}
+
+ // Canonicalize scalar-to-vector bitcasts into vector-to-vector bitcasts
+ // This allows for other simplifications (although some of them
+ // can only be handled by Analysis/ConstantFolding.cpp).
+ if (isa<ConstantInt>(V) || isa<ConstantFP>(V))
+ return ConstantExpr::getBitCast(ConstantVector::get(&V, 1), DestPTy);
}
-
+
// Finally, implement bitcast folding now. The code below doesn't handle
// bitcast right.
if (isa<ConstantPointerNull>(V)) // ptr->ptr cast.
return ConstantPointerNull::get(cast<PointerType>(DestTy));
-
+
// Handle integral constant input.
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
- if (DestTy->isInteger())
+ if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
+ if (DestTy->isIntegerTy())
// Integral -> Integral. This is a no-op because the bit widths must
// be the same. Consequently, we just fold to V.
return V;
-
- if (DestTy->isFloatingPoint()) {
- assert((DestTy == Type::DoubleTy || DestTy == Type::FloatTy) &&
- "Unknown FP type!");
- return ConstantFP::get(APFloat(CI->getValue()));
- }
+
+ if (DestTy->isFloatingPointTy())
+ return ConstantFP::get(DestTy->getContext(),
+ APFloat(CI->getValue(),
+ !DestTy->isPPC_FP128Ty()));
+
// Otherwise, can't fold this (vector?)
return 0;
}
+
+ // Handle ConstantFP input: FP -> Integral.
+ if (ConstantFP *FP = dyn_cast<ConstantFP>(V))
+ return ConstantInt::get(FP->getContext(),
+ FP->getValueAPF().bitcastToAPInt());
+
+ return 0;
+}
+
+
+/// ExtractConstantBytes - V is an integer constant which only has a subset of
+/// its bytes used. The bytes used are indicated by ByteStart (which is the
+/// first byte used, counting from the least significant byte) and ByteSize,
+/// which is the number of bytes used.
+///
+/// This function analyzes the specified constant to see if the specified byte
+/// range can be returned as a simplified constant. If so, the constant is
+/// returned, otherwise null is returned.
+///
+static Constant *ExtractConstantBytes(Constant *C, unsigned ByteStart,
+ unsigned ByteSize) {
+ assert(C->getType()->isIntegerTy() &&
+ (cast<IntegerType>(C->getType())->getBitWidth() & 7) == 0 &&
+ "Non-byte sized integer input");
+ unsigned CSize = cast<IntegerType>(C->getType())->getBitWidth()/8;
+ assert(ByteSize && "Must be accessing some piece");
+ assert(ByteStart+ByteSize <= CSize && "Extracting invalid piece from input");
+ assert(ByteSize != CSize && "Should not extract everything");
- // Handle ConstantFP input.
- if (const ConstantFP *FP = dyn_cast<ConstantFP>(V)) {
- // FP -> Integral.
- if (DestTy == Type::Int32Ty) {
- return ConstantInt::get(FP->getValueAPF().convertToAPInt());
- } else {
- assert(DestTy == Type::Int64Ty && "only support f32/f64 for now!");
- return ConstantInt::get(FP->getValueAPF().convertToAPInt());
+ // Constant Integers are simple.
+ if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) {
+ APInt V = CI->getValue();
+ if (ByteStart)
+ V = V.lshr(ByteStart*8);
+ V.trunc(ByteSize*8);
+ return ConstantInt::get(CI->getContext(), V);
+ }
+
+ // In the input is a constant expr, we might be able to recursively simplify.
+ // If not, we definitely can't do anything.
+ ConstantExpr *CE = dyn_cast<ConstantExpr>(C);
+ if (CE == 0) return 0;
+
+ switch (CE->getOpcode()) {
+ default: return 0;
+ case Instruction::Or: {
+ Constant *RHS = ExtractConstantBytes(CE->getOperand(1), ByteStart,ByteSize);
+ if (RHS == 0)
+ return 0;
+
+ // X | -1 -> -1.
+ if (ConstantInt *RHSC = dyn_cast<ConstantInt>(RHS))
+ if (RHSC->isAllOnesValue())
+ return RHSC;
+
+ Constant *LHS = ExtractConstantBytes(CE->getOperand(0), ByteStart,ByteSize);
+ if (LHS == 0)
+ return 0;
+ return ConstantExpr::getOr(LHS, RHS);
+ }
+ case Instruction::And: {
+ Constant *RHS = ExtractConstantBytes(CE->getOperand(1), ByteStart,ByteSize);
+ if (RHS == 0)
+ return 0;
+
+ // X & 0 -> 0.
+ if (RHS->isNullValue())
+ return RHS;
+
+ Constant *LHS = ExtractConstantBytes(CE->getOperand(0), ByteStart,ByteSize);
+ if (LHS == 0)
+ return 0;
+ return ConstantExpr::getAnd(LHS, RHS);
+ }
+ case Instruction::LShr: {
+ ConstantInt *Amt = dyn_cast<ConstantInt>(CE->getOperand(1));
+ if (Amt == 0)
+ return 0;
+ unsigned ShAmt = Amt->getZExtValue();
+ // Cannot analyze non-byte shifts.
+ if ((ShAmt & 7) != 0)
+ return 0;
+ ShAmt >>= 3;
+
+ // If the extract is known to be all zeros, return zero.
+ if (ByteStart >= CSize-ShAmt)
+ return Constant::getNullValue(IntegerType::get(CE->getContext(),
+ ByteSize*8));
+ // If the extract is known to be fully in the input, extract it.
+ if (ByteStart+ByteSize+ShAmt <= CSize)
+ return ExtractConstantBytes(CE->getOperand(0), ByteStart+ShAmt, ByteSize);
+
+ // TODO: Handle the 'partially zero' case.
+ return 0;
+ }
+
+ case Instruction::Shl: {
+ ConstantInt *Amt = dyn_cast<ConstantInt>(CE->getOperand(1));
+ if (Amt == 0)
+ return 0;
+ unsigned ShAmt = Amt->getZExtValue();
+ // Cannot analyze non-byte shifts.
+ if ((ShAmt & 7) != 0)
+ return 0;
+ ShAmt >>= 3;
+
+ // If the extract is known to be all zeros, return zero.
+ if (ByteStart+ByteSize <= ShAmt)
+ return Constant::getNullValue(IntegerType::get(CE->getContext(),
+ ByteSize*8));
+ // If the extract is known to be fully in the input, extract it.
+ if (ByteStart >= ShAmt)
+ return ExtractConstantBytes(CE->getOperand(0), ByteStart-ShAmt, ByteSize);
+
+ // TODO: Handle the 'partially zero' case.
+ return 0;
+ }
+
+ case Instruction::ZExt: {
+ unsigned SrcBitSize =
+ cast<IntegerType>(CE->getOperand(0)->getType())->getBitWidth();
+
+ // If extracting something that is completely zero, return 0.
+ if (ByteStart*8 >= SrcBitSize)
+ return Constant::getNullValue(IntegerType::get(CE->getContext(),
+ ByteSize*8));
+
+ // If exactly extracting the input, return it.
+ if (ByteStart == 0 && ByteSize*8 == SrcBitSize)
+ return CE->getOperand(0);
+
+ // If extracting something completely in the input, if if the input is a
+ // multiple of 8 bits, recurse.
+ if ((SrcBitSize&7) == 0 && (ByteStart+ByteSize)*8 <= SrcBitSize)
+ return ExtractConstantBytes(CE->getOperand(0), ByteStart, ByteSize);
+
+ // Otherwise, if extracting a subset of the input, which is not multiple of
+ // 8 bits, do a shift and trunc to get the bits.
+ if ((ByteStart+ByteSize)*8 < SrcBitSize) {
+ assert((SrcBitSize&7) && "Shouldn't get byte sized case here");
+ Constant *Res = CE->getOperand(0);
+ if (ByteStart)
+ Res = ConstantExpr::getLShr(Res,
+ ConstantInt::get(Res->getType(), ByteStart*8));
+ return ConstantExpr::getTrunc(Res, IntegerType::get(C->getContext(),
+ ByteSize*8));
}
+
+ // TODO: Handle the 'partially zero' case.
+ return 0;
}
- return 0;
+ }
+}
+
+/// getFoldedSizeOf - Return a ConstantExpr with type DestTy for sizeof
+/// on Ty, with any known factors factored out. If Folded is false,
+/// return null if no factoring was possible, to avoid endlessly
+/// bouncing an unfoldable expression back into the top-level folder.
+///
+static Constant *getFoldedSizeOf(const Type *Ty, const Type *DestTy,
+ bool Folded) {
+ if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
+ Constant *N = ConstantInt::get(DestTy, ATy->getNumElements());
+ Constant *E = getFoldedSizeOf(ATy->getElementType(), DestTy, true);
+ return ConstantExpr::getNUWMul(E, N);
+ }
+ if (const VectorType *VTy = dyn_cast<VectorType>(Ty)) {
+ Constant *N = ConstantInt::get(DestTy, VTy->getNumElements());
+ Constant *E = getFoldedSizeOf(VTy->getElementType(), DestTy, true);
+ return ConstantExpr::getNUWMul(E, N);
+ }
+ if (const StructType *STy = dyn_cast<StructType>(Ty))
+ if (!STy->isPacked()) {
+ unsigned NumElems = STy->getNumElements();
+ // An empty struct has size zero.
+ if (NumElems == 0)
+ return ConstantExpr::getNullValue(DestTy);
+ // Check for a struct with all members having the same size.
+ Constant *MemberSize =
+ getFoldedSizeOf(STy->getElementType(0), DestTy, true);
+ bool AllSame = true;
+ for (unsigned i = 1; i != NumElems; ++i)
+ if (MemberSize !=
+ getFoldedSizeOf(STy->getElementType(i), DestTy, true)) {
+ AllSame = false;
+ break;
+ }
+ if (AllSame) {
+ Constant *N = ConstantInt::get(DestTy, NumElems);
+ return ConstantExpr::getNUWMul(MemberSize, N);
+ }
+ }
+
+ // Pointer size doesn't depend on the pointee type, so canonicalize them
+ // to an arbitrary pointee.
+ if (const PointerType *PTy = dyn_cast<PointerType>(Ty))
+ if (!PTy->getElementType()->isIntegerTy(1))
+ return
+ getFoldedSizeOf(PointerType::get(IntegerType::get(PTy->getContext(), 1),
+ PTy->getAddressSpace()),
+ DestTy, true);
+
+ // If there's no interesting folding happening, bail so that we don't create
+ // a constant that looks like it needs folding but really doesn't.
+ if (!Folded)
+ return 0;
+
+ // Base case: Get a regular sizeof expression.
+ Constant *C = ConstantExpr::getSizeOf(Ty);
+ C = ConstantExpr::getCast(CastInst::getCastOpcode(C, false,
+ DestTy, false),
+ C, DestTy);
+ return C;
+}
+
+/// getFoldedAlignOf - Return a ConstantExpr with type DestTy for alignof
+/// on Ty, with any known factors factored out. If Folded is false,
+/// return null if no factoring was possible, to avoid endlessly
+/// bouncing an unfoldable expression back into the top-level folder.
+///
+static Constant *getFoldedAlignOf(const Type *Ty, const Type *DestTy,
+ bool Folded) {
+ // The alignment of an array is equal to the alignment of the
+ // array element. Note that this is not always true for vectors.
+ if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
+ Constant *C = ConstantExpr::getAlignOf(ATy->getElementType());
+ C = ConstantExpr::getCast(CastInst::getCastOpcode(C, false,
+ DestTy,
+ false),
+ C, DestTy);
+ return C;
+ }
+
+ if (const StructType *STy = dyn_cast<StructType>(Ty)) {
+ // Packed structs always have an alignment of 1.
+ if (STy->isPacked())
+ return ConstantInt::get(DestTy, 1);
+
+ // Otherwise, struct alignment is the maximum alignment of any member.
+ // Without target data, we can't compare much, but we can check to see
+ // if all the members have the same alignment.
+ unsigned NumElems = STy->getNumElements();
+ // An empty struct has minimal alignment.
+ if (NumElems == 0)
+ return ConstantInt::get(DestTy, 1);
+ // Check for a struct with all members having the same alignment.
+ Constant *MemberAlign =
+ getFoldedAlignOf(STy->getElementType(0), DestTy, true);
+ bool AllSame = true;
+ for (unsigned i = 1; i != NumElems; ++i)
+ if (MemberAlign != getFoldedAlignOf(STy->getElementType(i), DestTy, true)) {
+ AllSame = false;
+ break;
+ }
+ if (AllSame)
+ return MemberAlign;
+ }
+
+ // Pointer alignment doesn't depend on the pointee type, so canonicalize them
+ // to an arbitrary pointee.
+ if (const PointerType *PTy = dyn_cast<PointerType>(Ty))
+ if (!PTy->getElementType()->isIntegerTy(1))
+ return
+ getFoldedAlignOf(PointerType::get(IntegerType::get(PTy->getContext(),
+ 1),
+ PTy->getAddressSpace()),
+ DestTy, true);
+
+ // If there's no interesting folding happening, bail so that we don't create
+ // a constant that looks like it needs folding but really doesn't.
+ if (!Folded)
+ return 0;
+
+ // Base case: Get a regular alignof expression.
+ Constant *C = ConstantExpr::getAlignOf(Ty);
+ C = ConstantExpr::getCast(CastInst::getCastOpcode(C, false,
+ DestTy, false),
+ C, DestTy);
+ return C;
}
+/// getFoldedOffsetOf - Return a ConstantExpr with type DestTy for offsetof
+/// on Ty and FieldNo, with any known factors factored out. If Folded is false,
+/// return null if no factoring was possible, to avoid endlessly
+/// bouncing an unfoldable expression back into the top-level folder.
+///
+static Constant *getFoldedOffsetOf(const Type *Ty, Constant *FieldNo,
+ const Type *DestTy,
+ bool Folded) {
+ if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
+ Constant *N = ConstantExpr::getCast(CastInst::getCastOpcode(FieldNo, false,
+ DestTy, false),
+ FieldNo, DestTy);
+ Constant *E = getFoldedSizeOf(ATy->getElementType(), DestTy, true);
+ return ConstantExpr::getNUWMul(E, N);
+ }
+ if (const VectorType *VTy = dyn_cast<VectorType>(Ty)) {
+ Constant *N = ConstantExpr::getCast(CastInst::getCastOpcode(FieldNo, false,
+ DestTy, false),
+ FieldNo, DestTy);
+ Constant *E = getFoldedSizeOf(VTy->getElementType(), DestTy, true);
+ return ConstantExpr::getNUWMul(E, N);
+ }
+ if (const StructType *STy = dyn_cast<StructType>(Ty))
+ if (!STy->isPacked()) {
+ unsigned NumElems = STy->getNumElements();
+ // An empty struct has no members.
+ if (NumElems == 0)
+ return 0;
+ // Check for a struct with all members having the same size.
+ Constant *MemberSize =
+ getFoldedSizeOf(STy->getElementType(0), DestTy, true);
+ bool AllSame = true;
+ for (unsigned i = 1; i != NumElems; ++i)
+ if (MemberSize !=
+ getFoldedSizeOf(STy->getElementType(i), DestTy, true)) {
+ AllSame = false;
+ break;
+ }
+ if (AllSame) {
+ Constant *N = ConstantExpr::getCast(CastInst::getCastOpcode(FieldNo,
+ false,
+ DestTy,
+ false),
+ FieldNo, DestTy);
+ return ConstantExpr::getNUWMul(MemberSize, N);
+ }
+ }
+
+ // If there's no interesting folding happening, bail so that we don't create
+ // a constant that looks like it needs folding but really doesn't.
+ if (!Folded)
+ return 0;
+
+ // Base case: Get a regular offsetof expression.
+ Constant *C = ConstantExpr::getOffsetOf(Ty, FieldNo);
+ C = ConstantExpr::getCast(CastInst::getCastOpcode(C, false,
+ DestTy, false),
+ C, DestTy);
+ return C;
+}
-Constant *llvm::ConstantFoldCastInstruction(unsigned opc, const Constant *V,
+Constant *llvm::ConstantFoldCastInstruction(unsigned opc, Constant *V,
const Type *DestTy) {
if (isa<UndefValue>(V)) {
// zext(undef) = 0, because the top bits will be zero.
return UndefValue::get(DestTy);
}
// No compile-time operations on this type yet.
- if (V->getType() == Type::PPC_FP128Ty || DestTy == Type::PPC_FP128Ty)
+ if (V->getType()->isPPC_FP128Ty() || DestTy->isPPC_FP128Ty())
return 0;
// If the cast operand is a constant expression, there's a few things we can
// do to try to simplify it.
- if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
+ if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
if (CE->isCast()) {
// Try hard to fold cast of cast because they are often eliminable.
if (unsigned newOpc = foldConstantCastPair(opc, CE, DestTy))
}
}
+ // If the cast operand is a constant vector, perform the cast by
+ // operating on each element. In the cast of bitcasts, the element
+ // count may be mismatched; don't attempt to handle that here.
+ if (ConstantVector *CV = dyn_cast<ConstantVector>(V))
+ if (DestTy->isVectorTy() &&
+ cast<VectorType>(DestTy)->getNumElements() ==
+ CV->getType()->getNumElements()) {
+ std::vector<Constant*> res;
+ const VectorType *DestVecTy = cast<VectorType>(DestTy);
+ const Type *DstEltTy = DestVecTy->getElementType();
+ for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
+ res.push_back(ConstantExpr::getCast(opc,
+ CV->getOperand(i), DstEltTy));
+ return ConstantVector::get(DestVecTy, res);
+ }
+
// We actually have to do a cast now. Perform the cast according to the
// opcode specified.
switch (opc) {
+ default:
+ llvm_unreachable("Failed to cast constant expression");
case Instruction::FPTrunc:
case Instruction::FPExt:
- if (const ConstantFP *FPC = dyn_cast<ConstantFP>(V)) {
+ if (ConstantFP *FPC = dyn_cast<ConstantFP>(V)) {
+ bool ignored;
APFloat Val = FPC->getValueAPF();
- Val.convert(DestTy == Type::FloatTy ? APFloat::IEEEsingle :
- DestTy == Type::DoubleTy ? APFloat::IEEEdouble :
- DestTy == Type::X86_FP80Ty ? APFloat::x87DoubleExtended :
- DestTy == Type::FP128Ty ? APFloat::IEEEquad :
+ Val.convert(DestTy->isFloatTy() ? APFloat::IEEEsingle :
+ DestTy->isDoubleTy() ? APFloat::IEEEdouble :
+ DestTy->isX86_FP80Ty() ? APFloat::x87DoubleExtended :
+ DestTy->isFP128Ty() ? APFloat::IEEEquad :
APFloat::Bogus,
- APFloat::rmNearestTiesToEven);
- return ConstantFP::get(Val);
+ APFloat::rmNearestTiesToEven, &ignored);
+ return ConstantFP::get(V->getContext(), Val);
}
return 0; // Can't fold.
case Instruction::FPToUI:
case Instruction::FPToSI:
- if (const ConstantFP *FPC = dyn_cast<ConstantFP>(V)) {
+ if (ConstantFP *FPC = dyn_cast<ConstantFP>(V)) {
const APFloat &V = FPC->getValueAPF();
+ bool ignored;
uint64_t x[2];
uint32_t DestBitWidth = cast<IntegerType>(DestTy)->getBitWidth();
(void) V.convertToInteger(x, DestBitWidth, opc==Instruction::FPToSI,
- APFloat::rmTowardZero);
+ APFloat::rmTowardZero, &ignored);
APInt Val(DestBitWidth, 2, x);
- return ConstantInt::get(Val);
- }
- if (const ConstantVector *CV = dyn_cast<ConstantVector>(V)) {
- std::vector<Constant*> res;
- const VectorType *DestVecTy = cast<VectorType>(DestTy);
- const Type *DstEltTy = DestVecTy->getElementType();
- for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
- res.push_back(ConstantFoldCastInstruction(opc, V->getOperand(i),
- DstEltTy));
- return ConstantVector::get(DestVecTy, res);
+ return ConstantInt::get(FPC->getContext(), Val);
}
return 0; // Can't fold.
case Instruction::IntToPtr: //always treated as unsigned
return ConstantPointerNull::get(cast<PointerType>(DestTy));
return 0; // Other pointer types cannot be casted
case Instruction::PtrToInt: // always treated as unsigned
- if (V->isNullValue()) // is it a null pointer value?
+ // Is it a null pointer value?
+ if (V->isNullValue())
return ConstantInt::get(DestTy, 0);
- return 0; // Other pointer types cannot be casted
+ // If this is a sizeof-like expression, pull out multiplications by
+ // known factors to expose them to subsequent folding. If it's an
+ // alignof-like expression, factor out known factors.
+ if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
+ if (CE->getOpcode() == Instruction::GetElementPtr &&
+ CE->getOperand(0)->isNullValue()) {
+ const Type *Ty =
+ cast<PointerType>(CE->getOperand(0)->getType())->getElementType();
+ if (CE->getNumOperands() == 2) {
+ // Handle a sizeof-like expression.
+ Constant *Idx = CE->getOperand(1);
+ bool isOne = isa<ConstantInt>(Idx) && cast<ConstantInt>(Idx)->isOne();
+ if (Constant *C = getFoldedSizeOf(Ty, DestTy, !isOne)) {
+ Idx = ConstantExpr::getCast(CastInst::getCastOpcode(Idx, true,
+ DestTy, false),
+ Idx, DestTy);
+ return ConstantExpr::getMul(C, Idx);
+ }
+ } else if (CE->getNumOperands() == 3 &&
+ CE->getOperand(1)->isNullValue()) {
+ // Handle an alignof-like expression.
+ if (const StructType *STy = dyn_cast<StructType>(Ty))
+ if (!STy->isPacked()) {
+ ConstantInt *CI = cast<ConstantInt>(CE->getOperand(2));
+ if (CI->isOne() &&
+ STy->getNumElements() == 2 &&
+ STy->getElementType(0)->isIntegerTy(1)) {
+ return getFoldedAlignOf(STy->getElementType(1), DestTy, false);
+ }
+ }
+ // Handle an offsetof-like expression.
+ if (Ty->isStructTy() || Ty->isArrayTy() || Ty->isVectorTy()){
+ if (Constant *C = getFoldedOffsetOf(Ty, CE->getOperand(2),
+ DestTy, false))
+ return C;
+ }
+ }
+ }
+ // Other pointer types cannot be casted
+ return 0;
case Instruction::UIToFP:
case Instruction::SIToFP:
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
+ if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
APInt api = CI->getValue();
const uint64_t zero[] = {0, 0};
APFloat apf = APFloat(APInt(DestTy->getPrimitiveSizeInBits(),
(void)apf.convertFromAPInt(api,
opc==Instruction::SIToFP,
APFloat::rmNearestTiesToEven);
- return ConstantFP::get(apf);
- }
- if (const ConstantVector *CV = dyn_cast<ConstantVector>(V)) {
- std::vector<Constant*> res;
- const VectorType *DestVecTy = cast<VectorType>(DestTy);
- const Type *DstEltTy = DestVecTy->getElementType();
- for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
- res.push_back(ConstantFoldCastInstruction(opc, V->getOperand(i),
- DstEltTy));
- return ConstantVector::get(DestVecTy, res);
+ return ConstantFP::get(V->getContext(), apf);
}
return 0;
case Instruction::ZExt:
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
+ if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
uint32_t BitWidth = cast<IntegerType>(DestTy)->getBitWidth();
APInt Result(CI->getValue());
Result.zext(BitWidth);
- return ConstantInt::get(Result);
+ return ConstantInt::get(V->getContext(), Result);
}
return 0;
case Instruction::SExt:
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
+ if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
uint32_t BitWidth = cast<IntegerType>(DestTy)->getBitWidth();
APInt Result(CI->getValue());
Result.sext(BitWidth);
- return ConstantInt::get(Result);
+ return ConstantInt::get(V->getContext(), Result);
}
return 0;
- case Instruction::Trunc:
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
- uint32_t BitWidth = cast<IntegerType>(DestTy)->getBitWidth();
+ case Instruction::Trunc: {
+ uint32_t DestBitWidth = cast<IntegerType>(DestTy)->getBitWidth();
+ if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
APInt Result(CI->getValue());
- Result.trunc(BitWidth);
- return ConstantInt::get(Result);
+ Result.trunc(DestBitWidth);
+ return ConstantInt::get(V->getContext(), Result);
}
+
+ // The input must be a constantexpr. See if we can simplify this based on
+ // the bytes we are demanding. Only do this if the source and dest are an
+ // even multiple of a byte.
+ if ((DestBitWidth & 7) == 0 &&
+ (cast<IntegerType>(V->getType())->getBitWidth() & 7) == 0)
+ if (Constant *Res = ExtractConstantBytes(V, 0, DestBitWidth / 8))
+ return Res;
+
return 0;
+ }
case Instruction::BitCast:
- return FoldBitCast(const_cast<Constant*>(V), DestTy);
- default:
- assert(!"Invalid CE CastInst opcode");
- break;
+ return FoldBitCast(V, DestTy);
}
-
- assert(0 && "Failed to cast constant expression");
- return 0;
}
-Constant *llvm::ConstantFoldSelectInstruction(const Constant *Cond,
- const Constant *V1,
- const Constant *V2) {
- if (const ConstantInt *CB = dyn_cast<ConstantInt>(Cond))
- return const_cast<Constant*>(CB->getZExtValue() ? V1 : V2);
+Constant *llvm::ConstantFoldSelectInstruction(Constant *Cond,
+ Constant *V1, Constant *V2) {
+ if (ConstantInt *CB = dyn_cast<ConstantInt>(Cond))
+ return CB->getZExtValue() ? V1 : V2;
- if (isa<UndefValue>(V1)) return const_cast<Constant*>(V2);
- if (isa<UndefValue>(V2)) return const_cast<Constant*>(V1);
- if (isa<UndefValue>(Cond)) return const_cast<Constant*>(V1);
- if (V1 == V2) return const_cast<Constant*>(V1);
+ if (isa<UndefValue>(V1)) return V2;
+ if (isa<UndefValue>(V2)) return V1;
+ if (isa<UndefValue>(Cond)) return V1;
+ if (V1 == V2) return V1;
return 0;
}
-Constant *llvm::ConstantFoldExtractElementInstruction(const Constant *Val,
- const Constant *Idx) {
+Constant *llvm::ConstantFoldExtractElementInstruction(Constant *Val,
+ Constant *Idx) {
if (isa<UndefValue>(Val)) // ee(undef, x) -> undef
return UndefValue::get(cast<VectorType>(Val->getType())->getElementType());
if (Val->isNullValue()) // ee(zero, x) -> zero
return Constant::getNullValue(
cast<VectorType>(Val->getType())->getElementType());
-
- if (const ConstantVector *CVal = dyn_cast<ConstantVector>(Val)) {
- if (const ConstantInt *CIdx = dyn_cast<ConstantInt>(Idx)) {
+
+ if (ConstantVector *CVal = dyn_cast<ConstantVector>(Val)) {
+ if (ConstantInt *CIdx = dyn_cast<ConstantInt>(Idx)) {
return CVal->getOperand(CIdx->getZExtValue());
} else if (isa<UndefValue>(Idx)) {
// ee({w,x,y,z}, undef) -> w (an arbitrary value).
return 0;
}
-Constant *llvm::ConstantFoldInsertElementInstruction(const Constant *Val,
- const Constant *Elt,
- const Constant *Idx) {
- const ConstantInt *CIdx = dyn_cast<ConstantInt>(Idx);
+Constant *llvm::ConstantFoldInsertElementInstruction(Constant *Val,
+ Constant *Elt,
+ Constant *Idx) {
+ ConstantInt *CIdx = dyn_cast<ConstantInt>(Idx);
if (!CIdx) return 0;
APInt idxVal = CIdx->getValue();
if (isa<UndefValue>(Val)) {
// Insertion of scalar constant into vector undef
// Optimize away insertion of undef
if (isa<UndefValue>(Elt))
- return const_cast<Constant*>(Val);
+ return Val;
// Otherwise break the aggregate undef into multiple undefs and do
// the insertion
unsigned numOps =
std::vector<Constant*> Ops;
Ops.reserve(numOps);
for (unsigned i = 0; i < numOps; ++i) {
- const Constant *Op =
+ Constant *Op =
(idxVal == i) ? Elt : UndefValue::get(Elt->getType());
- Ops.push_back(const_cast<Constant*>(Op));
+ Ops.push_back(Op);
}
return ConstantVector::get(Ops);
}
// Insertion of scalar constant into vector aggregate zero
// Optimize away insertion of zero
if (Elt->isNullValue())
- return const_cast<Constant*>(Val);
+ return Val;
// Otherwise break the aggregate zero into multiple zeros and do
// the insertion
unsigned numOps =
std::vector<Constant*> Ops;
Ops.reserve(numOps);
for (unsigned i = 0; i < numOps; ++i) {
- const Constant *Op =
+ Constant *Op =
(idxVal == i) ? Elt : Constant::getNullValue(Elt->getType());
- Ops.push_back(const_cast<Constant*>(Op));
+ Ops.push_back(Op);
}
return ConstantVector::get(Ops);
}
- if (const ConstantVector *CVal = dyn_cast<ConstantVector>(Val)) {
+ if (ConstantVector *CVal = dyn_cast<ConstantVector>(Val)) {
// Insertion of scalar constant into vector constant
std::vector<Constant*> Ops;
Ops.reserve(CVal->getNumOperands());
for (unsigned i = 0; i < CVal->getNumOperands(); ++i) {
- const Constant *Op =
+ Constant *Op =
(idxVal == i) ? Elt : cast<Constant>(CVal->getOperand(i));
- Ops.push_back(const_cast<Constant*>(Op));
+ Ops.push_back(Op);
}
return ConstantVector::get(Ops);
}
/// GetVectorElement - If C is a ConstantVector, ConstantAggregateZero or Undef
/// return the specified element value. Otherwise return null.
-static Constant *GetVectorElement(const Constant *C, unsigned EltNo) {
- if (const ConstantVector *CV = dyn_cast<ConstantVector>(C))
+static Constant *GetVectorElement(Constant *C, unsigned EltNo) {
+ if (ConstantVector *CV = dyn_cast<ConstantVector>(C))
return CV->getOperand(EltNo);
-
+
const Type *EltTy = cast<VectorType>(C->getType())->getElementType();
if (isa<ConstantAggregateZero>(C))
return Constant::getNullValue(EltTy);
return 0;
}
-Constant *llvm::ConstantFoldShuffleVectorInstruction(const Constant *V1,
- const Constant *V2,
- const Constant *Mask) {
+Constant *llvm::ConstantFoldShuffleVectorInstruction(Constant *V1,
+ Constant *V2,
+ Constant *Mask) {
// Undefined shuffle mask -> undefined value.
if (isa<UndefValue>(Mask)) return UndefValue::get(V1->getType());
-
- unsigned NumElts = cast<VectorType>(V1->getType())->getNumElements();
+
+ unsigned MaskNumElts = cast<VectorType>(Mask->getType())->getNumElements();
+ unsigned SrcNumElts = cast<VectorType>(V1->getType())->getNumElements();
const Type *EltTy = cast<VectorType>(V1->getType())->getElementType();
-
+
// Loop over the shuffle mask, evaluating each element.
SmallVector<Constant*, 32> Result;
- for (unsigned i = 0; i != NumElts; ++i) {
+ for (unsigned i = 0; i != MaskNumElts; ++i) {
Constant *InElt = GetVectorElement(Mask, i);
if (InElt == 0) return 0;
-
+
if (isa<UndefValue>(InElt))
InElt = UndefValue::get(EltTy);
else if (ConstantInt *CI = dyn_cast<ConstantInt>(InElt)) {
unsigned Elt = CI->getZExtValue();
- if (Elt >= NumElts*2)
+ if (Elt >= SrcNumElts*2)
InElt = UndefValue::get(EltTy);
- else if (Elt >= NumElts)
- InElt = GetVectorElement(V2, Elt-NumElts);
+ else if (Elt >= SrcNumElts)
+ InElt = GetVectorElement(V2, Elt - SrcNumElts);
else
InElt = GetVectorElement(V1, Elt);
if (InElt == 0) return 0;
}
Result.push_back(InElt);
}
-
+
return ConstantVector::get(&Result[0], Result.size());
}
-Constant *llvm::ConstantFoldExtractValueInstruction(const Constant *Agg,
+Constant *llvm::ConstantFoldExtractValueInstruction(Constant *Agg,
const unsigned *Idxs,
unsigned NumIdx) {
// Base case: no indices, so return the entire value.
if (NumIdx == 0)
- return const_cast<Constant *>(Agg);
+ return Agg;
if (isa<UndefValue>(Agg)) // ev(undef, x) -> undef
return UndefValue::get(ExtractValueInst::getIndexedType(Agg->getType(),
Idxs + NumIdx));
// Otherwise recurse.
- return ConstantFoldExtractValueInstruction(Agg->getOperand(*Idxs),
+ if (ConstantStruct *CS = dyn_cast<ConstantStruct>(Agg))
+ return ConstantFoldExtractValueInstruction(CS->getOperand(*Idxs),
+ Idxs+1, NumIdx-1);
+
+ if (ConstantArray *CA = dyn_cast<ConstantArray>(Agg))
+ return ConstantFoldExtractValueInstruction(CA->getOperand(*Idxs),
+ Idxs+1, NumIdx-1);
+ ConstantVector *CV = cast<ConstantVector>(Agg);
+ return ConstantFoldExtractValueInstruction(CV->getOperand(*Idxs),
Idxs+1, NumIdx-1);
}
-Constant *llvm::ConstantFoldInsertValueInstruction(const Constant *Agg,
- const Constant *Val,
+Constant *llvm::ConstantFoldInsertValueInstruction(Constant *Agg,
+ Constant *Val,
const unsigned *Idxs,
unsigned NumIdx) {
// Base case: no indices, so replace the entire value.
if (NumIdx == 0)
- return const_cast<Constant *>(Val);
+ return Val;
if (isa<UndefValue>(Agg)) {
// Insertion of constant into aggregate undef
- // Optimize away insertion of undef
+ // Optimize away insertion of undef.
if (isa<UndefValue>(Val))
- return const_cast<Constant*>(Agg);
+ return Agg;
+
// Otherwise break the aggregate undef into multiple undefs and do
- // the insertion
+ // the insertion.
const CompositeType *AggTy = cast<CompositeType>(Agg->getType());
unsigned numOps;
if (const ArrayType *AR = dyn_cast<ArrayType>(AggTy))
numOps = AR->getNumElements();
+ else if (AggTy->isUnionTy())
+ numOps = 1;
else
numOps = cast<StructType>(AggTy)->getNumElements();
+
std::vector<Constant*> Ops(numOps);
for (unsigned i = 0; i < numOps; ++i) {
const Type *MemberTy = AggTy->getTypeAtIndex(i);
- const Constant *Op =
+ Constant *Op =
(*Idxs == i) ?
ConstantFoldInsertValueInstruction(UndefValue::get(MemberTy),
Val, Idxs+1, NumIdx-1) :
UndefValue::get(MemberTy);
- Ops[i] = const_cast<Constant*>(Op);
+ Ops[i] = Op;
}
- if (isa<StructType>(AggTy))
- return ConstantStruct::get(Ops);
- else
- return ConstantArray::get(cast<ArrayType>(AggTy), Ops);
+
+ if (const StructType* ST = dyn_cast<StructType>(AggTy))
+ return ConstantStruct::get(ST->getContext(), Ops, ST->isPacked());
+ if (const UnionType* UT = dyn_cast<UnionType>(AggTy)) {
+ assert(Ops.size() == 1 && "Union can only contain a single value!");
+ return ConstantUnion::get(UT, Ops[0]);
+ }
+ return ConstantArray::get(cast<ArrayType>(AggTy), Ops);
}
+
if (isa<ConstantAggregateZero>(Agg)) {
// Insertion of constant into aggregate zero
- // Optimize away insertion of zero
+ // Optimize away insertion of zero.
if (Val->isNullValue())
- return const_cast<Constant*>(Agg);
+ return Agg;
+
// Otherwise break the aggregate zero into multiple zeros and do
- // the insertion
+ // the insertion.
const CompositeType *AggTy = cast<CompositeType>(Agg->getType());
unsigned numOps;
if (const ArrayType *AR = dyn_cast<ArrayType>(AggTy))
numOps = AR->getNumElements();
else
numOps = cast<StructType>(AggTy)->getNumElements();
+
std::vector<Constant*> Ops(numOps);
for (unsigned i = 0; i < numOps; ++i) {
const Type *MemberTy = AggTy->getTypeAtIndex(i);
- const Constant *Op =
+ Constant *Op =
(*Idxs == i) ?
ConstantFoldInsertValueInstruction(Constant::getNullValue(MemberTy),
Val, Idxs+1, NumIdx-1) :
Constant::getNullValue(MemberTy);
- Ops[i] = const_cast<Constant*>(Op);
+ Ops[i] = Op;
}
- if (isa<StructType>(AggTy))
- return ConstantStruct::get(Ops);
- else
- return ConstantArray::get(cast<ArrayType>(AggTy), Ops);
+
+ if (const StructType *ST = dyn_cast<StructType>(AggTy))
+ return ConstantStruct::get(ST->getContext(), Ops, ST->isPacked());
+ return ConstantArray::get(cast<ArrayType>(AggTy), Ops);
}
+
if (isa<ConstantStruct>(Agg) || isa<ConstantArray>(Agg)) {
- // Insertion of constant into aggregate constant
+ // Insertion of constant into aggregate constant.
std::vector<Constant*> Ops(Agg->getNumOperands());
for (unsigned i = 0; i < Agg->getNumOperands(); ++i) {
- const Constant *Op =
- (*Idxs == i) ?
- ConstantFoldInsertValueInstruction(Agg->getOperand(i),
- Val, Idxs+1, NumIdx-1) :
- Agg->getOperand(i);
- Ops[i] = const_cast<Constant*>(Op);
+ Constant *Op = cast<Constant>(Agg->getOperand(i));
+ if (*Idxs == i)
+ Op = ConstantFoldInsertValueInstruction(Op, Val, Idxs+1, NumIdx-1);
+ Ops[i] = Op;
}
- Constant *C;
- if (isa<StructType>(Agg->getType()))
- C = ConstantStruct::get(Ops);
- else
- C = ConstantArray::get(cast<ArrayType>(Agg->getType()), Ops);
- return C;
+
+ if (const StructType* ST = dyn_cast<StructType>(Agg->getType()))
+ return ConstantStruct::get(ST->getContext(), Ops, ST->isPacked());
+ return ConstantArray::get(cast<ArrayType>(Agg->getType()), Ops);
}
return 0;
}
-/// EvalVectorOp - Given two vector constants and a function pointer, apply the
-/// function pointer to each element pair, producing a new ConstantVector
-/// constant. Either or both of V1 and V2 may be NULL, meaning a
-/// ConstantAggregateZero operand.
-static Constant *EvalVectorOp(const ConstantVector *V1,
- const ConstantVector *V2,
- const VectorType *VTy,
- Constant *(*FP)(Constant*, Constant*)) {
- std::vector<Constant*> Res;
- const Type *EltTy = VTy->getElementType();
- for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i) {
- const Constant *C1 = V1 ? V1->getOperand(i) : Constant::getNullValue(EltTy);
- const Constant *C2 = V2 ? V2->getOperand(i) : Constant::getNullValue(EltTy);
- Res.push_back(FP(const_cast<Constant*>(C1),
- const_cast<Constant*>(C2)));
- }
- return ConstantVector::get(Res);
-}
Constant *llvm::ConstantFoldBinaryInstruction(unsigned Opcode,
- const Constant *C1,
- const Constant *C2) {
+ Constant *C1, Constant *C2) {
// No compile-time operations on this type yet.
- if (C1->getType() == Type::PPC_FP128Ty)
+ if (C1->getType()->isPPC_FP128Ty())
return 0;
- // Handle UndefValue up front
+ // Handle UndefValue up front.
if (isa<UndefValue>(C1) || isa<UndefValue>(C2)) {
switch (Opcode) {
case Instruction::Xor:
return Constant::getNullValue(C1->getType());
case Instruction::UDiv:
case Instruction::SDiv:
- case Instruction::FDiv:
case Instruction::URem:
case Instruction::SRem:
- case Instruction::FRem:
if (!isa<UndefValue>(C2)) // undef / X -> 0
return Constant::getNullValue(C1->getType());
- return const_cast<Constant*>(C2); // X / undef -> undef
+ return C2; // X / undef -> undef
case Instruction::Or: // X | undef -> -1
if (const VectorType *PTy = dyn_cast<VectorType>(C1->getType()))
- return ConstantVector::getAllOnesValue(PTy);
- return ConstantInt::getAllOnesValue(C1->getType());
+ return Constant::getAllOnesValue(PTy);
+ return Constant::getAllOnesValue(C1->getType());
case Instruction::LShr:
if (isa<UndefValue>(C2) && isa<UndefValue>(C1))
- return const_cast<Constant*>(C1); // undef lshr undef -> undef
+ return C1; // undef lshr undef -> undef
return Constant::getNullValue(C1->getType()); // X lshr undef -> 0
// undef lshr X -> 0
case Instruction::AShr:
if (!isa<UndefValue>(C2))
- return const_cast<Constant*>(C1); // undef ashr X --> undef
+ return C1; // undef ashr X --> undef
else if (isa<UndefValue>(C1))
- return const_cast<Constant*>(C1); // undef ashr undef -> undef
+ return C1; // undef ashr undef -> undef
else
- return const_cast<Constant*>(C1); // X ashr undef --> X
+ return C1; // X ashr undef --> X
case Instruction::Shl:
// undef << X -> 0 or X << undef -> 0
return Constant::getNullValue(C1->getType());
}
}
- // Handle simplifications of the RHS when a constant int.
- if (const ConstantInt *CI2 = dyn_cast<ConstantInt>(C2)) {
+ // Handle simplifications when the RHS is a constant int.
+ if (ConstantInt *CI2 = dyn_cast<ConstantInt>(C2)) {
switch (Opcode) {
case Instruction::Add:
- if (CI2->equalsInt(0)) return const_cast<Constant*>(C1); // X + 0 == X
+ if (CI2->equalsInt(0)) return C1; // X + 0 == X
break;
case Instruction::Sub:
- if (CI2->equalsInt(0)) return const_cast<Constant*>(C1); // X - 0 == X
+ if (CI2->equalsInt(0)) return C1; // X - 0 == X
break;
case Instruction::Mul:
- if (CI2->equalsInt(0)) return const_cast<Constant*>(C2); // X * 0 == 0
+ if (CI2->equalsInt(0)) return C2; // X * 0 == 0
if (CI2->equalsInt(1))
- return const_cast<Constant*>(C1); // X * 1 == X
+ return C1; // X * 1 == X
break;
case Instruction::UDiv:
case Instruction::SDiv:
if (CI2->equalsInt(1))
- return const_cast<Constant*>(C1); // X / 1 == X
+ return C1; // X / 1 == X
+ if (CI2->equalsInt(0))
+ return UndefValue::get(CI2->getType()); // X / 0 == undef
break;
case Instruction::URem:
case Instruction::SRem:
if (CI2->equalsInt(1))
return Constant::getNullValue(CI2->getType()); // X % 1 == 0
+ if (CI2->equalsInt(0))
+ return UndefValue::get(CI2->getType()); // X % 0 == undef
break;
case Instruction::And:
- if (CI2->isZero()) return const_cast<Constant*>(C2); // X & 0 == 0
+ if (CI2->isZero()) return C2; // X & 0 == 0
if (CI2->isAllOnesValue())
- return const_cast<Constant*>(C1); // X & -1 == X
-
- if (const ConstantExpr *CE1 = dyn_cast<ConstantExpr>(C1)) {
+ return C1; // X & -1 == X
+
+ if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(C1)) {
// (zext i32 to i64) & 4294967295 -> (zext i32 to i64)
if (CE1->getOpcode() == Instruction::ZExt) {
unsigned DstWidth = CI2->getType()->getBitWidth();
CE1->getOperand(0)->getType()->getPrimitiveSizeInBits();
APInt PossiblySetBits(APInt::getLowBitsSet(DstWidth, SrcWidth));
if ((PossiblySetBits & CI2->getValue()) == PossiblySetBits)
- return const_cast<Constant*>(C1);
+ return C1;
}
-
+
// If and'ing the address of a global with a constant, fold it.
if (CE1->getOpcode() == Instruction::PtrToInt &&
isa<GlobalValue>(CE1->getOperand(0))) {
GlobalValue *GV = cast<GlobalValue>(CE1->getOperand(0));
-
+
// Functions are at least 4-byte aligned.
unsigned GVAlign = GV->getAlignment();
if (isa<Function>(GV))
GVAlign = std::max(GVAlign, 4U);
-
+
if (GVAlign > 1) {
unsigned DstWidth = CI2->getType()->getBitWidth();
unsigned SrcWidth = std::min(DstWidth, Log2_32(GVAlign));
}
break;
case Instruction::Or:
- if (CI2->equalsInt(0)) return const_cast<Constant*>(C1); // X | 0 == X
+ if (CI2->equalsInt(0)) return C1; // X | 0 == X
if (CI2->isAllOnesValue())
- return const_cast<Constant*>(C2); // X | -1 == -1
+ return C2; // X | -1 == -1
break;
case Instruction::Xor:
- if (CI2->equalsInt(0)) return const_cast<Constant*>(C1); // X ^ 0 == X
+ if (CI2->equalsInt(0)) return C1; // X ^ 0 == X
+
+ if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(C1)) {
+ switch (CE1->getOpcode()) {
+ default: break;
+ case Instruction::ICmp:
+ case Instruction::FCmp:
+ // cmp pred ^ true -> cmp !pred
+ assert(CI2->equalsInt(1));
+ CmpInst::Predicate pred = (CmpInst::Predicate)CE1->getPredicate();
+ pred = CmpInst::getInversePredicate(pred);
+ return ConstantExpr::getCompare(pred, CE1->getOperand(0),
+ CE1->getOperand(1));
+ }
+ }
break;
case Instruction::AShr:
// ashr (zext C to Ty), C2 -> lshr (zext C, CSA), C2
- if (const ConstantExpr *CE1 = dyn_cast<ConstantExpr>(C1))
+ if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(C1))
if (CE1->getOpcode() == Instruction::ZExt) // Top bits known zero.
- return ConstantExpr::getLShr(const_cast<Constant*>(C1),
- const_cast<Constant*>(C2));
+ return ConstantExpr::getLShr(C1, C2);
break;
}
+ } else if (isa<ConstantInt>(C1)) {
+ // If C1 is a ConstantInt and C2 is not, swap the operands.
+ if (Instruction::isCommutative(Opcode))
+ return ConstantExpr::get(Opcode, C2, C1);
}
-
+
// At this point we know neither constant is an UndefValue.
- if (const ConstantInt *CI1 = dyn_cast<ConstantInt>(C1)) {
- if (const ConstantInt *CI2 = dyn_cast<ConstantInt>(C2)) {
+ if (ConstantInt *CI1 = dyn_cast<ConstantInt>(C1)) {
+ if (ConstantInt *CI2 = dyn_cast<ConstantInt>(C2)) {
using namespace APIntOps;
const APInt &C1V = CI1->getValue();
const APInt &C2V = CI2->getValue();
default:
break;
case Instruction::Add:
- return ConstantInt::get(C1V + C2V);
+ return ConstantInt::get(CI1->getContext(), C1V + C2V);
case Instruction::Sub:
- return ConstantInt::get(C1V - C2V);
+ return ConstantInt::get(CI1->getContext(), C1V - C2V);
case Instruction::Mul:
- return ConstantInt::get(C1V * C2V);
+ return ConstantInt::get(CI1->getContext(), C1V * C2V);
case Instruction::UDiv:
- if (CI2->isNullValue())
- return 0; // X / 0 -> can't fold
- return ConstantInt::get(C1V.udiv(C2V));
+ assert(!CI2->isNullValue() && "Div by zero handled above");
+ return ConstantInt::get(CI1->getContext(), C1V.udiv(C2V));
case Instruction::SDiv:
- if (CI2->isNullValue())
- return 0; // X / 0 -> can't fold
+ assert(!CI2->isNullValue() && "Div by zero handled above");
if (C2V.isAllOnesValue() && C1V.isMinSignedValue())
- return 0; // MIN_INT / -1 -> overflow
- return ConstantInt::get(C1V.sdiv(C2V));
+ return UndefValue::get(CI1->getType()); // MIN_INT / -1 -> undef
+ return ConstantInt::get(CI1->getContext(), C1V.sdiv(C2V));
case Instruction::URem:
- if (C2->isNullValue())
- return 0; // X / 0 -> can't fold
- return ConstantInt::get(C1V.urem(C2V));
- case Instruction::SRem:
- if (CI2->isNullValue())
- return 0; // X % 0 -> can't fold
+ assert(!CI2->isNullValue() && "Div by zero handled above");
+ return ConstantInt::get(CI1->getContext(), C1V.urem(C2V));
+ case Instruction::SRem:
+ assert(!CI2->isNullValue() && "Div by zero handled above");
if (C2V.isAllOnesValue() && C1V.isMinSignedValue())
- return 0; // MIN_INT % -1 -> overflow
- return ConstantInt::get(C1V.srem(C2V));
+ return UndefValue::get(CI1->getType()); // MIN_INT % -1 -> undef
+ return ConstantInt::get(CI1->getContext(), C1V.srem(C2V));
case Instruction::And:
- return ConstantInt::get(C1V & C2V);
+ return ConstantInt::get(CI1->getContext(), C1V & C2V);
case Instruction::Or:
- return ConstantInt::get(C1V | C2V);
+ return ConstantInt::get(CI1->getContext(), C1V | C2V);
case Instruction::Xor:
- return ConstantInt::get(C1V ^ C2V);
+ return ConstantInt::get(CI1->getContext(), C1V ^ C2V);
case Instruction::Shl: {
uint32_t shiftAmt = C2V.getZExtValue();
if (shiftAmt < C1V.getBitWidth())
- return ConstantInt::get(C1V.shl(shiftAmt));
+ return ConstantInt::get(CI1->getContext(), C1V.shl(shiftAmt));
else
return UndefValue::get(C1->getType()); // too big shift is undef
}
case Instruction::LShr: {
uint32_t shiftAmt = C2V.getZExtValue();
if (shiftAmt < C1V.getBitWidth())
- return ConstantInt::get(C1V.lshr(shiftAmt));
+ return ConstantInt::get(CI1->getContext(), C1V.lshr(shiftAmt));
else
return UndefValue::get(C1->getType()); // too big shift is undef
}
case Instruction::AShr: {
uint32_t shiftAmt = C2V.getZExtValue();
if (shiftAmt < C1V.getBitWidth())
- return ConstantInt::get(C1V.ashr(shiftAmt));
+ return ConstantInt::get(CI1->getContext(), C1V.ashr(shiftAmt));
else
return UndefValue::get(C1->getType()); // too big shift is undef
}
}
}
- } else if (const ConstantFP *CFP1 = dyn_cast<ConstantFP>(C1)) {
- if (const ConstantFP *CFP2 = dyn_cast<ConstantFP>(C2)) {
+
+ switch (Opcode) {
+ case Instruction::SDiv:
+ case Instruction::UDiv:
+ case Instruction::URem:
+ case Instruction::SRem:
+ case Instruction::LShr:
+ case Instruction::AShr:
+ case Instruction::Shl:
+ if (CI1->equalsInt(0)) return C1;
+ break;
+ default:
+ break;
+ }
+ } else if (ConstantFP *CFP1 = dyn_cast<ConstantFP>(C1)) {
+ if (ConstantFP *CFP2 = dyn_cast<ConstantFP>(C2)) {
APFloat C1V = CFP1->getValueAPF();
APFloat C2V = CFP2->getValueAPF();
APFloat C3V = C1V; // copy for modification
switch (Opcode) {
default:
break;
- case Instruction::Add:
+ case Instruction::FAdd:
(void)C3V.add(C2V, APFloat::rmNearestTiesToEven);
- return ConstantFP::get(C3V);
- case Instruction::Sub:
+ return ConstantFP::get(C1->getContext(), C3V);
+ case Instruction::FSub:
(void)C3V.subtract(C2V, APFloat::rmNearestTiesToEven);
- return ConstantFP::get(C3V);
- case Instruction::Mul:
+ return ConstantFP::get(C1->getContext(), C3V);
+ case Instruction::FMul:
(void)C3V.multiply(C2V, APFloat::rmNearestTiesToEven);
- return ConstantFP::get(C3V);
+ return ConstantFP::get(C1->getContext(), C3V);
case Instruction::FDiv:
(void)C3V.divide(C2V, APFloat::rmNearestTiesToEven);
- return ConstantFP::get(C3V);
+ return ConstantFP::get(C1->getContext(), C3V);
case Instruction::FRem:
- if (C2V.isZero()) {
- // IEEE 754, Section 7.1, #5
- if (CFP1->getType() == Type::DoubleTy)
- return ConstantFP::get(APFloat(std::numeric_limits<double>::
- quiet_NaN()));
- if (CFP1->getType() == Type::FloatTy)
- return ConstantFP::get(APFloat(std::numeric_limits<float>::
- quiet_NaN()));
- break;
- }
(void)C3V.mod(C2V, APFloat::rmNearestTiesToEven);
- return ConstantFP::get(C3V);
+ return ConstantFP::get(C1->getContext(), C3V);
}
}
} else if (const VectorType *VTy = dyn_cast<VectorType>(C1->getType())) {
- const ConstantVector *CP1 = dyn_cast<ConstantVector>(C1);
- const ConstantVector *CP2 = dyn_cast<ConstantVector>(C2);
+ ConstantVector *CP1 = dyn_cast<ConstantVector>(C1);
+ ConstantVector *CP2 = dyn_cast<ConstantVector>(C2);
if ((CP1 != NULL || isa<ConstantAggregateZero>(C1)) &&
(CP2 != NULL || isa<ConstantAggregateZero>(C2))) {
+ std::vector<Constant*> Res;
+ const Type* EltTy = VTy->getElementType();
+ Constant *C1 = 0;
+ Constant *C2 = 0;
switch (Opcode) {
default:
break;
- case Instruction::Add:
- return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getAdd);
- case Instruction::Sub:
- return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getSub);
- case Instruction::Mul:
- return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getMul);
+ case Instruction::Add:
+ for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i) {
+ C1 = CP1 ? CP1->getOperand(i) : Constant::getNullValue(EltTy);
+ C2 = CP2 ? CP2->getOperand(i) : Constant::getNullValue(EltTy);
+ Res.push_back(ConstantExpr::getAdd(C1, C2));
+ }
+ return ConstantVector::get(Res);
+ case Instruction::FAdd:
+ for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i) {
+ C1 = CP1 ? CP1->getOperand(i) : Constant::getNullValue(EltTy);
+ C2 = CP2 ? CP2->getOperand(i) : Constant::getNullValue(EltTy);
+ Res.push_back(ConstantExpr::getFAdd(C1, C2));
+ }
+ return ConstantVector::get(Res);
+ case Instruction::Sub:
+ for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i) {
+ C1 = CP1 ? CP1->getOperand(i) : Constant::getNullValue(EltTy);
+ C2 = CP2 ? CP2->getOperand(i) : Constant::getNullValue(EltTy);
+ Res.push_back(ConstantExpr::getSub(C1, C2));
+ }
+ return ConstantVector::get(Res);
+ case Instruction::FSub:
+ for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i) {
+ C1 = CP1 ? CP1->getOperand(i) : Constant::getNullValue(EltTy);
+ C2 = CP2 ? CP2->getOperand(i) : Constant::getNullValue(EltTy);
+ Res.push_back(ConstantExpr::getFSub(C1, C2));
+ }
+ return ConstantVector::get(Res);
+ case Instruction::Mul:
+ for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i) {
+ C1 = CP1 ? CP1->getOperand(i) : Constant::getNullValue(EltTy);
+ C2 = CP2 ? CP2->getOperand(i) : Constant::getNullValue(EltTy);
+ Res.push_back(ConstantExpr::getMul(C1, C2));
+ }
+ return ConstantVector::get(Res);
+ case Instruction::FMul:
+ for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i) {
+ C1 = CP1 ? CP1->getOperand(i) : Constant::getNullValue(EltTy);
+ C2 = CP2 ? CP2->getOperand(i) : Constant::getNullValue(EltTy);
+ Res.push_back(ConstantExpr::getFMul(C1, C2));
+ }
+ return ConstantVector::get(Res);
case Instruction::UDiv:
- return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getUDiv);
+ for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i) {
+ C1 = CP1 ? CP1->getOperand(i) : Constant::getNullValue(EltTy);
+ C2 = CP2 ? CP2->getOperand(i) : Constant::getNullValue(EltTy);
+ Res.push_back(ConstantExpr::getUDiv(C1, C2));
+ }
+ return ConstantVector::get(Res);
case Instruction::SDiv:
- return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getSDiv);
+ for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i) {
+ C1 = CP1 ? CP1->getOperand(i) : Constant::getNullValue(EltTy);
+ C2 = CP2 ? CP2->getOperand(i) : Constant::getNullValue(EltTy);
+ Res.push_back(ConstantExpr::getSDiv(C1, C2));
+ }
+ return ConstantVector::get(Res);
case Instruction::FDiv:
- return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getFDiv);
+ for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i) {
+ C1 = CP1 ? CP1->getOperand(i) : Constant::getNullValue(EltTy);
+ C2 = CP2 ? CP2->getOperand(i) : Constant::getNullValue(EltTy);
+ Res.push_back(ConstantExpr::getFDiv(C1, C2));
+ }
+ return ConstantVector::get(Res);
case Instruction::URem:
- return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getURem);
+ for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i) {
+ C1 = CP1 ? CP1->getOperand(i) : Constant::getNullValue(EltTy);
+ C2 = CP2 ? CP2->getOperand(i) : Constant::getNullValue(EltTy);
+ Res.push_back(ConstantExpr::getURem(C1, C2));
+ }
+ return ConstantVector::get(Res);
case Instruction::SRem:
- return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getSRem);
+ for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i) {
+ C1 = CP1 ? CP1->getOperand(i) : Constant::getNullValue(EltTy);
+ C2 = CP2 ? CP2->getOperand(i) : Constant::getNullValue(EltTy);
+ Res.push_back(ConstantExpr::getSRem(C1, C2));
+ }
+ return ConstantVector::get(Res);
case Instruction::FRem:
- return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getFRem);
+ for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i) {
+ C1 = CP1 ? CP1->getOperand(i) : Constant::getNullValue(EltTy);
+ C2 = CP2 ? CP2->getOperand(i) : Constant::getNullValue(EltTy);
+ Res.push_back(ConstantExpr::getFRem(C1, C2));
+ }
+ return ConstantVector::get(Res);
case Instruction::And:
- return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getAnd);
- case Instruction::Or:
- return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getOr);
- case Instruction::Xor:
- return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getXor);
+ for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i) {
+ C1 = CP1 ? CP1->getOperand(i) : Constant::getNullValue(EltTy);
+ C2 = CP2 ? CP2->getOperand(i) : Constant::getNullValue(EltTy);
+ Res.push_back(ConstantExpr::getAnd(C1, C2));
+ }
+ return ConstantVector::get(Res);
+ case Instruction::Or:
+ for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i) {
+ C1 = CP1 ? CP1->getOperand(i) : Constant::getNullValue(EltTy);
+ C2 = CP2 ? CP2->getOperand(i) : Constant::getNullValue(EltTy);
+ Res.push_back(ConstantExpr::getOr(C1, C2));
+ }
+ return ConstantVector::get(Res);
+ case Instruction::Xor:
+ for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i) {
+ C1 = CP1 ? CP1->getOperand(i) : Constant::getNullValue(EltTy);
+ C2 = CP2 ? CP2->getOperand(i) : Constant::getNullValue(EltTy);
+ Res.push_back(ConstantExpr::getXor(C1, C2));
+ }
+ return ConstantVector::get(Res);
+ case Instruction::LShr:
+ for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i) {
+ C1 = CP1 ? CP1->getOperand(i) : Constant::getNullValue(EltTy);
+ C2 = CP2 ? CP2->getOperand(i) : Constant::getNullValue(EltTy);
+ Res.push_back(ConstantExpr::getLShr(C1, C2));
+ }
+ return ConstantVector::get(Res);
+ case Instruction::AShr:
+ for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i) {
+ C1 = CP1 ? CP1->getOperand(i) : Constant::getNullValue(EltTy);
+ C2 = CP2 ? CP2->getOperand(i) : Constant::getNullValue(EltTy);
+ Res.push_back(ConstantExpr::getAShr(C1, C2));
+ }
+ return ConstantVector::get(Res);
+ case Instruction::Shl:
+ for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i) {
+ C1 = CP1 ? CP1->getOperand(i) : Constant::getNullValue(EltTy);
+ C2 = CP2 ? CP2->getOperand(i) : Constant::getNullValue(EltTy);
+ Res.push_back(ConstantExpr::getShl(C1, C2));
+ }
+ return ConstantVector::get(Res);
}
}
}
- if (isa<ConstantExpr>(C1)) {
+ if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(C1)) {
// There are many possible foldings we could do here. We should probably
// at least fold add of a pointer with an integer into the appropriate
// getelementptr. This will improve alias analysis a bit.
+
+ // Given ((a + b) + c), if (b + c) folds to something interesting, return
+ // (a + (b + c)).
+ if (Instruction::isAssociative(Opcode, C1->getType()) &&
+ CE1->getOpcode() == Opcode) {
+ Constant *T = ConstantExpr::get(Opcode, CE1->getOperand(1), C2);
+ if (!isa<ConstantExpr>(T) || cast<ConstantExpr>(T)->getOpcode() != Opcode)
+ return ConstantExpr::get(Opcode, CE1->getOperand(0), T);
+ }
} else if (isa<ConstantExpr>(C2)) {
// If C2 is a constant expr and C1 isn't, flop them around and fold the
// other way if possible.
+ if (Instruction::isCommutative(Opcode))
+ return ConstantFoldBinaryInstruction(Opcode, C2, C1);
+ }
+
+ // i1 can be simplified in many cases.
+ if (C1->getType()->isIntegerTy(1)) {
switch (Opcode) {
case Instruction::Add:
+ case Instruction::Sub:
+ return ConstantExpr::getXor(C1, C2);
case Instruction::Mul:
- case Instruction::And:
- case Instruction::Or:
- case Instruction::Xor:
- // No change of opcode required.
- return ConstantFoldBinaryInstruction(Opcode, C2, C1);
-
+ return ConstantExpr::getAnd(C1, C2);
case Instruction::Shl:
case Instruction::LShr:
case Instruction::AShr:
- case Instruction::Sub:
+ // We can assume that C2 == 0. If it were one the result would be
+ // undefined because the shift value is as large as the bitwidth.
+ return C1;
case Instruction::SDiv:
case Instruction::UDiv:
- case Instruction::FDiv:
+ // We can assume that C2 == 1. If it were zero the result would be
+ // undefined through division by zero.
+ return C1;
case Instruction::URem:
case Instruction::SRem:
- case Instruction::FRem:
- default: // These instructions cannot be flopped around.
+ // We can assume that C2 == 1. If it were zero the result would be
+ // undefined through division by zero.
+ return ConstantInt::getFalse(C1->getContext());
+ default:
break;
}
}
-
+
// We don't know how to fold this.
return 0;
}
/// isZeroSizedType - This type is zero sized if its an array or structure of
/// zero sized types. The only leaf zero sized type is an empty structure.
static bool isMaybeZeroSizedType(const Type *Ty) {
- if (isa<OpaqueType>(Ty)) return true; // Can't say.
+ if (Ty->isOpaqueTy()) return true; // Can't say.
if (const StructType *STy = dyn_cast<StructType>(Ty)) {
// If all of elements have zero size, this does too.
/// first is less than the second, return -1, if the second is less than the
/// first, return 1. If the constants are not integral, return -2.
///
-static int IdxCompare(Constant *C1, Constant *C2, const Type *ElTy) {
+static int IdxCompare(Constant *C1, Constant *C2, const Type *ElTy) {
if (C1 == C2) return 0;
// Ok, we found a different index. If they are not ConstantInt, we can't do
// Ok, we have two differing integer indices. Sign extend them to be the same
// type. Long is always big enough, so we use it.
- if (C1->getType() != Type::Int64Ty)
- C1 = ConstantExpr::getSExt(C1, Type::Int64Ty);
+ if (!C1->getType()->isIntegerTy(64))
+ C1 = ConstantExpr::getSExt(C1, Type::getInt64Ty(C1->getContext()));
- if (C2->getType() != Type::Int64Ty)
- C2 = ConstantExpr::getSExt(C2, Type::Int64Ty);
+ if (!C2->getType()->isIntegerTy(64))
+ C2 = ConstantExpr::getSExt(C2, Type::getInt64Ty(C1->getContext()));
if (C1 == C2) return 0; // They are equal
/// To simplify this code we canonicalize the relation so that the first
/// operand is always the most "complex" of the two. We consider ConstantFP
/// to be the simplest, and ConstantExprs to be the most complex.
-static FCmpInst::Predicate evaluateFCmpRelation(const Constant *V1,
- const Constant *V2) {
+static FCmpInst::Predicate evaluateFCmpRelation(Constant *V1, Constant *V2) {
assert(V1->getType() == V2->getType() &&
"Cannot compare values of different types!");
// No compile-time operations on this type yet.
- if (V1->getType() == Type::PPC_FP128Ty)
+ if (V1->getType()->isPPC_FP128Ty())
return FCmpInst::BAD_FCMP_PREDICATE;
// Handle degenerate case quickly
if (!isa<ConstantExpr>(V2)) {
// We distilled thisUse the standard constant folder for a few cases
ConstantInt *R = 0;
- Constant *C1 = const_cast<Constant*>(V1);
- Constant *C2 = const_cast<Constant*>(V2);
R = dyn_cast<ConstantInt>(
- ConstantExpr::getFCmp(FCmpInst::FCMP_OEQ, C1, C2));
+ ConstantExpr::getFCmp(FCmpInst::FCMP_OEQ, V1, V2));
if (R && !R->isZero())
return FCmpInst::FCMP_OEQ;
R = dyn_cast<ConstantInt>(
- ConstantExpr::getFCmp(FCmpInst::FCMP_OLT, C1, C2));
+ ConstantExpr::getFCmp(FCmpInst::FCMP_OLT, V1, V2));
if (R && !R->isZero())
return FCmpInst::FCMP_OLT;
R = dyn_cast<ConstantInt>(
- ConstantExpr::getFCmp(FCmpInst::FCMP_OGT, C1, C2));
+ ConstantExpr::getFCmp(FCmpInst::FCMP_OGT, V1, V2));
if (R && !R->isZero())
return FCmpInst::FCMP_OGT;
// Nothing more we can do
return FCmpInst::BAD_FCMP_PREDICATE;
}
-
+
// If the first operand is simple and second is ConstantExpr, swap operands.
FCmpInst::Predicate SwappedRelation = evaluateFCmpRelation(V2, V1);
if (SwappedRelation != FCmpInst::BAD_FCMP_PREDICATE)
} else {
// Ok, the LHS is known to be a constantexpr. The RHS can be any of a
// constantexpr or a simple constant.
- const ConstantExpr *CE1 = cast<ConstantExpr>(V1);
+ ConstantExpr *CE1 = cast<ConstantExpr>(V1);
switch (CE1->getOpcode()) {
case Instruction::FPTrunc:
case Instruction::FPExt:
/// constants (like ConstantInt) to be the simplest, followed by
/// GlobalValues, followed by ConstantExpr's (the most complex).
///
-static ICmpInst::Predicate evaluateICmpRelation(const Constant *V1,
- const Constant *V2,
+static ICmpInst::Predicate evaluateICmpRelation(Constant *V1, Constant *V2,
bool isSigned) {
assert(V1->getType() == V2->getType() &&
"Cannot compare different types of values!");
if (V1 == V2) return ICmpInst::ICMP_EQ;
- if (!isa<ConstantExpr>(V1) && !isa<GlobalValue>(V1)) {
- if (!isa<GlobalValue>(V2) && !isa<ConstantExpr>(V2)) {
+ if (!isa<ConstantExpr>(V1) && !isa<GlobalValue>(V1) &&
+ !isa<BlockAddress>(V1)) {
+ if (!isa<GlobalValue>(V2) && !isa<ConstantExpr>(V2) &&
+ !isa<BlockAddress>(V2)) {
// We distilled this down to a simple case, use the standard constant
// folder.
ConstantInt *R = 0;
- Constant *C1 = const_cast<Constant*>(V1);
- Constant *C2 = const_cast<Constant*>(V2);
ICmpInst::Predicate pred = ICmpInst::ICMP_EQ;
- R = dyn_cast<ConstantInt>(ConstantExpr::getICmp(pred, C1, C2));
+ R = dyn_cast<ConstantInt>(ConstantExpr::getICmp(pred, V1, V2));
if (R && !R->isZero())
return pred;
pred = isSigned ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT;
- R = dyn_cast<ConstantInt>(ConstantExpr::getICmp(pred, C1, C2));
+ R = dyn_cast<ConstantInt>(ConstantExpr::getICmp(pred, V1, V2));
if (R && !R->isZero())
return pred;
- pred = isSigned ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT;
- R = dyn_cast<ConstantInt>(ConstantExpr::getICmp(pred, C1, C2));
+ pred = isSigned ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT;
+ R = dyn_cast<ConstantInt>(ConstantExpr::getICmp(pred, V1, V2));
if (R && !R->isZero())
return pred;
-
+
// If we couldn't figure it out, bail.
return ICmpInst::BAD_ICMP_PREDICATE;
}
-
+
// If the first operand is simple, swap operands.
ICmpInst::Predicate SwappedRelation =
evaluateICmpRelation(V2, V1, isSigned);
if (SwappedRelation != ICmpInst::BAD_ICMP_PREDICATE)
return ICmpInst::getSwappedPredicate(SwappedRelation);
- } else if (const GlobalValue *CPR1 = dyn_cast<GlobalValue>(V1)) {
+ } else if (const GlobalValue *GV = dyn_cast<GlobalValue>(V1)) {
if (isa<ConstantExpr>(V2)) { // Swap as necessary.
ICmpInst::Predicate SwappedRelation =
evaluateICmpRelation(V2, V1, isSigned);
if (SwappedRelation != ICmpInst::BAD_ICMP_PREDICATE)
return ICmpInst::getSwappedPredicate(SwappedRelation);
- else
- return ICmpInst::BAD_ICMP_PREDICATE;
+ return ICmpInst::BAD_ICMP_PREDICATE;
}
- // Now we know that the RHS is a GlobalValue or simple constant,
- // which (since the types must match) means that it's a ConstantPointerNull.
- if (const GlobalValue *CPR2 = dyn_cast<GlobalValue>(V2)) {
+ // Now we know that the RHS is a GlobalValue, BlockAddress or simple
+ // constant (which, since the types must match, means that it's a
+ // ConstantPointerNull).
+ if (const GlobalValue *GV2 = dyn_cast<GlobalValue>(V2)) {
// Don't try to decide equality of aliases.
- if (!isa<GlobalAlias>(CPR1) && !isa<GlobalAlias>(CPR2))
- if (!CPR1->hasExternalWeakLinkage() || !CPR2->hasExternalWeakLinkage())
+ if (!isa<GlobalAlias>(GV) && !isa<GlobalAlias>(GV2))
+ if (!GV->hasExternalWeakLinkage() || !GV2->hasExternalWeakLinkage())
return ICmpInst::ICMP_NE;
+ } else if (isa<BlockAddress>(V2)) {
+ return ICmpInst::ICMP_NE; // Globals never equal labels.
} else {
assert(isa<ConstantPointerNull>(V2) && "Canonicalization guarantee!");
- // GlobalVals can never be null. Don't try to evaluate aliases.
- if (!CPR1->hasExternalWeakLinkage() && !isa<GlobalAlias>(CPR1))
+ // GlobalVals can never be null unless they have external weak linkage.
+ // We don't try to evaluate aliases here.
+ if (!GV->hasExternalWeakLinkage() && !isa<GlobalAlias>(GV))
+ return ICmpInst::ICMP_NE;
+ }
+ } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(V1)) {
+ if (isa<ConstantExpr>(V2)) { // Swap as necessary.
+ ICmpInst::Predicate SwappedRelation =
+ evaluateICmpRelation(V2, V1, isSigned);
+ if (SwappedRelation != ICmpInst::BAD_ICMP_PREDICATE)
+ return ICmpInst::getSwappedPredicate(SwappedRelation);
+ return ICmpInst::BAD_ICMP_PREDICATE;
+ }
+
+ // Now we know that the RHS is a GlobalValue, BlockAddress or simple
+ // constant (which, since the types must match, means that it is a
+ // ConstantPointerNull).
+ if (const BlockAddress *BA2 = dyn_cast<BlockAddress>(V2)) {
+ // Block address in another function can't equal this one, but block
+ // addresses in the current function might be the same if blocks are
+ // empty.
+ if (BA2->getFunction() != BA->getFunction())
return ICmpInst::ICMP_NE;
+ } else {
+ // Block addresses aren't null, don't equal the address of globals.
+ assert((isa<ConstantPointerNull>(V2) || isa<GlobalValue>(V2)) &&
+ "Canonicalization guarantee!");
+ return ICmpInst::ICMP_NE;
}
} else {
// Ok, the LHS is known to be a constantexpr. The RHS can be any of a
- // constantexpr, a CPR, or a simple constant.
- const ConstantExpr *CE1 = cast<ConstantExpr>(V1);
- const Constant *CE1Op0 = CE1->getOperand(0);
+ // constantexpr, a global, block address, or a simple constant.
+ ConstantExpr *CE1 = cast<ConstantExpr>(V1);
+ Constant *CE1Op0 = CE1->getOperand(0);
switch (CE1->getOpcode()) {
case Instruction::Trunc:
// If the cast is not actually changing bits, and the second operand is a
// null pointer, do the comparison with the pre-casted value.
if (V2->isNullValue() &&
- (isa<PointerType>(CE1->getType()) || CE1->getType()->isInteger())) {
- bool sgnd = isSigned;
+ (CE1->getType()->isPointerTy() || CE1->getType()->isIntegerTy())) {
if (CE1->getOpcode() == Instruction::ZExt) isSigned = false;
if (CE1->getOpcode() == Instruction::SExt) isSigned = true;
return evaluateICmpRelation(CE1Op0,
Constant::getNullValue(CE1Op0->getType()),
- sgnd);
+ isSigned);
}
-
- // If the dest type is a pointer type, and the RHS is a constantexpr cast
- // from the same type as the src of the LHS, evaluate the inputs. This is
- // important for things like "icmp eq (cast 4 to int*), (cast 5 to int*)",
- // which happens a lot in compilers with tagged integers.
- if (const ConstantExpr *CE2 = dyn_cast<ConstantExpr>(V2))
- if (CE2->isCast() && isa<PointerType>(CE1->getType()) &&
- CE1->getOperand(0)->getType() == CE2->getOperand(0)->getType() &&
- CE1->getOperand(0)->getType()->isInteger()) {
- bool sgnd = isSigned;
- if (CE1->getOpcode() == Instruction::ZExt) isSigned = false;
- if (CE1->getOpcode() == Instruction::SExt) isSigned = true;
- return evaluateICmpRelation(CE1->getOperand(0), CE2->getOperand(0),
- sgnd);
- }
break;
case Instruction::GetElementPtr:
else
// If its not weak linkage, the GVal must have a non-zero address
// so the result is greater-than
- return isSigned ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT;
+ return isSigned ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT;
} else if (isa<ConstantPointerNull>(CE1Op0)) {
// If we are indexing from a null pointer, check to see if we have any
// non-zero indices.
return ICmpInst::ICMP_EQ;
}
// Otherwise, we can't really say if the first operand is null or not.
- } else if (const GlobalValue *CPR2 = dyn_cast<GlobalValue>(V2)) {
+ } else if (const GlobalValue *GV2 = dyn_cast<GlobalValue>(V2)) {
if (isa<ConstantPointerNull>(CE1Op0)) {
- if (CPR2->hasExternalWeakLinkage())
+ if (GV2->hasExternalWeakLinkage())
// Weak linkage GVals could be zero or not. We're comparing it to
// a null pointer, so its less-or-equal
return isSigned ? ICmpInst::ICMP_SLE : ICmpInst::ICMP_ULE;
// If its not weak linkage, the GVal must have a non-zero address
// so the result is less-than
return isSigned ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT;
- } else if (const GlobalValue *CPR1 = dyn_cast<GlobalValue>(CE1Op0)) {
- if (CPR1 == CPR2) {
+ } else if (const GlobalValue *GV = dyn_cast<GlobalValue>(CE1Op0)) {
+ if (GV == GV2) {
// If this is a getelementptr of the same global, then it must be
// different. Because the types must match, the getelementptr could
// only have at most one index, and because we fold getelementptr's
}
}
} else {
- const ConstantExpr *CE2 = cast<ConstantExpr>(V2);
- const Constant *CE2Op0 = CE2->getOperand(0);
+ ConstantExpr *CE2 = cast<ConstantExpr>(V2);
+ Constant *CE2Op0 = CE2->getOperand(0);
// There are MANY other foldings that we could perform here. They will
// probably be added on demand, as they seem needed.
// ordering of the resultant pointers.
unsigned i = 1;
+ // The logic below assumes that the result of the comparison
+ // can be determined by finding the first index that differs.
+ // This doesn't work if there is over-indexing in any
+ // subsequent indices, so check for that case first.
+ if (!CE1->isGEPWithNoNotionalOverIndexing() ||
+ !CE2->isGEPWithNoNotionalOverIndexing())
+ return ICmpInst::BAD_ICMP_PREDICATE; // Might be equal.
+
// Compare all of the operands the GEP's have in common.
gep_type_iterator GTI = gep_type_begin(CE1);
for (;i != CE1->getNumOperands() && i != CE2->getNumOperands();
++i, ++GTI)
- switch (IdxCompare(CE1->getOperand(i), CE2->getOperand(i),
- GTI.getIndexedType())) {
+ switch (IdxCompare(CE1->getOperand(i),
+ CE2->getOperand(i), GTI.getIndexedType())) {
case -1: return isSigned ? ICmpInst::ICMP_SLT:ICmpInst::ICMP_ULT;
case 1: return isSigned ? ICmpInst::ICMP_SGT:ICmpInst::ICMP_UGT;
case -2: return ICmpInst::BAD_ICMP_PREDICATE;
}
Constant *llvm::ConstantFoldCompareInstruction(unsigned short pred,
- const Constant *C1,
- const Constant *C2) {
+ Constant *C1, Constant *C2) {
+ const Type *ResultTy;
+ if (const VectorType *VT = dyn_cast<VectorType>(C1->getType()))
+ ResultTy = VectorType::get(Type::getInt1Ty(C1->getContext()),
+ VT->getNumElements());
+ else
+ ResultTy = Type::getInt1Ty(C1->getContext());
+
// Fold FCMP_FALSE/FCMP_TRUE unconditionally.
- if (pred == FCmpInst::FCMP_FALSE) {
- if (const VectorType *VT = dyn_cast<VectorType>(C1->getType()))
- return Constant::getNullValue(VectorType::getInteger(VT));
- else
- return ConstantInt::getFalse();
- }
-
- if (pred == FCmpInst::FCMP_TRUE) {
- if (const VectorType *VT = dyn_cast<VectorType>(C1->getType()))
- return Constant::getAllOnesValue(VectorType::getInteger(VT));
- else
- return ConstantInt::getTrue();
- }
-
+ if (pred == FCmpInst::FCMP_FALSE)
+ return Constant::getNullValue(ResultTy);
+
+ if (pred == FCmpInst::FCMP_TRUE)
+ return Constant::getAllOnesValue(ResultTy);
+
// Handle some degenerate cases first
- if (isa<UndefValue>(C1) || isa<UndefValue>(C2)) {
- // vicmp/vfcmp -> [vector] undef
- if (const VectorType *VTy = dyn_cast<VectorType>(C1->getType()))
- return UndefValue::get(VectorType::getInteger(VTy));
-
- // icmp/fcmp -> i1 undef
- return UndefValue::get(Type::Int1Ty);
- }
+ if (isa<UndefValue>(C1) || isa<UndefValue>(C2))
+ return UndefValue::get(ResultTy);
// No compile-time operations on this type yet.
- if (C1->getType() == Type::PPC_FP128Ty)
+ if (C1->getType()->isPPC_FP128Ty())
return 0;
// icmp eq/ne(null,GV) -> false/true
// Don't try to evaluate aliases. External weak GV can be null.
if (!isa<GlobalAlias>(GV) && !GV->hasExternalWeakLinkage()) {
if (pred == ICmpInst::ICMP_EQ)
- return ConstantInt::getFalse();
+ return ConstantInt::getFalse(C1->getContext());
else if (pred == ICmpInst::ICMP_NE)
- return ConstantInt::getTrue();
+ return ConstantInt::getTrue(C1->getContext());
}
// icmp eq/ne(GV,null) -> false/true
} else if (C2->isNullValue()) {
// Don't try to evaluate aliases. External weak GV can be null.
if (!isa<GlobalAlias>(GV) && !GV->hasExternalWeakLinkage()) {
if (pred == ICmpInst::ICMP_EQ)
- return ConstantInt::getFalse();
+ return ConstantInt::getFalse(C1->getContext());
else if (pred == ICmpInst::ICMP_NE)
- return ConstantInt::getTrue();
+ return ConstantInt::getTrue(C1->getContext());
}
}
+ // If the comparison is a comparison between two i1's, simplify it.
+ if (C1->getType()->isIntegerTy(1)) {
+ switch(pred) {
+ case ICmpInst::ICMP_EQ:
+ if (isa<ConstantInt>(C2))
+ return ConstantExpr::getXor(C1, ConstantExpr::getNot(C2));
+ return ConstantExpr::getXor(ConstantExpr::getNot(C1), C2);
+ case ICmpInst::ICMP_NE:
+ return ConstantExpr::getXor(C1, C2);
+ default:
+ break;
+ }
+ }
+
if (isa<ConstantInt>(C1) && isa<ConstantInt>(C2)) {
APInt V1 = cast<ConstantInt>(C1)->getValue();
APInt V2 = cast<ConstantInt>(C2)->getValue();
switch (pred) {
- default: assert(0 && "Invalid ICmp Predicate"); return 0;
- case ICmpInst::ICMP_EQ: return ConstantInt::get(Type::Int1Ty, V1 == V2);
- case ICmpInst::ICMP_NE: return ConstantInt::get(Type::Int1Ty, V1 != V2);
- case ICmpInst::ICMP_SLT:return ConstantInt::get(Type::Int1Ty, V1.slt(V2));
- case ICmpInst::ICMP_SGT:return ConstantInt::get(Type::Int1Ty, V1.sgt(V2));
- case ICmpInst::ICMP_SLE:return ConstantInt::get(Type::Int1Ty, V1.sle(V2));
- case ICmpInst::ICMP_SGE:return ConstantInt::get(Type::Int1Ty, V1.sge(V2));
- case ICmpInst::ICMP_ULT:return ConstantInt::get(Type::Int1Ty, V1.ult(V2));
- case ICmpInst::ICMP_UGT:return ConstantInt::get(Type::Int1Ty, V1.ugt(V2));
- case ICmpInst::ICMP_ULE:return ConstantInt::get(Type::Int1Ty, V1.ule(V2));
- case ICmpInst::ICMP_UGE:return ConstantInt::get(Type::Int1Ty, V1.uge(V2));
+ default: llvm_unreachable("Invalid ICmp Predicate"); return 0;
+ case ICmpInst::ICMP_EQ: return ConstantInt::get(ResultTy, V1 == V2);
+ case ICmpInst::ICMP_NE: return ConstantInt::get(ResultTy, V1 != V2);
+ case ICmpInst::ICMP_SLT: return ConstantInt::get(ResultTy, V1.slt(V2));
+ case ICmpInst::ICMP_SGT: return ConstantInt::get(ResultTy, V1.sgt(V2));
+ case ICmpInst::ICMP_SLE: return ConstantInt::get(ResultTy, V1.sle(V2));
+ case ICmpInst::ICMP_SGE: return ConstantInt::get(ResultTy, V1.sge(V2));
+ case ICmpInst::ICMP_ULT: return ConstantInt::get(ResultTy, V1.ult(V2));
+ case ICmpInst::ICMP_UGT: return ConstantInt::get(ResultTy, V1.ugt(V2));
+ case ICmpInst::ICMP_ULE: return ConstantInt::get(ResultTy, V1.ule(V2));
+ case ICmpInst::ICMP_UGE: return ConstantInt::get(ResultTy, V1.uge(V2));
}
} else if (isa<ConstantFP>(C1) && isa<ConstantFP>(C2)) {
APFloat C1V = cast<ConstantFP>(C1)->getValueAPF();
APFloat C2V = cast<ConstantFP>(C2)->getValueAPF();
APFloat::cmpResult R = C1V.compare(C2V);
switch (pred) {
- default: assert(0 && "Invalid FCmp Predicate"); return 0;
- case FCmpInst::FCMP_FALSE: return ConstantInt::getFalse();
- case FCmpInst::FCMP_TRUE: return ConstantInt::getTrue();
+ default: llvm_unreachable("Invalid FCmp Predicate"); return 0;
+ case FCmpInst::FCMP_FALSE: return Constant::getNullValue(ResultTy);
+ case FCmpInst::FCMP_TRUE: return Constant::getAllOnesValue(ResultTy);
case FCmpInst::FCMP_UNO:
- return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpUnordered);
+ return ConstantInt::get(ResultTy, R==APFloat::cmpUnordered);
case FCmpInst::FCMP_ORD:
- return ConstantInt::get(Type::Int1Ty, R!=APFloat::cmpUnordered);
+ return ConstantInt::get(ResultTy, R!=APFloat::cmpUnordered);
case FCmpInst::FCMP_UEQ:
- return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpUnordered ||
- R==APFloat::cmpEqual);
+ return ConstantInt::get(ResultTy, R==APFloat::cmpUnordered ||
+ R==APFloat::cmpEqual);
case FCmpInst::FCMP_OEQ:
- return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpEqual);
+ return ConstantInt::get(ResultTy, R==APFloat::cmpEqual);
case FCmpInst::FCMP_UNE:
- return ConstantInt::get(Type::Int1Ty, R!=APFloat::cmpEqual);
+ return ConstantInt::get(ResultTy, R!=APFloat::cmpEqual);
case FCmpInst::FCMP_ONE:
- return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpLessThan ||
- R==APFloat::cmpGreaterThan);
+ return ConstantInt::get(ResultTy, R==APFloat::cmpLessThan ||
+ R==APFloat::cmpGreaterThan);
case FCmpInst::FCMP_ULT:
- return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpUnordered ||
- R==APFloat::cmpLessThan);
+ return ConstantInt::get(ResultTy, R==APFloat::cmpUnordered ||
+ R==APFloat::cmpLessThan);
case FCmpInst::FCMP_OLT:
- return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpLessThan);
+ return ConstantInt::get(ResultTy, R==APFloat::cmpLessThan);
case FCmpInst::FCMP_UGT:
- return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpUnordered ||
- R==APFloat::cmpGreaterThan);
+ return ConstantInt::get(ResultTy, R==APFloat::cmpUnordered ||
+ R==APFloat::cmpGreaterThan);
case FCmpInst::FCMP_OGT:
- return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpGreaterThan);
+ return ConstantInt::get(ResultTy, R==APFloat::cmpGreaterThan);
case FCmpInst::FCMP_ULE:
- return ConstantInt::get(Type::Int1Ty, R!=APFloat::cmpGreaterThan);
+ return ConstantInt::get(ResultTy, R!=APFloat::cmpGreaterThan);
case FCmpInst::FCMP_OLE:
- return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpLessThan ||
- R==APFloat::cmpEqual);
+ return ConstantInt::get(ResultTy, R==APFloat::cmpLessThan ||
+ R==APFloat::cmpEqual);
case FCmpInst::FCMP_UGE:
- return ConstantInt::get(Type::Int1Ty, R!=APFloat::cmpLessThan);
+ return ConstantInt::get(ResultTy, R!=APFloat::cmpLessThan);
case FCmpInst::FCMP_OGE:
- return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpGreaterThan ||
- R==APFloat::cmpEqual);
+ return ConstantInt::get(ResultTy, R==APFloat::cmpGreaterThan ||
+ R==APFloat::cmpEqual);
}
- } else if (const ConstantVector *CP1 = dyn_cast<ConstantVector>(C1)) {
- if (const ConstantVector *CP2 = dyn_cast<ConstantVector>(C2)) {
- // If we can constant fold the comparison of each element, constant fold
- // the whole vector comparison.
- SmallVector<Constant*, 4> Elts;
- const Type *InEltTy = CP1->getOperand(0)->getType();
- bool isFP = InEltTy->isFloatingPoint();
- const Type *ResEltTy = InEltTy;
- if (isFP)
- ResEltTy = IntegerType::get(InEltTy->getPrimitiveSizeInBits());
-
- for (unsigned i = 0, e = CP1->getNumOperands(); i != e; ++i) {
- // Compare the elements, producing an i1 result or constant expr.
- Constant *C;
- if (isFP)
- C = ConstantExpr::getFCmp(pred, CP1->getOperand(i),
- CP2->getOperand(i));
- else
- C = ConstantExpr::getICmp(pred, CP1->getOperand(i),
- CP2->getOperand(i));
+ } else if (C1->getType()->isVectorTy()) {
+ SmallVector<Constant*, 16> C1Elts, C2Elts;
+ C1->getVectorElements(C1Elts);
+ C2->getVectorElements(C2Elts);
+ if (C1Elts.empty() || C2Elts.empty())
+ return 0;
- // If it is a bool or undef result, convert to the dest type.
- if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) {
- if (CI->isZero())
- Elts.push_back(Constant::getNullValue(ResEltTy));
- else
- Elts.push_back(Constant::getAllOnesValue(ResEltTy));
- } else if (isa<UndefValue>(C)) {
- Elts.push_back(UndefValue::get(ResEltTy));
- } else {
- break;
- }
- }
-
- if (Elts.size() == CP1->getNumOperands())
- return ConstantVector::get(&Elts[0], Elts.size());
+ // If we can constant fold the comparison of each element, constant fold
+ // the whole vector comparison.
+ SmallVector<Constant*, 4> ResElts;
+ for (unsigned i = 0, e = C1Elts.size(); i != e; ++i) {
+ // Compare the elements, producing an i1 result or constant expr.
+ ResElts.push_back(ConstantExpr::getCompare(pred, C1Elts[i], C2Elts[i]));
}
+ return ConstantVector::get(&ResElts[0], ResElts.size());
}
- if (C1->getType()->isFloatingPoint()) {
+ if (C1->getType()->isFloatingPointTy()) {
int Result = -1; // -1 = unknown, 0 = known false, 1 = known true.
switch (evaluateFCmpRelation(C1, C2)) {
- default: assert(0 && "Unknown relation!");
+ default: llvm_unreachable("Unknown relation!");
case FCmpInst::FCMP_UNO:
case FCmpInst::FCMP_ORD:
case FCmpInst::FCMP_UEQ:
Result = 1;
break;
}
-
+
// If we evaluated the result, return it now.
- if (Result != -1) {
- if (const VectorType *VT = dyn_cast<VectorType>(C1->getType())) {
- if (Result == 0)
- return Constant::getNullValue(VectorType::getInteger(VT));
- else
- return Constant::getAllOnesValue(VectorType::getInteger(VT));
- }
- return ConstantInt::get(Type::Int1Ty, Result);
- }
-
+ if (Result != -1)
+ return ConstantInt::get(ResultTy, Result);
+
} else {
// Evaluate the relation between the two constants, per the predicate.
int Result = -1; // -1 = unknown, 0 = known false, 1 = known true.
switch (evaluateICmpRelation(C1, C2, CmpInst::isSigned(pred))) {
- default: assert(0 && "Unknown relational!");
+ default: llvm_unreachable("Unknown relational!");
case ICmpInst::BAD_ICMP_PREDICATE:
break; // Couldn't determine anything about these constants.
case ICmpInst::ICMP_EQ: // We know the constants are equal!
// If we know the constants are equal, we can decide the result of this
// computation precisely.
- Result = (pred == ICmpInst::ICMP_EQ ||
- pred == ICmpInst::ICMP_ULE ||
- pred == ICmpInst::ICMP_SLE ||
- pred == ICmpInst::ICMP_UGE ||
- pred == ICmpInst::ICMP_SGE);
+ Result = ICmpInst::isTrueWhenEqual((ICmpInst::Predicate)pred);
break;
case ICmpInst::ICMP_ULT:
- // If we know that C1 < C2, we can decide the result of this computation
- // precisely.
- Result = (pred == ICmpInst::ICMP_ULT ||
- pred == ICmpInst::ICMP_NE ||
- pred == ICmpInst::ICMP_ULE);
+ switch (pred) {
+ case ICmpInst::ICMP_ULT: case ICmpInst::ICMP_NE: case ICmpInst::ICMP_ULE:
+ Result = 1; break;
+ case ICmpInst::ICMP_UGT: case ICmpInst::ICMP_EQ: case ICmpInst::ICMP_UGE:
+ Result = 0; break;
+ }
break;
case ICmpInst::ICMP_SLT:
- // If we know that C1 < C2, we can decide the result of this computation
- // precisely.
- Result = (pred == ICmpInst::ICMP_SLT ||
- pred == ICmpInst::ICMP_NE ||
- pred == ICmpInst::ICMP_SLE);
+ switch (pred) {
+ case ICmpInst::ICMP_SLT: case ICmpInst::ICMP_NE: case ICmpInst::ICMP_SLE:
+ Result = 1; break;
+ case ICmpInst::ICMP_SGT: case ICmpInst::ICMP_EQ: case ICmpInst::ICMP_SGE:
+ Result = 0; break;
+ }
break;
case ICmpInst::ICMP_UGT:
- // If we know that C1 > C2, we can decide the result of this computation
- // precisely.
- Result = (pred == ICmpInst::ICMP_UGT ||
- pred == ICmpInst::ICMP_NE ||
- pred == ICmpInst::ICMP_UGE);
+ switch (pred) {
+ case ICmpInst::ICMP_UGT: case ICmpInst::ICMP_NE: case ICmpInst::ICMP_UGE:
+ Result = 1; break;
+ case ICmpInst::ICMP_ULT: case ICmpInst::ICMP_EQ: case ICmpInst::ICMP_ULE:
+ Result = 0; break;
+ }
break;
case ICmpInst::ICMP_SGT:
- // If we know that C1 > C2, we can decide the result of this computation
- // precisely.
- Result = (pred == ICmpInst::ICMP_SGT ||
- pred == ICmpInst::ICMP_NE ||
- pred == ICmpInst::ICMP_SGE);
+ switch (pred) {
+ case ICmpInst::ICMP_SGT: case ICmpInst::ICMP_NE: case ICmpInst::ICMP_SGE:
+ Result = 1; break;
+ case ICmpInst::ICMP_SLT: case ICmpInst::ICMP_EQ: case ICmpInst::ICMP_SLE:
+ Result = 0; break;
+ }
break;
case ICmpInst::ICMP_ULE:
- // If we know that C1 <= C2, we can only partially decide this relation.
if (pred == ICmpInst::ICMP_UGT) Result = 0;
- if (pred == ICmpInst::ICMP_ULT) Result = 1;
+ if (pred == ICmpInst::ICMP_ULT || pred == ICmpInst::ICMP_ULE) Result = 1;
break;
case ICmpInst::ICMP_SLE:
- // If we know that C1 <= C2, we can only partially decide this relation.
if (pred == ICmpInst::ICMP_SGT) Result = 0;
- if (pred == ICmpInst::ICMP_SLT) Result = 1;
+ if (pred == ICmpInst::ICMP_SLT || pred == ICmpInst::ICMP_SLE) Result = 1;
break;
-
case ICmpInst::ICMP_UGE:
- // If we know that C1 >= C2, we can only partially decide this relation.
if (pred == ICmpInst::ICMP_ULT) Result = 0;
- if (pred == ICmpInst::ICMP_UGT) Result = 1;
+ if (pred == ICmpInst::ICMP_UGT || pred == ICmpInst::ICMP_UGE) Result = 1;
break;
case ICmpInst::ICMP_SGE:
- // If we know that C1 >= C2, we can only partially decide this relation.
if (pred == ICmpInst::ICMP_SLT) Result = 0;
- if (pred == ICmpInst::ICMP_SGT) Result = 1;
+ if (pred == ICmpInst::ICMP_SGT || pred == ICmpInst::ICMP_SGE) Result = 1;
break;
-
case ICmpInst::ICMP_NE:
- // If we know that C1 != C2, we can only partially decide this relation.
if (pred == ICmpInst::ICMP_EQ) Result = 0;
if (pred == ICmpInst::ICMP_NE) Result = 1;
break;
}
-
+
// If we evaluated the result, return it now.
- if (Result != -1) {
- if (const VectorType *VT = dyn_cast<VectorType>(C1->getType())) {
- if (Result == 0)
- return Constant::getNullValue(VT);
- else
- return Constant::getAllOnesValue(VT);
+ if (Result != -1)
+ return ConstantInt::get(ResultTy, Result);
+
+ // If the right hand side is a bitcast, try using its inverse to simplify
+ // it by moving it to the left hand side. We can't do this if it would turn
+ // a vector compare into a scalar compare or visa versa.
+ if (ConstantExpr *CE2 = dyn_cast<ConstantExpr>(C2)) {
+ Constant *CE2Op0 = CE2->getOperand(0);
+ if (CE2->getOpcode() == Instruction::BitCast &&
+ CE2->getType()->isVectorTy()==CE2Op0->getType()->isVectorTy()) {
+ Constant *Inverse = ConstantExpr::getBitCast(C1, CE2Op0->getType());
+ return ConstantExpr::getICmp(pred, Inverse, CE2Op0);
}
- return ConstantInt::get(Type::Int1Ty, Result);
}
-
- if (!isa<ConstantExpr>(C1) && isa<ConstantExpr>(C2)) {
- // If C2 is a constant expr and C1 isn't, flop them around and fold the
+
+ // If the left hand side is an extension, try eliminating it.
+ if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(C1)) {
+ if (CE1->getOpcode() == Instruction::SExt ||
+ CE1->getOpcode() == Instruction::ZExt) {
+ Constant *CE1Op0 = CE1->getOperand(0);
+ Constant *CE1Inverse = ConstantExpr::getTrunc(CE1, CE1Op0->getType());
+ if (CE1Inverse == CE1Op0) {
+ // Check whether we can safely truncate the right hand side.
+ Constant *C2Inverse = ConstantExpr::getTrunc(C2, CE1Op0->getType());
+ if (ConstantExpr::getZExt(C2Inverse, C2->getType()) == C2) {
+ return ConstantExpr::getICmp(pred, CE1Inverse, C2Inverse);
+ }
+ }
+ }
+ }
+
+ if ((!isa<ConstantExpr>(C1) && isa<ConstantExpr>(C2)) ||
+ (C1->isNullValue() && !C2->isNullValue())) {
+ // If C2 is a constant expr and C1 isn't, flip them around and fold the
// other way if possible.
+ // Also, if C1 is null and C2 isn't, flip them around.
switch (pred) {
case ICmpInst::ICMP_EQ:
case ICmpInst::ICMP_NE:
// No change of predicate required.
- return ConstantFoldCompareInstruction(pred, C2, C1);
+ return ConstantExpr::getICmp(pred, C2, C1);
case ICmpInst::ICMP_ULT:
case ICmpInst::ICMP_SLT:
case ICmpInst::ICMP_SGE:
// Change the predicate as necessary to swap the operands.
pred = ICmpInst::getSwappedPredicate((ICmpInst::Predicate)pred);
- return ConstantFoldCompareInstruction(pred, C2, C1);
+ return ConstantExpr::getICmp(pred, C2, C1);
default: // These predicates cannot be flopped around.
break;
return 0;
}
-Constant *llvm::ConstantFoldGetElementPtr(const Constant *C,
+/// isInBoundsIndices - Test whether the given sequence of *normalized* indices
+/// is "inbounds".
+static bool isInBoundsIndices(Constant *const *Idxs, size_t NumIdx) {
+ // No indices means nothing that could be out of bounds.
+ if (NumIdx == 0) return true;
+
+ // If the first index is zero, it's in bounds.
+ if (Idxs[0]->isNullValue()) return true;
+
+ // If the first index is one and all the rest are zero, it's in bounds,
+ // by the one-past-the-end rule.
+ if (!cast<ConstantInt>(Idxs[0])->isOne())
+ return false;
+ for (unsigned i = 1, e = NumIdx; i != e; ++i)
+ if (!Idxs[i]->isNullValue())
+ return false;
+ return true;
+}
+
+Constant *llvm::ConstantFoldGetElementPtr(Constant *C,
+ bool inBounds,
Constant* const *Idxs,
unsigned NumIdx) {
if (NumIdx == 0 ||
(NumIdx == 1 && Idxs[0]->isNullValue()))
- return const_cast<Constant*>(C);
+ return C;
if (isa<UndefValue>(C)) {
const PointerType *Ptr = cast<PointerType>(C->getType());
(Value**)Idxs,
(Value**)Idxs+NumIdx);
assert(Ty != 0 && "Invalid indices for GEP!");
- return
- ConstantPointerNull::get(PointerType::get(Ty,Ptr->getAddressSpace()));
+ return ConstantPointerNull::get(
+ PointerType::get(Ty,Ptr->getAddressSpace()));
}
}
- if (ConstantExpr *CE = dyn_cast<ConstantExpr>(const_cast<Constant*>(C))) {
+ if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
// Combine Indices - If the source pointer to this getelementptr instruction
// is a getelementptr instruction, combine the indices of the two
// getelementptr instructions into a single instruction.
I != E; ++I)
LastTy = *I;
- if ((LastTy && isa<ArrayType>(LastTy)) || Idx0->isNullValue()) {
+ if ((LastTy && LastTy->isArrayTy()) || Idx0->isNullValue()) {
SmallVector<Value*, 16> NewIndices;
NewIndices.reserve(NumIdx + CE->getNumOperands());
for (unsigned i = 1, e = CE->getNumOperands()-1; i != e; ++i)
if (!Idx0->isNullValue()) {
const Type *IdxTy = Combined->getType();
if (IdxTy != Idx0->getType()) {
- Constant *C1 = ConstantExpr::getSExtOrBitCast(Idx0, Type::Int64Ty);
- Constant *C2 = ConstantExpr::getSExtOrBitCast(Combined,
- Type::Int64Ty);
+ const Type *Int64Ty = Type::getInt64Ty(IdxTy->getContext());
+ Constant *C1 = ConstantExpr::getSExtOrBitCast(Idx0, Int64Ty);
+ Constant *C2 = ConstantExpr::getSExtOrBitCast(Combined, Int64Ty);
Combined = ConstantExpr::get(Instruction::Add, C1, C2);
} else {
Combined =
NewIndices.push_back(Combined);
NewIndices.insert(NewIndices.end(), Idxs+1, Idxs+NumIdx);
- return ConstantExpr::getGetElementPtr(CE->getOperand(0), &NewIndices[0],
- NewIndices.size());
+ return (inBounds && cast<GEPOperator>(CE)->isInBounds()) ?
+ ConstantExpr::getInBoundsGetElementPtr(CE->getOperand(0),
+ &NewIndices[0],
+ NewIndices.size()) :
+ ConstantExpr::getGetElementPtr(CE->getOperand(0),
+ &NewIndices[0],
+ NewIndices.size());
}
}
// Implement folding of:
- // int* getelementptr ([2 x int]* cast ([3 x int]* %X to [2 x int]*),
+ // int* getelementptr ([2 x int]* bitcast ([3 x int]* %X to [2 x int]*),
// long 0, long 0)
// To: int* getelementptr ([3 x int]* %X, long 0, long 0)
//
if (const ArrayType *CAT =
dyn_cast<ArrayType>(cast<PointerType>(C->getType())->getElementType()))
if (CAT->getElementType() == SAT->getElementType())
- return ConstantExpr::getGetElementPtr(
+ return inBounds ?
+ ConstantExpr::getInBoundsGetElementPtr(
+ (Constant*)CE->getOperand(0), Idxs, NumIdx) :
+ ConstantExpr::getGetElementPtr(
(Constant*)CE->getOperand(0), Idxs, NumIdx);
}
-
- // Fold: getelementptr (i8* inttoptr (i64 1 to i8*), i32 -1)
- // Into: inttoptr (i64 0 to i8*)
- // This happens with pointers to member functions in C++.
- if (CE->getOpcode() == Instruction::IntToPtr && NumIdx == 1 &&
- isa<ConstantInt>(CE->getOperand(0)) && isa<ConstantInt>(Idxs[0]) &&
- cast<PointerType>(CE->getType())->getElementType() == Type::Int8Ty) {
- Constant *Base = CE->getOperand(0);
- Constant *Offset = Idxs[0];
-
- // Convert the smaller integer to the larger type.
- if (Offset->getType()->getPrimitiveSizeInBits() <
- Base->getType()->getPrimitiveSizeInBits())
- Offset = ConstantExpr::getSExt(Offset, Base->getType());
- else if (Base->getType()->getPrimitiveSizeInBits() <
- Offset->getType()->getPrimitiveSizeInBits())
- Base = ConstantExpr::getZExt(Base, Base->getType());
-
- Base = ConstantExpr::getAdd(Base, Offset);
- return ConstantExpr::getIntToPtr(Base, CE->getType());
+ }
+
+ // Check to see if any array indices are not within the corresponding
+ // notional array bounds. If so, try to determine if they can be factored
+ // out into preceding dimensions.
+ bool Unknown = false;
+ SmallVector<Constant *, 8> NewIdxs;
+ const Type *Ty = C->getType();
+ const Type *Prev = 0;
+ for (unsigned i = 0; i != NumIdx;
+ Prev = Ty, Ty = cast<CompositeType>(Ty)->getTypeAtIndex(Idxs[i]), ++i) {
+ if (ConstantInt *CI = dyn_cast<ConstantInt>(Idxs[i])) {
+ if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty))
+ if (ATy->getNumElements() <= INT64_MAX &&
+ ATy->getNumElements() != 0 &&
+ CI->getSExtValue() >= (int64_t)ATy->getNumElements()) {
+ if (isa<SequentialType>(Prev)) {
+ // It's out of range, but we can factor it into the prior
+ // dimension.
+ NewIdxs.resize(NumIdx);
+ ConstantInt *Factor = ConstantInt::get(CI->getType(),
+ ATy->getNumElements());
+ NewIdxs[i] = ConstantExpr::getSRem(CI, Factor);
+
+ Constant *PrevIdx = Idxs[i-1];
+ Constant *Div = ConstantExpr::getSDiv(CI, Factor);
+
+ // Before adding, extend both operands to i64 to avoid
+ // overflow trouble.
+ if (!PrevIdx->getType()->isIntegerTy(64))
+ PrevIdx = ConstantExpr::getSExt(PrevIdx,
+ Type::getInt64Ty(Div->getContext()));
+ if (!Div->getType()->isIntegerTy(64))
+ Div = ConstantExpr::getSExt(Div,
+ Type::getInt64Ty(Div->getContext()));
+
+ NewIdxs[i-1] = ConstantExpr::getAdd(PrevIdx, Div);
+ } else {
+ // It's out of range, but the prior dimension is a struct
+ // so we can't do anything about it.
+ Unknown = true;
+ }
+ }
+ } else {
+ // We don't know if it's in range or not.
+ Unknown = true;
}
}
+
+ // If we did any factoring, start over with the adjusted indices.
+ if (!NewIdxs.empty()) {
+ for (unsigned i = 0; i != NumIdx; ++i)
+ if (!NewIdxs[i]) NewIdxs[i] = Idxs[i];
+ return inBounds ?
+ ConstantExpr::getInBoundsGetElementPtr(C, NewIdxs.data(),
+ NewIdxs.size()) :
+ ConstantExpr::getGetElementPtr(C, NewIdxs.data(), NewIdxs.size());
+ }
+
+ // If all indices are known integers and normalized, we can do a simple
+ // check for the "inbounds" property.
+ if (!Unknown && !inBounds &&
+ isa<GlobalVariable>(C) && isInBoundsIndices(Idxs, NumIdx))
+ return ConstantExpr::getInBoundsGetElementPtr(C, Idxs, NumIdx);
+
return 0;
}
-