//
// The LLVM Compiler Infrastructure
//
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// 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/LLVMContext.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"
// ConstantFold*Instruction Implementations
//===----------------------------------------------------------------------===//
-/// CastConstantVector - Convert the specified ConstantVector node to the
+/// BitCastConstantVector - Convert the specified ConstantVector node to the
/// specified vector type. At this point, we know that the elements of the
/// input vector constant are all simple integer or FP values.
-static Constant *CastConstantVector(ConstantVector *CV,
- const VectorType *DstTy) {
- unsigned SrcNumElts = CV->getType()->getNumElements();
- unsigned DstNumElts = DstTy->getNumElements();
- const Type *SrcEltTy = CV->getType()->getElementType();
- const Type *DstEltTy = DstTy->getElementType();
-
- // If both vectors have the same number of elements (thus, the elements
- // are the same size), perform the conversion now.
- if (SrcNumElts == DstNumElts) {
- std::vector<Constant*> Result;
-
- // If the src and dest elements are both integers, or both floats, we can
- // just BitCast each element because the elements are the same size.
- if ((SrcEltTy->isInteger() && DstEltTy->isInteger()) ||
- (SrcEltTy->isFloatingPoint() && DstEltTy->isFloatingPoint())) {
- for (unsigned i = 0; i != SrcNumElts; ++i)
- Result.push_back(
- ConstantExpr::getBitCast(CV->getOperand(i), DstEltTy));
- return ConstantVector::get(Result);
- }
-
- // If this is an int-to-fp cast ..
- if (SrcEltTy->isInteger()) {
- // Ensure that it is int-to-fp cast
- assert(DstEltTy->isFloatingPoint());
- if (DstEltTy->getTypeID() == Type::DoubleTyID) {
- for (unsigned i = 0; i != SrcNumElts; ++i) {
- ConstantInt *CI = cast<ConstantInt>(CV->getOperand(i));
- double V = CI->getValue().bitsToDouble();
- Result.push_back(ConstantFP::get(Type::DoubleTy, APFloat(V)));
- }
- return ConstantVector::get(Result);
- }
- assert(DstEltTy == Type::FloatTy && "Unknown fp type!");
- for (unsigned i = 0; i != SrcNumElts; ++i) {
- ConstantInt *CI = cast<ConstantInt>(CV->getOperand(i));
- float V = CI->getValue().bitsToFloat();
- Result.push_back(ConstantFP::get(Type::FloatTy, APFloat(V)));
- }
- return ConstantVector::get(Result);
- }
-
- // Otherwise, this is an fp-to-int cast.
- assert(SrcEltTy->isFloatingPoint() && DstEltTy->isInteger());
-
- if (SrcEltTy->getTypeID() == Type::DoubleTyID) {
- for (unsigned i = 0; i != SrcNumElts; ++i) {
- uint64_t V = cast<ConstantFP>(CV->getOperand(i))->
- getValueAPF().convertToAPInt().getZExtValue();
- Constant *C = ConstantInt::get(Type::Int64Ty, V);
- Result.push_back(ConstantExpr::getBitCast(C, DstEltTy ));
- }
- return ConstantVector::get(Result);
- }
+static Constant *BitCastConstantVector(LLVMContext &Context, ConstantVector *CV,
+ const VectorType *DstTy) {
+ // If this cast changes element count then we can't handle it here:
+ // doing so requires endianness information. This should be handled by
+ // Analysis/ConstantFolding.cpp
+ unsigned NumElts = DstTy->getNumElements();
+ if (NumElts != CV->getNumOperands())
+ return 0;
- assert(SrcEltTy->getTypeID() == Type::FloatTyID);
- for (unsigned i = 0; i != SrcNumElts; ++i) {
- uint32_t V = (uint32_t)cast<ConstantFP>(CV->getOperand(i))->
- getValueAPF().convertToAPInt().getZExtValue();
- Constant *C = ConstantInt::get(Type::Int32Ty, V);
- Result.push_back(ConstantExpr::getBitCast(C, DstEltTy));
- }
- return ConstantVector::get(Result);
+ // Check to verify that all elements of the input are simple.
+ for (unsigned i = 0; i != NumElts; ++i) {
+ if (!isa<ConstantInt>(CV->getOperand(i)) &&
+ !isa<ConstantFP>(CV->getOperand(i)))
+ return 0;
}
-
- // Otherwise, this is a cast that changes element count and size. Handle
- // casts which shrink the elements here.
-
- // FIXME: We need to know endianness to do this!
-
- return 0;
+
+ // Bitcast each element now.
+ 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));
+ return ConstantVector::get(Result);
}
/// This function determines which opcode to use to fold two constant cast
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()));
}
-Constant *llvm::ConstantFoldCastInstruction(unsigned opc, const Constant *V,
- const Type *DestTy) {
+static Constant *FoldBitCast(LLVMContext &Context,
+ 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;
+ Value *Zero = Constant::getNullValue(Type::getInt32Ty(Context));
+ 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(Zero);
+ } else if (const SequentialType *STy =
+ dyn_cast<SequentialType>(ElTy)) {
+ if (isa<PointerType>(ElTy)) break; // Can't index into pointers!
+ ElTy = STy->getElementType();
+ IdxList.push_back(Zero);
+ } else {
+ break;
+ }
+ }
+
+ if (ElTy == DPTy->getElementType())
+ // 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(Context, 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 (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
+ if (DestTy->isInteger())
+ // 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())
+ return ConstantFP::get(Context, APFloat(CI->getValue(),
+ DestTy != Type::getPPC_FP128Ty(Context)));
+
+ // Otherwise, can't fold this (vector?)
+ return 0;
+ }
+
+ // Handle ConstantFP input.
+ if (ConstantFP *FP = dyn_cast<ConstantFP>(V))
+ // FP -> Integral.
+ return ConstantInt::get(Context, 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(isa<IntegerType>(C->getType()) &&
+ (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");
+
+ // 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;
+ }
+ }
+}
+
+
+Constant *llvm::ConstantFoldCastInstruction(LLVMContext &Context,
+ unsigned opc, Constant *V,
+ const Type *DestTy) {
if (isa<UndefValue>(V)) {
// zext(undef) = 0, because the top bits will be zero.
// sext(undef) = 0, because the top bits will all be the same.
- if (opc == Instruction::ZExt || opc == Instruction::SExt)
+ // [us]itofp(undef) = 0, because the result value is bounded.
+ if (opc == Instruction::ZExt || opc == Instruction::SExt ||
+ opc == Instruction::UIToFP || opc == Instruction::SIToFP)
return Constant::getNullValue(DestTy);
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 (isa<VectorType>(DestTy) &&
+ 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(DestTy, Val);
+ APFloat::rmNearestTiesToEven, &ignored);
+ return ConstantFP::get(Context, 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);
+ return ConstantInt::get(Context, Val);
}
return 0; // Can't fold.
case Instruction::IntToPtr: //always treated as unsigned
return 0; // Other pointer types cannot be casted
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};
- uint32_t BitWidth = cast<IntegerType>(SrcTy)->getBitWidth();
APFloat apf = APFloat(APInt(DestTy->getPrimitiveSizeInBits(),
2, zero));
- (void)apf.convertFromZeroExtendedInteger(api.getRawData(), BitWidth,
- opc==Instruction::SIToFP,
- APFloat::rmNearestTiesToEven);
- return ConstantFP::get(DestTy, apf);
+ (void)apf.convertFromAPInt(api,
+ opc==Instruction::SIToFP,
+ APFloat::rmNearestTiesToEven);
+ return ConstantFP::get(Context, 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(Context, 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(Context, 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(Context, Result);
}
- return 0;
- case Instruction::BitCast:
- if (SrcTy == DestTy)
- return (Constant*)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)) {
- SmallVector<Value*, 8> IdxList;
- IdxList.push_back(Constant::getNullValue(Type::Int32Ty));
- 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));
- } else if (const SequentialType *STy =
- dyn_cast<SequentialType>(ElTy)) {
- if (isa<PointerType>(ElTy)) break; // Can't index into pointers!
- ElTy = STy->getElementType();
- IdxList.push_back(IdxList[0]);
- } else {
- break;
- }
- }
-
- if (ElTy == DPTy->getElementType())
- return ConstantExpr::getGetElementPtr(
- const_cast<Constant*>(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!");
- // First, check for null and undef
- if (isa<ConstantAggregateZero>(V))
- return Constant::getNullValue(DestTy);
- if (isa<UndefValue>(V))
- return UndefValue::get(DestTy);
-
- if (const ConstantVector *CV = dyn_cast<ConstantVector>(V)) {
- // This is a cast from a ConstantVector of one type to a
- // ConstantVector of another type. Check to see if all elements of
- // the input are simple.
- bool AllSimpleConstants = true;
- for (unsigned i = 0, e = CV->getNumOperands(); i != e; ++i) {
- if (!isa<ConstantInt>(CV->getOperand(i)) &&
- !isa<ConstantFP>(CV->getOperand(i))) {
- AllSimpleConstants = false;
- break;
- }
- }
-
- // If all of the elements are simple constants, we can fold this.
- if (AllSimpleConstants)
- return CastConstantVector(const_cast<ConstantVector*>(CV), 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())
- // Integral -> Integral. This is a no-op because the bit widths must
- // be the same. Consequently, we just fold to V.
- return const_cast<Constant*>(V);
-
- if (DestTy->isFloatingPoint()) {
- assert((DestTy == Type::DoubleTy || DestTy == Type::FloatTy) &&
- "Unknown FP type!");
- return ConstantFP::get(DestTy, APFloat(CI->getValue()));
- }
- // Otherwise, can't fold this (vector?)
- return 0;
- }
+ // 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;
- // 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());
- }
- }
return 0;
- default:
- assert(!"Invalid CE CastInst opcode");
- break;
}
-
- assert(0 && "Failed to cast constant expression");
- return 0;
+ case Instruction::BitCast:
+ return FoldBitCast(Context, V, DestTy);
+ }
}
-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(LLVMContext&,
+ 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(LLVMContext &Context,
+ 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)) {
- return const_cast<Constant*>(CVal->getOperand(CIdx->getZExtValue()));
+
+ 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 const_cast<Constant*>(CVal->getOperand(0));
+ return CVal->getOperand(0);
}
}
return 0;
}
-Constant *llvm::ConstantFoldInsertElementInstruction(const Constant *Val,
- const Constant *Elt,
- const Constant *Idx) {
- const ConstantInt *CIdx = dyn_cast<ConstantInt>(Idx);
+Constant *llvm::ConstantFoldInsertElementInstruction(LLVMContext &Context,
+ 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);
}
+
return 0;
}
-Constant *llvm::ConstantFoldShuffleVectorInstruction(const Constant *V1,
- const Constant *V2,
- const Constant *Mask) {
- // TODO:
+/// GetVectorElement - If C is a ConstantVector, ConstantAggregateZero or Undef
+/// return the specified element value. Otherwise return null.
+static Constant *GetVectorElement(LLVMContext &Context, 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);
+ if (isa<UndefValue>(C))
+ return UndefValue::get(EltTy);
return 0;
}
-/// EvalVectorOp - Given two vector constants and a function pointer, apply the
-/// function pointer to each element pair, producing a new ConstantVector
-/// constant.
-static Constant *EvalVectorOp(const ConstantVector *V1,
- const ConstantVector *V2,
- Constant *(*FP)(Constant*, Constant*)) {
- std::vector<Constant*> Res;
- for (unsigned i = 0, e = V1->getNumOperands(); i != e; ++i)
- Res.push_back(FP(const_cast<Constant*>(V1->getOperand(i)),
- const_cast<Constant*>(V2->getOperand(i))));
- return ConstantVector::get(Res);
+Constant *llvm::ConstantFoldShuffleVectorInstruction(LLVMContext &Context,
+ Constant *V1,
+ Constant *V2,
+ Constant *Mask) {
+ // Undefined shuffle mask -> undefined value.
+ if (isa<UndefValue>(Mask)) return UndefValue::get(V1->getType());
+
+ 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 != MaskNumElts; ++i) {
+ Constant *InElt = GetVectorElement(Context, 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 >= SrcNumElts*2)
+ InElt = UndefValue::get(EltTy);
+ else if (Elt >= SrcNumElts)
+ InElt = GetVectorElement(Context, V2, Elt - SrcNumElts);
+ else
+ InElt = GetVectorElement(Context, V1, Elt);
+ if (InElt == 0) return 0;
+ } else {
+ // Unknown value.
+ return 0;
+ }
+ Result.push_back(InElt);
+ }
+
+ return ConstantVector::get(&Result[0], Result.size());
+}
+
+Constant *llvm::ConstantFoldExtractValueInstruction(LLVMContext &Context,
+ Constant *Agg,
+ const unsigned *Idxs,
+ unsigned NumIdx) {
+ // Base case: no indices, so return the entire value.
+ if (NumIdx == 0)
+ return Agg;
+
+ if (isa<UndefValue>(Agg)) // ev(undef, x) -> undef
+ return UndefValue::get(ExtractValueInst::getIndexedType(Agg->getType(),
+ Idxs,
+ Idxs + NumIdx));
+
+ if (isa<ConstantAggregateZero>(Agg)) // ev(0, x) -> 0
+ return
+ Constant::getNullValue(ExtractValueInst::getIndexedType(Agg->getType(),
+ Idxs,
+ Idxs + NumIdx));
+
+ // Otherwise recurse.
+ if (ConstantStruct *CS = dyn_cast<ConstantStruct>(Agg))
+ return ConstantFoldExtractValueInstruction(Context, CS->getOperand(*Idxs),
+ Idxs+1, NumIdx-1);
+
+ if (ConstantArray *CA = dyn_cast<ConstantArray>(Agg))
+ return ConstantFoldExtractValueInstruction(Context, CA->getOperand(*Idxs),
+ Idxs+1, NumIdx-1);
+ ConstantVector *CV = cast<ConstantVector>(Agg);
+ return ConstantFoldExtractValueInstruction(Context, CV->getOperand(*Idxs),
+ Idxs+1, NumIdx-1);
}
-Constant *llvm::ConstantFoldBinaryInstruction(unsigned Opcode,
- const Constant *C1,
- const Constant *C2) {
+Constant *llvm::ConstantFoldInsertValueInstruction(LLVMContext &Context,
+ Constant *Agg,
+ Constant *Val,
+ const unsigned *Idxs,
+ unsigned NumIdx) {
+ // Base case: no indices, so replace the entire value.
+ if (NumIdx == 0)
+ return Val;
+
+ if (isa<UndefValue>(Agg)) {
+ // Insertion of constant into aggregate undef
+ // Optimize away insertion of undef.
+ if (isa<UndefValue>(Val))
+ return Agg;
+
+ // Otherwise break the aggregate undef into multiple undefs and do
+ // 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);
+ Constant *Op =
+ (*Idxs == i) ?
+ ConstantFoldInsertValueInstruction(Context, UndefValue::get(MemberTy),
+ Val, Idxs+1, NumIdx-1) :
+ UndefValue::get(MemberTy);
+ Ops[i] = Op;
+ }
+
+ if (const StructType* ST = dyn_cast<StructType>(AggTy))
+ return ConstantStruct::get(Context, Ops, ST->isPacked());
+ return ConstantArray::get(cast<ArrayType>(AggTy), Ops);
+ }
+
+ if (isa<ConstantAggregateZero>(Agg)) {
+ // Insertion of constant into aggregate zero
+ // Optimize away insertion of zero.
+ if (Val->isNullValue())
+ return Agg;
+
+ // Otherwise break the aggregate zero into multiple zeros and do
+ // 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);
+ Constant *Op =
+ (*Idxs == i) ?
+ ConstantFoldInsertValueInstruction(Context,
+ Constant::getNullValue(MemberTy),
+ Val, Idxs+1, NumIdx-1) :
+ Constant::getNullValue(MemberTy);
+ Ops[i] = Op;
+ }
+
+ if (const StructType* ST = dyn_cast<StructType>(AggTy))
+ return ConstantStruct::get(Context, Ops, ST->isPacked());
+ return ConstantArray::get(cast<ArrayType>(AggTy), Ops);
+ }
+
+ if (isa<ConstantStruct>(Agg) || isa<ConstantArray>(Agg)) {
+ // Insertion of constant into aggregate constant.
+ std::vector<Constant*> Ops(Agg->getNumOperands());
+ for (unsigned i = 0; i < Agg->getNumOperands(); ++i) {
+ Constant *Op = cast<Constant>(Agg->getOperand(i));
+ if (*Idxs == i)
+ Op = ConstantFoldInsertValueInstruction(Context, Op,
+ Val, Idxs+1, NumIdx-1);
+ Ops[i] = Op;
+ }
+
+ if (const StructType* ST = dyn_cast<StructType>(Agg->getType()))
+ return ConstantStruct::get(Context, Ops, ST->isPacked());
+ return ConstantArray::get(cast<ArrayType>(Agg->getType()), Ops);
+ }
+
+ return 0;
+}
+
+
+Constant *llvm::ConstantFoldBinaryInstruction(LLVMContext &Context,
+ unsigned Opcode,
+ 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:
+ if (isa<UndefValue>(C1) && isa<UndefValue>(C2))
+ // Handle undef ^ undef -> 0 special case. This is a common
+ // idiom (misuse).
+ return Constant::getNullValue(C1->getType());
+ // Fallthrough
case Instruction::Add:
case Instruction::Sub:
- case Instruction::Xor:
return UndefValue::get(C1->getType());
case Instruction::Mul:
case Instruction::And:
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());
}
}
- if (const ConstantExpr *CE1 = dyn_cast<ConstantExpr>(C1)) {
- if (isa<ConstantExpr>(C2)) {
- // 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.
- } else {
- // Just implement a couple of simple identities.
- switch (Opcode) {
- case Instruction::Add:
- if (C2->isNullValue()) return const_cast<Constant*>(C1); // X + 0 == X
- break;
- case Instruction::Sub:
- if (C2->isNullValue()) return const_cast<Constant*>(C1); // X - 0 == X
- break;
- case Instruction::Mul:
- if (C2->isNullValue()) return const_cast<Constant*>(C2); // X * 0 == 0
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(C2))
- if (CI->equalsInt(1))
- return const_cast<Constant*>(C1); // X * 1 == X
- break;
- case Instruction::UDiv:
- case Instruction::SDiv:
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(C2))
- if (CI->equalsInt(1))
- return const_cast<Constant*>(C1); // X / 1 == X
- break;
- case Instruction::URem:
- case Instruction::SRem:
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(C2))
- if (CI->equalsInt(1))
- return Constant::getNullValue(CI->getType()); // X % 1 == 0
- break;
- case Instruction::And:
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(C2)) {
- if (CI->isZero()) return const_cast<Constant*>(C2); // X & 0 == 0
- if (CI->isAllOnesValue())
- return const_cast<Constant*>(C1); // X & -1 == X
-
- // (zext i32 to i64) & 4294967295 -> (zext i32 to i64)
- if (CE1->getOpcode() == Instruction::ZExt) {
- APInt PossiblySetBits
- = cast<IntegerType>(CE1->getOperand(0)->getType())->getMask();
- PossiblySetBits.zext(C1->getType()->getPrimitiveSizeInBits());
- if ((PossiblySetBits & CI->getValue()) == PossiblySetBits)
- return const_cast<Constant*>(C1);
- }
- }
- if (CE1->isCast() && isa<GlobalValue>(CE1->getOperand(0))) {
- GlobalValue *CPR = cast<GlobalValue>(CE1->getOperand(0));
-
- // Functions are at least 4-byte aligned. If and'ing the address of a
- // function with a constant < 4, fold it to zero.
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(C2))
- if (CI->getValue().ult(APInt(CI->getType()->getBitWidth(),4)) &&
- isa<Function>(CPR))
- return Constant::getNullValue(CI->getType());
- }
- break;
- case Instruction::Or:
- if (C2->isNullValue()) return const_cast<Constant*>(C1); // X | 0 == X
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(C2))
- if (CI->isAllOnesValue())
- return const_cast<Constant*>(C2); // X | -1 == -1
- break;
- case Instruction::Xor:
- if (C2->isNullValue()) return const_cast<Constant*>(C1); // X ^ 0 == X
- break;
- case Instruction::AShr:
- // ashr (zext C to Ty), C2 -> lshr (zext C, CSA), C2
- if (CE1->getOpcode() == Instruction::ZExt) // Top bits known zero.
- return ConstantExpr::getLShr(const_cast<Constant*>(C1),
- const_cast<Constant*>(C2));
- break;
- }
- }
- } 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.
+ // 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 C1; // X + 0 == X
+ break;
+ case Instruction::Sub:
+ if (CI2->equalsInt(0)) return C1; // X - 0 == X
+ break;
case Instruction::Mul:
+ if (CI2->equalsInt(0)) return C2; // X * 0 == 0
+ if (CI2->equalsInt(1))
+ return C1; // X * 1 == X
+ break;
+ case Instruction::UDiv:
+ case Instruction::SDiv:
+ if (CI2->equalsInt(1))
+ 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 C2; // X & 0 == 0
+ if (CI2->isAllOnesValue())
+ 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();
+ unsigned SrcWidth =
+ CE1->getOperand(0)->getType()->getPrimitiveSizeInBits();
+ APInt PossiblySetBits(APInt::getLowBitsSet(DstWidth, SrcWidth));
+ if ((PossiblySetBits & CI2->getValue()) == PossiblySetBits)
+ 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));
+ APInt BitsNotSet(APInt::getLowBitsSet(DstWidth, SrcWidth));
+
+ // If checking bits we know are clear, return zero.
+ if ((CI2->getValue() & BitsNotSet) == CI2->getValue())
+ return Constant::getNullValue(CI2->getType());
+ }
+ }
+ }
+ break;
case Instruction::Or:
+ if (CI2->equalsInt(0)) return C1; // X | 0 == X
+ if (CI2->isAllOnesValue())
+ return C2; // X | -1 == -1
+ break;
case Instruction::Xor:
- // No change of opcode required.
- return ConstantFoldBinaryInstruction(Opcode, C2, C1);
+ if (CI2->equalsInt(0)) return C1; // X ^ 0 == X
- case Instruction::Shl:
- case Instruction::LShr:
+ 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:
- case Instruction::Sub:
- case Instruction::SDiv:
- case Instruction::UDiv:
- case Instruction::FDiv:
- case Instruction::URem:
- case Instruction::SRem:
- case Instruction::FRem:
- default: // These instructions cannot be flopped around.
- return 0;
+ // ashr (zext C to Ty), C2 -> lshr (zext C, CSA), C2
+ if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(C1))
+ if (CE1->getOpcode() == Instruction::ZExt) // Top bits known zero.
+ return ConstantExpr::getLShr(C1, C2);
+ break;
}
}
- // At this point we know neither constant is an UndefValue nor a ConstantExpr
- // so look at directly computing the value.
- if (const ConstantInt *CI1 = dyn_cast<ConstantInt>(C1)) {
- if (const ConstantInt *CI2 = dyn_cast<ConstantInt>(C2)) {
+ // At this point we know neither constant is an UndefValue.
+ if (ConstantInt *CI1 = dyn_cast<ConstantInt>(C1)) {
+ if (ConstantInt *CI2 = dyn_cast<ConstantInt>(C2)) {
using namespace APIntOps;
- APInt C1V = CI1->getValue();
- APInt C2V = CI2->getValue();
+ const APInt &C1V = CI1->getValue();
+ const APInt &C2V = CI2->getValue();
switch (Opcode) {
default:
break;
case Instruction::Add:
- return ConstantInt::get(C1V + C2V);
+ return ConstantInt::get(Context, C1V + C2V);
case Instruction::Sub:
- return ConstantInt::get(C1V - C2V);
+ return ConstantInt::get(Context, C1V - C2V);
case Instruction::Mul:
- return ConstantInt::get(C1V * C2V);
+ return ConstantInt::get(Context, 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(Context, 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(Context, 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(Context, 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(Context, C1V.srem(C2V));
case Instruction::And:
- return ConstantInt::get(C1V & C2V);
+ return ConstantInt::get(Context, C1V & C2V);
case Instruction::Or:
- return ConstantInt::get(C1V | C2V);
+ return ConstantInt::get(Context, C1V | C2V);
case Instruction::Xor:
- return ConstantInt::get(C1V ^ C2V);
- case Instruction::Shl:
- if (uint32_t shiftAmt = C2V.getZExtValue())
- if (shiftAmt < C1V.getBitWidth())
- return ConstantInt::get(C1V.shl(shiftAmt));
- else
- return UndefValue::get(C1->getType()); // too big shift is undef
- return const_cast<ConstantInt*>(CI1); // Zero shift is identity
- case Instruction::LShr:
- if (uint32_t shiftAmt = C2V.getZExtValue())
- if (shiftAmt < C1V.getBitWidth())
- return ConstantInt::get(C1V.lshr(shiftAmt));
- else
- return UndefValue::get(C1->getType()); // too big shift is undef
- return const_cast<ConstantInt*>(CI1); // Zero shift is identity
- case Instruction::AShr:
- if (uint32_t shiftAmt = C2V.getZExtValue())
- if (shiftAmt < C1V.getBitWidth())
- return ConstantInt::get(C1V.ashr(shiftAmt));
- else
- return UndefValue::get(C1->getType()); // too big shift is undef
- return const_cast<ConstantInt*>(CI1); // Zero shift is identity
+ return ConstantInt::get(Context, C1V ^ C2V);
+ case Instruction::Shl: {
+ uint32_t shiftAmt = C2V.getZExtValue();
+ if (shiftAmt < C1V.getBitWidth())
+ return ConstantInt::get(Context, 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(Context, 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(Context, 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
- bool isDouble = CFP1->getType()==Type::DoubleTy;
switch (Opcode) {
default:
break;
- case Instruction::Add:
+ case Instruction::FAdd:
(void)C3V.add(C2V, APFloat::rmNearestTiesToEven);
- return ConstantFP::get(CFP1->getType(), C3V);
- case Instruction::Sub:
+ return ConstantFP::get(Context, C3V);
+ case Instruction::FSub:
(void)C3V.subtract(C2V, APFloat::rmNearestTiesToEven);
- return ConstantFP::get(CFP1->getType(), C3V);
- case Instruction::Mul:
+ return ConstantFP::get(Context, C3V);
+ case Instruction::FMul:
(void)C3V.multiply(C2V, APFloat::rmNearestTiesToEven);
- return ConstantFP::get(CFP1->getType(), C3V);
+ return ConstantFP::get(Context, C3V);
case Instruction::FDiv:
(void)C3V.divide(C2V, APFloat::rmNearestTiesToEven);
- return ConstantFP::get(CFP1->getType(), C3V);
+ return ConstantFP::get(Context, C3V);
case Instruction::FRem:
- if (C2V.isZero())
- // IEEE 754, Section 7.1, #5
- return ConstantFP::get(CFP1->getType(), isDouble ?
- APFloat(std::numeric_limits<double>::quiet_NaN()) :
- APFloat(std::numeric_limits<float>::quiet_NaN()));
(void)C3V.mod(C2V, APFloat::rmNearestTiesToEven);
- return ConstantFP::get(CFP1->getType(), C3V);
+ return ConstantFP::get(Context, C3V);
}
}
- } else if (const ConstantVector *CP1 = dyn_cast<ConstantVector>(C1)) {
- if (const ConstantVector *CP2 = dyn_cast<ConstantVector>(C2)) {
+ } else if (const VectorType *VTy = dyn_cast<VectorType>(C1->getType())) {
+ 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, ConstantExpr::getAdd);
- case Instruction::Sub:
- return EvalVectorOp(CP1, CP2, ConstantExpr::getSub);
- case Instruction::Mul:
- return EvalVectorOp(CP1, CP2, ConstantExpr::getMul);
- case Instruction::UDiv:
- return EvalVectorOp(CP1, CP2, ConstantExpr::getUDiv);
- case Instruction::SDiv:
- return EvalVectorOp(CP1, CP2, ConstantExpr::getSDiv);
- case Instruction::FDiv:
- return EvalVectorOp(CP1, CP2, ConstantExpr::getFDiv);
- case Instruction::URem:
- return EvalVectorOp(CP1, CP2, ConstantExpr::getURem);
- case Instruction::SRem:
- return EvalVectorOp(CP1, CP2, ConstantExpr::getSRem);
- case Instruction::FRem:
- return EvalVectorOp(CP1, CP2, ConstantExpr::getFRem);
- case Instruction::And:
- return EvalVectorOp(CP1, CP2, ConstantExpr::getAnd);
- case Instruction::Or:
- return EvalVectorOp(CP1, CP2, ConstantExpr::getOr);
- case Instruction::Xor:
- return EvalVectorOp(CP1, CP2, ConstantExpr::getXor);
+ default:
+ break;
+ 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:
+ 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:
+ 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:
+ 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:
+ 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:
+ 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:
+ 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:
+ 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);
}
}
}
- // We don't know how to fold this
+ if (isa<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.
+ } 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.
+ switch (Opcode) {
+ case Instruction::Add:
+ case Instruction::FAdd:
+ case Instruction::Mul:
+ case Instruction::FMul:
+ case Instruction::And:
+ case Instruction::Or:
+ case Instruction::Xor:
+ // No change of opcode required.
+ return ConstantFoldBinaryInstruction(Context, Opcode, C2, C1);
+
+ case Instruction::Shl:
+ case Instruction::LShr:
+ case Instruction::AShr:
+ case Instruction::Sub:
+ case Instruction::FSub:
+ case Instruction::SDiv:
+ case Instruction::UDiv:
+ case Instruction::FDiv:
+ case Instruction::URem:
+ case Instruction::SRem:
+ case Instruction::FRem:
+ default: // These instructions cannot be flopped around.
+ break;
+ }
+ }
+
+ // i1 can be simplified in many cases.
+ if (C1->getType()->isInteger(1)) {
+ switch (Opcode) {
+ case Instruction::Add:
+ case Instruction::Sub:
+ return ConstantExpr::getXor(C1, C2);
+ case Instruction::Mul:
+ return ConstantExpr::getAnd(C1, C2);
+ case Instruction::Shl:
+ case Instruction::LShr:
+ case Instruction::AShr:
+ // 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:
+ // 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:
+ // We can assume that C2 == 1. If it were zero the result would be
+ // undefined through division by zero.
+ return ConstantInt::getFalse(Context);
+ default:
+ break;
+ }
+ }
+
+ // We don't know how to fold this.
return 0;
}
/// 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(LLVMContext &Context, 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()->isInteger(64))
+ C1 = ConstantExpr::getSExt(C1, Type::getInt64Ty(Context));
- if (C2->getType() != Type::Int64Ty)
- C2 = ConstantExpr::getSExt(C2, Type::Int64Ty);
+ if (!C2->getType()->isInteger(64))
+ C2 = ConstantExpr::getSExt(C2, Type::getInt64Ty(Context));
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(LLVMContext &Context,
+ 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);
+ FCmpInst::Predicate SwappedRelation = evaluateFCmpRelation(Context, V2, V1);
if (SwappedRelation != FCmpInst::BAD_FCMP_PREDICATE)
return FCmpInst::getSwappedPredicate(SwappedRelation);
} 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(LLVMContext &Context,
+ Constant *V1,
+ Constant *V2,
bool isSigned) {
assert(V1->getType() == V2->getType() &&
"Cannot compare different types of values!");
// 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);
+ evaluateICmpRelation(Context, V2, V1, isSigned);
if (SwappedRelation != ICmpInst::BAD_ICMP_PREDICATE)
return ICmpInst::getSwappedPredicate(SwappedRelation);
} else if (const GlobalValue *CPR1 = dyn_cast<GlobalValue>(V1)) {
if (isa<ConstantExpr>(V2)) { // Swap as necessary.
ICmpInst::Predicate SwappedRelation =
- evaluateICmpRelation(V2, V1, isSigned);
+ evaluateICmpRelation(Context, V2, V1, isSigned);
if (SwappedRelation != ICmpInst::BAD_ICMP_PREDICATE)
return ICmpInst::getSwappedPredicate(SwappedRelation);
else
} 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 *CE1 = cast<ConstantExpr>(V1);
+ Constant *CE1Op0 = CE1->getOperand(0);
switch (CE1->getOpcode()) {
case Instruction::Trunc:
case Instruction::UIToFP:
case Instruction::SIToFP:
- case Instruction::IntToPtr:
case Instruction::BitCast:
case Instruction::ZExt:
case Instruction::SExt:
- case Instruction::PtrToInt:
// 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 = CE1->getOpcode() == Instruction::ZExt ? false :
- (CE1->getOpcode() == Instruction::SExt ? true :
- (CE1->getOpcode() == Instruction::PtrToInt ? false : isSigned));
- return evaluateICmpRelation(
- CE1Op0, Constant::getNullValue(CE1Op0->getType()), sgnd);
+ if (CE1->getOpcode() == Instruction::ZExt) isSigned = false;
+ if (CE1->getOpcode() == Instruction::SExt) isSigned = true;
+ return evaluateICmpRelation(Context, CE1Op0,
+ Constant::getNullValue(CE1Op0->getType()),
+ 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 = CE1->getOpcode() == Instruction::ZExt ? false :
- (CE1->getOpcode() == Instruction::SExt ? true :
- (CE1->getOpcode() == Instruction::PtrToInt ? false : isSigned));
- 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.
}
}
} 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(Context, 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;
// Ok, we ran out of things they have in common. If any leftovers
// are non-zero then we have a difference, otherwise we are equal.
for (; i < CE1->getNumOperands(); ++i)
- if (!CE1->getOperand(i)->isNullValue())
+ if (!CE1->getOperand(i)->isNullValue()) {
if (isa<ConstantInt>(CE1->getOperand(i)))
return isSigned ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT;
else
return ICmpInst::BAD_ICMP_PREDICATE; // Might be equal.
+ }
for (; i < CE2->getNumOperands(); ++i)
- if (!CE2->getOperand(i)->isNullValue())
+ if (!CE2->getOperand(i)->isNullValue()) {
if (isa<ConstantInt>(CE2->getOperand(i)))
return isSigned ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT;
else
return ICmpInst::BAD_ICMP_PREDICATE; // Might be equal.
+ }
return ICmpInst::ICMP_EQ;
}
}
return ICmpInst::BAD_ICMP_PREDICATE;
}
-Constant *llvm::ConstantFoldCompareInstruction(unsigned short pred,
- const Constant *C1,
- const Constant *C2) {
+Constant *llvm::ConstantFoldCompareInstruction(LLVMContext &Context,
+ unsigned short pred,
+ Constant *C1, Constant *C2) {
+ const Type *ResultTy;
+ if (const VectorType *VT = dyn_cast<VectorType>(C1->getType()))
+ ResultTy = VectorType::get(Type::getInt1Ty(Context), VT->getNumElements());
+ else
+ ResultTy = Type::getInt1Ty(Context);
+
+ // Fold FCMP_FALSE/FCMP_TRUE unconditionally.
+ 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))
- return UndefValue::get(Type::Int1Ty);
+ 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
if (C1->isNullValue()) {
if (const GlobalValue *GV = dyn_cast<GlobalValue>(C2))
// Don't try to evaluate aliases. External weak GV can be null.
- if (!isa<GlobalAlias>(GV) && !GV->hasExternalWeakLinkage())
+ if (!isa<GlobalAlias>(GV) && !GV->hasExternalWeakLinkage()) {
if (pred == ICmpInst::ICMP_EQ)
- return ConstantInt::getFalse();
+ return ConstantInt::getFalse(Context);
else if (pred == ICmpInst::ICMP_NE)
- return ConstantInt::getTrue();
+ return ConstantInt::getTrue(Context);
+ }
// icmp eq/ne(GV,null) -> false/true
} else if (C2->isNullValue()) {
if (const GlobalValue *GV = dyn_cast<GlobalValue>(C1))
// Don't try to evaluate aliases. External weak GV can be null.
- if (!isa<GlobalAlias>(GV) && !GV->hasExternalWeakLinkage())
+ if (!isa<GlobalAlias>(GV) && !GV->hasExternalWeakLinkage()) {
if (pred == ICmpInst::ICMP_EQ)
- return ConstantInt::getFalse();
+ return ConstantInt::getFalse(Context);
else if (pred == ICmpInst::ICMP_NE)
- return ConstantInt::getTrue();
+ return ConstantInt::getTrue(Context);
+ }
+ }
+
+ // If the comparison is a comparison between two i1's, simplify it.
+ if (C1->getType()->isInteger(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(Type::getInt1Ty(Context), V1 == V2);
+ case ICmpInst::ICMP_NE:
+ return ConstantInt::get(Type::getInt1Ty(Context), V1 != V2);
+ case ICmpInst::ICMP_SLT:
+ return ConstantInt::get(Type::getInt1Ty(Context), V1.slt(V2));
+ case ICmpInst::ICMP_SGT:
+ return ConstantInt::get(Type::getInt1Ty(Context), V1.sgt(V2));
+ case ICmpInst::ICMP_SLE:
+ return ConstantInt::get(Type::getInt1Ty(Context), V1.sle(V2));
+ case ICmpInst::ICMP_SGE:
+ return ConstantInt::get(Type::getInt1Ty(Context), V1.sge(V2));
+ case ICmpInst::ICMP_ULT:
+ return ConstantInt::get(Type::getInt1Ty(Context), V1.ult(V2));
+ case ICmpInst::ICMP_UGT:
+ return ConstantInt::get(Type::getInt1Ty(Context), V1.ugt(V2));
+ case ICmpInst::ICMP_ULE:
+ return ConstantInt::get(Type::getInt1Ty(Context), V1.ule(V2));
+ case ICmpInst::ICMP_UGE:
+ return ConstantInt::get(Type::getInt1Ty(Context), 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 ConstantInt::getFalse(Context);
+ case FCmpInst::FCMP_TRUE: return ConstantInt::getTrue(Context);
case FCmpInst::FCMP_UNO:
- return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpUnordered);
+ return ConstantInt::get(Type::getInt1Ty(Context), R==APFloat::cmpUnordered);
case FCmpInst::FCMP_ORD:
- return ConstantInt::get(Type::Int1Ty, R!=APFloat::cmpUnordered);
+ return ConstantInt::get(Type::getInt1Ty(Context), R!=APFloat::cmpUnordered);
case FCmpInst::FCMP_UEQ:
- return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpUnordered ||
+ return ConstantInt::get(Type::getInt1Ty(Context), R==APFloat::cmpUnordered ||
R==APFloat::cmpEqual);
case FCmpInst::FCMP_OEQ:
- return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpEqual);
+ return ConstantInt::get(Type::getInt1Ty(Context), R==APFloat::cmpEqual);
case FCmpInst::FCMP_UNE:
- return ConstantInt::get(Type::Int1Ty, R!=APFloat::cmpEqual);
+ return ConstantInt::get(Type::getInt1Ty(Context), R!=APFloat::cmpEqual);
case FCmpInst::FCMP_ONE:
- return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpLessThan ||
+ return ConstantInt::get(Type::getInt1Ty(Context), R==APFloat::cmpLessThan ||
R==APFloat::cmpGreaterThan);
case FCmpInst::FCMP_ULT:
- return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpUnordered ||
+ return ConstantInt::get(Type::getInt1Ty(Context), R==APFloat::cmpUnordered ||
R==APFloat::cmpLessThan);
case FCmpInst::FCMP_OLT:
- return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpLessThan);
+ return ConstantInt::get(Type::getInt1Ty(Context), R==APFloat::cmpLessThan);
case FCmpInst::FCMP_UGT:
- return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpUnordered ||
+ return ConstantInt::get(Type::getInt1Ty(Context), R==APFloat::cmpUnordered ||
R==APFloat::cmpGreaterThan);
case FCmpInst::FCMP_OGT:
- return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpGreaterThan);
+ return ConstantInt::get(Type::getInt1Ty(Context), R==APFloat::cmpGreaterThan);
case FCmpInst::FCMP_ULE:
- return ConstantInt::get(Type::Int1Ty, R!=APFloat::cmpGreaterThan);
+ return ConstantInt::get(Type::getInt1Ty(Context), R!=APFloat::cmpGreaterThan);
case FCmpInst::FCMP_OLE:
- return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpLessThan ||
+ return ConstantInt::get(Type::getInt1Ty(Context), R==APFloat::cmpLessThan ||
R==APFloat::cmpEqual);
case FCmpInst::FCMP_UGE:
- return ConstantInt::get(Type::Int1Ty, R!=APFloat::cmpLessThan);
+ return ConstantInt::get(Type::getInt1Ty(Context), R!=APFloat::cmpLessThan);
case FCmpInst::FCMP_OGE:
- return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpGreaterThan ||
+ return ConstantInt::get(Type::getInt1Ty(Context), R==APFloat::cmpGreaterThan ||
R==APFloat::cmpEqual);
}
- } else if (const ConstantVector *CP1 = dyn_cast<ConstantVector>(C1)) {
- if (const ConstantVector *CP2 = dyn_cast<ConstantVector>(C2)) {
- if (pred == FCmpInst::FCMP_OEQ || pred == FCmpInst::FCMP_UEQ) {
- for (unsigned i = 0, e = CP1->getNumOperands(); i != e; ++i) {
- Constant *C= ConstantExpr::getFCmp(FCmpInst::FCMP_OEQ,
- const_cast<Constant*>(CP1->getOperand(i)),
- const_cast<Constant*>(CP2->getOperand(i)));
- if (ConstantInt *CB = dyn_cast<ConstantInt>(C))
- return CB;
- }
- // Otherwise, could not decide from any element pairs.
- return 0;
- } else if (pred == ICmpInst::ICMP_EQ) {
- for (unsigned i = 0, e = CP1->getNumOperands(); i != e; ++i) {
- Constant *C = ConstantExpr::getICmp(ICmpInst::ICMP_EQ,
- const_cast<Constant*>(CP1->getOperand(i)),
- const_cast<Constant*>(CP2->getOperand(i)));
- if (ConstantInt *CB = dyn_cast<ConstantInt>(C))
- return CB;
- }
- // Otherwise, could not decide from any element pairs.
- return 0;
- }
+ } else if (isa<VectorType>(C1->getType())) {
+ SmallVector<Constant*, 16> C1Elts, C2Elts;
+ C1->getVectorElements(Context, C1Elts);
+ C2->getVectorElements(Context, C2Elts);
+
+ // 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()) {
- switch (evaluateFCmpRelation(C1, C2)) {
- default: assert(0 && "Unknown relation!");
+ int Result = -1; // -1 = unknown, 0 = known false, 1 = known true.
+ switch (evaluateFCmpRelation(Context, C1, C2)) {
+ default: llvm_unreachable("Unknown relation!");
case FCmpInst::FCMP_UNO:
case FCmpInst::FCMP_ORD:
case FCmpInst::FCMP_UEQ:
case FCmpInst::BAD_FCMP_PREDICATE:
break; // Couldn't determine anything about these constants.
case FCmpInst::FCMP_OEQ: // We know that C1 == C2
- return ConstantInt::get(Type::Int1Ty,
- pred == FCmpInst::FCMP_UEQ || pred == FCmpInst::FCMP_OEQ ||
- pred == FCmpInst::FCMP_ULE || pred == FCmpInst::FCMP_OLE ||
- pred == FCmpInst::FCMP_UGE || pred == FCmpInst::FCMP_OGE);
+ Result = (pred == FCmpInst::FCMP_UEQ || pred == FCmpInst::FCMP_OEQ ||
+ pred == FCmpInst::FCMP_ULE || pred == FCmpInst::FCMP_OLE ||
+ pred == FCmpInst::FCMP_UGE || pred == FCmpInst::FCMP_OGE);
+ break;
case FCmpInst::FCMP_OLT: // We know that C1 < C2
- return ConstantInt::get(Type::Int1Ty,
- pred == FCmpInst::FCMP_UNE || pred == FCmpInst::FCMP_ONE ||
- pred == FCmpInst::FCMP_ULT || pred == FCmpInst::FCMP_OLT ||
- pred == FCmpInst::FCMP_ULE || pred == FCmpInst::FCMP_OLE);
+ Result = (pred == FCmpInst::FCMP_UNE || pred == FCmpInst::FCMP_ONE ||
+ pred == FCmpInst::FCMP_ULT || pred == FCmpInst::FCMP_OLT ||
+ pred == FCmpInst::FCMP_ULE || pred == FCmpInst::FCMP_OLE);
+ break;
case FCmpInst::FCMP_OGT: // We know that C1 > C2
- return ConstantInt::get(Type::Int1Ty,
- pred == FCmpInst::FCMP_UNE || pred == FCmpInst::FCMP_ONE ||
- pred == FCmpInst::FCMP_UGT || pred == FCmpInst::FCMP_OGT ||
- pred == FCmpInst::FCMP_UGE || pred == FCmpInst::FCMP_OGE);
+ Result = (pred == FCmpInst::FCMP_UNE || pred == FCmpInst::FCMP_ONE ||
+ pred == FCmpInst::FCMP_UGT || pred == FCmpInst::FCMP_OGT ||
+ pred == FCmpInst::FCMP_UGE || pred == FCmpInst::FCMP_OGE);
+ break;
case FCmpInst::FCMP_OLE: // We know that C1 <= C2
// We can only partially decide this relation.
if (pred == FCmpInst::FCMP_UGT || pred == FCmpInst::FCMP_OGT)
- return ConstantInt::getFalse();
- if (pred == FCmpInst::FCMP_ULT || pred == FCmpInst::FCMP_OLT)
- return ConstantInt::getTrue();
+ Result = 0;
+ else if (pred == FCmpInst::FCMP_ULT || pred == FCmpInst::FCMP_OLT)
+ Result = 1;
break;
case FCmpInst::FCMP_OGE: // We known that C1 >= C2
// We can only partially decide this relation.
if (pred == FCmpInst::FCMP_ULT || pred == FCmpInst::FCMP_OLT)
- return ConstantInt::getFalse();
- if (pred == FCmpInst::FCMP_UGT || pred == FCmpInst::FCMP_OGT)
- return ConstantInt::getTrue();
+ Result = 0;
+ else if (pred == FCmpInst::FCMP_UGT || pred == FCmpInst::FCMP_OGT)
+ Result = 1;
break;
case ICmpInst::ICMP_NE: // We know that C1 != C2
// We can only partially decide this relation.
if (pred == FCmpInst::FCMP_OEQ || pred == FCmpInst::FCMP_UEQ)
- return ConstantInt::getFalse();
- if (pred == FCmpInst::FCMP_ONE || pred == FCmpInst::FCMP_UNE)
- return ConstantInt::getTrue();
+ Result = 0;
+ else if (pred == FCmpInst::FCMP_ONE || pred == FCmpInst::FCMP_UNE)
+ Result = 1;
break;
}
+
+ // If we evaluated the result, return it now.
+ if (Result != -1)
+ return ConstantInt::get(Type::getInt1Ty(Context), Result);
+
} else {
// Evaluate the relation between the two constants, per the predicate.
- switch (evaluateICmpRelation(C1, C2, CmpInst::isSigned(pred))) {
- default: assert(0 && "Unknown relational!");
+ int Result = -1; // -1 = unknown, 0 = known false, 1 = known true.
+ switch (evaluateICmpRelation(Context, C1, C2, CmpInst::isSigned(pred))) {
+ 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.
- return ConstantInt::get(Type::Int1Ty,
- 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.
- return ConstantInt::get(Type::Int1Ty,
- 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.
- return ConstantInt::get(Type::Int1Ty,
- 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.
- return ConstantInt::get(Type::Int1Ty,
- 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.
- return ConstantInt::get(Type::Int1Ty,
- 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) return ConstantInt::getFalse();
- if (pred == ICmpInst::ICMP_ULT) return ConstantInt::getTrue();
+ if (pred == ICmpInst::ICMP_UGT) Result = 0;
+ 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) return ConstantInt::getFalse();
- if (pred == ICmpInst::ICMP_SLT) return ConstantInt::getTrue();
+ if (pred == ICmpInst::ICMP_SGT) Result = 0;
+ 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) return ConstantInt::getFalse();
- if (pred == ICmpInst::ICMP_UGT) return ConstantInt::getTrue();
+ if (pred == ICmpInst::ICMP_ULT) Result = 0;
+ 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) return ConstantInt::getFalse();
- if (pred == ICmpInst::ICMP_SGT) return ConstantInt::getTrue();
+ if (pred == ICmpInst::ICMP_SLT) Result = 0;
+ 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) return ConstantInt::getFalse();
- if (pred == ICmpInst::ICMP_NE) return ConstantInt::getTrue();
+ if (pred == ICmpInst::ICMP_EQ) Result = 0;
+ if (pred == ICmpInst::ICMP_NE) Result = 1;
break;
}
- if (!isa<ConstantExpr>(C1) && isa<ConstantExpr>(C2)) {
- // If C2 is a constant expr and C1 isn't, flop them around and fold the
+ // If we evaluated the result, return it now.
+ if (Result != -1)
+ return ConstantInt::get(Type::getInt1Ty(Context), Result);
+
+ // If the right hand side is a bitcast, try using its inverse to simplify
+ // it by moving it to the left hand side.
+ if (ConstantExpr *CE2 = dyn_cast<ConstantExpr>(C2)) {
+ if (CE2->getOpcode() == Instruction::BitCast) {
+ Constant *CE2Op0 = CE2->getOperand(0);
+ Constant *Inverse = ConstantExpr::getBitCast(C1, CE2Op0->getType());
+ return ConstantExpr::getICmp(pred, Inverse, CE2Op0);
+ }
+ }
+
+ // 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(LLVMContext &Context,
+ 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 Type *Ty = GetElementPtrInst::getIndexedType(C->getType(),
+ const PointerType *Ptr = cast<PointerType>(C->getType());
+ const Type *Ty = GetElementPtrInst::getIndexedType(Ptr,
(Value **)Idxs,
- (Value **)Idxs+NumIdx,
- true);
+ (Value **)Idxs+NumIdx);
assert(Ty != 0 && "Invalid indices for GEP!");
- return UndefValue::get(PointerType::get(Ty));
+ return UndefValue::get(PointerType::get(Ty, Ptr->getAddressSpace()));
}
Constant *Idx0 = Idxs[0];
break;
}
if (isNull) {
- const Type *Ty = GetElementPtrInst::getIndexedType(C->getType(),
+ const PointerType *Ptr = cast<PointerType>(C->getType());
+ const Type *Ty = GetElementPtrInst::getIndexedType(Ptr,
(Value**)Idxs,
- (Value**)Idxs+NumIdx,
- true);
+ (Value**)Idxs+NumIdx);
assert(Ty != 0 && "Invalid indices for GEP!");
- return ConstantPointerNull::get(PointerType::get(Ty));
+ 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.
if (!Idx0->isNullValue()) {
const Type *IdxTy = Combined->getType();
if (IdxTy != Idx0->getType()) {
- Constant *C1 = ConstantExpr::getSExtOrBitCast(Idx0, Type::Int64Ty);
+ Constant *C1 =
+ ConstantExpr::getSExtOrBitCast(Idx0, Type::getInt64Ty(Context));
Constant *C2 = ConstantExpr::getSExtOrBitCast(Combined,
- Type::Int64Ty);
+ Type::getInt64Ty(Context));
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());
}
}
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) {
+ cast<PointerType>(CE->getType())->getElementType() ==
+ Type::getInt8Ty(Context)) {
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::getZExt(Base, Offset->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()->isInteger(64))
+ PrevIdx = ConstantExpr::getSExt(PrevIdx,
+ Type::getInt64Ty(Context));
+ if (!Div->getType()->isInteger(64))
+ Div = ConstantExpr::getSExt(Div,
+ Type::getInt64Ty(Context));
+
+ 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;
}
-