-//===- ConstantHandling.cpp - Implement ConstantHandling.h ----------------===//
+//===- ConstantFold.cpp - LLVM constant folder ----------------------------===//
//
-// This file implements the various intrinsic operations, on constant values.
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements folding of constants for LLVM. This implements the
+// (internal) ConstantFold.h interface, which is used by the
+// 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.
//
//===----------------------------------------------------------------------===//
-#include "llvm/ConstantHandling.h"
-#include "llvm/iPHINode.h"
-#include "llvm/InstrTypes.h"
+#include "ConstantFold.h"
+#include "llvm/Constants.h"
+#include "llvm/Instructions.h"
#include "llvm/DerivedTypes.h"
-#include <cmath>
-
-AnnotationID ConstRules::AID(AnnotationManager::getID("opt::ConstRules",
- &ConstRules::find));
-
-// ConstantFoldInstruction - Attempt to constant fold the specified instruction.
-// If successful, the constant result is returned, if not, null is returned.
-//
-Constant *ConstantFoldInstruction(Instruction *I) {
- if (PHINode *PN = dyn_cast<PHINode>(I)) {
- if (PN->getNumIncomingValues() == 0)
- return Constant::getNullValue(PN->getType());
-
- Constant *Result = dyn_cast<Constant>(PN->getIncomingValue(0));
- if (Result == 0) return 0;
+#include "llvm/Function.h"
+#include "llvm/GlobalAlias.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/GetElementPtrTypeIterator.h"
+#include "llvm/Support/ManagedStatic.h"
+#include "llvm/Support/MathExtras.h"
+#include <limits>
+using namespace llvm;
- // Handle PHI nodes specially here...
- for (unsigned i = 1, e = PN->getNumIncomingValues(); i != e; ++i)
- if (PN->getIncomingValue(i) != Result)
- return 0; // Not all the same incoming constants...
+//===----------------------------------------------------------------------===//
+// ConstantFold*Instruction Implementations
+//===----------------------------------------------------------------------===//
- // If we reach here, all incoming values are the same constant.
- return Result;
+/// 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 *BitCastConstantVector(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;
+
+ // 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;
}
- Constant *Op0 = 0;
- Constant *Op1 = 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);
+}
- if (I->getNumOperands() != 0) { // Get first operand if it's a constant...
- Op0 = dyn_cast<Constant>(I->getOperand(0));
- if (Op0 == 0) return 0; // Not a constant?, can't fold
+/// This function determines which opcode to use to fold two constant cast
+/// expressions together. It uses CastInst::isEliminableCastPair to determine
+/// the opcode. Consequently its just a wrapper around that function.
+/// @brief Determine if it is valid to fold a cast of a cast
+static unsigned
+foldConstantCastPair(
+ unsigned opc, ///< opcode of the second cast constant expression
+ const 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();
+ Instruction::CastOps firstOp = Instruction::CastOps(Op->getOpcode());
+ Instruction::CastOps secondOp = Instruction::CastOps(opc);
+
+ // Let CastInst::isEliminableCastPair do the heavy lifting.
+ return CastInst::isEliminableCastPair(firstOp, secondOp, SrcTy, MidTy, DstTy,
+ Type::Int64Ty);
+}
- if (I->getNumOperands() != 1) { // Get second operand if it's a constant...
- Op1 = dyn_cast<Constant>(I->getOperand(1));
- if (Op1 == 0) return 0; // Not a constant?, can't fold
+static Constant *FoldBitCast(Constant *V, const Type *DestTy) {
+ const Type *SrcTy = V->getType();
+ if (SrcTy == DestTy)
+ return V; // no-op cast
+
+ // Check to see if we are casting a pointer to an aggregate to a pointer to
+ // the first element. If so, return the appropriate GEP instruction.
+ if (const PointerType *PTy = dyn_cast<PointerType>(V->getType()))
+ if (const PointerType *DPTy = dyn_cast<PointerType>(DestTy))
+ if (PTy->getAddressSpace() == DPTy->getAddressSpace()) {
+ SmallVector<Value*, 8> IdxList;
+ IdxList.push_back(Constant::getNullValue(Type::Int32Ty));
+ 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(V, &IdxList[0], IdxList.size());
+ }
+
+ // Handle casts from one vector constant to another. We know that the src
+ // and dest type have the same size (otherwise its an illegal cast).
+ if (const VectorType *DestPTy = dyn_cast<VectorType>(DestTy)) {
+ if (const VectorType *SrcTy = dyn_cast<VectorType>(V->getType())) {
+ assert(DestPTy->getBitWidth() == SrcTy->getBitWidth() &&
+ "Not cast between same sized vectors!");
+ SrcTy = NULL;
+ // First, check for null. Undef is already handled.
+ if (isa<ConstantAggregateZero>(V))
+ return Constant::getNullValue(DestTy);
+
+ if (ConstantVector *CV = dyn_cast<ConstantVector>(V))
+ return BitCastConstantVector(CV, DestPTy);
}
- }
- if (isa<BinaryOperator>(I))
- return ConstantExpr::get(I->getOpcode(), Op0, Op1);
-
- switch (I->getOpcode()) {
- case Instruction::Cast:
- return ConstantExpr::getCast(Op0, I->getType());
- case Instruction::Shl:
- case Instruction::Shr:
- return ConstantExpr::getShift(I->getOpcode(), Op0, Op1);
- case Instruction::GetElementPtr: {
- std::vector<Constant*> IdxList;
- IdxList.reserve(I->getNumOperands()-1);
- if (Op1) IdxList.push_back(Op1);
- for (unsigned i = 2, e = I->getNumOperands(); i != e; ++i)
- if (Constant *C = dyn_cast<Constant>(I->getOperand(i)))
- IdxList.push_back(C);
- else
- return 0; // Non-constant operand
- return ConstantExpr::getGetElementPtr(Op0, IdxList);
+ // 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);
}
- default:
+
+ // 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 V;
+
+ if (DestTy->isFloatingPoint())
+ return ConstantFP::get(APFloat(CI->getValue(),
+ DestTy != Type::PPC_FP128Ty));
+
+ // Otherwise, can't fold this (vector?)
return 0;
}
-}
-static unsigned getSize(const Type *Ty) {
- unsigned S = Ty->getPrimitiveSize();
- return S ? S : 8; // Treat pointers at 8 bytes
+ // Handle ConstantFP input.
+ if (const ConstantFP *FP = dyn_cast<ConstantFP>(V))
+ // FP -> Integral.
+ return ConstantInt::get(FP->getValueAPF().bitcastToAPInt());
+
+ return 0;
}
-Constant *ConstantFoldCastInstruction(const Constant *V, const Type *DestTy) {
- if (V->getType() == DestTy) return (Constant*)V;
-
- if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
- if (CE->getOpcode() == Instruction::Cast) {
- Constant *Op = const_cast<Constant*>(CE->getOperand(0));
- // Try to not produce a cast of a cast, which is almost always redundant.
- if (!Op->getType()->isFloatingPoint() &&
- !CE->getType()->isFloatingPoint() &&
- !DestTy->getType()->isFloatingPoint()) {
- unsigned S1 = getSize(Op->getType()), S2 = getSize(CE->getType());
- unsigned S3 = getSize(DestTy);
- if (Op->getType() == DestTy && S3 >= S2)
- return Op;
- if (S1 >= S2 && S2 >= S3)
- return ConstantExpr::getCast(Op, DestTy);
- if (S1 <= S2 && S2 >= S3 && S1 <= S3)
- return ConstantExpr::getCast(Op, DestTy);
- }
+
+Constant *llvm::ConstantFoldCastInstruction(unsigned opc, const 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.
+ // [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)
+ 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 (CE->isCast()) {
+ // Try hard to fold cast of cast because they are often eliminable.
+ if (unsigned newOpc = foldConstantCastPair(opc, CE, DestTy))
+ return ConstantExpr::getCast(newOpc, CE->getOperand(0), DestTy);
+ } else if (CE->getOpcode() == Instruction::GetElementPtr) {
+ // If all of the indexes in the GEP are null values, there is no pointer
+ // adjustment going on. We might as well cast the source pointer.
+ bool isAllNull = true;
+ for (unsigned i = 1, e = CE->getNumOperands(); i != e; ++i)
+ if (!CE->getOperand(i)->isNullValue()) {
+ isAllNull = false;
+ break;
+ }
+ if (isAllNull)
+ // This is casting one pointer type to another, always BitCast
+ return ConstantExpr::getPointerCast(CE->getOperand(0), DestTy);
+ }
+ }
+
+ // We actually have to do a cast now. Perform the cast according to the
+ // opcode specified.
+ switch (opc) {
+ case Instruction::FPTrunc:
+ case Instruction::FPExt:
+ if (const 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 :
+ APFloat::Bogus,
+ APFloat::rmNearestTiesToEven, &ignored);
+ return ConstantFP::get(Val);
+ }
+ return 0; // Can't fold.
+ case Instruction::FPToUI:
+ case Instruction::FPToSI:
+ if (const 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, &ignored);
+ APInt Val(DestBitWidth, 2, x);
+ return ConstantInt::get(Val);
+ }
+ if (const ConstantVector *CV = dyn_cast<ConstantVector>(V)) {
+ std::vector<Constant*> res;
+ const VectorType *DestVecTy = cast<VectorType>(DestTy);
+ const Type *DstEltTy = DestVecTy->getElementType();
+ for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
+ res.push_back(ConstantExpr::getCast(opc, CV->getOperand(i), DstEltTy));
+ return ConstantVector::get(DestVecTy, res);
+ }
+ return 0; // Can't fold.
+ case Instruction::IntToPtr: //always treated as unsigned
+ if (V->isNullValue()) // Is it an integral null value?
+ return ConstantPointerNull::get(cast<PointerType>(DestTy));
+ return 0; // Other pointer types cannot be casted
+ case Instruction::PtrToInt: // always treated as unsigned
+ if (V->isNullValue()) // is it a null pointer value?
+ return ConstantInt::get(DestTy, 0);
+ return 0; // Other pointer types cannot be casted
+ case Instruction::UIToFP:
+ case Instruction::SIToFP:
+ if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
+ APInt api = CI->getValue();
+ const uint64_t zero[] = {0, 0};
+ APFloat apf = APFloat(APInt(DestTy->getPrimitiveSizeInBits(),
+ 2, zero));
+ (void)apf.convertFromAPInt(api,
+ opc==Instruction::SIToFP,
+ APFloat::rmNearestTiesToEven);
+ return ConstantFP::get(apf);
+ }
+ if (const ConstantVector *CV = dyn_cast<ConstantVector>(V)) {
+ std::vector<Constant*> res;
+ const VectorType *DestVecTy = cast<VectorType>(DestTy);
+ const Type *DstEltTy = DestVecTy->getElementType();
+ for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
+ res.push_back(ConstantExpr::getCast(opc, CV->getOperand(i), DstEltTy));
+ return ConstantVector::get(DestVecTy, res);
+ }
+ return 0;
+ case Instruction::ZExt:
+ if (const 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 0;
+ case Instruction::SExt:
+ if (const 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 0;
+ case Instruction::Trunc:
+ if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
+ uint32_t BitWidth = cast<IntegerType>(DestTy)->getBitWidth();
+ APInt Result(CI->getValue());
+ Result.trunc(BitWidth);
+ return ConstantInt::get(Result);
}
+ return 0;
+ case Instruction::BitCast:
+ return FoldBitCast(const_cast<Constant*>(V), DestTy);
+ default:
+ assert(!"Invalid CE CastInst opcode");
+ break;
+ }
- return ConstRules::get(*V, *V)->castTo(V, DestTy);
+ assert(0 && "Failed to cast constant expression");
+ return 0;
}
-Constant *ConstantFoldBinaryInstruction(unsigned Opcode, const Constant *V1,
- const Constant *V2) {
- switch (Opcode) {
- case Instruction::Add: return *V1 + *V2;
- case Instruction::Sub: return *V1 - *V2;
- case Instruction::Mul: return *V1 * *V2;
- case Instruction::Div: return *V1 / *V2;
- case Instruction::Rem: return *V1 % *V2;
- case Instruction::And: return *V1 & *V2;
- case Instruction::Or: return *V1 | *V2;
- case Instruction::Xor: return *V1 ^ *V2;
-
- case Instruction::SetEQ: return *V1 == *V2;
- case Instruction::SetNE: return *V1 != *V2;
- case Instruction::SetLE: return *V1 <= *V2;
- case Instruction::SetGE: return *V1 >= *V2;
- case Instruction::SetLT: return *V1 < *V2;
- case Instruction::SetGT: return *V1 > *V2;
- }
+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);
+
+ 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);
return 0;
}
-Constant *ConstantFoldShiftInstruction(unsigned Opcode, const Constant *V1,
- const Constant *V2) {
- switch (Opcode) {
- case Instruction::Shl: return *V1 << *V2;
- case Instruction::Shr: return *V1 >> *V2;
- default: return 0;
+Constant *llvm::ConstantFoldExtractElementInstruction(const Constant *Val,
+ const 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 CVal->getOperand(CIdx->getZExtValue());
+ } else if (isa<UndefValue>(Idx)) {
+ // ee({w,x,y,z}, undef) -> w (an arbitrary value).
+ return CVal->getOperand(0);
+ }
}
+ return 0;
}
-Constant *ConstantFoldGetElementPtr(const Constant *C,
- const std::vector<Constant*> &IdxList) {
- if (IdxList.size() == 0 ||
- (IdxList.size() == 1 && IdxList[0]->isNullValue()))
- return const_cast<Constant*>(C);
-
- // If C is null and all idx's are null, return null of the right type.
+Constant *llvm::ConstantFoldInsertElementInstruction(const Constant *Val,
+ const Constant *Elt,
+ const Constant *Idx) {
+ const 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);
+ // Otherwise break the aggregate undef into multiple undefs and do
+ // the insertion
+ unsigned numOps =
+ cast<VectorType>(Val->getType())->getNumElements();
+ std::vector<Constant*> Ops;
+ Ops.reserve(numOps);
+ for (unsigned i = 0; i < numOps; ++i) {
+ const Constant *Op =
+ (idxVal == i) ? Elt : UndefValue::get(Elt->getType());
+ Ops.push_back(const_cast<Constant*>(Op));
+ }
+ return ConstantVector::get(Ops);
+ }
+ if (isa<ConstantAggregateZero>(Val)) {
+ // Insertion of scalar constant into vector aggregate zero
+ // Optimize away insertion of zero
+ if (Elt->isNullValue())
+ return const_cast<Constant*>(Val);
+ // Otherwise break the aggregate zero into multiple zeros and do
+ // the insertion
+ unsigned numOps =
+ cast<VectorType>(Val->getType())->getNumElements();
+ std::vector<Constant*> Ops;
+ Ops.reserve(numOps);
+ for (unsigned i = 0; i < numOps; ++i) {
+ const Constant *Op =
+ (idxVal == i) ? Elt : Constant::getNullValue(Elt->getType());
+ Ops.push_back(const_cast<Constant*>(Op));
+ }
+ return ConstantVector::get(Ops);
+ }
+ if (const 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 =
+ (idxVal == i) ? Elt : cast<Constant>(CVal->getOperand(i));
+ Ops.push_back(const_cast<Constant*>(Op));
+ }
+ return ConstantVector::get(Ops);
+ }
- // FIXME: Implement folding of GEP constant exprs the same as instcombine does
+ return 0;
+}
- // Implement folding of:
- // int* getelementptr ([2 x int]* cast ([3 x int]* %X to [2 x int]*),
- // long 0, long 0)
- // To: int* getelementptr ([3 x int]* %X, long 0, long 0)
- //
- if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
- if (CE->getOpcode() == Instruction::Cast && IdxList.size() > 1 &&
- IdxList[0]->isNullValue())
- if (const PointerType *SPT =
- dyn_cast<PointerType>(CE->getOperand(0)->getType()))
- if (const ArrayType *SAT = dyn_cast<ArrayType>(SPT->getElementType()))
- if (const ArrayType *CAT =
- dyn_cast<ArrayType>(cast<PointerType>(C->getType())->getElementType()))
- if (CAT->getElementType() == SAT->getElementType())
- return ConstantExpr::getGetElementPtr(
- (Constant*)CE->getOperand(0), IdxList);
+/// GetVectorElement - If C is a ConstantVector, ConstantAggregateZero or Undef
+/// return the specified element value. Otherwise return null.
+static Constant *GetVectorElement(const Constant *C, unsigned EltNo) {
+ if (const ConstantVector *CV = dyn_cast<ConstantVector>(C))
+ 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;
}
+Constant *llvm::ConstantFoldShuffleVectorInstruction(const Constant *V1,
+ const Constant *V2,
+ const 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(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(V2, Elt - SrcNumElts);
+ else
+ InElt = GetVectorElement(V1, Elt);
+ if (InElt == 0) return 0;
+ } else {
+ // Unknown value.
+ return 0;
+ }
+ Result.push_back(InElt);
+ }
-//===----------------------------------------------------------------------===//
-// TemplateRules Class
-//===----------------------------------------------------------------------===//
-//
-// TemplateRules - Implement a subclass of ConstRules that provides all
-// operations as noops. All other rules classes inherit from this class so
-// that if functionality is needed in the future, it can simply be added here
-// and to ConstRules without changing anything else...
-//
-// This class also provides subclasses with typesafe implementations of methods
-// so that don't have to do type casting.
-//
-template<class ArgType, class SubClassName>
-class TemplateRules : public ConstRules {
+ return ConstantVector::get(&Result[0], Result.size());
+}
- //===--------------------------------------------------------------------===//
- // Redirecting functions that cast to the appropriate types
- //===--------------------------------------------------------------------===//
+Constant *llvm::ConstantFoldExtractValueInstruction(const Constant *Agg,
+ const unsigned *Idxs,
+ unsigned NumIdx) {
+ // Base case: no indices, so return the entire value.
+ if (NumIdx == 0)
+ return const_cast<Constant *>(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.
+ return ConstantFoldExtractValueInstruction(Agg->getOperand(*Idxs),
+ Idxs+1, NumIdx-1);
+}
- virtual Constant *add(const Constant *V1, const Constant *V2) const {
- return SubClassName::Add((const ArgType *)V1, (const ArgType *)V2);
- }
- virtual Constant *sub(const Constant *V1, const Constant *V2) const {
- return SubClassName::Sub((const ArgType *)V1, (const ArgType *)V2);
- }
- virtual Constant *mul(const Constant *V1, const Constant *V2) const {
- return SubClassName::Mul((const ArgType *)V1, (const ArgType *)V2);
- }
- virtual Constant *div(const Constant *V1, const Constant *V2) const {
- return SubClassName::Div((const ArgType *)V1, (const ArgType *)V2);
- }
- virtual Constant *rem(const Constant *V1, const Constant *V2) const {
- return SubClassName::Rem((const ArgType *)V1, (const ArgType *)V2);
- }
- virtual Constant *op_and(const Constant *V1, const Constant *V2) const {
- return SubClassName::And((const ArgType *)V1, (const ArgType *)V2);
- }
- virtual Constant *op_or(const Constant *V1, const Constant *V2) const {
- return SubClassName::Or((const ArgType *)V1, (const ArgType *)V2);
- }
- virtual Constant *op_xor(const Constant *V1, const Constant *V2) const {
- return SubClassName::Xor((const ArgType *)V1, (const ArgType *)V2);
+Constant *llvm::ConstantFoldInsertValueInstruction(const Constant *Agg,
+ const Constant *Val,
+ const unsigned *Idxs,
+ unsigned NumIdx) {
+ // Base case: no indices, so replace the entire value.
+ if (NumIdx == 0)
+ return const_cast<Constant *>(Val);
+
+ if (isa<UndefValue>(Agg)) {
+ // Insertion of constant into aggregate undef
+ // Optimize away insertion of undef
+ if (isa<UndefValue>(Val))
+ return const_cast<Constant*>(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);
+ const Constant *Op =
+ (*Idxs == i) ?
+ ConstantFoldInsertValueInstruction(UndefValue::get(MemberTy),
+ Val, Idxs+1, NumIdx-1) :
+ UndefValue::get(MemberTy);
+ Ops[i] = const_cast<Constant*>(Op);
+ }
+ if (isa<StructType>(AggTy))
+ return ConstantStruct::get(Ops);
+ else
+ return ConstantArray::get(cast<ArrayType>(AggTy), Ops);
}
- virtual Constant *shl(const Constant *V1, const Constant *V2) const {
- return SubClassName::Shl((const ArgType *)V1, (const ArgType *)V2);
+ if (isa<ConstantAggregateZero>(Agg)) {
+ // Insertion of constant into aggregate zero
+ // Optimize away insertion of zero
+ if (Val->isNullValue())
+ return const_cast<Constant*>(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);
+ const Constant *Op =
+ (*Idxs == i) ?
+ ConstantFoldInsertValueInstruction(Constant::getNullValue(MemberTy),
+ Val, Idxs+1, NumIdx-1) :
+ Constant::getNullValue(MemberTy);
+ Ops[i] = const_cast<Constant*>(Op);
+ }
+ if (isa<StructType>(AggTy))
+ return ConstantStruct::get(Ops);
+ else
+ return ConstantArray::get(cast<ArrayType>(AggTy), Ops);
}
- virtual Constant *shr(const Constant *V1, const Constant *V2) const {
- return SubClassName::Shr((const ArgType *)V1, (const ArgType *)V2);
+ 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) {
+ const Constant *Op =
+ (*Idxs == i) ?
+ ConstantFoldInsertValueInstruction(Agg->getOperand(i),
+ Val, Idxs+1, NumIdx-1) :
+ Agg->getOperand(i);
+ Ops[i] = const_cast<Constant*>(Op);
+ }
+ Constant *C;
+ if (isa<StructType>(Agg->getType()))
+ C = ConstantStruct::get(Ops);
+ else
+ C = ConstantArray::get(cast<ArrayType>(Agg->getType()), Ops);
+ return C;
}
- virtual ConstantBool *lessthan(const Constant *V1,
- const Constant *V2) const {
- return SubClassName::LessThan((const ArgType *)V1, (const ArgType *)V2);
- }
+ return 0;
+}
- // Casting operators. ick
- virtual ConstantBool *castToBool(const Constant *V) const {
- return SubClassName::CastToBool((const ArgType*)V);
- }
- virtual ConstantSInt *castToSByte(const Constant *V) const {
- return SubClassName::CastToSByte((const ArgType*)V);
- }
- virtual ConstantUInt *castToUByte(const Constant *V) const {
- return SubClassName::CastToUByte((const ArgType*)V);
- }
- virtual ConstantSInt *castToShort(const Constant *V) const {
- return SubClassName::CastToShort((const ArgType*)V);
- }
- virtual ConstantUInt *castToUShort(const Constant *V) const {
- return SubClassName::CastToUShort((const ArgType*)V);
- }
- virtual ConstantSInt *castToInt(const Constant *V) const {
- return SubClassName::CastToInt((const ArgType*)V);
- }
- virtual ConstantUInt *castToUInt(const Constant *V) const {
- return SubClassName::CastToUInt((const ArgType*)V);
- }
- virtual ConstantSInt *castToLong(const Constant *V) const {
- return SubClassName::CastToLong((const ArgType*)V);
- }
- virtual ConstantUInt *castToULong(const Constant *V) const {
- return SubClassName::CastToULong((const ArgType*)V);
- }
- virtual ConstantFP *castToFloat(const Constant *V) const {
- return SubClassName::CastToFloat((const ArgType*)V);
- }
- virtual ConstantFP *castToDouble(const Constant *V) const {
- return SubClassName::CastToDouble((const ArgType*)V);
- }
- virtual Constant *castToPointer(const Constant *V,
- const PointerType *Ty) const {
- return SubClassName::CastToPointer((const ArgType*)V, Ty);
+/// EvalVectorOp - Given two vector constants and a function pointer, apply the
+/// function pointer to each element pair, producing a new ConstantVector
+/// constant. Either or both of V1 and V2 may be NULL, meaning a
+/// ConstantAggregateZero operand.
+static Constant *EvalVectorOp(const ConstantVector *V1,
+ const ConstantVector *V2,
+ const VectorType *VTy,
+ Constant *(*FP)(Constant*, Constant*)) {
+ std::vector<Constant*> Res;
+ const Type *EltTy = VTy->getElementType();
+ for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i) {
+ const Constant *C1 = V1 ? V1->getOperand(i) : Constant::getNullValue(EltTy);
+ const Constant *C2 = V2 ? V2->getOperand(i) : Constant::getNullValue(EltTy);
+ Res.push_back(FP(const_cast<Constant*>(C1),
+ const_cast<Constant*>(C2)));
}
+ return ConstantVector::get(Res);
+}
- //===--------------------------------------------------------------------===//
- // Default "noop" implementations
- //===--------------------------------------------------------------------===//
-
- static Constant *Add(const ArgType *V1, const ArgType *V2) { return 0; }
- static Constant *Sub(const ArgType *V1, const ArgType *V2) { return 0; }
- static Constant *Mul(const ArgType *V1, const ArgType *V2) { return 0; }
- static Constant *Div(const ArgType *V1, const ArgType *V2) { return 0; }
- static Constant *Rem(const ArgType *V1, const ArgType *V2) { return 0; }
- static Constant *And(const ArgType *V1, const ArgType *V2) { return 0; }
- static Constant *Or (const ArgType *V1, const ArgType *V2) { return 0; }
- static Constant *Xor(const ArgType *V1, const ArgType *V2) { return 0; }
- static Constant *Shl(const ArgType *V1, const ArgType *V2) { return 0; }
- static Constant *Shr(const ArgType *V1, const ArgType *V2) { return 0; }
- static ConstantBool *LessThan(const ArgType *V1, const ArgType *V2) {
+Constant *llvm::ConstantFoldBinaryInstruction(unsigned Opcode,
+ const Constant *C1,
+ const Constant *C2) {
+ // No compile-time operations on this type yet.
+ if (C1->getType() == Type::PPC_FP128Ty)
return 0;
- }
-
- // Casting operators. ick
- static ConstantBool *CastToBool (const Constant *V) { return 0; }
- static ConstantSInt *CastToSByte (const Constant *V) { return 0; }
- static ConstantUInt *CastToUByte (const Constant *V) { return 0; }
- static ConstantSInt *CastToShort (const Constant *V) { return 0; }
- static ConstantUInt *CastToUShort(const Constant *V) { return 0; }
- static ConstantSInt *CastToInt (const Constant *V) { return 0; }
- static ConstantUInt *CastToUInt (const Constant *V) { return 0; }
- static ConstantSInt *CastToLong (const Constant *V) { return 0; }
- static ConstantUInt *CastToULong (const Constant *V) { return 0; }
- static ConstantFP *CastToFloat (const Constant *V) { return 0; }
- static ConstantFP *CastToDouble(const Constant *V) { return 0; }
- static Constant *CastToPointer(const Constant *,
- const PointerType *) {return 0;}
-};
-
-
-
-//===----------------------------------------------------------------------===//
-// EmptyRules Class
-//===----------------------------------------------------------------------===//
-//
-// EmptyRules provides a concrete base class of ConstRules that does nothing
-//
-struct EmptyRules : public TemplateRules<Constant, EmptyRules> {
-};
-
-
-
-//===----------------------------------------------------------------------===//
-// BoolRules Class
-//===----------------------------------------------------------------------===//
-//
-// BoolRules provides a concrete base class of ConstRules for the 'bool' type.
-//
-struct BoolRules : public TemplateRules<ConstantBool, BoolRules> {
- static ConstantBool *LessThan(const ConstantBool *V1, const ConstantBool *V2){
- return ConstantBool::get(V1->getValue() < V2->getValue());
+ // 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:
+ 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
+ case Instruction::Or: // X | undef -> -1
+ if (const VectorType *PTy = dyn_cast<VectorType>(C1->getType()))
+ return ConstantVector::getAllOnesValue(PTy);
+ return ConstantInt::getAllOnesValue(C1->getType());
+ case Instruction::LShr:
+ if (isa<UndefValue>(C2) && isa<UndefValue>(C1))
+ return const_cast<Constant*>(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
+ else if (isa<UndefValue>(C1))
+ return const_cast<Constant*>(C1); // undef ashr undef -> undef
+ else
+ return const_cast<Constant*>(C1); // X ashr undef --> X
+ case Instruction::Shl:
+ // undef << X -> 0 or X << undef -> 0
+ return Constant::getNullValue(C1->getType());
+ }
}
- static Constant *And(const ConstantBool *V1, const ConstantBool *V2) {
- return ConstantBool::get(V1->getValue() & V2->getValue());
+ // Handle simplifications of the RHS when a constant int.
+ if (const ConstantInt *CI2 = dyn_cast<ConstantInt>(C2)) {
+ switch (Opcode) {
+ case Instruction::Add:
+ if (CI2->equalsInt(0)) return const_cast<Constant*>(C1); // X + 0 == X
+ break;
+ case Instruction::Sub:
+ if (CI2->equalsInt(0)) return const_cast<Constant*>(C1); // X - 0 == X
+ break;
+ case Instruction::Mul:
+ if (CI2->equalsInt(0)) return const_cast<Constant*>(C2); // X * 0 == 0
+ if (CI2->equalsInt(1))
+ return const_cast<Constant*>(C1); // X * 1 == X
+ break;
+ case Instruction::UDiv:
+ case Instruction::SDiv:
+ if (CI2->equalsInt(1))
+ return const_cast<Constant*>(C1); // X / 1 == X
+ if (CI2->equalsInt(0))
+ return UndefValue::get(CI2->getType()); // X / 0 == undef
+ break;
+ case Instruction::URem:
+ case Instruction::SRem:
+ if (CI2->equalsInt(1))
+ return Constant::getNullValue(CI2->getType()); // X % 1 == 0
+ if (CI2->equalsInt(0))
+ return UndefValue::get(CI2->getType()); // X % 0 == undef
+ break;
+ case Instruction::And:
+ if (CI2->isZero()) return const_cast<Constant*>(C2); // X & 0 == 0
+ if (CI2->isAllOnesValue())
+ return const_cast<Constant*>(C1); // X & -1 == X
+
+ if (const 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 const_cast<Constant*>(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 const_cast<Constant*>(C1); // X | 0 == X
+ if (CI2->isAllOnesValue())
+ return const_cast<Constant*>(C2); // X | -1 == -1
+ break;
+ case Instruction::Xor:
+ if (CI2->equalsInt(0)) return const_cast<Constant*>(C1); // X ^ 0 == X
+ break;
+ case Instruction::AShr:
+ // ashr (zext C to Ty), C2 -> lshr (zext C, CSA), C2
+ if (const ConstantExpr *CE1 = dyn_cast<ConstantExpr>(C1))
+ if (CE1->getOpcode() == Instruction::ZExt) // Top bits known zero.
+ return ConstantExpr::getLShr(const_cast<Constant*>(C1),
+ const_cast<Constant*>(C2));
+ break;
+ }
}
-
- static Constant *Or(const ConstantBool *V1, const ConstantBool *V2) {
- return ConstantBool::get(V1->getValue() | V2->getValue());
+
+ // At this point we know neither constant is an UndefValue.
+ if (const ConstantInt *CI1 = dyn_cast<ConstantInt>(C1)) {
+ if (const ConstantInt *CI2 = dyn_cast<ConstantInt>(C2)) {
+ using namespace APIntOps;
+ const APInt &C1V = CI1->getValue();
+ const APInt &C2V = CI2->getValue();
+ switch (Opcode) {
+ default:
+ break;
+ case Instruction::Add:
+ return ConstantInt::get(C1V + C2V);
+ case Instruction::Sub:
+ return ConstantInt::get(C1V - C2V);
+ case Instruction::Mul:
+ return ConstantInt::get(C1V * C2V);
+ case Instruction::UDiv:
+ assert(!CI2->isNullValue() && "Div by zero handled above");
+ return ConstantInt::get(C1V.udiv(C2V));
+ case Instruction::SDiv:
+ assert(!CI2->isNullValue() && "Div by zero handled above");
+ if (C2V.isAllOnesValue() && C1V.isMinSignedValue())
+ return UndefValue::get(CI1->getType()); // MIN_INT / -1 -> undef
+ return ConstantInt::get(C1V.sdiv(C2V));
+ case Instruction::URem:
+ assert(!CI2->isNullValue() && "Div by zero handled above");
+ return ConstantInt::get(C1V.urem(C2V));
+ case Instruction::SRem:
+ assert(!CI2->isNullValue() && "Div by zero handled above");
+ if (C2V.isAllOnesValue() && C1V.isMinSignedValue())
+ return UndefValue::get(CI1->getType()); // MIN_INT % -1 -> undef
+ return ConstantInt::get(C1V.srem(C2V));
+ case Instruction::And:
+ return ConstantInt::get(C1V & C2V);
+ case Instruction::Or:
+ return ConstantInt::get(C1V | C2V);
+ case Instruction::Xor:
+ return ConstantInt::get(C1V ^ C2V);
+ case Instruction::Shl: {
+ 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
+ }
+ case Instruction::LShr: {
+ 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
+ }
+ case Instruction::AShr: {
+ 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
+ }
+ }
+ }
+ } else if (const ConstantFP *CFP1 = dyn_cast<ConstantFP>(C1)) {
+ if (const ConstantFP *CFP2 = dyn_cast<ConstantFP>(C2)) {
+ APFloat C1V = CFP1->getValueAPF();
+ APFloat C2V = CFP2->getValueAPF();
+ APFloat C3V = C1V; // copy for modification
+ switch (Opcode) {
+ default:
+ break;
+ case Instruction::Add:
+ (void)C3V.add(C2V, APFloat::rmNearestTiesToEven);
+ return ConstantFP::get(C3V);
+ case Instruction::Sub:
+ (void)C3V.subtract(C2V, APFloat::rmNearestTiesToEven);
+ return ConstantFP::get(C3V);
+ case Instruction::Mul:
+ (void)C3V.multiply(C2V, APFloat::rmNearestTiesToEven);
+ return ConstantFP::get(C3V);
+ case Instruction::FDiv:
+ (void)C3V.divide(C2V, APFloat::rmNearestTiesToEven);
+ return ConstantFP::get(C3V);
+ case Instruction::FRem:
+ (void)C3V.mod(C2V, APFloat::rmNearestTiesToEven);
+ return ConstantFP::get(C3V);
+ }
+ }
+ } else if (const VectorType *VTy = dyn_cast<VectorType>(C1->getType())) {
+ const ConstantVector *CP1 = dyn_cast<ConstantVector>(C1);
+ const ConstantVector *CP2 = dyn_cast<ConstantVector>(C2);
+ if ((CP1 != NULL || isa<ConstantAggregateZero>(C1)) &&
+ (CP2 != NULL || isa<ConstantAggregateZero>(C2))) {
+ switch (Opcode) {
+ default:
+ break;
+ case Instruction::Add:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getAdd);
+ case Instruction::Sub:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getSub);
+ case Instruction::Mul:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getMul);
+ case Instruction::UDiv:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getUDiv);
+ case Instruction::SDiv:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getSDiv);
+ case Instruction::FDiv:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getFDiv);
+ case Instruction::URem:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getURem);
+ case Instruction::SRem:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getSRem);
+ case Instruction::FRem:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getFRem);
+ case Instruction::And:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getAnd);
+ case Instruction::Or:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getOr);
+ case Instruction::Xor:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getXor);
+ }
+ }
}
- static Constant *Xor(const ConstantBool *V1, const ConstantBool *V2) {
- return ConstantBool::get(V1->getValue() ^ V2->getValue());
+ 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::Mul:
+ case Instruction::And:
+ case Instruction::Or:
+ case Instruction::Xor:
+ // No change of opcode required.
+ return ConstantFoldBinaryInstruction(Opcode, C2, C1);
+
+ case Instruction::Shl:
+ case Instruction::LShr:
+ 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.
+ break;
+ }
}
-};
+
+ // We don't know how to fold this.
+ return 0;
+}
+/// isZeroSizedType - This type is zero sized if its an array or structure of
+/// zero sized types. The only leaf zero sized type is an empty structure.
+static bool isMaybeZeroSizedType(const Type *Ty) {
+ if (isa<OpaqueType>(Ty)) return true; // Can't say.
+ if (const StructType *STy = dyn_cast<StructType>(Ty)) {
-//===----------------------------------------------------------------------===//
-// PointerRules Class
-//===----------------------------------------------------------------------===//
-//
-// PointerRules provides a concrete base class of ConstRules for pointer types
-//
-struct PointerRules : public TemplateRules<ConstantPointer, PointerRules> {
- static ConstantBool *CastToBool (const Constant *V) {
- if (V->isNullValue()) return ConstantBool::False;
- return 0; // Can't const prop other types of pointers
- }
- static ConstantSInt *CastToSByte (const Constant *V) {
- if (V->isNullValue()) return ConstantSInt::get(Type::SByteTy, 0);
- return 0; // Can't const prop other types of pointers
- }
- static ConstantUInt *CastToUByte (const Constant *V) {
- if (V->isNullValue()) return ConstantUInt::get(Type::UByteTy, 0);
- return 0; // Can't const prop other types of pointers
- }
- static ConstantSInt *CastToShort (const Constant *V) {
- if (V->isNullValue()) return ConstantSInt::get(Type::ShortTy, 0);
- return 0; // Can't const prop other types of pointers
- }
- static ConstantUInt *CastToUShort(const Constant *V) {
- if (V->isNullValue()) return ConstantUInt::get(Type::UShortTy, 0);
- return 0; // Can't const prop other types of pointers
- }
- static ConstantSInt *CastToInt (const Constant *V) {
- if (V->isNullValue()) return ConstantSInt::get(Type::IntTy, 0);
- return 0; // Can't const prop other types of pointers
- }
- static ConstantUInt *CastToUInt (const Constant *V) {
- if (V->isNullValue()) return ConstantUInt::get(Type::UIntTy, 0);
- return 0; // Can't const prop other types of pointers
- }
- static ConstantSInt *CastToLong (const Constant *V) {
- if (V->isNullValue()) return ConstantSInt::get(Type::LongTy, 0);
- return 0; // Can't const prop other types of pointers
- }
- static ConstantUInt *CastToULong (const Constant *V) {
- if (V->isNullValue()) return ConstantUInt::get(Type::ULongTy, 0);
- return 0; // Can't const prop other types of pointers
- }
- static ConstantFP *CastToFloat (const Constant *V) {
- if (V->isNullValue()) return ConstantFP::get(Type::FloatTy, 0);
- return 0; // Can't const prop other types of pointers
- }
- static ConstantFP *CastToDouble(const Constant *V) {
- if (V->isNullValue()) return ConstantFP::get(Type::DoubleTy, 0);
- return 0; // Can't const prop other types of pointers
- }
+ // If all of elements have zero size, this does too.
+ for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i)
+ if (!isMaybeZeroSizedType(STy->getElementType(i))) return false;
+ return true;
- static Constant *CastToPointer(const ConstantPointer *V,
- const PointerType *PTy) {
- if (V->getType() == PTy)
- return const_cast<ConstantPointer*>(V); // Allow cast %PTy %ptr to %PTy
- if (V->isNullValue())
- return ConstantPointerNull::get(PTy);
- return 0; // Can't const prop other types of pointers
+ } else if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
+ return isMaybeZeroSizedType(ATy->getElementType());
}
-};
+ return false;
+}
+/// IdxCompare - Compare the two constants as though they were getelementptr
+/// indices. This allows coersion of the types to be the same thing.
+///
+/// If the two constants are the "same" (after coersion), return 0. If the
+/// 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) {
+ if (C1 == C2) return 0;
+
+ // Ok, we found a different index. If they are not ConstantInt, we can't do
+ // anything with them.
+ if (!isa<ConstantInt>(C1) || !isa<ConstantInt>(C2))
+ return -2; // don't know!
+
+ // 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 (C2->getType() != Type::Int64Ty)
+ C2 = ConstantExpr::getSExt(C2, Type::Int64Ty);
+
+ if (C1 == C2) return 0; // They are equal
+
+ // If the type being indexed over is really just a zero sized type, there is
+ // no pointer difference being made here.
+ if (isMaybeZeroSizedType(ElTy))
+ return -2; // dunno.
+
+ // If they are really different, now that they are the same type, then we
+ // found a difference!
+ if (cast<ConstantInt>(C1)->getSExtValue() <
+ cast<ConstantInt>(C2)->getSExtValue())
+ return -1;
+ else
+ return 1;
+}
-//===----------------------------------------------------------------------===//
-// DirectRules Class
-//===----------------------------------------------------------------------===//
-//
-// DirectRules provides a concrete base classes of ConstRules for a variety of
-// different types. This allows the C++ compiler to automatically generate our
-// constant handling operations in a typesafe and accurate manner.
-//
-template<class ConstantClass, class BuiltinType, Type **Ty, class SuperClass>
-struct DirectRules : public TemplateRules<ConstantClass, SuperClass> {
- static Constant *Add(const ConstantClass *V1, const ConstantClass *V2) {
- BuiltinType R = (BuiltinType)V1->getValue() + (BuiltinType)V2->getValue();
- return ConstantClass::get(*Ty, R);
+/// evaluateFCmpRelation - This function determines if there is anything we can
+/// decide about the two constants provided. This doesn't need to handle simple
+/// things like ConstantFP comparisons, but should instead handle ConstantExprs.
+/// If we can determine that the two constants have a particular relation to
+/// each other, we should return the corresponding FCmpInst predicate,
+/// otherwise return FCmpInst::BAD_FCMP_PREDICATE. This is used below in
+/// ConstantFoldCompareInstruction.
+///
+/// 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) {
+ 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)
+ return FCmpInst::BAD_FCMP_PREDICATE;
+
+ // Handle degenerate case quickly
+ if (V1 == V2) return FCmpInst::FCMP_OEQ;
+
+ if (!isa<ConstantExpr>(V1)) {
+ 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));
+ if (R && !R->isZero())
+ return FCmpInst::FCMP_OEQ;
+ R = dyn_cast<ConstantInt>(
+ ConstantExpr::getFCmp(FCmpInst::FCMP_OLT, C1, C2));
+ if (R && !R->isZero())
+ return FCmpInst::FCMP_OLT;
+ R = dyn_cast<ConstantInt>(
+ ConstantExpr::getFCmp(FCmpInst::FCMP_OGT, C1, C2));
+ if (R && !R->isZero())
+ return FCmpInst::FCMP_OGT;
+
+ // Nothing more we can do
+ return FCmpInst::BAD_FCMP_PREDICATE;
+ }
+
+ // If the first operand is simple and second is ConstantExpr, swap operands.
+ FCmpInst::Predicate SwappedRelation = evaluateFCmpRelation(V2, V1);
+ if (SwappedRelation != FCmpInst::BAD_FCMP_PREDICATE)
+ 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);
+ switch (CE1->getOpcode()) {
+ case Instruction::FPTrunc:
+ case Instruction::FPExt:
+ case Instruction::UIToFP:
+ case Instruction::SIToFP:
+ // We might be able to do something with these but we don't right now.
+ break;
+ default:
+ break;
+ }
}
+ // There are MANY other foldings that we could perform here. They will
+ // probably be added on demand, as they seem needed.
+ return FCmpInst::BAD_FCMP_PREDICATE;
+}
- static Constant *Sub(const ConstantClass *V1, const ConstantClass *V2) {
- BuiltinType R = (BuiltinType)V1->getValue() - (BuiltinType)V2->getValue();
- return ConstantClass::get(*Ty, R);
- }
+/// evaluateICmpRelation - This function determines if there is anything we can
+/// decide about the two constants provided. This doesn't need to handle simple
+/// things like integer comparisons, but should instead handle ConstantExprs
+/// and GlobalValues. If we can determine that the two constants have a
+/// particular relation to each other, we should return the corresponding ICmp
+/// predicate, otherwise return ICmpInst::BAD_ICMP_PREDICATE.
+///
+/// To simplify this code we canonicalize the relation so that the first
+/// operand is always the most "complex" of the two. We consider simple
+/// 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,
+ bool isSigned) {
+ assert(V1->getType() == V2->getType() &&
+ "Cannot compare different types of values!");
+ if (V1 == V2) return ICmpInst::ICMP_EQ;
+
+ if (!isa<ConstantExpr>(V1) && !isa<GlobalValue>(V1)) {
+ if (!isa<GlobalValue>(V2) && !isa<ConstantExpr>(V2)) {
+ // 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));
+ if (R && !R->isZero())
+ return pred;
+ pred = isSigned ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT;
+ R = dyn_cast<ConstantInt>(ConstantExpr::getICmp(pred, C1, C2));
+ if (R && !R->isZero())
+ return pred;
+ pred = isSigned ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT;
+ R = dyn_cast<ConstantInt>(ConstantExpr::getICmp(pred, C1, C2));
+ if (R && !R->isZero())
+ return pred;
+
+ // If we couldn't figure it out, bail.
+ return ICmpInst::BAD_ICMP_PREDICATE;
+ }
+
+ // If the first operand is simple, swap operands.
+ ICmpInst::Predicate SwappedRelation =
+ evaluateICmpRelation(V2, V1, isSigned);
+ if (SwappedRelation != ICmpInst::BAD_ICMP_PREDICATE)
+ return ICmpInst::getSwappedPredicate(SwappedRelation);
+
+ } else if (const GlobalValue *CPR1 = dyn_cast<GlobalValue>(V1)) {
+ if (isa<ConstantExpr>(V2)) { // Swap as necessary.
+ ICmpInst::Predicate SwappedRelation =
+ evaluateICmpRelation(V2, V1, isSigned);
+ if (SwappedRelation != ICmpInst::BAD_ICMP_PREDICATE)
+ return ICmpInst::getSwappedPredicate(SwappedRelation);
+ else
+ return ICmpInst::BAD_ICMP_PREDICATE;
+ }
- static Constant *Mul(const ConstantClass *V1, const ConstantClass *V2) {
- BuiltinType R = (BuiltinType)V1->getValue() * (BuiltinType)V2->getValue();
- return ConstantClass::get(*Ty, R);
- }
+ // Now we know that the RHS is a GlobalValue or simple constant,
+ // which (since the types must match) means that it's a ConstantPointerNull.
+ if (const GlobalValue *CPR2 = dyn_cast<GlobalValue>(V2)) {
+ // Don't try to decide equality of aliases.
+ if (!isa<GlobalAlias>(CPR1) && !isa<GlobalAlias>(CPR2))
+ if (!CPR1->hasExternalWeakLinkage() || !CPR2->hasExternalWeakLinkage())
+ return ICmpInst::ICMP_NE;
+ } else {
+ assert(isa<ConstantPointerNull>(V2) && "Canonicalization guarantee!");
+ // GlobalVals can never be null. Don't try to evaluate aliases.
+ if (!CPR1->hasExternalWeakLinkage() && !isa<GlobalAlias>(CPR1))
+ return ICmpInst::ICMP_NE;
+ }
+ } else {
+ // Ok, the LHS is known to be a constantexpr. The RHS can be any of a
+ // constantexpr, a CPR, or a simple constant.
+ const ConstantExpr *CE1 = cast<ConstantExpr>(V1);
+ const Constant *CE1Op0 = CE1->getOperand(0);
+
+ switch (CE1->getOpcode()) {
+ case Instruction::Trunc:
+ case Instruction::FPTrunc:
+ case Instruction::FPExt:
+ case Instruction::FPToUI:
+ case Instruction::FPToSI:
+ break; // We can't evaluate floating point casts or truncations.
+
+ case Instruction::UIToFP:
+ case Instruction::SIToFP:
+ case Instruction::BitCast:
+ case Instruction::ZExt:
+ case Instruction::SExt:
+ // If the cast is not actually changing bits, and the second operand is a
+ // null pointer, do the comparison with the pre-casted value.
+ if (V2->isNullValue() &&
+ (isa<PointerType>(CE1->getType()) || CE1->getType()->isInteger())) {
+ bool sgnd = isSigned;
+ if (CE1->getOpcode() == Instruction::ZExt) isSigned = false;
+ if (CE1->getOpcode() == Instruction::SExt) isSigned = true;
+ return evaluateICmpRelation(CE1Op0,
+ Constant::getNullValue(CE1Op0->getType()),
+ sgnd);
+ }
- static Constant *Div(const ConstantClass *V1, const ConstantClass *V2) {
- if (V2->isNullValue()) return 0;
- BuiltinType R = (BuiltinType)V1->getValue() / (BuiltinType)V2->getValue();
- return ConstantClass::get(*Ty, R);
+ // If the dest type is a pointer type, and the RHS is a constantexpr cast
+ // from the same type as the src of the LHS, evaluate the inputs. This is
+ // important for things like "icmp eq (cast 4 to int*), (cast 5 to int*)",
+ // which happens a lot in compilers with tagged integers.
+ if (const ConstantExpr *CE2 = dyn_cast<ConstantExpr>(V2))
+ if (CE2->isCast() && isa<PointerType>(CE1->getType()) &&
+ CE1->getOperand(0)->getType() == CE2->getOperand(0)->getType() &&
+ CE1->getOperand(0)->getType()->isInteger()) {
+ bool sgnd = isSigned;
+ if (CE1->getOpcode() == Instruction::ZExt) isSigned = false;
+ if (CE1->getOpcode() == Instruction::SExt) isSigned = true;
+ return evaluateICmpRelation(CE1->getOperand(0), CE2->getOperand(0),
+ sgnd);
+ }
+ break;
+
+ case Instruction::GetElementPtr:
+ // Ok, since this is a getelementptr, we know that the constant has a
+ // pointer type. Check the various cases.
+ if (isa<ConstantPointerNull>(V2)) {
+ // If we are comparing a GEP to a null pointer, check to see if the base
+ // of the GEP equals the null pointer.
+ if (const GlobalValue *GV = dyn_cast<GlobalValue>(CE1Op0)) {
+ if (GV->hasExternalWeakLinkage())
+ // Weak linkage GVals could be zero or not. We're comparing that
+ // to null pointer so its greater-or-equal
+ return isSigned ? ICmpInst::ICMP_SGE : ICmpInst::ICMP_UGE;
+ 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;
+ } else if (isa<ConstantPointerNull>(CE1Op0)) {
+ // If we are indexing from a null pointer, check to see if we have any
+ // non-zero indices.
+ for (unsigned i = 1, e = CE1->getNumOperands(); i != e; ++i)
+ if (!CE1->getOperand(i)->isNullValue())
+ // Offsetting from null, must not be equal.
+ return isSigned ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT;
+ // Only zero indexes from null, must still be zero.
+ return ICmpInst::ICMP_EQ;
+ }
+ // Otherwise, we can't really say if the first operand is null or not.
+ } else if (const GlobalValue *CPR2 = dyn_cast<GlobalValue>(V2)) {
+ if (isa<ConstantPointerNull>(CE1Op0)) {
+ if (CPR2->hasExternalWeakLinkage())
+ // Weak linkage GVals could be zero or not. We're comparing it to
+ // a null pointer, so its less-or-equal
+ return isSigned ? ICmpInst::ICMP_SLE : ICmpInst::ICMP_ULE;
+ else
+ // If its not weak linkage, the GVal must have a non-zero address
+ // so the result is less-than
+ return isSigned ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT;
+ } else if (const GlobalValue *CPR1 = dyn_cast<GlobalValue>(CE1Op0)) {
+ if (CPR1 == CPR2) {
+ // If this is a getelementptr of the same global, then it must be
+ // different. Because the types must match, the getelementptr could
+ // only have at most one index, and because we fold getelementptr's
+ // with a single zero index, it must be nonzero.
+ assert(CE1->getNumOperands() == 2 &&
+ !CE1->getOperand(1)->isNullValue() &&
+ "Suprising getelementptr!");
+ return isSigned ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT;
+ } else {
+ // If they are different globals, we don't know what the value is,
+ // but they can't be equal.
+ return ICmpInst::ICMP_NE;
+ }
+ }
+ } else {
+ const ConstantExpr *CE2 = cast<ConstantExpr>(V2);
+ const 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.
+ switch (CE2->getOpcode()) {
+ default: break;
+ case Instruction::GetElementPtr:
+ // By far the most common case to handle is when the base pointers are
+ // obviously to the same or different globals.
+ if (isa<GlobalValue>(CE1Op0) && isa<GlobalValue>(CE2Op0)) {
+ if (CE1Op0 != CE2Op0) // Don't know relative ordering, but not equal
+ return ICmpInst::ICMP_NE;
+ // Ok, we know that both getelementptr instructions are based on the
+ // same global. From this, we can precisely determine the relative
+ // ordering of the resultant pointers.
+ unsigned i = 1;
+
+ // 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())) {
+ 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 (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 (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;
+ }
+ }
+ }
+ default:
+ break;
+ }
}
- static ConstantBool *LessThan(const ConstantClass *V1,
- const ConstantClass *V2) {
- bool R = (BuiltinType)V1->getValue() < (BuiltinType)V2->getValue();
- return ConstantBool::get(R);
- }
-
- static Constant *CastToPointer(const ConstantClass *V,
- const PointerType *PTy) {
- if (V->isNullValue()) // Is it a FP or Integral null value?
- return ConstantPointerNull::get(PTy);
- return 0; // Can't const prop other types of pointers
- }
+ return ICmpInst::BAD_ICMP_PREDICATE;
+}
- // Casting operators. ick
-#define DEF_CAST(TYPE, CLASS, CTYPE) \
- static CLASS *CastTo##TYPE (const ConstantClass *V) { \
- return CLASS::get(Type::TYPE##Ty, (CTYPE)(BuiltinType)V->getValue()); \
+Constant *llvm::ConstantFoldCompareInstruction(unsigned short pred,
+ const Constant *C1,
+ const Constant *C2) {
+ // Fold FCMP_FALSE/FCMP_TRUE unconditionally.
+ if (pred == FCmpInst::FCMP_FALSE) {
+ if (const VectorType *VT = dyn_cast<VectorType>(C1->getType()))
+ return Constant::getNullValue(VectorType::getInteger(VT));
+ else
+ return ConstantInt::getFalse();
+ }
+
+ if (pred == FCmpInst::FCMP_TRUE) {
+ if (const VectorType *VT = dyn_cast<VectorType>(C1->getType()))
+ return Constant::getAllOnesValue(VectorType::getInteger(VT));
+ else
+ return ConstantInt::getTrue();
+ }
+
+ // Handle some degenerate cases first
+ if (isa<UndefValue>(C1) || isa<UndefValue>(C2)) {
+ // vicmp/vfcmp -> [vector] undef
+ if (const VectorType *VTy = dyn_cast<VectorType>(C1->getType()))
+ return UndefValue::get(VectorType::getInteger(VTy));
+
+ // icmp/fcmp -> i1 undef
+ return UndefValue::get(Type::Int1Ty);
}
- DEF_CAST(Bool , ConstantBool, bool)
- DEF_CAST(SByte , ConstantSInt, signed char)
- DEF_CAST(UByte , ConstantUInt, unsigned char)
- DEF_CAST(Short , ConstantSInt, signed short)
- DEF_CAST(UShort, ConstantUInt, unsigned short)
- DEF_CAST(Int , ConstantSInt, signed int)
- DEF_CAST(UInt , ConstantUInt, unsigned int)
- DEF_CAST(Long , ConstantSInt, int64_t)
- DEF_CAST(ULong , ConstantUInt, uint64_t)
- DEF_CAST(Float , ConstantFP , float)
- DEF_CAST(Double, ConstantFP , double)
-#undef DEF_CAST
-};
-
+ // No compile-time operations on this type yet.
+ if (C1->getType() == Type::PPC_FP128Ty)
+ return 0;
-//===----------------------------------------------------------------------===//
-// DirectIntRules Class
-//===----------------------------------------------------------------------===//
-//
-// DirectIntRules provides implementations of functions that are valid on
-// integer types, but not all types in general.
-//
-template <class ConstantClass, class BuiltinType, Type **Ty>
-struct DirectIntRules
- : public DirectRules<ConstantClass, BuiltinType, Ty,
- DirectIntRules<ConstantClass, BuiltinType, Ty> > {
-
- static Constant *Div(const ConstantClass *V1, const ConstantClass *V2) {
- if (V2->isNullValue()) return 0;
- if (V2->isAllOnesValue() && // MIN_INT / -1
- (BuiltinType)V1->getValue() == -(BuiltinType)V1->getValue())
- return 0;
- BuiltinType R = (BuiltinType)V1->getValue() / (BuiltinType)V2->getValue();
- return ConstantClass::get(*Ty, R);
+ // 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 (pred == ICmpInst::ICMP_EQ)
+ return ConstantInt::getFalse();
+ else if (pred == ICmpInst::ICMP_NE)
+ return ConstantInt::getTrue();
+ }
+ // 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 (pred == ICmpInst::ICMP_EQ)
+ return ConstantInt::getFalse();
+ else if (pred == ICmpInst::ICMP_NE)
+ return ConstantInt::getTrue();
+ }
}
- static Constant *Rem(const ConstantClass *V1,
- const ConstantClass *V2) {
- if (V2->isNullValue()) return 0; // X / 0
- if (V2->isAllOnesValue() && // MIN_INT / -1
- (BuiltinType)V1->getValue() == -(BuiltinType)V1->getValue())
- return 0;
- BuiltinType R = (BuiltinType)V1->getValue() % (BuiltinType)V2->getValue();
- return ConstantClass::get(*Ty, R);
+ 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));
+ }
+ } 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();
+ case FCmpInst::FCMP_UNO:
+ return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpUnordered);
+ case FCmpInst::FCMP_ORD:
+ return ConstantInt::get(Type::Int1Ty, R!=APFloat::cmpUnordered);
+ case FCmpInst::FCMP_UEQ:
+ return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpUnordered ||
+ R==APFloat::cmpEqual);
+ case FCmpInst::FCMP_OEQ:
+ return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpEqual);
+ case FCmpInst::FCMP_UNE:
+ return ConstantInt::get(Type::Int1Ty, R!=APFloat::cmpEqual);
+ case FCmpInst::FCMP_ONE:
+ return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpLessThan ||
+ R==APFloat::cmpGreaterThan);
+ case FCmpInst::FCMP_ULT:
+ return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpUnordered ||
+ R==APFloat::cmpLessThan);
+ case FCmpInst::FCMP_OLT:
+ return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpLessThan);
+ case FCmpInst::FCMP_UGT:
+ return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpUnordered ||
+ R==APFloat::cmpGreaterThan);
+ case FCmpInst::FCMP_OGT:
+ return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpGreaterThan);
+ case FCmpInst::FCMP_ULE:
+ return ConstantInt::get(Type::Int1Ty, R!=APFloat::cmpGreaterThan);
+ case FCmpInst::FCMP_OLE:
+ return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpLessThan ||
+ R==APFloat::cmpEqual);
+ case FCmpInst::FCMP_UGE:
+ return ConstantInt::get(Type::Int1Ty, R!=APFloat::cmpLessThan);
+ case FCmpInst::FCMP_OGE:
+ return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpGreaterThan ||
+ R==APFloat::cmpEqual);
+ }
+ } else if (isa<VectorType>(C1->getType())) {
+ SmallVector<Constant*, 16> C1Elts, C2Elts;
+ C1->getVectorElements(C1Elts);
+ C2->getVectorElements(C2Elts);
+
+ // If we can constant fold the comparison of each element, constant fold
+ // the whole vector comparison.
+ SmallVector<Constant*, 4> ResElts;
+ const Type *InEltTy = C1Elts[0]->getType();
+ bool isFP = InEltTy->isFloatingPoint();
+ const Type *ResEltTy = InEltTy;
+ if (isFP)
+ ResEltTy = IntegerType::get(InEltTy->getPrimitiveSizeInBits());
+
+ for (unsigned i = 0, e = C1Elts.size(); i != e; ++i) {
+ // Compare the elements, producing an i1 result or constant expr.
+ Constant *C;
+ if (isFP)
+ C = ConstantExpr::getFCmp(pred, C1Elts[i], C2Elts[i]);
+ else
+ C = ConstantExpr::getICmp(pred, C1Elts[i], C2Elts[i]);
+
+ // If it is a bool or undef result, convert to the dest type.
+ if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) {
+ if (CI->isZero())
+ ResElts.push_back(Constant::getNullValue(ResEltTy));
+ else
+ ResElts.push_back(Constant::getAllOnesValue(ResEltTy));
+ } else if (isa<UndefValue>(C)) {
+ ResElts.push_back(UndefValue::get(ResEltTy));
+ } else {
+ break;
+ }
+ }
+
+ if (ResElts.size() == C1Elts.size())
+ return ConstantVector::get(&ResElts[0], ResElts.size());
}
- static Constant *And(const ConstantClass *V1, const ConstantClass *V2) {
- BuiltinType R = (BuiltinType)V1->getValue() & (BuiltinType)V2->getValue();
- return ConstantClass::get(*Ty, R);
- }
- static Constant *Or(const ConstantClass *V1, const ConstantClass *V2) {
- BuiltinType R = (BuiltinType)V1->getValue() | (BuiltinType)V2->getValue();
- return ConstantClass::get(*Ty, R);
- }
- static Constant *Xor(const ConstantClass *V1, const ConstantClass *V2) {
- BuiltinType R = (BuiltinType)V1->getValue() ^ (BuiltinType)V2->getValue();
- return ConstantClass::get(*Ty, R);
+ if (C1->getType()->isFloatingPoint()) {
+ int Result = -1; // -1 = unknown, 0 = known false, 1 = known true.
+ switch (evaluateFCmpRelation(C1, C2)) {
+ default: assert(0 && "Unknown relation!");
+ case FCmpInst::FCMP_UNO:
+ case FCmpInst::FCMP_ORD:
+ case FCmpInst::FCMP_UEQ:
+ case FCmpInst::FCMP_UNE:
+ case FCmpInst::FCMP_ULT:
+ case FCmpInst::FCMP_UGT:
+ case FCmpInst::FCMP_ULE:
+ case FCmpInst::FCMP_UGE:
+ case FCmpInst::FCMP_TRUE:
+ case FCmpInst::FCMP_FALSE:
+ case FCmpInst::BAD_FCMP_PREDICATE:
+ break; // Couldn't determine anything about these constants.
+ case FCmpInst::FCMP_OEQ: // We know that C1 == C2
+ 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
+ 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
+ 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)
+ 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)
+ 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)
+ 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) {
+ if (const VectorType *VT = dyn_cast<VectorType>(C1->getType())) {
+ if (Result == 0)
+ return Constant::getNullValue(VectorType::getInteger(VT));
+ else
+ return Constant::getAllOnesValue(VectorType::getInteger(VT));
+ }
+ return ConstantInt::get(Type::Int1Ty, Result);
+ }
+
+ } else {
+ // Evaluate the relation between the two constants, per the predicate.
+ int Result = -1; // -1 = unknown, 0 = known false, 1 = known true.
+ switch (evaluateICmpRelation(C1, C2, CmpInst::isSigned(pred))) {
+ default: assert(0 && "Unknown relational!");
+ case ICmpInst::BAD_ICMP_PREDICATE:
+ break; // Couldn't determine anything about these constants.
+ case ICmpInst::ICMP_EQ: // We know the constants are equal!
+ // If we know the constants are equal, we can decide the result of this
+ // computation precisely.
+ Result = (pred == ICmpInst::ICMP_EQ ||
+ pred == ICmpInst::ICMP_ULE ||
+ pred == ICmpInst::ICMP_SLE ||
+ pred == ICmpInst::ICMP_UGE ||
+ pred == ICmpInst::ICMP_SGE);
+ break;
+ case ICmpInst::ICMP_ULT:
+ // If we know that C1 < C2, we can decide the result of this computation
+ // precisely.
+ Result = (pred == ICmpInst::ICMP_ULT ||
+ pred == ICmpInst::ICMP_NE ||
+ pred == ICmpInst::ICMP_ULE);
+ break;
+ case ICmpInst::ICMP_SLT:
+ // If we know that C1 < C2, we can decide the result of this computation
+ // precisely.
+ Result = (pred == ICmpInst::ICMP_SLT ||
+ pred == ICmpInst::ICMP_NE ||
+ pred == ICmpInst::ICMP_SLE);
+ break;
+ case ICmpInst::ICMP_UGT:
+ // If we know that C1 > C2, we can decide the result of this computation
+ // precisely.
+ Result = (pred == ICmpInst::ICMP_UGT ||
+ pred == ICmpInst::ICMP_NE ||
+ pred == ICmpInst::ICMP_UGE);
+ break;
+ case ICmpInst::ICMP_SGT:
+ // If we know that C1 > C2, we can decide the result of this computation
+ // precisely.
+ Result = (pred == ICmpInst::ICMP_SGT ||
+ pred == ICmpInst::ICMP_NE ||
+ pred == ICmpInst::ICMP_SGE);
+ break;
+ case ICmpInst::ICMP_ULE:
+ // If we know that C1 <= C2, we can only partially decide this relation.
+ if (pred == ICmpInst::ICMP_UGT) Result = 0;
+ if (pred == ICmpInst::ICMP_ULT) Result = 1;
+ break;
+ case ICmpInst::ICMP_SLE:
+ // If we know that C1 <= C2, we can only partially decide this relation.
+ if (pred == ICmpInst::ICMP_SGT) Result = 0;
+ if (pred == ICmpInst::ICMP_SLT) Result = 1;
+ break;
+
+ case ICmpInst::ICMP_UGE:
+ // If we know that C1 >= C2, we can only partially decide this relation.
+ if (pred == ICmpInst::ICMP_ULT) Result = 0;
+ if (pred == ICmpInst::ICMP_UGT) Result = 1;
+ break;
+ case ICmpInst::ICMP_SGE:
+ // If we know that C1 >= C2, we can only partially decide this relation.
+ if (pred == ICmpInst::ICMP_SLT) Result = 0;
+ if (pred == ICmpInst::ICMP_SGT) Result = 1;
+ break;
+
+ case ICmpInst::ICMP_NE:
+ // If we know that C1 != C2, we can only partially decide this relation.
+ if (pred == ICmpInst::ICMP_EQ) Result = 0;
+ if (pred == ICmpInst::ICMP_NE) Result = 1;
+ break;
+ }
+
+ // If we evaluated the result, return it now.
+ if (Result != -1) {
+ if (const VectorType *VT = dyn_cast<VectorType>(C1->getType())) {
+ if (Result == 0)
+ return Constant::getNullValue(VT);
+ else
+ return Constant::getAllOnesValue(VT);
+ }
+ return ConstantInt::get(Type::Int1Ty, Result);
+ }
+
+ if (!isa<ConstantExpr>(C1) && isa<ConstantExpr>(C2)) {
+ // If C2 is a constant expr and C1 isn't, flop them around and fold the
+ // other way if possible.
+ switch (pred) {
+ case ICmpInst::ICMP_EQ:
+ case ICmpInst::ICMP_NE:
+ // No change of predicate required.
+ return ConstantFoldCompareInstruction(pred, C2, C1);
+
+ case ICmpInst::ICMP_ULT:
+ case ICmpInst::ICMP_SLT:
+ case ICmpInst::ICMP_UGT:
+ case ICmpInst::ICMP_SGT:
+ case ICmpInst::ICMP_ULE:
+ case ICmpInst::ICMP_SLE:
+ case ICmpInst::ICMP_UGE:
+ case ICmpInst::ICMP_SGE:
+ // Change the predicate as necessary to swap the operands.
+ pred = ICmpInst::getSwappedPredicate((ICmpInst::Predicate)pred);
+ return ConstantFoldCompareInstruction(pred, C2, C1);
+
+ default: // These predicates cannot be flopped around.
+ break;
+ }
+ }
}
+ return 0;
+}
- static Constant *Shl(const ConstantClass *V1, const ConstantClass *V2) {
- BuiltinType R = (BuiltinType)V1->getValue() << (BuiltinType)V2->getValue();
- return ConstantClass::get(*Ty, R);
- }
+Constant *llvm::ConstantFoldGetElementPtr(const Constant *C,
+ Constant* const *Idxs,
+ unsigned NumIdx) {
+ if (NumIdx == 0 ||
+ (NumIdx == 1 && Idxs[0]->isNullValue()))
+ return const_cast<Constant*>(C);
- static Constant *Shr(const ConstantClass *V1, const ConstantClass *V2) {
- BuiltinType R = (BuiltinType)V1->getValue() >> (BuiltinType)V2->getValue();
- return ConstantClass::get(*Ty, R);
+ if (isa<UndefValue>(C)) {
+ const PointerType *Ptr = cast<PointerType>(C->getType());
+ const Type *Ty = GetElementPtrInst::getIndexedType(Ptr,
+ (Value **)Idxs,
+ (Value **)Idxs+NumIdx);
+ assert(Ty != 0 && "Invalid indices for GEP!");
+ return UndefValue::get(PointerType::get(Ty, Ptr->getAddressSpace()));
}
-};
-
-//===----------------------------------------------------------------------===//
-// DirectFPRules Class
-//===----------------------------------------------------------------------===//
-//
-// DirectFPRules provides implementations of functions that are valid on
-// floating point types, but not all types in general.
-//
-template <class ConstantClass, class BuiltinType, Type **Ty>
-struct DirectFPRules
- : public DirectRules<ConstantClass, BuiltinType, Ty,
- DirectFPRules<ConstantClass, BuiltinType, Ty> > {
- static Constant *Rem(const ConstantClass *V1, const ConstantClass *V2) {
- if (V2->isNullValue()) return 0;
- BuiltinType Result = std::fmod((BuiltinType)V1->getValue(),
- (BuiltinType)V2->getValue());
- return ConstantClass::get(*Ty, Result);
+ Constant *Idx0 = Idxs[0];
+ if (C->isNullValue()) {
+ bool isNull = true;
+ for (unsigned i = 0, e = NumIdx; i != e; ++i)
+ if (!Idxs[i]->isNullValue()) {
+ isNull = false;
+ break;
+ }
+ if (isNull) {
+ const PointerType *Ptr = cast<PointerType>(C->getType());
+ const Type *Ty = GetElementPtrInst::getIndexedType(Ptr,
+ (Value**)Idxs,
+ (Value**)Idxs+NumIdx);
+ assert(Ty != 0 && "Invalid indices for GEP!");
+ return
+ ConstantPointerNull::get(PointerType::get(Ty,Ptr->getAddressSpace()));
+ }
}
-};
-//===----------------------------------------------------------------------===//
-// DirectRules Subclasses
-//===----------------------------------------------------------------------===//
-//
-// Given the DirectRules class we can now implement lots of types with little
-// code. Thank goodness C++ compilers are great at stomping out layers of
-// templates... can you imagine having to do this all by hand? (/me is lazy :)
-//
+ if (ConstantExpr *CE = dyn_cast<ConstantExpr>(const_cast<Constant*>(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 (CE->getOpcode() == Instruction::GetElementPtr) {
+ const Type *LastTy = 0;
+ for (gep_type_iterator I = gep_type_begin(CE), E = gep_type_end(CE);
+ I != E; ++I)
+ LastTy = *I;
+
+ if ((LastTy && isa<ArrayType>(LastTy)) || Idx0->isNullValue()) {
+ SmallVector<Value*, 16> NewIndices;
+ NewIndices.reserve(NumIdx + CE->getNumOperands());
+ for (unsigned i = 1, e = CE->getNumOperands()-1; i != e; ++i)
+ NewIndices.push_back(CE->getOperand(i));
+
+ // Add the last index of the source with the first index of the new GEP.
+ // Make sure to handle the case when they are actually different types.
+ Constant *Combined = CE->getOperand(CE->getNumOperands()-1);
+ // Otherwise it must be an array.
+ if (!Idx0->isNullValue()) {
+ const Type *IdxTy = Combined->getType();
+ if (IdxTy != Idx0->getType()) {
+ Constant *C1 = ConstantExpr::getSExtOrBitCast(Idx0, Type::Int64Ty);
+ Constant *C2 = ConstantExpr::getSExtOrBitCast(Combined,
+ Type::Int64Ty);
+ Combined = ConstantExpr::get(Instruction::Add, C1, C2);
+ } else {
+ Combined =
+ ConstantExpr::get(Instruction::Add, Idx0, Combined);
+ }
+ }
+
+ NewIndices.push_back(Combined);
+ NewIndices.insert(NewIndices.end(), Idxs+1, Idxs+NumIdx);
+ return ConstantExpr::getGetElementPtr(CE->getOperand(0), &NewIndices[0],
+ NewIndices.size());
+ }
+ }
-// ConstRules::find - Return the constant rules that take care of the specified
-// type.
-//
-Annotation *ConstRules::find(AnnotationID AID, const Annotable *TyA, void *) {
- assert(AID == ConstRules::AID && "Bad annotation for factory!");
- const Type *Ty = cast<Type>((const Value*)TyA);
-
- switch (Ty->getPrimitiveID()) {
- case Type::BoolTyID: return new BoolRules();
- case Type::PointerTyID: return new PointerRules();
- case Type::SByteTyID:
- return new DirectIntRules<ConstantSInt, signed char , &Type::SByteTy>();
- case Type::UByteTyID:
- return new DirectIntRules<ConstantUInt, unsigned char , &Type::UByteTy>();
- case Type::ShortTyID:
- return new DirectIntRules<ConstantSInt, signed short, &Type::ShortTy>();
- case Type::UShortTyID:
- return new DirectIntRules<ConstantUInt, unsigned short, &Type::UShortTy>();
- case Type::IntTyID:
- return new DirectIntRules<ConstantSInt, signed int , &Type::IntTy>();
- case Type::UIntTyID:
- return new DirectIntRules<ConstantUInt, unsigned int , &Type::UIntTy>();
- case Type::LongTyID:
- return new DirectIntRules<ConstantSInt, int64_t , &Type::LongTy>();
- case Type::ULongTyID:
- return new DirectIntRules<ConstantUInt, uint64_t , &Type::ULongTy>();
- case Type::FloatTyID:
- return new DirectFPRules<ConstantFP , float , &Type::FloatTy>();
- case Type::DoubleTyID:
- return new DirectFPRules<ConstantFP , double , &Type::DoubleTy>();
- default:
- return new EmptyRules();
+ // Implement folding of:
+ // int* getelementptr ([2 x int]* cast ([3 x int]* %X to [2 x int]*),
+ // long 0, long 0)
+ // To: int* getelementptr ([3 x int]* %X, long 0, long 0)
+ //
+ if (CE->isCast() && NumIdx > 1 && Idx0->isNullValue()) {
+ if (const PointerType *SPT =
+ dyn_cast<PointerType>(CE->getOperand(0)->getType()))
+ if (const ArrayType *SAT = dyn_cast<ArrayType>(SPT->getElementType()))
+ if (const ArrayType *CAT =
+ dyn_cast<ArrayType>(cast<PointerType>(C->getType())->getElementType()))
+ if (CAT->getElementType() == SAT->getElementType())
+ return ConstantExpr::getGetElementPtr(
+ (Constant*)CE->getOperand(0), Idxs, NumIdx);
+ }
+
+ // Fold: getelementptr (i8* inttoptr (i64 1 to i8*), i32 -1)
+ // Into: inttoptr (i64 0 to i8*)
+ // This happens with pointers to member functions in C++.
+ if (CE->getOpcode() == Instruction::IntToPtr && NumIdx == 1 &&
+ isa<ConstantInt>(CE->getOperand(0)) && isa<ConstantInt>(Idxs[0]) &&
+ cast<PointerType>(CE->getType())->getElementType() == Type::Int8Ty) {
+ Constant *Base = CE->getOperand(0);
+ Constant *Offset = Idxs[0];
+
+ // Convert the smaller integer to the larger type.
+ if (Offset->getType()->getPrimitiveSizeInBits() <
+ Base->getType()->getPrimitiveSizeInBits())
+ Offset = ConstantExpr::getSExt(Offset, Base->getType());
+ else if (Base->getType()->getPrimitiveSizeInBits() <
+ Offset->getType()->getPrimitiveSizeInBits())
+ Base = ConstantExpr::getZExt(Base, Base->getType());
+
+ Base = ConstantExpr::getAdd(Base, Offset);
+ return ConstantExpr::getIntToPtr(Base, CE->getType());
+ }
}
+ return 0;
}
-ConstRules *ConstRules::getConstantExprRules() {
- static EmptyRules CERules;
- return &CERules;
-}
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