-//===- ConstantFolding.cpp - LLVM constant folder -------------------------===//
-//
+//===- ConstantFold.cpp - LLVM constant folder ----------------------------===//
+//
// 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 implements folding of constants for LLVM. This implements the
-// (internal) ConstantFolding.h interface, which is used by 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
//
//===----------------------------------------------------------------------===//
-#include "ConstantFolding.h"
+#include "ConstantFold.h"
#include "llvm/Constants.h"
#include "llvm/Instructions.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Function.h"
+#include "llvm/GlobalAlias.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/Support/Compiler.h"
#include "llvm/Support/GetElementPtrTypeIterator.h"
-#include <cmath>
+#include "llvm/Support/ManagedStatic.h"
+#include "llvm/Support/MathExtras.h"
+#include <limits>
using namespace llvm;
-namespace {
- struct ConstRules {
- ConstRules() {}
-
- // Binary Operators...
- virtual Constant *add(const Constant *V1, const Constant *V2) const = 0;
- virtual Constant *sub(const Constant *V1, const Constant *V2) const = 0;
- virtual Constant *mul(const Constant *V1, const Constant *V2) const = 0;
- virtual Constant *div(const Constant *V1, const Constant *V2) const = 0;
- virtual Constant *rem(const Constant *V1, const Constant *V2) const = 0;
- virtual Constant *op_and(const Constant *V1, const Constant *V2) const = 0;
- virtual Constant *op_or (const Constant *V1, const Constant *V2) const = 0;
- virtual Constant *op_xor(const Constant *V1, const Constant *V2) const = 0;
- virtual Constant *shl(const Constant *V1, const Constant *V2) const = 0;
- virtual Constant *shr(const Constant *V1, const Constant *V2) const = 0;
- virtual Constant *lessthan(const Constant *V1, const Constant *V2) const =0;
- virtual Constant *equalto(const Constant *V1, const Constant *V2) const = 0;
-
- // Casting operators.
- virtual Constant *castToBool (const Constant *V) const = 0;
- virtual Constant *castToSByte (const Constant *V) const = 0;
- virtual Constant *castToUByte (const Constant *V) const = 0;
- virtual Constant *castToShort (const Constant *V) const = 0;
- virtual Constant *castToUShort(const Constant *V) const = 0;
- virtual Constant *castToInt (const Constant *V) const = 0;
- virtual Constant *castToUInt (const Constant *V) const = 0;
- virtual Constant *castToLong (const Constant *V) const = 0;
- virtual Constant *castToULong (const Constant *V) const = 0;
- virtual Constant *castToFloat (const Constant *V) const = 0;
- virtual Constant *castToDouble(const Constant *V) const = 0;
- virtual Constant *castToPointer(const Constant *V,
- const PointerType *Ty) const = 0;
-
- // ConstRules::get - Return an instance of ConstRules for the specified
- // constant operands.
- //
- static ConstRules &get(const Constant *V1, const Constant *V2);
- private:
- ConstRules(const ConstRules &); // Do not implement
- ConstRules &operator=(const ConstRules &); // Do not implement
- };
-}
-
-
//===----------------------------------------------------------------------===//
-// TemplateRules Class
+// ConstantFold*Instruction Implementations
//===----------------------------------------------------------------------===//
-//
-// 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 {
- //===--------------------------------------------------------------------===//
- // Redirecting functions that cast to the appropriate types
- //===--------------------------------------------------------------------===//
+/// CastConstantVector - 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);
+ }
- 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);
- }
- virtual Constant *shl(const Constant *V1, const Constant *V2) const {
- return SubClassName::Shl((const ArgType *)V1, (const ArgType *)V2);
- }
- virtual Constant *shr(const Constant *V1, const Constant *V2) const {
- return SubClassName::Shr((const ArgType *)V1, (const ArgType *)V2);
+ 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);
}
+
+ // 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;
+}
- virtual Constant *lessthan(const Constant *V1, const Constant *V2) const {
- return SubClassName::LessThan((const ArgType *)V1, (const ArgType *)V2);
- }
- virtual Constant *equalto(const Constant *V1, const Constant *V2) const {
- return SubClassName::EqualTo((const ArgType *)V1, (const ArgType *)V2);
- }
+/// 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);
+}
- // Casting operators. ick
- virtual Constant *castToBool(const Constant *V) const {
- return SubClassName::CastToBool((const ArgType*)V);
- }
- virtual Constant *castToSByte(const Constant *V) const {
- return SubClassName::CastToSByte((const ArgType*)V);
- }
- virtual Constant *castToUByte(const Constant *V) const {
- return SubClassName::CastToUByte((const ArgType*)V);
- }
- virtual Constant *castToShort(const Constant *V) const {
- return SubClassName::CastToShort((const ArgType*)V);
- }
- virtual Constant *castToUShort(const Constant *V) const {
- return SubClassName::CastToUShort((const ArgType*)V);
- }
- virtual Constant *castToInt(const Constant *V) const {
- return SubClassName::CastToInt((const ArgType*)V);
- }
- virtual Constant *castToUInt(const Constant *V) const {
- return SubClassName::CastToUInt((const ArgType*)V);
- }
- virtual Constant *castToLong(const Constant *V) const {
- return SubClassName::CastToLong((const ArgType*)V);
- }
- virtual Constant *castToULong(const Constant *V) const {
- return SubClassName::CastToULong((const ArgType*)V);
- }
- virtual Constant *castToFloat(const Constant *V) const {
- return SubClassName::CastToFloat((const ArgType*)V);
- }
- virtual Constant *castToDouble(const Constant *V) const {
- return SubClassName::CastToDouble((const ArgType*)V);
+Constant *llvm::ConstantFoldCastInstruction(unsigned opc, const Constant *V,
+ const Type *DestTy) {
+ const Type *SrcTy = V->getType();
+
+ 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)
+ return Constant::getNullValue(DestTy);
+ return UndefValue::get(DestTy);
}
- virtual Constant *castToPointer(const Constant *V,
- const PointerType *Ty) const {
- return SubClassName::CastToPointer((const ArgType*)V, Ty);
+
+ // 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);
+ }
}
- //===--------------------------------------------------------------------===//
- // 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 Constant *LessThan(const ArgType *V1, const ArgType *V2) {
+ // 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)) {
+ 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);
+ return ConstantFP::get(DestTy, Val);
+ }
+ return 0; // Can't fold.
+ case Instruction::FPToUI:
+ case Instruction::FPToSI:
+ if (const ConstantFP *FPC = dyn_cast<ConstantFP>(V)) {
+ APFloat V = FPC->getValueAPF();
+ uint64_t x[2];
+ uint32_t DestBitWidth = cast<IntegerType>(DestTy)->getBitWidth();
+ (void) V.convertToInteger(x, DestBitWidth, opc==Instruction::FPToSI,
+ APFloat::rmTowardZero);
+ APInt Val(DestBitWidth, 2, x);
+ return ConstantInt::get(Val);
+ }
+ 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};
+ 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);
+ }
return 0;
- }
- static Constant *EqualTo(const ArgType *V1, const ArgType *V2) {
+ 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;
- }
-
- // Casting operators. ick
- static Constant *CastToBool (const Constant *V) { return 0; }
- static Constant *CastToSByte (const Constant *V) { return 0; }
- static Constant *CastToUByte (const Constant *V) { return 0; }
- static Constant *CastToShort (const Constant *V) { return 0; }
- static Constant *CastToUShort(const Constant *V) { return 0; }
- static Constant *CastToInt (const Constant *V) { return 0; }
- static Constant *CastToUInt (const Constant *V) { return 0; }
- static Constant *CastToLong (const Constant *V) { return 0; }
- static Constant *CastToULong (const Constant *V) { return 0; }
- static Constant *CastToFloat (const Constant *V) { return 0; }
- static Constant *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> {
- static Constant *EqualTo(const Constant *V1, const Constant *V2) {
- if (V1 == V2) return ConstantBool::True;
+ 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;
- }
-};
-
-
-
-//===----------------------------------------------------------------------===//
-// BoolRules Class
-//===----------------------------------------------------------------------===//
-//
-// BoolRules provides a concrete base class of ConstRules for the 'bool' type.
-//
-struct BoolRules : public TemplateRules<ConstantBool, BoolRules> {
-
- static Constant *LessThan(const ConstantBool *V1, const ConstantBool *V2){
- return ConstantBool::get(V1->getValue() < V2->getValue());
- }
-
- static Constant *EqualTo(const Constant *V1, const Constant *V2) {
- return ConstantBool::get(V1 == V2);
- }
-
- static Constant *And(const ConstantBool *V1, const ConstantBool *V2) {
- return ConstantBool::get(V1->getValue() & V2->getValue());
- }
-
- static Constant *Or(const ConstantBool *V1, const ConstantBool *V2) {
- return ConstantBool::get(V1->getValue() | V2->getValue());
- }
-
- static Constant *Xor(const ConstantBool *V1, const ConstantBool *V2) {
- return ConstantBool::get(V1->getValue() ^ V2->getValue());
- }
-
- // Casting operators. ick
-#define DEF_CAST(TYPE, CLASS, CTYPE) \
- static Constant *CastTo##TYPE (const ConstantBool *V) { \
- return CLASS::get(Type::TYPE##Ty, (CTYPE)(bool)V->getValue()); \
- }
-
- 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
-};
-
+ 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:
+ 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;
+ }
+ }
-//===----------------------------------------------------------------------===//
-// NullPointerRules Class
-//===----------------------------------------------------------------------===//
-//
-// NullPointerRules provides a concrete base class of ConstRules for null
-// pointers.
-//
-struct NullPointerRules : public TemplateRules<ConstantPointerNull,
- NullPointerRules> {
- static Constant *EqualTo(const Constant *V1, const Constant *V2) {
- return ConstantBool::True; // Null pointers are always equal
- }
- static Constant *CastToBool(const Constant *V) {
- return ConstantBool::False;
- }
- static Constant *CastToSByte (const Constant *V) {
- return ConstantSInt::get(Type::SByteTy, 0);
- }
- static Constant *CastToUByte (const Constant *V) {
- return ConstantUInt::get(Type::UByteTy, 0);
- }
- static Constant *CastToShort (const Constant *V) {
- return ConstantSInt::get(Type::ShortTy, 0);
- }
- static Constant *CastToUShort(const Constant *V) {
- return ConstantUInt::get(Type::UShortTy, 0);
- }
- static Constant *CastToInt (const Constant *V) {
- return ConstantSInt::get(Type::IntTy, 0);
- }
- static Constant *CastToUInt (const Constant *V) {
- return ConstantUInt::get(Type::UIntTy, 0);
- }
- static Constant *CastToLong (const Constant *V) {
- return ConstantSInt::get(Type::LongTy, 0);
- }
- static Constant *CastToULong (const Constant *V) {
- return ConstantUInt::get(Type::ULongTy, 0);
- }
- static Constant *CastToFloat (const Constant *V) {
- return ConstantFP::get(Type::FloatTy, 0);
- }
- static Constant *CastToDouble(const Constant *V) {
- return ConstantFP::get(Type::DoubleTy, 0);
- }
+ 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);
+ }
+ }
+ }
- static Constant *CastToPointer(const ConstantPointerNull *V,
- const PointerType *PTy) {
- return ConstantPointerNull::get(PTy);
+ // 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;
+ }
+
+ // 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;
+}
-//===----------------------------------------------------------------------===//
-// 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);
- }
+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);
- static Constant *Sub(const ConstantClass *V1, const ConstantClass *V2) {
- BuiltinType R = (BuiltinType)V1->getValue() - (BuiltinType)V2->getValue();
- return ConstantClass::get(*Ty, R);
- }
+ 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;
+}
- static Constant *Mul(const ConstantClass *V1, const ConstantClass *V2) {
- BuiltinType R = (BuiltinType)V1->getValue() * (BuiltinType)V2->getValue();
- return ConstantClass::get(*Ty, R);
+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 const_cast<Constant*>(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 0;
+}
- 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);
+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);
}
+ return 0;
+}
- static Constant *LessThan(const ConstantClass *V1, const ConstantClass *V2) {
- bool R = (BuiltinType)V1->getValue() < (BuiltinType)V2->getValue();
- return ConstantBool::get(R);
- }
-
- static Constant *EqualTo(const ConstantClass *V1, const ConstantClass *V2) {
- bool R = (BuiltinType)V1->getValue() == (BuiltinType)V2->getValue();
- return ConstantBool::get(R);
- }
+Constant *llvm::ConstantFoldShuffleVectorInstruction(const Constant *V1,
+ const Constant *V2,
+ const Constant *Mask) {
+ // TODO:
+ return 0;
+}
- 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
- }
+/// 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);
+}
- // Casting operators. ick
-#define DEF_CAST(TYPE, CLASS, CTYPE) \
- static Constant *CastTo##TYPE (const ConstantClass *V) { \
- return CLASS::get(Type::TYPE##Ty, (CTYPE)(BuiltinType)V->getValue()); \
+Constant *llvm::ConstantFoldBinaryInstruction(unsigned Opcode,
+ const Constant *C1,
+ const Constant *C2) {
+ // Handle UndefValue up front
+ if (isa<UndefValue>(C1) || isa<UndefValue>(C2)) {
+ switch (Opcode) {
+ 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
+ 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());
+ }
}
- 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
-};
-
+ 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));
-//===----------------------------------------------------------------------===//
-// 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);
- }
+ // 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.
+ 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);
- 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())
+ 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.
return 0;
- BuiltinType R = (BuiltinType)V1->getValue() % (BuiltinType)V2->getValue();
- return ConstantClass::get(*Ty, R);
- }
-
- 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);
- }
-
- static Constant *Shl(const ConstantClass *V1, const ConstantClass *V2) {
- BuiltinType R = (BuiltinType)V1->getValue() << (BuiltinType)V2->getValue();
- return ConstantClass::get(*Ty, R);
- }
-
- static Constant *Shr(const ConstantClass *V1, const ConstantClass *V2) {
- BuiltinType R = (BuiltinType)V1->getValue() >> (BuiltinType)V2->getValue();
- return ConstantClass::get(*Ty, R);
- }
-};
-
-
-//===----------------------------------------------------------------------===//
-// 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);
- }
-};
-
-
-/// ConstRules::get - This method returns the constant rules implementation that
-/// implements the semantics of the two specified constants.
-ConstRules &ConstRules::get(const Constant *V1, const Constant *V2) {
- static EmptyRules EmptyR;
- static BoolRules BoolR;
- static NullPointerRules NullPointerR;
- static DirectIntRules<ConstantSInt, signed char , &Type::SByteTy> SByteR;
- static DirectIntRules<ConstantUInt, unsigned char , &Type::UByteTy> UByteR;
- static DirectIntRules<ConstantSInt, signed short, &Type::ShortTy> ShortR;
- static DirectIntRules<ConstantUInt, unsigned short, &Type::UShortTy> UShortR;
- static DirectIntRules<ConstantSInt, signed int , &Type::IntTy> IntR;
- static DirectIntRules<ConstantUInt, unsigned int , &Type::UIntTy> UIntR;
- static DirectIntRules<ConstantSInt, int64_t , &Type::LongTy> LongR;
- static DirectIntRules<ConstantUInt, uint64_t , &Type::ULongTy> ULongR;
- static DirectFPRules <ConstantFP , float , &Type::FloatTy> FloatR;
- static DirectFPRules <ConstantFP , double , &Type::DoubleTy> DoubleR;
-
- if (isa<ConstantExpr>(V1) || isa<ConstantExpr>(V2) ||
- isa<GlobalValue>(V1) || isa<GlobalValue>(V2) ||
- isa<UndefValue>(V1) || isa<UndefValue>(V2))
- return EmptyR;
-
- switch (V1->getType()->getTypeID()) {
- default: assert(0 && "Unknown value type for constant folding!");
- case Type::BoolTyID: return BoolR;
- case Type::PointerTyID: return NullPointerR;
- case Type::SByteTyID: return SByteR;
- case Type::UByteTyID: return UByteR;
- case Type::ShortTyID: return ShortR;
- case Type::UShortTyID: return UShortR;
- case Type::IntTyID: return IntR;
- case Type::UIntTyID: return UIntR;
- case Type::LongTyID: return LongR;
- case Type::ULongTyID: return ULongR;
- case Type::FloatTyID: return FloatR;
- case Type::DoubleTyID: return DoubleR;
+ }
}
-}
-
-
-//===----------------------------------------------------------------------===//
-// ConstantFold*Instruction Implementations
-//===----------------------------------------------------------------------===//
-//
-// These methods contain the special case hackery required to symbolically
-// evaluate some constant expression cases, and use the ConstantRules class to
-// evaluate normal constants.
-//
-static unsigned getSize(const Type *Ty) {
- unsigned S = Ty->getPrimitiveSize();
- return S ? S : 8; // Treat pointers at 8 bytes
-}
-Constant *llvm::ConstantFoldCastInstruction(const Constant *V,
- const Type *DestTy) {
- if (V->getType() == DestTy) return (Constant*)V;
-
- // Cast of a global address to boolean is always true.
- if (const GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
- if (DestTy == Type::BoolTy)
- // FIXME: When we support 'external weak' references, we have to prevent
- // this transformation from happening. In the meantime we avoid folding
- // any cast of an external symbol.
- if (!GV->isExternal())
- return ConstantBool::True;
- } else 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->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);
+ // 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)) {
+ using namespace APIntOps;
+ APInt C1V = CI1->getValue();
+ 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:
+ if (CI2->isNullValue())
+ return 0; // X / 0 -> can't fold
+ return ConstantInt::get(C1V.udiv(C2V));
+ case Instruction::SDiv:
+ if (CI2->isNullValue())
+ return 0; // X / 0 -> can't fold
+ if (C2V.isAllOnesValue() && C1V.isMinSignedValue())
+ return 0; // MIN_INT / -1 -> overflow
+ return ConstantInt::get(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
+ if (C2V.isAllOnesValue() && C1V.isMinSignedValue())
+ return 0; // MIN_INT % -1 -> overflow
+ 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:
+ 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
}
- } 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)
- return ConstantExpr::getCast(CE->getOperand(0), DestTy);
}
- } else if (isa<UndefValue>(V)) {
- return UndefValue::get(DestTy);
- }
-
- // Check to see if we are casting an 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)) {
- std::vector<Value*> IdxList;
- IdxList.push_back(Constant::getNullValue(Type::IntTy));
- 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::UIntTy));
- } 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 {
+ } 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
+ bool isDouble = CFP1->getType()==Type::DoubleTy;
+ switch (Opcode) {
+ default:
+ break;
+ case Instruction::Add:
+ (void)C3V.add(C2V, APFloat::rmNearestTiesToEven);
+ return ConstantFP::get(CFP1->getType(), C3V);
+ case Instruction::Sub:
+ (void)C3V.subtract(C2V, APFloat::rmNearestTiesToEven);
+ return ConstantFP::get(CFP1->getType(), C3V);
+ case Instruction::Mul:
+ (void)C3V.multiply(C2V, APFloat::rmNearestTiesToEven);
+ return ConstantFP::get(CFP1->getType(), C3V);
+ case Instruction::FDiv:
+ (void)C3V.divide(C2V, APFloat::rmNearestTiesToEven);
+ return ConstantFP::get(CFP1->getType(), 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);
+ }
+ }
+ } else if (const ConstantVector *CP1 = dyn_cast<ConstantVector>(C1)) {
+ if (const ConstantVector *CP2 = dyn_cast<ConstantVector>(C2)) {
+ 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);
}
-
- if (ElTy == DPTy->getElementType())
- return ConstantExpr::getGetElementPtr(const_cast<Constant*>(V),IdxList);
}
-
- ConstRules &Rules = ConstRules::get(V, V);
-
- switch (DestTy->getTypeID()) {
- case Type::BoolTyID: return Rules.castToBool(V);
- case Type::UByteTyID: return Rules.castToUByte(V);
- case Type::SByteTyID: return Rules.castToSByte(V);
- case Type::UShortTyID: return Rules.castToUShort(V);
- case Type::ShortTyID: return Rules.castToShort(V);
- case Type::UIntTyID: return Rules.castToUInt(V);
- case Type::IntTyID: return Rules.castToInt(V);
- case Type::ULongTyID: return Rules.castToULong(V);
- case Type::LongTyID: return Rules.castToLong(V);
- case Type::FloatTyID: return Rules.castToFloat(V);
- case Type::DoubleTyID: return Rules.castToDouble(V);
- case Type::PointerTyID:
- return Rules.castToPointer(V, cast<PointerType>(DestTy));
- default: return 0;
}
-}
-Constant *llvm::ConstantFoldSelectInstruction(const Constant *Cond,
- const Constant *V1,
- const Constant *V2) {
- if (Cond == ConstantBool::True)
- return const_cast<Constant*>(V1);
- else if (Cond == ConstantBool::False)
- return const_cast<Constant*>(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);
+ // 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)) {
+
+ // 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;
+
+ } 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.
/// 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) {
+static int IdxCompare(Constant *C1, Constant *C2, const Type *ElTy) {
if (C1 == C2) return 0;
- // Ok, we found a different index. Are either of the operands
- // ConstantExprs? If so, we can't do anything with them.
+ // 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.
- C1 = ConstantExpr::getSignExtend(C1, Type::LongTy);
- C2 = ConstantExpr::getSignExtend(C2, Type::LongTy);
- if (C1 == C2) return 0; // Are they just differing types?
+ 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<ConstantSInt>(C1)->getValue() < cast<ConstantSInt>(C2)->getValue())
+ if (cast<ConstantInt>(C1)->getSExtValue() <
+ cast<ConstantInt>(C2)->getSExtValue())
return -1;
else
return 1;
}
-/// evaluateRelation - This function determines if there is anything we can
+/// 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!");
+ // 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;
+}
+
+/// 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 GlobalValuess. If we can determine that the two constants have a
-/// particular relation to each other, we should return the corresponding SetCC
-/// code, otherwise return Instruction::BinaryOpsEnd.
+/// 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 Instruction::BinaryOps evaluateRelation(const Constant *V1,
- const Constant *V2) {
+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 Instruction::SetEQ;
+ 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.
- assert((isa<GlobalValue>(V2) || isa<ConstantExpr>(V2)) &&
- "Simple cases should have been handled by caller!");
- Instruction::BinaryOps SwappedRelation = evaluateRelation(V2, V1);
- if (SwappedRelation != Instruction::BinaryOpsEnd)
- return SetCondInst::getSwappedCondition(SwappedRelation);
+ ICmpInst::Predicate SwappedRelation =
+ evaluateICmpRelation(V2, V1, isSigned);
+ if (SwappedRelation != ICmpInst::BAD_ICMP_PREDICATE)
+ return ICmpInst::getSwappedPredicate(SwappedRelation);
- } else if (const GlobalValue *CPR1 = dyn_cast<GlobalValue>(V1)){
+ } else if (const GlobalValue *CPR1 = dyn_cast<GlobalValue>(V1)) {
if (isa<ConstantExpr>(V2)) { // Swap as necessary.
- Instruction::BinaryOps SwappedRelation = evaluateRelation(V2, V1);
- if (SwappedRelation != Instruction::BinaryOpsEnd)
- return SetCondInst::getSwappedCondition(SwappedRelation);
- else
- return Instruction::BinaryOpsEnd;
+ ICmpInst::Predicate SwappedRelation =
+ evaluateICmpRelation(V2, V1, isSigned);
+ if (SwappedRelation != ICmpInst::BAD_ICMP_PREDICATE)
+ return ICmpInst::getSwappedPredicate(SwappedRelation);
+ else
+ return ICmpInst::BAD_ICMP_PREDICATE;
}
// Now we know that the RHS is a GlobalValue or simple constant,
// which (since the types must match) means that it's a ConstantPointerNull.
if (const GlobalValue *CPR2 = dyn_cast<GlobalValue>(V2)) {
- assert(CPR1 != CPR2 &&
- "GVs for the same value exist at different addresses??");
- // FIXME: If both globals are external weak, they might both be null!
- return Instruction::SetNE;
+ // 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!");
- // Global can never be null. FIXME: if we implement external weak
- // linkage, this is not necessarily true!
- return Instruction::SetNE;
+ // 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);
- Constant *CE1Op0 = CE1->getOperand(0);
+ const Constant *CE1Op0 = CE1->getOperand(0);
switch (CE1->getOpcode()) {
- case Instruction::Cast:
+ 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::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() &&
- CE1->getType()->isLosslesslyConvertibleTo(CE1Op0->getType()))
- return evaluateRelation(CE1Op0,
- Constant::getNullValue(CE1Op0->getType()));
+ (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 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:
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 (isa<GlobalValue>(CE1Op0)) {
- // FIXME: this is not true when we have external weak references!
- // No offset can go from a global to a null pointer.
- return Instruction::SetGT;
+ 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 Instruction::SetGT;
+ return isSigned ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT;
// Only zero indexes from null, must still be zero.
- return Instruction::SetEQ;
+ 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)) {
- // FIXME: This is not true with external weak references.
- return Instruction::SetLT;
+ 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
assert(CE1->getNumOperands() == 2 &&
!CE1->getOperand(1)->isNullValue() &&
"Suprising getelementptr!");
- return Instruction::SetGT;
+ 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 Instruction::SetNE;
+ return ICmpInst::ICMP_NE;
}
}
} else {
// 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 Instruction::SetNE;
+ 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.
- for (;i != CE1->getNumOperands() && i != CE2->getNumOperands(); ++i)
- switch (IdxCompare(CE1->getOperand(i), CE2->getOperand(i))) {
- case -1: return Instruction::SetLT;
- case 1: return Instruction::SetGT;
- case -2: return Instruction::BinaryOpsEnd;
+ 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())
- return Instruction::SetGT;
+ 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())
- return Instruction::SetLT;
- return Instruction::SetEQ;
+ 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;
}
}
- return Instruction::BinaryOpsEnd;
+ return ICmpInst::BAD_ICMP_PREDICATE;
}
-Constant *llvm::ConstantFoldBinaryInstruction(unsigned Opcode,
- const Constant *V1,
- const Constant *V2) {
- Constant *C = 0;
- switch (Opcode) {
- default: break;
- case Instruction::Add: C = ConstRules::get(V1, V2).add(V1, V2); break;
- case Instruction::Sub: C = ConstRules::get(V1, V2).sub(V1, V2); break;
- case Instruction::Mul: C = ConstRules::get(V1, V2).mul(V1, V2); break;
- case Instruction::Div: C = ConstRules::get(V1, V2).div(V1, V2); break;
- case Instruction::Rem: C = ConstRules::get(V1, V2).rem(V1, V2); break;
- case Instruction::And: C = ConstRules::get(V1, V2).op_and(V1, V2); break;
- case Instruction::Or: C = ConstRules::get(V1, V2).op_or (V1, V2); break;
- case Instruction::Xor: C = ConstRules::get(V1, V2).op_xor(V1, V2); break;
- case Instruction::Shl: C = ConstRules::get(V1, V2).shl(V1, V2); break;
- case Instruction::Shr: C = ConstRules::get(V1, V2).shr(V1, V2); break;
- case Instruction::SetEQ: C = ConstRules::get(V1, V2).equalto(V1, V2); break;
- case Instruction::SetLT: C = ConstRules::get(V1, V2).lessthan(V1, V2);break;
- case Instruction::SetGT: C = ConstRules::get(V1, V2).lessthan(V2, V1);break;
- case Instruction::SetNE: // V1 != V2 === !(V1 == V2)
- C = ConstRules::get(V1, V2).equalto(V1, V2);
- if (C) return ConstantExpr::get(Instruction::Xor, C, ConstantBool::True);
- break;
- case Instruction::SetLE: // V1 <= V2 === !(V2 < V1)
- C = ConstRules::get(V1, V2).lessthan(V2, V1);
- if (C) return ConstantExpr::get(Instruction::Xor, C, ConstantBool::True);
- break;
- case Instruction::SetGE: // V1 >= V2 === !(V1 < V2)
- C = ConstRules::get(V1, V2).lessthan(V1, V2);
- if (C) return ConstantExpr::get(Instruction::Xor, C, ConstantBool::True);
- break;
+Constant *llvm::ConstantFoldCompareInstruction(unsigned short pred,
+ const Constant *C1,
+ const Constant *C2) {
+
+ // Handle some degenerate cases first
+ if (isa<UndefValue>(C1) || isa<UndefValue>(C2))
+ return UndefValue::get(Type::Int1Ty);
+
+ // 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();
+ }
+
+ 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 (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;
+ }
+ }
}
- // If we successfully folded the expression, return it now.
- if (C) return C;
-
- if (SetCondInst::isRelational(Opcode)) {
- if (isa<UndefValue>(V1) || isa<UndefValue>(V2))
- return UndefValue::get(Type::BoolTy);
- switch (evaluateRelation(V1, V2)) {
+ if (C1->getType()->isFloatingPoint()) {
+ 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
+ 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);
+ 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);
+ 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);
+ 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();
+ 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();
+ 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();
+ break;
+ }
+ } else {
+ // Evaluate the relation between the two constants, per the predicate.
+ switch (evaluateICmpRelation(C1, C2, CmpInst::isSigned(pred))) {
default: assert(0 && "Unknown relational!");
- case Instruction::BinaryOpsEnd:
+ case ICmpInst::BAD_ICMP_PREDICATE:
break; // Couldn't determine anything about these constants.
- case Instruction::SetEQ: // We know the constants are equal!
+ 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 ConstantBool::get(Opcode == Instruction::SetEQ ||
- Opcode == Instruction::SetLE ||
- Opcode == Instruction::SetGE);
- case Instruction::SetLT:
- // If we know that V1 < V2, we can decide the result of this computation
+ 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);
+ 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);
+ 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);
+ case ICmpInst::ICMP_UGT:
+ // If we know that C1 > C2, we can decide the result of this computation
// precisely.
- return ConstantBool::get(Opcode == Instruction::SetLT ||
- Opcode == Instruction::SetNE ||
- Opcode == Instruction::SetLE);
- case Instruction::SetGT:
- // If we know that V1 > V2, we can decide the result of this computation
+ return ConstantInt::get(Type::Int1Ty,
+ pred == ICmpInst::ICMP_UGT ||
+ pred == ICmpInst::ICMP_NE ||
+ pred == ICmpInst::ICMP_UGE);
+ case ICmpInst::ICMP_SGT:
+ // If we know that C1 > C2, we can decide the result of this computation
// precisely.
- return ConstantBool::get(Opcode == Instruction::SetGT ||
- Opcode == Instruction::SetNE ||
- Opcode == Instruction::SetGE);
- case Instruction::SetLE:
- // If we know that V1 <= V2, we can only partially decide this relation.
- if (Opcode == Instruction::SetGT) return ConstantBool::False;
- if (Opcode == Instruction::SetLT) return ConstantBool::True;
+ return ConstantInt::get(Type::Int1Ty,
+ pred == ICmpInst::ICMP_SGT ||
+ pred == ICmpInst::ICMP_NE ||
+ pred == ICmpInst::ICMP_SGE);
+ 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();
+ 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();
break;
- case Instruction::SetGE:
- // If we know that V1 >= V2, we can only partially decide this relation.
- if (Opcode == Instruction::SetLT) return ConstantBool::False;
- if (Opcode == Instruction::SetGT) return ConstantBool::True;
+ 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();
break;
-
- case Instruction::SetNE:
- // If we know that V1 != V2, we can only partially decide this relation.
- if (Opcode == Instruction::SetEQ) return ConstantBool::False;
- if (Opcode == Instruction::SetNE) return ConstantBool::True;
+ 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();
break;
- }
- }
-
- if (isa<UndefValue>(V1) || isa<UndefValue>(V2)) {
- switch (Opcode) {
- case Instruction::Add:
- case Instruction::Sub:
- case Instruction::Xor:
- return UndefValue::get(V1->getType());
- case Instruction::Mul:
- case Instruction::And:
- return Constant::getNullValue(V1->getType());
- case Instruction::Div:
- case Instruction::Rem:
- if (!isa<UndefValue>(V2)) // undef/X -> 0
- return Constant::getNullValue(V1->getType());
- return const_cast<Constant*>(V2); // X/undef -> undef
- case Instruction::Or: // X|undef -> -1
- return ConstantInt::getAllOnesValue(V1->getType());
- case Instruction::Shr:
- if (!isa<UndefValue>(V2)) {
- if (V1->getType()->isSigned())
- return const_cast<Constant*>(V1); // undef >>s X -> undef
- // undef >>u X -> 0
- } else if (isa<UndefValue>(V1)) {
- return const_cast<Constant*>(V1); // undef >> undef -> undef
- } else {
- if (V1->getType()->isSigned())
- return const_cast<Constant*>(V1); // X >>s undef -> X
- // X >>u undef -> 0
- }
- return Constant::getNullValue(V1->getType());
-
- case Instruction::Shl:
- // undef << X -> 0 X << undef -> 0
- return Constant::getNullValue(V1->getType());
+ 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();
+ break;
}
- }
-
- if (const ConstantExpr *CE1 = dyn_cast<ConstantExpr>(V1)) {
- if (const ConstantExpr *CE2 = dyn_cast<ConstantExpr>(V2)) {
- // 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 (V2->isNullValue()) return const_cast<Constant*>(V1); // X + 0 == X
- break;
- case Instruction::Sub:
- if (V2->isNullValue()) return const_cast<Constant*>(V1); // X - 0 == X
- break;
- case Instruction::Mul:
- if (V2->isNullValue()) return const_cast<Constant*>(V2); // X * 0 == 0
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(V2))
- if (CI->getRawValue() == 1)
- return const_cast<Constant*>(V1); // X * 1 == X
- break;
- case Instruction::Div:
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(V2))
- if (CI->getRawValue() == 1)
- return const_cast<Constant*>(V1); // X / 1 == X
- break;
- case Instruction::Rem:
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(V2))
- if (CI->getRawValue() == 1)
- return Constant::getNullValue(CI->getType()); // X % 1 == 0
- break;
- case Instruction::And:
- if (cast<ConstantIntegral>(V2)->isAllOnesValue())
- return const_cast<Constant*>(V1); // X & -1 == X
- if (V2->isNullValue()) return const_cast<Constant*>(V2); // X & 0 == 0
- if (CE1->getOpcode() == Instruction::Cast &&
- 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>(V2))
- if (CI->getRawValue() < 4 && isa<Function>(CPR))
- return Constant::getNullValue(CI->getType());
- }
- break;
- case Instruction::Or:
- if (V2->isNullValue()) return const_cast<Constant*>(V1); // X | 0 == X
- if (cast<ConstantIntegral>(V2)->isAllOnesValue())
- return const_cast<Constant*>(V2); // X | -1 == -1
- break;
- case Instruction::Xor:
- if (V2->isNullValue()) return const_cast<Constant*>(V1); // X ^ 0 == X
+ 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;
}
}
-
- } else if (const ConstantExpr *CE2 = dyn_cast<ConstantExpr>(V2)) {
- // If V2 is a constant expr and V1 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:
- case Instruction::SetEQ:
- case Instruction::SetNE:
- // No change of opcode required.
- return ConstantFoldBinaryInstruction(Opcode, V2, V1);
-
- case Instruction::SetLT:
- case Instruction::SetGT:
- case Instruction::SetLE:
- case Instruction::SetGE:
- // Change the opcode as necessary to swap the operands.
- Opcode = SetCondInst::getSwappedCondition((Instruction::BinaryOps)Opcode);
- return ConstantFoldBinaryInstruction(Opcode, V2, V1);
-
- case Instruction::Shl:
- case Instruction::Shr:
- case Instruction::Sub:
- case Instruction::Div:
- case Instruction::Rem:
- default: // These instructions cannot be flopped around.
- break;
- }
}
return 0;
}
Constant *llvm::ConstantFoldGetElementPtr(const Constant *C,
- const std::vector<Value*> &IdxList) {
- if (IdxList.size() == 0 ||
- (IdxList.size() == 1 && cast<Constant>(IdxList[0])->isNullValue()))
+ Constant* const *Idxs,
+ unsigned NumIdx) {
+ if (NumIdx == 0 ||
+ (NumIdx == 1 && Idxs[0]->isNullValue()))
return const_cast<Constant*>(C);
if (isa<UndefValue>(C)) {
- const Type *Ty = GetElementPtrInst::getIndexedType(C->getType(), IdxList,
+ const Type *Ty = GetElementPtrInst::getIndexedType(C->getType(),
+ (Value **)Idxs,
+ (Value **)Idxs+NumIdx,
true);
assert(Ty != 0 && "Invalid indices for GEP!");
return UndefValue::get(PointerType::get(Ty));
}
- Constant *Idx0 = cast<Constant>(IdxList[0]);
+ Constant *Idx0 = Idxs[0];
if (C->isNullValue()) {
bool isNull = true;
- for (unsigned i = 0, e = IdxList.size(); i != e; ++i)
- if (!cast<Constant>(IdxList[i])->isNullValue()) {
+ for (unsigned i = 0, e = NumIdx; i != e; ++i)
+ if (!Idxs[i]->isNullValue()) {
isNull = false;
break;
}
if (isNull) {
- const Type *Ty = GetElementPtrInst::getIndexedType(C->getType(), IdxList,
+ const Type *Ty = GetElementPtrInst::getIndexedType(C->getType(),
+ (Value**)Idxs,
+ (Value**)Idxs+NumIdx,
true);
assert(Ty != 0 && "Invalid indices for GEP!");
return ConstantPointerNull::get(PointerType::get(Ty));
}
-
- if (IdxList.size() == 1) {
- const Type *ElTy = cast<PointerType>(C->getType())->getElementType();
- if (unsigned ElSize = ElTy->getPrimitiveSize()) {
- // gep null, C is equal to C*sizeof(nullty). If nullty is a known llvm
- // type, we can statically fold this.
- Constant *R = ConstantUInt::get(Type::UIntTy, ElSize);
- R = ConstantExpr::getCast(R, Idx0->getType());
- R = ConstantExpr::getMul(R, Idx0);
- return ConstantExpr::getCast(R, C->getType());
- }
- }
}
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(const_cast<Constant*>(C))) {
LastTy = *I;
if ((LastTy && isa<ArrayType>(LastTy)) || Idx0->isNullValue()) {
- std::vector<Value*> NewIndices;
- NewIndices.reserve(IdxList.size() + CE->getNumOperands());
+ 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));
// Otherwise it must be an array.
if (!Idx0->isNullValue()) {
const Type *IdxTy = Combined->getType();
- if (IdxTy != Idx0->getType()) IdxTy = Type::LongTy;
- Combined =
- ConstantExpr::get(Instruction::Add,
- ConstantExpr::getCast(Idx0, IdxTy),
- ConstantExpr::getCast(Combined, IdxTy));
+ 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(), IdxList.begin()+1, IdxList.end());
- return ConstantExpr::getGetElementPtr(CE->getOperand(0), NewIndices);
+ NewIndices.insert(NewIndices.end(), Idxs+1, Idxs+NumIdx);
+ return ConstantExpr::getGetElementPtr(CE->getOperand(0), &NewIndices[0],
+ NewIndices.size());
}
}
// long 0, long 0)
// To: int* getelementptr ([3 x int]* %X, long 0, long 0)
//
- if (CE->getOpcode() == Instruction::Cast && IdxList.size() > 1 &&
- Idx0->isNullValue())
- if (const PointerType *SPT =
+ 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()))
+ dyn_cast<ArrayType>(cast<PointerType>(C->getType())->getElementType()))
if (CAT->getElementType() == SAT->getElementType())
return ConstantExpr::getGetElementPtr(
- (Constant*)CE->getOperand(0), IdxList);
+ (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;
}
projects / oota-llvm.git / blobdiff