git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92790 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2010-01-05 22:07:33 +00:00
parent c0f79af143
commit 274ad68cc7

View File

@ -498,22 +498,21 @@ Instruction *InstCombiner::commonIntCastTransforms(CastInst &CI) {
if (Instruction *Result = commonCastTransforms(CI))
return Result;
Value *Src = CI.getOperand(0);
const Type *SrcTy = Src->getType();
const Type *DestTy = CI.getType();
uint32_t SrcBitSize = SrcTy->getScalarSizeInBits();
uint32_t DestBitSize = DestTy->getScalarSizeInBits();
// See if we can simplify any instructions used by the LHS whose sole
// purpose is to compute bits we don't care about.
if (SimplifyDemandedInstructionBits(CI))
return &CI;
// If the source isn't an instruction or has more than one use then we
// can't do anything more.
Instruction *SrcI = dyn_cast<Instruction>(Src);
if (!SrcI || !Src->hasOneUse())
Instruction *Src = dyn_cast<Instruction>(CI.getOperand(0));
if (!Src || !Src->hasOneUse())
return 0;
const Type *SrcTy = Src->getType();
const Type *DestTy = CI.getType();
uint32_t SrcBitSize = SrcTy->getScalarSizeInBits();
uint32_t DestBitSize = DestTy->getScalarSizeInBits();
// Attempt to propagate the cast into the instruction for int->int casts.
int NumCastsRemoved = 0;
@ -521,8 +520,8 @@ Instruction *InstCombiner::commonIntCastTransforms(CastInst &CI) {
// expression tree to something weird like i93 unless the source is also
// strange.
if ((isa<VectorType>(DestTy) ||
ShouldChangeType(SrcI->getType(), DestTy)) &&
CanEvaluateInDifferentType(SrcI, DestTy,
ShouldChangeType(Src->getType(), DestTy)) &&
CanEvaluateInDifferentType(Src, DestTy,
CI.getOpcode(), NumCastsRemoved)) {
// If this cast is a truncate, evaluting in a different type always
// eliminates the cast, so it is always a win. If this is a zero-extension,
@ -546,7 +545,7 @@ Instruction *InstCombiner::commonIntCastTransforms(CastInst &CI) {
if (!DoXForm && 0) {
// If it's unnecessary to issue an AND to clear the high bits, it's
// always profitable to do this xform.
Value *TryRes = EvaluateInDifferentType(SrcI, DestTy, false);
Value *TryRes = EvaluateInDifferentType(Src, DestTy, false);
APInt Mask(APInt::getBitsSet(DestBitSize, SrcBitSize, DestBitSize));
if (MaskedValueIsZero(TryRes, Mask))
return ReplaceInstUsesWith(CI, TryRes);
@ -559,7 +558,7 @@ Instruction *InstCombiner::commonIntCastTransforms(CastInst &CI) {
}
case Instruction::SExt: {
DoXForm = NumCastsRemoved >= 2;
if (!DoXForm && !isa<TruncInst>(SrcI) && 0) {
if (!DoXForm && !isa<TruncInst>(Src) && 0) {
// If we do not have to emit the truncate + sext pair, then it's always
// profitable to do this xform.
//
@ -569,7 +568,7 @@ Instruction *InstCombiner::commonIntCastTransforms(CastInst &CI) {
// t3 = sext i16 t2 to i32
// !=
// i32 t1
Value *TryRes = EvaluateInDifferentType(SrcI, DestTy, true);
Value *TryRes = EvaluateInDifferentType(Src, DestTy, true);
unsigned NumSignBits = ComputeNumSignBits(TryRes);
if (NumSignBits > (DestBitSize - SrcBitSize))
return ReplaceInstUsesWith(CI, TryRes);
@ -585,7 +584,7 @@ Instruction *InstCombiner::commonIntCastTransforms(CastInst &CI) {
if (DoXForm) {
DEBUG(errs() << "ICE: EvaluateInDifferentType converting expression type"
" to avoid cast: " << CI);
Value *Res = EvaluateInDifferentType(SrcI, DestTy,
Value *Res = EvaluateInDifferentType(Src, DestTy,
CI.getOpcode() == Instruction::SExt);
if (JustReplace)
// Just replace this cast with the result.
@ -634,11 +633,9 @@ Instruction *InstCombiner::visitTrunc(TruncInst &CI) {
Value *Src = CI.getOperand(0);
const Type *DestTy = CI.getType();
uint32_t DestBitWidth = DestTy->getScalarSizeInBits();
uint32_t SrcBitWidth = Src->getType()->getScalarSizeInBits();
// Canonicalize trunc x to i1 -> (icmp ne (and x, 1), 0)
if (DestBitWidth == 1) {
if (DestTy->isInteger(1)) {
Constant *One = ConstantInt::get(Src->getType(), 1);
Src = Builder->CreateAnd(Src, One, "tmp");
Value *Zero = Constant::getNullValue(Src->getType());