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Only do masking for unsigned values! 

llvm-svn: 2504
This commit is contained in:
Chris Lattner 2002-05-06 18:54:59 +00:00
parent cfa675c142
commit a6e047a5d9
1 changed files with 7 additions and 8 deletions
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9
llvm/lib/Transforms/Scalar/InstructionCombining.cpp
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@ -249,16 +249,15 @@ static Constant *getMaxValue(const Type *Ty) {
if (Ty == Type::BoolTy)
return ConstantBool::True;
if (Ty->isSigned())
return ConstantSInt::get(Ty, -1);
else if (Ty->isUnsigned()) {
// Calculate -1 casted to the right type...
unsigned TypeBits = Ty->getPrimitiveSize()*8;
uint64_t Val = (uint64_t)-1LL; // All ones
Val >>= 64-TypeBits; // Shift out unwanted 1 bits...
if (Ty->isSigned())
return ConstantSInt::get(Ty, (int64_t)Val);
else if (Ty->isUnsigned())
return ConstantUInt::get(Ty, Val);
}
return 0;
}