Fix miscompilations of consumer-typeset, telecomm-gsm, and 176.gcc.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@33902 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2007-02-05 05:57:49 +00:00
parent 0974ea0911
commit b0b991a2c8

View File

@ -5675,7 +5675,7 @@ Instruction *InstCombiner::FoldShiftByConstant(Value *Op0, ConstantInt *Op1,
} else if (ShiftAmt1 < ShiftAmt2) {
unsigned ShiftDiff = ShiftAmt2-ShiftAmt1;
// (X >>? C1) << C2 --> X << (C2-C1) & (-1 << C1)
// (X >>? C1) << C2 --> X << (C2-C1) & (-1 << C2)
if (I.getOpcode() == Instruction::Shl) {
assert(ShiftOp->getOpcode() == Instruction::LShr ||
ShiftOp->getOpcode() == Instruction::AShr);
@ -5683,18 +5683,18 @@ Instruction *InstCombiner::FoldShiftByConstant(Value *Op0, ConstantInt *Op1,
BinaryOperator::createShl(X, ConstantInt::get(Ty, ShiftDiff));
InsertNewInstBefore(Shift, I);
uint64_t Mask = Ty->getBitMask() << ShiftAmt1;
uint64_t Mask = Ty->getBitMask() << ShiftAmt2;
return BinaryOperator::createAnd(Shift, ConstantInt::get(Ty, Mask));
}
// (X << C1) >>u C2 --> X >>u (C2-C1) & (-1 >> C1)
// (X << C1) >>u C2 --> X >>u (C2-C1) & (-1 >> C2)
if (I.getOpcode() == Instruction::LShr) {
assert(ShiftOp->getOpcode() == Instruction::Shl);
Instruction *Shift =
BinaryOperator::createLShr(X, ConstantInt::get(Ty, ShiftDiff));
InsertNewInstBefore(Shift, I);
uint64_t Mask = Ty->getBitMask() >> ShiftAmt1;
uint64_t Mask = Ty->getBitMask() >> ShiftAmt2;
return BinaryOperator::createAnd(Shift, ConstantInt::get(Ty, Mask));
}
@ -5703,7 +5703,7 @@ Instruction *InstCombiner::FoldShiftByConstant(Value *Op0, ConstantInt *Op1,
assert(ShiftAmt2 < ShiftAmt1);
unsigned ShiftDiff = ShiftAmt1-ShiftAmt2;
// (X >>? C1) << C2 --> X >>? (C1-C2) & (-1 << C1)
// (X >>? C1) << C2 --> X >>? (C1-C2) & (-1 << C2)
if (I.getOpcode() == Instruction::Shl) {
assert(ShiftOp->getOpcode() == Instruction::LShr ||
ShiftOp->getOpcode() == Instruction::AShr);
@ -5716,7 +5716,7 @@ Instruction *InstCombiner::FoldShiftByConstant(Value *Op0, ConstantInt *Op1,
return BinaryOperator::createAnd(Shift, ConstantInt::get(Ty, Mask));
}
// (X << C1) >>u C2 --> X << (C1-C2) & (-1 >> C1)
// (X << C1) >>u C2 --> X << (C1-C2) & (-1 >> C2)
if (I.getOpcode() == Instruction::LShr) {
assert(ShiftOp->getOpcode() == Instruction::Shl);
Instruction *Shift =