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Implement rem.ll:test3 

llvm-svn: 14640
This commit is contained in:
Chris Lattner 2004-07-06 07:38:18 +00:00
parent eca92d3106
commit 23b47b6af9
1 changed files with 18 additions and 0 deletions
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18
llvm/lib/Transforms/Scalar/InstructionCombining.cpp
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@ -1528,6 +1528,24 @@ Instruction *InstCombiner::visitSetCondInst(BinaryOperator &I) {
// operand is a constant, simplify a bit.
if (BinaryOperator *BO = dyn_cast<BinaryOperator>(Op0)) {
switch (BO->getOpcode()) {
case Instruction::Rem:
// If we have a signed (X % (2^c)) == 0, turn it into an unsigned one.
if (CI->isNullValue() && isa<ConstantSInt>(BO->getOperand(1)) &&
BO->hasOneUse() &&
cast<ConstantSInt>(BO->getOperand(1))->getValue() > 1)
if (unsigned L2 =
Log2(cast<ConstantSInt>(BO->getOperand(1))->getValue())) {
const Type *UTy = BO->getType()->getUnsignedVersion();
Value *NewX = InsertNewInstBefore(new CastInst(BO->getOperand(0),
UTy, "tmp"), I);
Constant *RHSCst = ConstantUInt::get(UTy, 1ULL << L2);
Value *NewRem =InsertNewInstBefore(BinaryOperator::createRem(NewX,
RHSCst, BO->getName()), I);
return BinaryOperator::create(I.getOpcode(), NewRem,
Constant::getNullValue(UTy));
}
break;
case Instruction::Add:
// Replace ((add A, B) != C) with (A != C-B) if B & C are constants.
if (ConstantInt *BOp1C = dyn_cast<ConstantInt>(BO->getOperand(1))) {