Implement rem.ll:test3

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@14640 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2004-07-06 07:38:18 +00:00
parent 970c17889a
commit 3571b72606

View File

@ -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))) {