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Implement InstCombine/xor.ll:test(15|16) 

llvm-svn: 9708
This commit is contained in:
Chris Lattner 2003-11-04 23:37:10 +00:00
parent e3a932c6d0
commit 0f68fa6569
1 changed files with 8 additions and 1 deletions
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9
llvm/lib/Transforms/Scalar/InstructionCombining.cpp
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@ -1002,7 +1002,14 @@ Instruction *InstCombiner::visitXor(BinaryOperator &I) {
SCI->getOperand(0), SCI->getOperand(1));
if (ConstantInt *Op0CI = dyn_cast<ConstantInt>(Op0I->getOperand(1)))
if (Op0I->getOpcode() == Instruction::And) {
if (Op0I->getOpcode() == Instruction::Add) {
// ~(X-c) --> (-c-1)-X
if (RHS->isAllOnesValue())
return BinaryOperator::create(Instruction::Sub,
*-*Op0CI -
*ConstantInt::get(I.getType(), 1),
Op0I->getOperand(0));
} else if (Op0I->getOpcode() == Instruction::And) {
// (X & C1) ^ C2 --> (X & C1) | C2 iff (C1&C2) == 0
if ((*RHS & *Op0CI)->isNullValue())
return BinaryOperator::create(Instruction::Or, Op0, RHS);