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- InstCombine: (X | C1) & C2 --> X & C2 iff C1 & C1 == 0

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- InstCombine: (X | C) & C --> C
  - InstCombine: (X | C1) & C2 --> (X | (C1&C2)) & C2


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@7269 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2003-07-23 19:25:52 +00:00
parent b5cfb6cb1a
commit 5840326ae6
1 changed files with 33 additions and 10 deletions
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43
lib/Transforms/Scalar/InstructionCombining.cpp
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@ -497,16 +497,39 @@ Instruction *InstCombiner::visitAnd(BinaryOperator &I) {
if (RHS->isAllOnesValue())
return ReplaceInstUsesWith(I, Op0);
// (X ^ C1) & C2 --> (X & C2) ^ (C1&C2)
if (Instruction *Op0I = dyn_cast<Instruction>(Op0))
if (Op0I->getOpcode() == Instruction::Xor && isOnlyUse(Op0))
if (ConstantInt *Op0CI = dyn_cast<ConstantInt>(Op0I->getOperand(1))) {
std::string Op0Name = Op0I->getName(); Op0I->setName("");
Instruction *And = BinaryOperator::create(Instruction::And,
Op0I->getOperand(0), RHS,
Op0Name);
InsertNewInstBefore(And, I);
return BinaryOperator::create(Instruction::Xor, And, *RHS & *Op0CI);
if (BinaryOperator *Op0I = dyn_cast<BinaryOperator>(Op0))
if (ConstantInt *Op0CI = dyn_cast<ConstantInt>(Op0I->getOperand(1)))
if (Op0I->getOpcode() == Instruction::Xor) {
if (isOnlyUse(Op0)) {
// (X ^ C1) & C2 --> (X & C2) ^ (C1&C2)
std::string Op0Name = Op0I->getName(); Op0I->setName("");
Instruction *And = BinaryOperator::create(Instruction::And,
Op0I->getOperand(0), RHS,
Op0Name);
InsertNewInstBefore(And, I);
return BinaryOperator::create(Instruction::Xor, And, *RHS & *Op0CI);
}
} else if (Op0I->getOpcode() == Instruction::Or) {
// (X | C1) & C2 --> X & C2 iff C1 & C1 == 0
if ((*RHS & *Op0CI)->isNullValue())
return BinaryOperator::create(Instruction::And, Op0I->getOperand(0),
RHS);
Constant *Together = *RHS & *Op0CI;
if (Together == RHS) // (X | C) & C --> C
return ReplaceInstUsesWith(I, RHS);
if (isOnlyUse(Op0)) {
if (Together != Op0CI) {
// (X | C1) & C2 --> (X | (C1&C2)) & C2
std::string Op0Name = Op0I->getName(); Op0I->setName("");
Instruction *Or = BinaryOperator::create(Instruction::Or,
Op0I->getOperand(0),
Together, Op0Name);
InsertNewInstBefore(Or, I);
return BinaryOperator::create(Instruction::And, Or, RHS);
}
}
}
}