[llvm-commits] CVS: llvm/lib/Transforms/Scalar/InstructionCombining.cpp
Chris Lattner
lattner at cs.uiuc.edu
Wed Jul 23 14:27:00 PDT 2003
Changes in directory llvm/lib/Transforms/Scalar:
InstructionCombining.cpp updated: 1.102 -> 1.103
---
Log message:
- InstCombine: (X | C1) & C2 --> X & C2 iff C1 & C1 == 0
- InstCombine: (X | C) & C --> C
- InstCombine: (X | C1) & C2 --> (X | (C1&C2)) & C2
---
Diffs of the changes:
Index: llvm/lib/Transforms/Scalar/InstructionCombining.cpp
diff -u llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.102 llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.103
--- llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.102 Wed Jul 23 13:29:44 2003
+++ llvm/lib/Transforms/Scalar/InstructionCombining.cpp Wed Jul 23 14:25:52 2003
@@ -497,16 +497,39 @@
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);
+ }
+ }
}
}
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