Changes in directory llvm/lib/Transforms/Scalar:
InstructionCombining.cpp updated: 1.456 -> 1.457
---
Log message:
Fold A^(B&A) -> (B&A)^A
Fold (B&A)^A == ~B & A
This implements InstCombine/xor.ll:test2[56]
---
Diffs of the changes: (+46 -7)
InstructionCombining.cpp | 53 ++++++++++++++++++++++++++++++++++++++++-------
1 files changed, 46 insertions(+), 7 deletions(-)
Index: llvm/lib/Transforms/Scalar/InstructionCombining.cpp
diff -u llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.456
llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.457
--- llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.456 Fri Mar 31
17:01:56 2006
+++ llvm/lib/Transforms/Scalar/InstructionCombining.cpp Sat Apr 1 02:03:55 2006
@@ -2508,6 +2508,30 @@
if (match(Op1, m_Or(m_Value(A), m_Value(B))))
if (A == Op0 || B == Op0) // A & (A | ?) --> A
return ReplaceInstUsesWith(I, Op0);
+
+ if (Op0->hasOneUse() &&
+ match(Op0, m_Xor(m_Value(A), m_Value(B)))) {
+ if (A == Op1) { // (A^B)&A -> A&(A^B)
+ I.swapOperands(); // Simplify below
+ std::swap(Op0, Op1);
+ } else if (B == Op1) { // (A^B)&B -> B&(B^A)
+ cast<BinaryOperator>(Op0)->swapOperands();
+ I.swapOperands(); // Simplify below
+ std::swap(Op0, Op1);
+ }
+ }
+ if (Op1->hasOneUse() &&
+ match(Op1, m_Xor(m_Value(A), m_Value(B)))) {
+ if (B == Op0) { // B&(A^B) -> B&(B^A)
+ cast<BinaryOperator>(Op1)->swapOperands();
+ std::swap(A, B);
+ }
+ if (A == Op0) { // A&(A^B) -> A & ~B
+ Instruction *NotB = BinaryOperator::createNot(B, "tmp");
+ InsertNewInstBefore(NotB, I);
+ return BinaryOperator::createAnd(A, NotB);
+ }
+ }
}
@@ -2943,14 +2967,14 @@
return ReplaceInstUsesWith(I,
ConstantIntegral::getAllOnesValue(I.getType()));
- if (Instruction *Op1I = dyn_cast<Instruction>(Op1))
+ if (BinaryOperator *Op1I = dyn_cast<BinaryOperator>(Op1))
if (Op1I->getOpcode() == Instruction::Or) {
if (Op1I->getOperand(0) == Op0) { // B^(B|A) == (A|B)^B
- cast<BinaryOperator>(Op1I)->swapOperands();
+ Op1I->swapOperands();
I.swapOperands();
std::swap(Op0, Op1);
} else if (Op1I->getOperand(1) == Op0) { // B^(A|B) == (A|B)^B
- I.swapOperands();
+ I.swapOperands(); // Simplified below.
std::swap(Op0, Op1);
}
} else if (Op1I->getOpcode() == Instruction::Xor) {
@@ -2958,15 +2982,22 @@
return ReplaceInstUsesWith(I, Op1I->getOperand(1));
else if (Op0 == Op1I->getOperand(1)) // A^(B^A) == B
return ReplaceInstUsesWith(I, Op1I->getOperand(0));
+ } else if (Op1I->getOpcode() == Instruction::And && Op1I->hasOneUse()) {
+ if (Op1I->getOperand(0) == Op0) // A^(A&B) ->
A^(B&A)
+ Op1I->swapOperands();
+ if (Op0 == Op1I->getOperand(1)) { // A^(B&A) ->
(B&A)^A
+ I.swapOperands(); // Simplified below.
+ std::swap(Op0, Op1);
+ }
}
- if (Instruction *Op0I = dyn_cast<Instruction>(Op0))
+ if (BinaryOperator *Op0I = dyn_cast<BinaryOperator>(Op0))
if (Op0I->getOpcode() == Instruction::Or && Op0I->hasOneUse()) {
if (Op0I->getOperand(0) == Op1) // (B|A)^B == (A|B)^B
- cast<BinaryOperator>(Op0I)->swapOperands();
+ Op0I->swapOperands();
if (Op0I->getOperand(1) == Op1) { // (A|B)^B == A & ~B
- Value *NotB = InsertNewInstBefore(BinaryOperator::createNot(Op1,
- Op1->getName()+".not"),
I);
+ Instruction *NotB = BinaryOperator::createNot(Op1, "tmp");
+ InsertNewInstBefore(NotB, I);
return BinaryOperator::createAnd(Op0I->getOperand(0), NotB);
}
} else if (Op0I->getOpcode() == Instruction::Xor) {
@@ -2974,6 +3005,14 @@
return ReplaceInstUsesWith(I, Op0I->getOperand(1));
else if (Op1 == Op0I->getOperand(1)) // (B^A)^A == B
return ReplaceInstUsesWith(I, Op0I->getOperand(0));
+ } else if (Op0I->getOpcode() == Instruction::And && Op0I->hasOneUse()) {
+ if (Op0I->getOperand(0) == Op1) // (A&B)^A ->
(B&A)^A
+ Op0I->swapOperands();
+ if (Op0I->getOperand(1) == Op1) { // (B&A)^A == ~B & A
+ Instruction *N = BinaryOperator::createNot(Op0I->getOperand(0), "tmp");
+ InsertNewInstBefore(N, I);
+ return BinaryOperator::createAnd(N, Op1);
+ }
}
// (setcc1 A, B) ^ (setcc2 A, B) --> (setcc3 A, B)
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