Changes in directory llvm/lib/Transforms/Scalar:
InstructionCombining.cpp updated: 1.439 -> 1.440
---
Log message:
Fold (A^B) == A -> B == 0
and (A-B) == A -> B == 0
---
Diffs of the changes: (+26 -0)
InstructionCombining.cpp | 26 ++++++++++++++++++++++++++
1 files changed, 26 insertions(+)
Index: llvm/lib/Transforms/Scalar/InstructionCombining.cpp
diff -u llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.439
llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.440
--- llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.439 Sun Feb 26
13:57:54 2006
+++ llvm/lib/Transforms/Scalar/InstructionCombining.cpp Sun Feb 26 19:44:11 2006
@@ -3876,6 +3876,32 @@
if (Instruction *R = visitSetCondInstWithCastAndCast(I))
return R;
}
+
+ if (I.getOpcode() == Instruction::SetNE ||
+ I.getOpcode() == Instruction::SetEQ) {
+ Value *A, *B;
+ if (match(Op0, m_Xor(m_Value(A), m_Value(B))) &&
+ (A == Op1 || B == Op1)) {
+ // (A^B) == A -> B == 0
+ Value *OtherVal = A == Op1 ? B : A;
+ return BinaryOperator::create(I.getOpcode(), OtherVal,
+ Constant::getNullValue(A->getType()));
+ } else if (match(Op1, m_Xor(m_Value(A), m_Value(B))) &&
+ (A == Op0 || B == Op0)) {
+ // A == (A^B) -> B == 0
+ Value *OtherVal = A == Op0 ? B : A;
+ return BinaryOperator::create(I.getOpcode(), OtherVal,
+ Constant::getNullValue(A->getType()));
+ } else if (match(Op0, m_Sub(m_Value(A), m_Value(B))) && A == Op1) {
+ // (A-B) == A -> B == 0
+ return BinaryOperator::create(I.getOpcode(), B,
+ Constant::getNullValue(B->getType()));
+ } else if (match(Op1, m_Sub(m_Value(A), m_Value(B))) && A == Op0) {
+ // A == (A-B) -> B == 0
+ return BinaryOperator::create(I.getOpcode(), B,
+ Constant::getNullValue(B->getType()));
+ }
+ }
return Changed ? &I : 0;
}
_______________________________________________
llvm-commits mailing list
llvm-commits@cs.uiuc.edu
http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
