Changes in directory llvm/lib/Transforms/Scalar:
InstructionCombining.cpp updated: 1.578 -> 1.579
---
Log message:
Compile X + ~X to -1. This implements Instcombine/add.ll:test34
---
Diffs of the changes: (+7 -1)
InstructionCombining.cpp | 8 +++++++-
1 files changed, 7 insertions(+), 1 deletion(-)
Index: llvm/lib/Transforms/Scalar/InstructionCombining.cpp
diff -u llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.578
llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.579
--- llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.578 Wed Jan 3
23:23:51 2007
+++ llvm/lib/Transforms/Scalar/InstructionCombining.cpp Thu Jan 4 20:17:46 2007
@@ -1871,10 +1871,16 @@
if (dyn_castFoldableMul(RHS, C2) == LHS)
return BinaryOperator::createMul(LHS, AddOne(C2));
+ // X + ~X --> -1 since ~X = -X-1
+ if (dyn_castNotVal(LHS) == RHS ||
+ dyn_castNotVal(RHS) == LHS)
+ return ReplaceInstUsesWith(I, ConstantInt::getAllOnesValue(I.getType()));
+
// (A & C1)+(B & C2) --> (A & C1)|(B & C2) iff C1&C2 == 0
if (match(RHS, m_And(m_Value(), m_ConstantInt(C2))))
- if (Instruction *R = AssociativeOpt(I, AddMaskingAnd(C2))) return R;
+ if (Instruction *R = AssociativeOpt(I, AddMaskingAnd(C2)))
+ return R;
if (ConstantInt *CRHS = dyn_cast<ConstantInt>(RHS)) {
Value *X = 0;
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