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Compile X + ~X to -1. This implements Instcombine/add.ll:test34

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@32890 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2007-01-05 02:17:46 +00:00
parent 0a2c88dafc
commit e617c9ed5d
1 changed files with 7 additions and 1 deletions
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8
lib/Transforms/Scalar/InstructionCombining.cpp
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@ -1871,10 +1871,16 @@ FoundSExt:
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;