From f4d4c879851bd3c6f4c71b435c544917212921ec Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Sat, 7 May 2005 23:49:08 +0000 Subject: [PATCH] Fix a miscompilation of crafty by clobbering the "A" variable. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@21770 91177308-0d34-0410-b5e6-96231b3b80d8 --- .../Scalar/InstructionCombining.cpp | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index 72b45319c0c..6cafc257771 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -1856,8 +1856,16 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) { return NV; } - // (A & C1)|(A & C2) == A & (C1|C2) Value *A, *B; ConstantInt *C1, *C2; + + if (match(Op0, m_And(m_Value(A), m_Value(B)))) + if (A == Op1 || B == Op1) // (A & ?) | A --> A + return ReplaceInstUsesWith(I, Op1); + if (match(Op1, m_And(m_Value(A), m_Value(B)))) + if (A == Op0 || B == Op0) // A | (A & ?) --> A + return ReplaceInstUsesWith(I, Op0); + + // (A & C1)|(A & C2) == A & (C1|C2) if (match(Op0, m_And(m_Value(A), m_ConstantInt(C1))) && match(Op1, m_And(m_Value(B), m_ConstantInt(C2))) && A == B) return BinaryOperator::createAnd(A, ConstantExpr::getOr(C1, C2)); @@ -1869,14 +1877,7 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) { } else { A = 0; } - - if (match(Op0, m_And(m_Value(A), m_Value(B)))) - if (A == Op1 || B == Op1) // (A & ?) | A --> A - return ReplaceInstUsesWith(I, Op1); - if (match(Op1, m_And(m_Value(A), m_Value(B)))) - if (A == Op0 || B == Op0) // A | (A & ?) --> A - return ReplaceInstUsesWith(I, Op0); - + // Note, A is still live here! if (match(Op1, m_Not(m_Value(B)))) { // Op0 | ~B if (Op0 == B) return ReplaceInstUsesWith(I,