diff options
Diffstat (limited to 'llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp index dc55b5a31596..de1034c910d5 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp @@ -1795,6 +1795,55 @@ static Instruction *foldComplexAndOrPatterns(BinaryOperator &I, } } + // (~A & B & C) | ... --> ... + // (~A | B | C) | ... --> ... + // TODO: One use checks are conservative. We just need to check that a total + // number of multiple used values does not exceed reduction + // in operations. + if (match(Op0, + m_OneUse(m_c_BinOp(FlippedOpcode, + m_BinOp(FlippedOpcode, m_Value(B), m_Value(C)), + m_CombineAnd(m_Value(X), m_Not(m_Value(A)))))) || + match(Op0, m_OneUse(m_c_BinOp( + FlippedOpcode, + m_c_BinOp(FlippedOpcode, m_Value(C), + m_CombineAnd(m_Value(X), m_Not(m_Value(A)))), + m_Value(B))))) { + // X = ~A + // (~A & B & C) | ~(A | B | C) --> ~(A | (B ^ C)) + // (~A | B | C) & ~(A & B & C) --> (~A | (B ^ C)) + if (match(Op1, m_OneUse(m_Not(m_c_BinOp( + Opcode, m_c_BinOp(Opcode, m_Specific(A), m_Specific(B)), + m_Specific(C))))) || + match(Op1, m_OneUse(m_Not(m_c_BinOp( + Opcode, m_c_BinOp(Opcode, m_Specific(B), m_Specific(C)), + m_Specific(A))))) || + match(Op1, m_OneUse(m_Not(m_c_BinOp( + Opcode, m_c_BinOp(Opcode, m_Specific(A), m_Specific(C)), + m_Specific(B)))))) { + Value *Xor = Builder.CreateXor(B, C); + return (Opcode == Instruction::Or) + ? BinaryOperator::CreateNot(Builder.CreateOr(Xor, A)) + : BinaryOperator::CreateOr(Xor, X); + } + + // (~A & B & C) | ~(A | B) --> (C | ~B) & ~A + // (~A | B | C) & ~(A & B) --> (C & ~B) | ~A + if (match(Op1, m_OneUse(m_Not(m_OneUse( + m_c_BinOp(Opcode, m_Specific(A), m_Specific(B))))))) + return BinaryOperator::Create( + FlippedOpcode, Builder.CreateBinOp(Opcode, C, Builder.CreateNot(B)), + X); + + // (~A & B & C) | ~(A | C) --> (B | ~C) & ~A + // (~A | B | C) & ~(A & C) --> (B & ~C) | ~A + if (match(Op1, m_OneUse(m_Not(m_OneUse( + m_c_BinOp(Opcode, m_Specific(A), m_Specific(C))))))) + return BinaryOperator::Create( + FlippedOpcode, Builder.CreateBinOp(Opcode, B, Builder.CreateNot(C)), + X); + } + return nullptr; } @@ -2102,6 +2151,15 @@ Instruction *InstCombinerImpl::visitAnd(BinaryOperator &I) { Value *Cmp = Builder.CreateICmpSLT(X, Zero, "isneg"); return SelectInst::Create(Cmp, Y, Zero); } + // If there's a 'not' of the shifted value, swap the select operands: + // ~(iN X s>> (N-1)) & Y --> (X s< 0) ? 0 : Y + if (match(&I, m_c_And(m_OneUse(m_Not( + m_AShr(m_Value(X), m_SpecificInt(FullShift)))), + m_Value(Y)))) { + Constant *Zero = ConstantInt::getNullValue(Ty); + Value *Cmp = Builder.CreateICmpSLT(X, Zero, "isneg"); + return SelectInst::Create(Cmp, Zero, Y); + } // (~x) & y --> ~(x | (~y)) iff that gets rid of inversions if (sinkNotIntoOtherHandOfAndOrOr(I)) |