Index: llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp =================================================================== --- llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp +++ llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp @@ -1295,6 +1295,16 @@ if (match(Op1, m_Xor(m_Specific(B), m_Specific(A)))) if (Op0->hasOneUse() || cast(Op0)->hasOneUse()) return BinaryOperator::CreateAnd(Op1, Builder->CreateNot(C)); + + // (A | B) & ((~A) ^ B) -> (A & B) + if (match(Op0, m_Or(m_Value(A), m_Value(B))) && + match(Op1, m_Xor(m_Not(m_Specific(A)), m_Specific(B)))) + return BinaryOperator::CreateAnd(A, B); + + // ((~A) ^ B) & (A | B) -> (A & B) + if (match(Op0, m_Xor(m_Not(m_Value(A)), m_Value(B))) && + match(Op1, m_Or(m_Specific(A), m_Specific(B)))) + return BinaryOperator::CreateAnd(A, B); } if (ICmpInst *RHS = dyn_cast(Op1)) Index: llvm/trunk/test/Transforms/InstCombine/or-xor.ll =================================================================== --- llvm/trunk/test/Transforms/InstCombine/or-xor.ll +++ llvm/trunk/test/Transforms/InstCombine/or-xor.ll @@ -112,3 +112,27 @@ ; CHECK-LABEL: @test11( ; CHECK-NEXT: ret i32 -1 } + +; (x | y) & ((~x) ^ y) -> (x & y) +define i32 @test12(i32 %x, i32 %y) { + %or = or i32 %x, %y + %neg = xor i32 %x, -1 + %xor = xor i32 %neg, %y + %and = and i32 %or, %xor + ret i32 %and +; CHECK-LABEL: @test12( +; CHECK-NEXT: %and = and i32 %x, %y +; CHECK-NEXT: ret i32 %and +} + +; ((~x) ^ y) & (x | y) -> (x & y) +define i32 @test13(i32 %x, i32 %y) { + %neg = xor i32 %x, -1 + %xor = xor i32 %neg, %y + %or = or i32 %x, %y + %and = and i32 %xor, %or + ret i32 %and +; CHECK-LABEL: @test13( +; CHECK-NEXT: %and = and i32 %x, %y +; CHECK-NEXT: ret i32 %and +}