Index: lib/Transforms/InstCombine/InstCombineAndOrXor.cpp =================================================================== --- lib/Transforms/InstCombine/InstCombineAndOrXor.cpp +++ lib/Transforms/InstCombine/InstCombineAndOrXor.cpp @@ -1283,6 +1283,15 @@ if (match(Op1, m_Or(m_Not(m_Specific(Op0)), m_Value(A))) || match(Op1, m_Or(m_Value(A), m_Not(m_Specific(Op0))))) return BinaryOperator::CreateAnd(A, Op0); + + // (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: test/Transforms/InstCombine/or-xor.ll =================================================================== --- test/Transforms/InstCombine/or-xor.ll +++ test/Transforms/InstCombine/or-xor.ll @@ -92,3 +92,27 @@ ; CHECK-NEXT: %z = or i32 %y.not, %x ; CHECK-NEXT: ret i32 %z } + +; (x | y) & ((~x) ^ y) -> (x & y) +define i32 @test10(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: @test10( +; CHECK-NEXT: %and = and i32 %x, %y +; CHECK-NEXT: ret i32 %and +} + +; ((~x) ^ y) & (x | y) -> (x & y) +define i32 @test11(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: @test11( +; CHECK-NEXT: %and = and i32 %x, %y +; CHECK-NEXT: ret i32 %and +}