Index: llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp =================================================================== --- llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp +++ llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp @@ -2796,6 +2796,22 @@ if (match(Op0, m_And(m_Or(m_Specific(Op1), m_Value(C)), m_Value(A)))) return BinaryOperator::CreateOr(Op1, Builder.CreateAnd(A, C)); + // (~(A | B) & C) | (~(A | C) & B) --> (B ^ C) & ~A + if (match(Op0, m_OneUse(m_c_And(m_OneUse(m_Not(m_Or(m_Value(A), m_Value(B)))), + m_Value(C))))) { + if (match(Op1, m_OneUse(m_c_And( + m_OneUse(m_Not(m_c_Or(m_Specific(A), m_Specific(C)))), + m_Specific(B))))) + return BinaryOperator::CreateAnd(Builder.CreateXor(B, C), + Builder.CreateNot(A)); + + if (match(Op1, m_OneUse(m_c_And( + m_OneUse(m_Not(m_c_Or(m_Specific(B), m_Specific(C)))), + m_Specific(A))))) + return BinaryOperator::CreateAnd(Builder.CreateXor(A, C), + Builder.CreateNot(B)); + } + if (Instruction *DeMorgan = matchDeMorgansLaws(I, Builder)) return DeMorgan; Index: llvm/test/Transforms/InstCombine/and-xor-or.ll =================================================================== --- llvm/test/Transforms/InstCombine/and-xor-or.ll +++ llvm/test/Transforms/InstCombine/and-xor-or.ll @@ -703,13 +703,9 @@ define i32 @or_not_and(i32 %a, i32 %b, i32 %c) { ; CHECK-LABEL: @or_not_and( -; CHECK-NEXT: [[OR1:%.*]] = or i32 [[A:%.*]], [[B:%.*]] -; CHECK-NEXT: [[NOT1:%.*]] = xor i32 [[OR1]], -1 -; CHECK-NEXT: [[AND1:%.*]] = and i32 [[NOT1]], [[C:%.*]] -; CHECK-NEXT: [[OR2:%.*]] = or i32 [[A]], [[C]] -; CHECK-NEXT: [[NOT2:%.*]] = xor i32 [[OR2]], -1 -; CHECK-NEXT: [[AND2:%.*]] = and i32 [[NOT2]], [[B]] -; CHECK-NEXT: [[OR3:%.*]] = or i32 [[AND1]], [[AND2]] +; CHECK-NEXT: [[TMP1:%.*]] = xor i32 [[B:%.*]], [[C:%.*]] +; CHECK-NEXT: [[TMP2:%.*]] = xor i32 [[A:%.*]], -1 +; CHECK-NEXT: [[OR3:%.*]] = and i32 [[TMP1]], [[TMP2]] ; CHECK-NEXT: ret i32 [[OR3]] ; %or1 = or i32 %a, %b @@ -725,13 +721,9 @@ define i32 @or_not_and_commute1(i32 %a, i32 %b0, i32 %c) { ; CHECK-LABEL: @or_not_and_commute1( ; CHECK-NEXT: [[B:%.*]] = sdiv i32 42, [[B0:%.*]] -; CHECK-NEXT: [[OR1:%.*]] = or i32 [[B]], [[A:%.*]] -; CHECK-NEXT: [[NOT1:%.*]] = xor i32 [[OR1]], -1 -; CHECK-NEXT: [[AND1:%.*]] = and i32 [[NOT1]], [[C:%.*]] -; CHECK-NEXT: [[OR2:%.*]] = or i32 [[A]], [[C]] -; CHECK-NEXT: [[NOT2:%.*]] = xor i32 [[OR2]], -1 -; CHECK-NEXT: [[AND2:%.*]] = and i32 [[B]], [[NOT2]] -; CHECK-NEXT: [[OR3:%.*]] = or i32 [[AND1]], [[AND2]] +; CHECK-NEXT: [[TMP1:%.*]] = xor i32 [[B]], [[C:%.*]] +; CHECK-NEXT: [[TMP2:%.*]] = xor i32 [[A:%.*]], -1 +; CHECK-NEXT: [[OR3:%.*]] = and i32 [[TMP1]], [[TMP2]] ; CHECK-NEXT: ret i32 [[OR3]] ; %b = sdiv i32 42, %b0 ; thwart complexity-based canonicalization @@ -748,13 +740,9 @@ define i32 @or_not_and_commute2(i32 %a, i32 %b0, i32 %c) { ; CHECK-LABEL: @or_not_and_commute2( ; CHECK-NEXT: [[B:%.*]] = sdiv i32 42, [[B0:%.*]] -; CHECK-NEXT: [[OR1:%.*]] = or i32 [[B]], [[A:%.*]] -; CHECK-NEXT: [[NOT1:%.*]] = xor i32 [[OR1]], -1 -; CHECK-NEXT: [[AND1:%.*]] = and i32 [[NOT1]], [[C:%.*]] -; CHECK-NEXT: [[OR2:%.*]] = or i32 [[A]], [[C]] -; CHECK-NEXT: [[NOT2:%.*]] = xor i32 [[OR2]], -1 -; CHECK-NEXT: [[AND2:%.*]] = and i32 [[B]], [[NOT2]] -; CHECK-NEXT: [[OR3:%.*]] = or i32 [[AND2]], [[AND1]] +; CHECK-NEXT: [[TMP1:%.*]] = xor i32 [[B]], [[C:%.*]] +; CHECK-NEXT: [[TMP2:%.*]] = xor i32 [[A:%.*]], -1 +; CHECK-NEXT: [[OR3:%.*]] = and i32 [[TMP1]], [[TMP2]] ; CHECK-NEXT: ret i32 [[OR3]] ; %b = sdiv i32 42, %b0 ; thwart complexity-based canonicalization @@ -770,13 +758,9 @@ define i32 @or_not_and_commute3(i32 %a, i32 %b, i32 %c) { ; CHECK-LABEL: @or_not_and_commute3( -; CHECK-NEXT: [[OR1:%.*]] = or i32 [[B:%.*]], [[A:%.*]] -; CHECK-NEXT: [[NOT1:%.*]] = xor i32 [[OR1]], -1 -; CHECK-NEXT: [[AND1:%.*]] = and i32 [[NOT1]], [[C:%.*]] -; CHECK-NEXT: [[OR2:%.*]] = or i32 [[C]], [[A]] -; CHECK-NEXT: [[NOT2:%.*]] = xor i32 [[OR2]], -1 -; CHECK-NEXT: [[AND2:%.*]] = and i32 [[NOT2]], [[B]] -; CHECK-NEXT: [[OR3:%.*]] = or i32 [[AND1]], [[AND2]] +; CHECK-NEXT: [[TMP1:%.*]] = xor i32 [[B:%.*]], [[C:%.*]] +; CHECK-NEXT: [[TMP2:%.*]] = xor i32 [[A:%.*]], -1 +; CHECK-NEXT: [[OR3:%.*]] = and i32 [[TMP1]], [[TMP2]] ; CHECK-NEXT: ret i32 [[OR3]] ; %or1 = or i32 %b, %a