Index: lib/Transforms/InstCombine/InstCombineAddSub.cpp =================================================================== --- lib/Transforms/InstCombine/InstCombineAddSub.cpp +++ lib/Transforms/InstCombine/InstCombineAddSub.cpp @@ -1725,6 +1725,15 @@ return BinaryOperator::CreateXor(A, B); } + // (sub (and A, B) (or A, B)) --> neg (xor A, B) + { + Value *A, *B; + if (match(Op0, m_And(m_Value(A), m_Value(B))) && + match(Op1, m_c_Or(m_Specific(A), m_Specific(B))) && + (Op0->hasOneUse() || Op1->hasOneUse())) + return BinaryOperator::CreateNeg(Builder.CreateXor(A, B)); + } + // (sub (or A, B), (xor A, B)) --> (and A, B) { Value *A, *B; Index: test/Transforms/InstCombine/sub-and-or-not-xor.ll =================================================================== --- test/Transforms/InstCombine/sub-and-or-not-xor.ll +++ test/Transforms/InstCombine/sub-and-or-not-xor.ll @@ -5,9 +5,8 @@ define i32 @sub_to_xor(i32 %x, i32 %y) { ; CHECK-LABEL: @sub_to_xor( -; CHECK-NEXT: [[OR:%.*]] = or i32 [[X:%.*]], [[Y:%.*]] -; CHECK-NEXT: [[AND:%.*]] = and i32 [[X]], [[Y]] -; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[AND]], [[OR]] +; CHECK-NEXT: [[TMP1:%.*]] = xor i32 [[X:%.*]], [[Y:%.*]] +; CHECK-NEXT: [[SUB:%.*]] = sub i32 0, [[TMP1]] ; CHECK-NEXT: ret i32 [[SUB]] ; %or = or i32 %x, %y @@ -18,9 +17,8 @@ define i32 @sub_to_xor_extra_use_sub(i32 %x, i32 %y) { ; CHECK-LABEL: @sub_to_xor_extra_use_sub( -; CHECK-NEXT: [[OR:%.*]] = or i32 [[X:%.*]], [[Y:%.*]] -; CHECK-NEXT: [[AND:%.*]] = and i32 [[X]], [[Y]] -; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[AND]], [[OR]] +; CHECK-NEXT: [[TMP1:%.*]] = xor i32 [[X:%.*]], [[Y:%.*]] +; CHECK-NEXT: [[SUB:%.*]] = sub i32 0, [[TMP1]] ; CHECK-NEXT: call void @use(i32 [[SUB]]) ; CHECK-NEXT: ret i32 [[SUB]] ; @@ -33,10 +31,10 @@ define i32 @sub_to_xor_extra_use_and(i32 %x, i32 %y) { ; CHECK-LABEL: @sub_to_xor_extra_use_and( -; CHECK-NEXT: [[OR:%.*]] = or i32 [[X:%.*]], [[Y:%.*]] -; CHECK-NEXT: [[AND:%.*]] = and i32 [[X]], [[Y]] +; CHECK-NEXT: [[AND:%.*]] = and i32 [[X:%.*]], [[Y:%.*]] ; CHECK-NEXT: call void @use(i32 [[AND]]) -; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[AND]], [[OR]] +; CHECK-NEXT: [[TMP1:%.*]] = xor i32 [[X]], [[Y]] +; CHECK-NEXT: [[SUB:%.*]] = sub i32 0, [[TMP1]] ; CHECK-NEXT: ret i32 [[SUB]] ; %or = or i32 %x, %y @@ -50,8 +48,8 @@ ; CHECK-LABEL: @sub_to_xor_extra_use_or( ; CHECK-NEXT: [[OR:%.*]] = or i32 [[X:%.*]], [[Y:%.*]] ; CHECK-NEXT: call void @use(i32 [[OR]]) -; CHECK-NEXT: [[AND:%.*]] = and i32 [[X]], [[Y]] -; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[AND]], [[OR]] +; CHECK-NEXT: [[TMP1:%.*]] = xor i32 [[X]], [[Y]] +; CHECK-NEXT: [[SUB:%.*]] = sub i32 0, [[TMP1]] ; CHECK-NEXT: ret i32 [[SUB]] ; %or = or i32 %x, %y @@ -63,9 +61,8 @@ define i32 @sub_to_xor_or_commuted(i32 %x, i32 %y) { ; CHECK-LABEL: @sub_to_xor_or_commuted( -; CHECK-NEXT: [[OR:%.*]] = or i32 [[Y:%.*]], [[X:%.*]] -; CHECK-NEXT: [[AND:%.*]] = and i32 [[X]], [[Y]] -; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[AND]], [[OR]] +; CHECK-NEXT: [[TMP1:%.*]] = xor i32 [[X:%.*]], [[Y:%.*]] +; CHECK-NEXT: [[SUB:%.*]] = sub i32 0, [[TMP1]] ; CHECK-NEXT: ret i32 [[SUB]] ; %or = or i32 %y, %x @@ -76,9 +73,8 @@ define i32 @sub_to_xor_and_commuted(i32 %x, i32 %y) { ; CHECK-LABEL: @sub_to_xor_and_commuted( -; CHECK-NEXT: [[OR:%.*]] = or i32 [[X:%.*]], [[Y:%.*]] -; CHECK-NEXT: [[AND:%.*]] = and i32 [[Y]], [[X]] -; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[AND]], [[OR]] +; CHECK-NEXT: [[TMP1:%.*]] = xor i32 [[Y:%.*]], [[X:%.*]] +; CHECK-NEXT: [[SUB:%.*]] = sub i32 0, [[TMP1]] ; CHECK-NEXT: ret i32 [[SUB]] ; %or = or i32 %x, %y @@ -89,9 +85,8 @@ define <2 x i32> @sub_to_xor_vec(<2 x i32> %x, <2 x i32> %y) { ; CHECK-LABEL: @sub_to_xor_vec( -; CHECK-NEXT: [[OR:%.*]] = or <2 x i32> [[X:%.*]], [[Y:%.*]] -; CHECK-NEXT: [[AND:%.*]] = and <2 x i32> [[Y]], [[X]] -; CHECK-NEXT: [[SUB:%.*]] = sub <2 x i32> [[AND]], [[OR]] +; CHECK-NEXT: [[TMP1:%.*]] = xor <2 x i32> [[Y:%.*]], [[X:%.*]] +; CHECK-NEXT: [[SUB:%.*]] = sub <2 x i32> zeroinitializer, [[TMP1]] ; CHECK-NEXT: ret <2 x i32> [[SUB]] ; %or = or <2 x i32> %x, %y