ret i32 %C
}
+; FIXME:
+; (~X) - (~Y) --> Y - X
+; Also, show that we can handle extra uses and vectors.
+
+declare void @use8(i8)
+
+define i8 @notnotsub(i8 %x, i8 %y) {
+; CHECK-LABEL: @notnotsub(
+; CHECK-NEXT: [[NX:%.*]] = xor i8 [[X:%.*]], -1
+; CHECK-NEXT: [[NY:%.*]] = xor i8 [[Y:%.*]], -1
+; CHECK-NEXT: [[SUB:%.*]] = sub i8 [[NX]], [[NY]]
+; CHECK-NEXT: call void @use8(i8 [[NX]])
+; CHECK-NEXT: call void @use8(i8 [[NY]])
+; CHECK-NEXT: ret i8 [[SUB]]
+;
+ %nx = xor i8 %x, -1
+ %ny = xor i8 %y, -1
+ %sub = sub i8 %nx, %ny
+ call void @use8(i8 %nx)
+ call void @use8(i8 %ny)
+ ret i8 %sub
+}
+
+define <2 x i8> @notnotsub_vec(<2 x i8> %x, <2 x i8> %y) {
+; CHECK-LABEL: @notnotsub_vec(
+; CHECK-NEXT: [[NX:%.*]] = xor <2 x i8> [[X:%.*]], <i8 -1, i8 -1>
+; CHECK-NEXT: [[NY:%.*]] = xor <2 x i8> [[Y:%.*]], <i8 -1, i8 -1>
+; CHECK-NEXT: [[SUB:%.*]] = sub <2 x i8> [[NX]], [[NY]]
+; CHECK-NEXT: ret <2 x i8> [[SUB]]
+;
+ %nx = xor <2 x i8> %x, <i8 -1, i8 -1>
+ %ny = xor <2 x i8> %y, <i8 -1, i8 -1>
+ %sub = sub <2 x i8> %nx, %ny
+ ret <2 x i8> %sub
+}
+
define i32 @test5(i32 %A, i32 %B, i32 %C) {
; CHECK-LABEL: @test5(
; CHECK-NEXT: [[D1:%.*]] = sub i32 [[C:%.*]], [[B:%.*]]