ComputeSignBit(Y, YKnownNonNegative, YKnownNegative, TD, Depth);
// If X and Y are both non-negative (as signed values) then their sum is not
- // zero.
+ // zero unless both X and Y are zero.
if (XKnownNonNegative && YKnownNonNegative)
- return false;
-// return true;
+ if (isKnownNonZero(X, TD, Depth) || isKnownNonZero(Y, TD, Depth))
+ return true;
// If X and Y are both negative (as signed values) then their sum is not
// zero unless both X and Y equal INT_MIN.
}
define i1 @add(i32 %x, i32 %y) {
+; CHECK: @add
%l = lshr i32 %x, 1
- %r = lshr i32 %y, 1
+ %q = lshr i32 %y, 1
+ %r = or i32 %q, 1
%s = add i32 %l, %r
%c = icmp eq i32 %s, 0
ret i1 %c
+; CHECK: ret i1 false
}
define i1 @add2(i8 %x, i8 %y) {
; CHECK: ret i1 false
}
+define i1 @add3(i8 %x, i8 %y) {
+; CHECK: @add3
+ %l = zext i8 %x to i32
+ %r = zext i8 %y to i32
+ %s = add i32 %l, %r
+ %c = icmp eq i32 %s, 0
+ ret i1 %c
+; CHECK: ret i1 %c
+}
+
define i1 @addpowtwo(i32 %x, i32 %y) {
; CHECK: @addpowtwo
%l = lshr i32 %x, 1