https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104360
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Note it is easier to detect the vector version of this though:
isN_3 = x_2(D) < { 0, 0, 0, 0, 0, 0, 0, 0 };
x_4 = x_2(D) ^ isN_3;
_5 = x_4 - isN_3;
Pattern here:
(minus @0 (bit_xor:c @0 (lt@1 @0 vertor_zero_p)))
than the scalar version:
_10 = x_6(D) < 0;
_11 = (int) _10;
_12 = -_11;
_1 = (short int) _12;
x_7 = _1 ^ x_6(D);
x.1_2 = (unsigned short) x_7;
_3 = (unsigned short) _12;
_4 = x.1_2 - _3;
_8 = (i16) _4;
Because of the overflow and such.
If we used -fwrapv we get:
_7 = x_3(D) < 0;
_8 = (int) _7;
_9 = -_8;
_1 = (short int) _9;
x_4 = _1 ^ x_3(D);
_5 = x_4 - _1;
Where we could reduce _1 to just:
t = (short int) _7;
_1 = -t;
And then it is just pattern matching.
For int we get:
_6 = x_2(D) < 0;
_7 = (int) _6;
_8 = -_7;
x_3 = x_2(D) ^ _8;
_4 = x_3 + _7;
Which should be easy to pattern match.
(plus:c (bit_xor:c @0 (neg (convert@1 (lt @0 zero_p)))) @1)
