[Bug middle-end/78115] Missed optimization for "int modulo 2^31"

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78115

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |enhancement

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
We get now:
  if (num_2(D) < 0)
    goto <bb 3>; [41.00%]
  else
    goto <bb 4>; [59.00%]

  <bb 3> [local count: 440234144]:
  num_3 = num_2(D) - -2147483648;

  <bb 4> [local count: 1073741824]:
  # num_1 = PHI <num_2(D)(2), num_3(3)>

So something like (psedu code):
(simplify
 (cond (lt @0 integer_zerop) (minus @0 INTEGER_CST@1) @0)
 (if (TYPE_SIGN (type) == SIGNED && @1 == type_min(type))
  (bit_and @0 type_max(type))))