[Bug tree-optimization/94892] (x >> 31) + 1 not getting narrowed to compare

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94892

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Two things we should simplify:
  _4 = _3 >> 31;
  _4 != -1

Into:
  _3 >= 0 (if _3 is signed, otherwise false)

(this will solve f0)


And:
  _4 = x_3(D) >> 31;
  _7 = -x_3(D);
  _8 = (unsigned int) _7;
  _9 = _8 >> 31;
  _10 = (int) _9;
  _11 = _4 | _10;

Into:
_4 = x_3(D) >> 31; // keep around
_t = _4 | 1;
_11 = x != 0 ? _t : 0;