[Bug tree-optimization/96298] [11 Regression] wrong code with -O -fno-tree-forwprop

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96298

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Target|powerpc64-unknown-linux-gnu |powerpc64-unknown-linux-gnu
                   |                            |, x86_64-*-*
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2020-07-23
             Status|UNCONFIRMED                 |NEW
   Target Milestone|---                         |11.0

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
On ppc64le I for example see

  <bb 2> [local count: 119292720]:
  a.0_1 = a;
  _13 = VIEW_CONVERT_EXPR<long unsigned int>(a.0_1);
  _6 = ~_13;
  _10 = _13 & 9187201950435737471;
  _12 = _6 & 9259542123273814144;
  _21 = _10 + 9187201950435737471;
  _22 = _21 ^ _12;
  _23 = VIEW_CONVERT_EXPR<vector(8) unsigned char>(_22);
  _28 = 9259542123273814144 - _10;
  _29 = _12 ^ _28;
  _30 = VIEW_CONVERT_EXPR<vector(8) unsigned char>(_29);
  _31 = VIEW_CONVERT_EXPR<long unsigned int>(_30);
  _32 = VIEW_CONVERT_EXPR<long unsigned int>(_23);
  _33 = _32 ^ _31;
  _34 = VIEW_CONVERT_EXPR<vector(8) unsigned char>(_33);
  x = _34;

likewise on x86_64 with -mno-sse where it fails as well.