[Bug tree-optimization/57380] [4.7/4.8/4.9 Regression] GCC 4.9.0 will not vectorize std::max and similar functions

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57380

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2013-05-23
      Known to work|                            |4.5.4
           Assignee|unassigned at gcc dot gnu.org      |rguenth at gcc dot 
gnu.org
   Target Milestone|---                         |4.7.4
            Summary|GCC 4.9.0 will not          |[4.7/4.8/4.9 Regression]
                   |vectorize std::max and      |GCC 4.9.0 will not
                   |similar functions           |vectorize std::max and
                   |                            |similar functions
     Ever confirmed|0                           |1

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
For some reason phiprop doesn't work here.  I'll investigate, but I guess
it is because the addresses are not constant but depend on the loop IV:

  <bb 3>:
  _3 = &b.data[i_2];
  _4 = &a.data[i_2];
  _10 = MEM[(const int &)&a].data[i_2];
  _11 = MEM[(const int &)&b].data[i_2];
  if (_10 < _11)
    goto <bb 5>;
  else
    goto <bb 4>;

  <bb 4>:

  <bb 5>:
  # iftmp.0_12 = PHI <_3(3), _4(4)>

  <bb 6>:
  _6 = *iftmp.0_12;