[Bug tree-optimization/101139] Unable to remove double byteswap in fast path

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101139

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2021-06-20
           Assignee|unassigned at gcc dot gnu.org      |pinskia at gcc dot 
gnu.org
         Depends on|                            |13563
             Status|UNCONFIRMED                 |ASSIGNED
           Keywords|                            |missed-optimization
     Ever confirmed|0                           |1

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
  if (b_13 < h.0_15)
    goto <bb 4>; [51.12%]
  else
    goto <bb 5>; [48.88%]

  <bb 4> [local count: 548896825]:
  _16 = (short unsigned int) f$ab_14;
  _17 = (int) _16;
  _18 = __builtin_bswap16 (_17);
  goto <bb 6>; [100.00%]

  <bb 5> [local count: 524845000]:
  k_22 = i ();
  c.1_23 = (short unsigned int) k_22;
  _24 = (int) c.1_23;
  _25 = __builtin_bswap16 (_24);

  <bb 6> [local count: 1073741824]:
  # prephitmp_32 = PHI <_18(4), _25(5)>

Basically the same issue as PR 13563.


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=13563
[Bug 13563] if-conversion not agressive enough