[Bug rtl-optimization/83123] Int compare - different asm code for different return type

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83123

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |missed-optimization
             Target|                            |x86_64-*-*, i?86-*-*
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2017-11-23
                 CC|                            |segher at gcc dot gnu.org
          Component|c                           |rtl-optimization
     Ever confirmed|0                           |1

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
The first case is somehow optimized by combine while the latter is not.
The gimple is almost equal, so is the expanded RTL.

test1 (int a, int b)
{
  _Bool _1;
  _Bool _2;
  _Bool _3;
  int _6;

  <bb 2> [local count: 1073741825]:
  _1 = a_4(D) < 0;
  _2 = b_5(D) < 0;
  _3 = _1 & _2;
  _6 = (int) _3;
  return _6;

test2 (int a, int b)
{
  _Bool _1;
  _Bool _2;
  _Bool _3;

  <bb 2> [local count: 1073741825]:
  _1 = a_4(D) < 0;
  _2 = b_5(D) < 0;
  _3 = _1 & _2;
  return _3;