[Bug target/36557] New: -m32 -mpowerpc64 produces better code than -m64 for a!=0

["pinskia at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

Testcase:
unsigned char f(unsigned int m_pAttachedTo)
{
  return m_pAttachedTo != 0;
}

When merging the PS3 specific changes up to 4.3.0, I Noticed that -m32
-mpowerpc64 produces better code in some cases than -m64, this is one such
case.
Right now with -m64 we produce:
        srawi 0,3,31
        xor 3,0,3
        subf 3,3,0
        rldicl 3,3,33,63
        blr
But since m_pAttachedTo is passed as a zero extended 64bit we should be able to
produce:
        addic 9,3,-1
        subfe 0,9,3
        blr
As we do for -m32 and also for 64bit unsigned integers with -m64.


-- 
           Summary: -m32 -mpowerpc64 produces better code than -m64 for a!=0
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: enhancement
          Priority: P3
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pinskia at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36557