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* [Bug target/36557]  New: -m32 -mpowerpc64 produces better code than -m64 for a!=0
@ 2008-06-17 20:12 pinskia at gcc dot gnu dot org
  0 siblings, 0 replies; only message in thread
From: pinskia at gcc dot gnu dot org @ 2008-06-17 20:12 UTC (permalink / raw)
  To: gcc-bugs

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


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2008-06-17 20:12 [Bug target/36557] New: -m32 -mpowerpc64 produces better code than -m64 for a!=0 pinskia at gcc dot gnu dot org

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