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* [Bug target/33008]  New: [4.1/4.2 regression] code pessimization after -fforce-mem removal.
@ 2007-08-07  7:19 pluto at agmk dot net
  2007-09-26 19:14 ` [Bug target/33008] " pinskia at gcc dot gnu dot org
                   ` (6 more replies)
  0 siblings, 7 replies; 8+ messages in thread
From: pluto at agmk dot net @ 2007-08-07  7:19 UTC (permalink / raw)
  To: gcc-bugs

unsigned short load( void* p )
{
        unsigned short v;
        __builtin_memcpy( &v, p, sizeof( v ) );
        return v;
}

recent 4.2 branch produces:

load:   movzwl  (%rdi), %eax
        movw    %ax, -2(%rsp)
        movzwl  %ax, %eax
        ret

revsion 101665 produces optimal code:

load:   movzwl  (%rdi), %eax
        ret

the regression was introduced by Fariborz Jahanian:
http://gcc.gnu.org/viewcvs?view=rev&revision=101666


-- 
           Summary: [4.1/4.2 regression] code pessimization after -fforce-
                    mem removal.
           Product: gcc
           Version: 4.2.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pluto at agmk dot net
GCC target triplet: x86_64-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33008


^ permalink raw reply	[flat|nested] 8+ messages in thread
end of thread, other threads:[~2009-03-30 22:14 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2007-08-07  7:19 [Bug target/33008] New: [4.1/4.2 regression] code pessimization after -fforce-mem removal pluto at agmk dot net
2007-09-26 19:14 ` [Bug target/33008] " pinskia at gcc dot gnu dot org
2007-09-28  3:56 ` mmitchel at gcc dot gnu dot org
2007-10-09 19:27 ` mmitchel at gcc dot gnu dot org
2008-02-01 17:04 ` jsm28 at gcc dot gnu dot org
2008-05-19 20:28 ` jsm28 at gcc dot gnu dot org
2008-07-04 22:50 ` [Bug target/33008] [4.2 " jsm28 at gcc dot gnu dot org
2009-03-30 22:14 ` jsm28 at gcc dot gnu dot org

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