public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
* [Bug c/31245]  New: SSE2 generation bug with 4.1.2 and -O3
@ 2007-03-17 15:52 prakash at punnoor dot de
  2007-03-17 15:53 ` [Bug c/31245] " prakash at punnoor dot de
                   ` (10 more replies)
  0 siblings, 11 replies; 12+ messages in thread
From: prakash at punnoor dot de @ 2007-03-17 15:52 UTC (permalink / raw)
  To: gcc-bugs

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain, Size: 1087 bytes --]

This is my simple test proggie.

test1 is always ok, but test2 fails with -O3 (produces output 1 0 0 0 for 
test2), but -O2 makes it behave.


I  am on x86_64. -m32 has interesting effects:

-O3 -Wall -m32 -msse2 -march=i486 is ok (output 1 0 3 0, as expected)
-O3 -Wall -m32 -msse2 -march=i586 is broken (output 0 2 3 4)
-O3 -Wall -m32 -msse2 -march=athlon is broken (output 1 0 0 0)

Is this the aliasing issues I read about with 4.1 compiler? Is there an easy 
work-around? In fact I need to pass data as aligned buffer, so I need test2 
to behave correctly. :-(

Do you need anything else?


-- 
           Summary: SSE2 generation bug with 4.1.2 and -O3
           Product: gcc
           Version: 4.1.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: prakash at punnoor dot de
 GCC build triplet: x86_64-pc-linux-gnu
  GCC host triplet: x86_64-pc-linux-gnu
GCC target triplet: x86_64-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31245


^ permalink raw reply	[flat|nested] 12+ messages in thread
end of thread, other threads:[~2007-04-28  4:18 UTC | newest]

Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2007-03-17 15:52 [Bug c/31245] New: SSE2 generation bug with 4.1.2 and -O3 prakash at punnoor dot de
2007-03-17 15:53 ` [Bug c/31245] " prakash at punnoor dot de
2007-03-17 16:49 ` [Bug target/31245] " prakash at punnoor dot de
2007-03-17 16:51 ` prakash at punnoor dot de
2007-03-18 15:58 ` prakash at punnoor dot de
2007-03-18 16:31 ` pinskia at gcc dot gnu dot org
2007-03-20 17:09 ` rth at gcc dot gnu dot org
2007-03-21 15:47 ` rth at gcc dot gnu dot org
2007-03-21 15:50 ` rth at gcc dot gnu dot org
2007-03-21 15:52 ` rth at gcc dot gnu dot org
2007-03-23 16:31 ` rth at gcc dot gnu dot org
2007-04-28  4:19 ` kargl at gcc dot gnu dot org

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).