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* [Bug c/32328]  New: 4.2.0: -O2 causes skipped code
@ 2007-06-13 21:18 tdragon at tdragon dot net
  2007-06-13 21:20 ` [Bug c/32328] " tdragon at tdragon dot net
                   ` (33 more replies)
  0 siblings, 34 replies; 36+ messages in thread
From: tdragon at tdragon dot net @ 2007-06-13 21:18 UTC (permalink / raw)
  To: gcc-bugs

When the attached file is compiled with a mingw32 build of GCC 4.2.0 using the
-O2 option (gcc -O2 -c timestamp2.i), lines 159 and 160 are never executed when
running the program that uses this file. Since the hashitem function modifies
the variable b which is passed to it by-address, leaving those statements out
is definitely not a valid optimization. Compiling without -O2 (gcc -c
timestamp2.i) gives the correct result. Sorry I can't read assembler, or I'd
try to narrow things down more.

This is a regression from 4.1.2, which works correctly with or without -O2. If
it helps, the GCC binaries I use (and sources) can be downloaded at
http://hosted.filefront.com/tldragon7.


-- 
           Summary: 4.2.0: -O2 causes skipped code
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: tdragon at tdragon dot net
 GCC build triplet: i386-pc-mingw32
  GCC host triplet: i386-pc-mingw32
GCC target triplet: i386-pc-mingw32


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32328


^ permalink raw reply	[flat|nested] 36+ messages in thread

end of thread, other threads:[~2009-03-30 22:07 UTC | newest]

Thread overview: 36+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2007-06-13 21:18 [Bug c/32328] New: 4.2.0: -O2 causes skipped code tdragon at tdragon dot net
2007-06-13 21:20 ` [Bug c/32328] " tdragon at tdragon dot net
2007-06-13 22:21 ` [Bug rtl-optimization/32328] " pinskia at gcc dot gnu dot org
2007-06-13 22:27 ` [Bug tree-optimization/32328] " tdragon at tdragon dot net
2007-06-13 22:36 ` tdragon at tdragon dot net
2007-06-13 22:47 ` tdragon at tdragon dot net
2007-06-20 14:45 ` tdragon at tdragon dot net
2007-06-20 14:47 ` tdragon at tdragon dot net
2007-06-20 14:52 ` tdragon at tdragon dot net
2007-06-20 15:13 ` [Bug tree-optimization/32328] [4.2 Regression] -fstrict-aliasing " rguenth at gcc dot gnu dot org
2007-06-20 15:16 ` [Bug tree-optimization/32328] [4.2/4.3 " rguenth at gcc dot gnu dot org
2007-06-20 15:36 ` tdragon at tdragon dot net
2007-06-20 20:04 ` dberlin at dberlin dot org
2007-06-20 20:09 ` dberlin at gcc dot gnu dot org
2007-07-04  3:29 ` mmitchel at gcc dot gnu dot org
2007-07-04 14:16   ` Daniel Berlin
2007-07-04 14:17 ` dberlin at dberlin dot org
2007-07-16 13:39 ` giovannibajo at libero dot it
2007-07-16 13:58 ` dberlin at dberlin dot org
2007-07-16 14:27 ` rguenth at gcc dot gnu dot org
2007-07-16 15:51 ` rguenth at gcc dot gnu dot org
2007-07-16 22:29 ` dberlin at dberlin dot org
2007-07-20  3:50 ` mmitchel at gcc dot gnu dot org
2007-08-19 23:24 ` dberlin at gcc dot gnu dot org
2007-08-20  1:54 ` dberlin at gcc dot gnu dot org
2007-08-22 15:52 ` rguenth at gcc dot gnu dot org
2007-08-23 12:42 ` [Bug tree-optimization/32328] [4.2 " rguenth at gcc dot gnu dot org
2007-09-05  6:47 ` giovannibajo at libero dot it
2007-09-05  8:29 ` rguenth at gcc dot gnu dot org
2007-09-05 11:51 ` dberlin at dberlin dot org
2007-10-09 19:30 ` mmitchel at gcc dot gnu dot org
2008-02-01 17:05 ` jsm28 at gcc dot gnu dot org
2008-02-22 18:15 ` tdragon at tdragon dot net
2008-02-22 18:48 ` pinskia at gcc dot gnu dot org
2008-05-19 20:27 ` jsm28 at gcc dot gnu dot org
2009-03-30 22:07 ` jsm28 at gcc dot gnu dot org

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