public inbox for gcc-bugs@sourceware.org help / color / mirror / Atom feed
* [Bug c/16309] New: different behavior in lvalue assignment in -O0 & -O2 @ 2004-07-01 8:49 nakkore at libero dot it 2004-07-01 9:08 ` [Bug c/16309] " falk at debian dot org ` (2 more replies) 0 siblings, 3 replies; 4+ messages in thread From: nakkore at libero dot it @ 2004-07-01 8:49 UTC (permalink / raw) To: gcc-bugs Compiling with -O2 and -O0 the following code i obtain different result with gcc version > 3.2 ( i tryed 3.3.3,3.3.4) unsigned char dest[10],source[10]={1,2,3,4,5,6,7,8,9,10}; int main(void) { int i = 1; int step = 1; while (i < 8) dest[i] = source[(i++*step) % 7]; for(i=0; i < 8; i++) printf("%02x ",dest[i]); printf("\n"); i=1; while (i < 8) { dest[i] = source[(i*step) % 7]; i++; } for(i=0; i < 8; i++) printf("%02x ",dest[i]); printf("\n"); return(i+dest[6]); } the difference is how dest[i] is addressed via the index i. -- Summary: different behavior in lvalue assignment in -O0 & -O2 Product: gcc Version: 3.3.3 Status: UNCONFIRMED Severity: normal Priority: P2 Component: c AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: nakkore at libero dot it CC: gcc-bugs at gcc dot gnu dot org GCC build triplet: Reading specs from /usr/lib/gcc-lib/i686-pc-linux- gnu/3.3.3/spec GCC host triplet: i386 GCC target triplet: i386 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16309 ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c/16309] different behavior in lvalue assignment in -O0 & -O2 2004-07-01 8:49 [Bug c/16309] New: different behavior in lvalue assignment in -O0 & -O2 nakkore at libero dot it @ 2004-07-01 9:08 ` falk at debian dot org 2004-08-13 16:01 ` bangerth at dealii dot org 2004-08-13 16:05 ` bangerth at dealii dot org 2 siblings, 0 replies; 4+ messages in thread From: falk at debian dot org @ 2004-07-01 9:08 UTC (permalink / raw) To: gcc-bugs ------- Additional Comments From falk at debian dot org 2004-07-01 09:08 ------- With -Wall, you get: test.c:9: warning: operation on `i' may be undefined and in fact it is; see documentation on -Wsequence-point. -- What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution| |INVALID Summary|different behavior in lvalue|different behavior in lvalue |assignment in -O0 & -O2 |assignment in -O0 & -O2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16309 ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c/16309] different behavior in lvalue assignment in -O0 & -O2 2004-07-01 8:49 [Bug c/16309] New: different behavior in lvalue assignment in -O0 & -O2 nakkore at libero dot it 2004-07-01 9:08 ` [Bug c/16309] " falk at debian dot org @ 2004-08-13 16:01 ` bangerth at dealii dot org 2004-08-13 16:05 ` bangerth at dealii dot org 2 siblings, 0 replies; 4+ messages in thread From: bangerth at dealii dot org @ 2004-08-13 16:01 UTC (permalink / raw) To: gcc-bugs ------- Additional Comments From bangerth at dealii dot org 2004-08-13 16:01 ------- Reopening to mark as a duplicate of... -- What |Removed |Added ---------------------------------------------------------------------------- Status|RESOLVED |UNCONFIRMED Resolution|INVALID | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16309 ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c/16309] different behavior in lvalue assignment in -O0 & -O2 2004-07-01 8:49 [Bug c/16309] New: different behavior in lvalue assignment in -O0 & -O2 nakkore at libero dot it 2004-07-01 9:08 ` [Bug c/16309] " falk at debian dot org 2004-08-13 16:01 ` bangerth at dealii dot org @ 2004-08-13 16:05 ` bangerth at dealii dot org 2 siblings, 0 replies; 4+ messages in thread From: bangerth at dealii dot org @ 2004-08-13 16:05 UTC (permalink / raw) To: gcc-bugs ------- Additional Comments From bangerth at dealii dot org 2004-08-13 16:04 ------- ...PR 11751. *** This bug has been marked as a duplicate of 11751 *** -- What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution| |DUPLICATE http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16309 ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2004-08-13 16:04 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2004-07-01 8:49 [Bug c/16309] New: different behavior in lvalue assignment in -O0 & -O2 nakkore at libero dot it 2004-07-01 9:08 ` [Bug c/16309] " falk at debian dot org 2004-08-13 16:01 ` bangerth at dealii dot org 2004-08-13 16:05 ` bangerth at dealii 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).