------- Comment #8 from pinskia at gcc dot gnu dot org 2006-04-12 01:14 -------
GRRRRRRR.
This is partly caused by the patch for PR 23669.
(In reply to comment #7)
> > I disagree. Could you give an explicit example?
> Sorry, my mistake, I should not have suggested this testcase: this
> optimization
> is indeed fine (yet GCC 4.1 does not apply it). The following testcase is not
> fine though (directly derived from the original testcase):
> int f(int a, int b) { return (-1 - a) / (-b); }
> GCC 4.2 generates the division "(a + 1) / b". This optimization is wrong when
> "a" contains the biggest positive integer.
This is undefined only if b is known to be negative otherwise it is defined.
Note I cannot patch anything right now so if someone wants to revert my patch
that is fine.
--
pinskia at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |pinskia at gcc dot gnu dot
| |org
OtherBugsDependingO| |23669
nThis| |
Known to work|4.1.0 4.0.3 |
Target Milestone|--- |4.2.0
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27116
