Re: gcc-3.3 bugs Debian unstable hppa
On Fri, Feb 20, 2004 at 11:49:35AM -0500, Camm Maguire wrote:
> Base switches required: -fPIC -ffunction-sections
>
> -O0 -O1 -O2
> gcl PASS PASS PASS
> maxima PASS PASS FAIL
> acl2 PASS FAIL
> axiom PASS
Intersting.
> The acl2 failure at -O1 was intermittently reproducible: some test
> runs with the same executable would pass, some would fail in precisely
> the same place, failing to find a / character when searching through a
> directory string.
Could you narrow down the failure? I find most of the time the code is
to blame, usually because you forget to mark a variable as volatile,
modified it globally, but gcc optimized it out of a loop. I know the
compiler has bugs, but they aren't horrible bad bugs.
> We're about to finalize the stable 2.6.2 gcl release. Any
> recommendations on what the default flags should be? I'm thinking
> there are few enough users that would care about the performance hit
> that -O0 by default for all programs might be best.
If you have to release, then you have to release, it's best to get
users. What worries me is the "blank" in your diagram, does that mean
that axiom doesn't compile in -O0? I compile glibc with -O2 without
problems, and *everything* relies on glibc. I'm *almost* guaranteed that
the code is probably wrong.
> BTW, is it worth filing a bug against gcc, or are people already
> actively working on the hppa backend anyway? I'm a bit short on time,
> so a very detailed report by me is probably not feasible right now.
It's definately worth investigating, can you find out why? Perhaps
narrow it down a little. Even a smaller context would allow me to
suggest something, or perhaps I've already seem a similar bug.
Cheers,
c.
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