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Re: core dumps in optimized case with gcc 3.0 and 3.0.1 (regression a
- To: wilhelm dot nuesser at sap dot com (Nuesser, Wilhelm)
- Subject: Re: core dumps in optimized case with gcc 3.0 and 3.0.1 (regression a
- From: Joe Buck <jbuck at synopsys dot COM>
- Date: Sat, 25 Aug 2001 17:18:25 -0700 (PDT)
- Cc: gcc at gcc dot gnu dot org ('gcc at gcc dot gnu dot org'), thomas dot hiller at sap dot com (Hiller Thomas)
> when compiling our software ( binary size approx. 40 MB) with gcc 3.0 and
> 3.0.1 with -O2 on
> Linux ia32,
> RedHat 6.2 and SuSE 7.0 (i.e. glibc 2.1.3),
> kernel 2.2.19 and 2.4.4
> we find core dumps which do not appear when compiling with 2.95.[2,3]
> (with or without optimization) or with gcc 3* without optimizations.
While a compiler bug is possible, it's also possible that there is a
problem with your source code: uninitialized variables, or constructs
with undefined behavior such as
a[i] = i++;
can result in optimized code functioning differently from unoptimized code.
> We suspect gcc bugs, since our software run on many 32 and 64 bit platforms,
> but - of course -
> we are not sure. We have no idea what is actually going on so we can not
> produce any testcase
> at the moment.
I suggest trying to isolate the function which is being miscompiled (if
your suspicion of a compiler bug is correct). Try compiling some files
with -O2 and some with -O0, find the file that is being effected by
optimization level, then try to isolate the function.
Then you'll have a short test case you can send in as a bug report.