This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: 100x -O0 Compile Time Regression {3.2,3.3} -> {3.4,3.5}
- From: "Zack Weinberg" <zack at codesourcery dot com>
- To: John Vickers <John at xza5 dot com>
- Cc: gcc at gcc dot gnu dot org
- Date: Thu, 12 Feb 2004 16:40:40 -0800
- Subject: Re: 100x -O0 Compile Time Regression {3.2,3.3} -> {3.4,3.5}
- References: <402BF520.3000505@xza5.com>
John Vickers <John@xza5.com> writes:
> Hello.
>
> We've got some generated C++ which compiles in about 10s (on a P4
> 2800) at -O0 with gcc-3.2 or 3.3.2, but takes about 1000s with 3.4.0
> or 3.5.0. -ftime-report says that the parser time has gone from
> 8.04s (gcc-3.3.2) to 958.19s (gcc-3.4.0)
The most efficient way to track this down is probably to apply a
function-level profiler (oprofile is convenient as it doesn't require
recompiling anything; gprof also works; I can supply instructions for
building the compiler with gprof instrumentation if you like)
> Any suggestions as to where to start digging ? I can supply
> preprocessed source to anyone interested.
Please file a bug report and attach the preprocessed source to that.
zw