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Re: Do we get the other 15% performance back too?
- From: Joe Buck <Joe dot Buck at synopsys dot com>
- To: militzer at llnl dot gov (Burkhard Militzer)
- Cc: gcc at gcc dot gnu dot org
- Date: Mon, 26 Aug 2002 13:33:30 -0700 (PDT)
- Subject: Re: Do we get the other 15% performance back too?
> As a fan of the C++ gnu compiler project, I would like to congratulate the
> gurus on the recent performance increase probably coming from corrections
> in the prefetch routines. My benchmark shows
>
> Processor/OS Compiler/options Time(sec)
> Pentium 4 1.7Ghz pgCC -O3 -fast -Minline=3/4 8.27
> Pentium 4 1.7Ghz gnu g++ -O3 (2.95.2) 8.62 <-- fastest
> Pentium 4 1.7Ghz Intel icpc 5.0 -O3 8.65
> Pentium 4 1.7Ghz gnu g++ -O3 (2.95.3) 10.94
> Pentium 4 1.7Ghz gnu g++ -O3 (3.2) 11.30 <-- new
> Pentium 4 1.7Ghz gnu g++ -O3 (3.01) 15.09 <-- previous
You don't explain just what you are timing here.
I don't understand why you are getting such different results for 2.95.2
and 2.95.3, considering that there aren't really any differences to speak
of; the only job of the 2.95.2 -> 2.95.3 patch was to fix some breakage
having to do with compatibility with glibc 2.2, as well as to fix a couple
of minor bugs in a way that should not have had any effect on compiler
performance.
How did you produce these compilers? Did you build them yourself, or
download them from somewhere? If they are from .rpm's or .deb's, were
they built for 686 or 386?