From: Anthony Danalis <danalis@cis.udel.edu>
To: gcc@gcc.gnu.org
Subject: c++ performance regressions in gcc > 2.95.3
Date: Sat, 06 Aug 2005 00:57:00 -0000 [thread overview]
Message-ID: <42F40AD8.6080602@cis.udel.edu> (raw)
We observed that certain large C++ applications perform worse
in gcc-3.x and gcc-4.x than they did in gcc-2.95.3.
On the theory that at least some of the cause
would show up in microbenchmarks, we tried running
bench++ with both old and new toolchains.
Because we suspect that part of the regression is due to
libstdc++, we also measured performance using stlport.
Here are our results.
A table of nanoseconds-per-iteration for each individual microbenchmark in bench++
for g++-2.95.3, and for g++-4.0.1 and g++-4.1.0-20050723
with and without STLport, is at
http://www.cis.udel.edu/~danalis/OSS/bench_plus_plus/files/report-f15_m2_X_2.6-absolute.txt
A table normalized relative to the gcc-2.95.3 results is at
http://www.cis.udel.edu/~danalis/OSS/bench_plus_plus/files/report-f15_m2_X_2.6.txt
The interesting bits are summarized in a table showing just the performance regressions,
and annotated with descriptions of the microbenchmarks which regressed.
It's at
http://www.cis.udel.edu/~danalis/OSS/bench_plus_plus/results.html
We reported one of the regressions already as http://gcc.gnu.org/PR22563 .
There seem to be at least ten others that might be worth
reporting. I'll try to post bug reports for a few, but
my summer internship is running out soon. If anyone else
has time to look at the data, I'd appreciate suggestions or
criticism; maybe I can fix a few problems in my benchmark scripts
before I turn into a pumpkin.
Anthony Danalis & Dan Kegel
next reply other threads:[~2005-08-06 0:57 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-08-06 0:57 Anthony Danalis [this message]
2005-08-06 23:46 dank
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=42F40AD8.6080602@cis.udel.edu \
--to=danalis@cis.udel.edu \
--cc=gcc@gcc.gnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).