public inbox for gcc-help@gcc.gnu.org
 help / color / mirror / Atom feed
* profile directed feedback.
@ 2005-07-12 20:29 girish vaitheeswaran
  0 siblings, 0 replies; only message in thread
From: girish vaitheeswaran @ 2005-07-12 20:29 UTC (permalink / raw)
  To: gcc-help

Has anyone gotten performance gains on account of
profile directed feedback optimization. I used
gcc-3.4.3 and tried using profile directed feedback.
This is what I did

1. Compiled the program using -fprofile-generate. I
used this flag both in the compile flags and as part
of the link flags. I also had to use libgcov.a during
the link phase otherwise it would die looking for gcov
functions.
2. Ran a representative work-load
3. Followed (1) except that instead of
-fprofile-generate used -fprofile-use

I had to drop the "-fprofile-use" on 2 files as they
had corrupted profile data. So far so good.

When I ran the profile directed feedback optimized
executable, the performance was 20% slower.

Anyone has experience with PDF they can share and
point out what I am doing wrong?

Thanks
-girish

^ permalink raw reply	[flat|nested] only message in thread

only message in thread, other threads:[~2005-07-12 20:29 UTC | newest]

Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2005-07-12 20:29 profile directed feedback girish vaitheeswaran

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).