Gentoo Archives: gentoo-dev

From: Chris Davies <c.davies@×××××××.org>
To: gentoo-dev@g.o
Subject: Re: [gentoo-dev] -fbranch-probabilities optimisation
Date: Sat, 17 May 2003 16:45:09
Message-Id: 20030517164702.GG6515@vaughan.foofalicious.com
In Reply to: Re: [gentoo-dev] -fbranch-probabilities optimisation by Paul de Vrieze
1 * Paul de Vrieze (pauldv@g.o) wrote:
2 Content-Description: signed data
3 > On Saturday 17 May 2003 16:13, Werner Van Belle wrote:
4 > > On Saturday 17 May 2003 15:57, Sven Vermeulen wrote:
5 > > > Aah, then I'm completely in favor of adding this to Portage :)
6 > >
7 > > Maybe first investigate how good this thing works. I've done a quick check
8 > > and I suspect this technique doesn't work on multithreaded programs.
9 >
10 > If the profiles can be created correctly there should be nothing stopping this
11 > from working. The problem is thought that this not so much has to be
12 > implemented by portage as by specific packages that benefit from this.
13 >
14 > Paul
15 >
16
17 The current release of gcc doesn't contain threadsafe profiling, and indeed may never do. The cfg branch, where this work is being carried out reports that merging threadsafe profiling with main is problematic, and the code may be dropped.
18
19 Still, there a whole bunch of single thread programs that can benifit from this stuff, especially on architectures like x86 which have tiny numbers of registers.
20
21 Thanks,
22 C.Davies
23
24
25 --
26 gentoo-dev@g.o mailing list

Replies

Subject Author
Re: [gentoo-dev] -fbranch-probabilities optimisation Paul de Vrieze <pauldv@g.o>
Re: [gentoo-dev] -fbranch-probabilities optimisation Sven Vermeulen <swift@g.o>