Gentoo Archives: gentoo-dev

From: Mike Gilbert <floppym@g.o>
To: gentoo-dev@l.g.o
Subject: Re: [gentoo-dev] filter-mfpmath: has Gentoo out grown it ?
Date: Sat, 03 Dec 2011 02:06:30
In Reply to: [gentoo-dev] filter-mfpmath: has Gentoo out grown it ? by Mike Frysinger
1 On 12/02/2011 05:57 PM, Mike Frysinger wrote:
2 > i'd like to think Gentoo has grown up now to the point where we don't bother
3 > with trivial ricer behavior. to that end, i'd like to EOL `filter-mfpmath`.
4 >
5 > my main beef with filtering -mfpmath is that we use this only when someone
6 > actually notices and reports misbehavior with the package in question, the
7 > behavior can fluctuate between gcc versions, and it's questionable whether the
8 > flag makes a significant difference in performance. considering this is x86-
9 > only, and our main user base is amd64 based, it doesn't see nearly the amount
10 > of attention that it did in the past. i'd prefer we leave this flag to the
11 > respective upstream packages to validate when it should be used (i.e. the
12 > mplayer's and ffmpeg's and such in the world).
13 >
14 > Ryan did a check and it seems we've got all of 5 packages (and one eclass)
15 > using this. so i say it's time to scrub the tree, punt the func, and then
16 > punt people who attempt to report bugs when building their whole system with -
17 > mfpmath and see misbehavior.
18 > -mike
20 I've never thought of -mfpmath=sse as a "ricer" flag. If anything, it
21 should make floating point calculations more consistent. Back when I
22 used x86, I had it in my global CFLAGS and can't remember it causing any
23 issues.
25 The varying behavior between gcc versions seems like a possibly good
26 reason to not "support" it, but I'm not familiar with this. Has it
27 stabilized recently or is it still in flux?
29 I would rather leave this in the hands of package maintainers than punt
30 it globally.


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Subject Author
[gentoo-dev] Re: filter-mfpmath: has Gentoo out grown it ? Ryan Hill <dirtyepic@g.o>