On 12/02/2011 05:57 PM, Mike Frysinger wrote:
> i'd like to think Gentoo has grown up now to the point where we don't bother 
> with trivial ricer behavior.  to that end, i'd like to EOL `filter-mfpmath`.
> 
> my main beef with filtering -mfpmath is that we use this only when someone 
> actually notices and reports misbehavior with the package in question, the 
> behavior can fluctuate between gcc versions, and it's questionable whether the 
> flag makes a significant difference in performance.  considering this is x86-
> only, and our main user base is amd64 based, it doesn't see nearly the amount 
> of attention that it did in the past.  i'd prefer we leave this flag to the 
> respective upstream packages to validate when it should be used (i.e. the 
> mplayer's and ffmpeg's and such in the world).
> 
> Ryan did a check and it seems we've got all of 5 packages (and one eclass) 
> using this.  so i say it's time to scrub the tree, punt the func, and then 
> punt people who attempt to report bugs when building their whole system with -
> mfpmath and see misbehavior.
> -mike

I've never thought of -mfpmath=sse as a "ricer" flag. If anything, it
should make floating point calculations more consistent. Back when I
used x86, I had it in my global CFLAGS and can't remember it causing any
issues.

The varying behavior between gcc versions seems like a possibly good
reason to not "support" it, but I'm not familiar with this. Has it
stabilized recently or is it still in flux?

I would rather leave this in the hands of package maintainers than punt
it globally.