[gentoo-dev] Re: filter-mfpmath: has Gentoo out grown it ?

[Ryan Hill <dirtyepic@gentoo.org>]

[-- Attachment #1: Type: text/plain, Size: 1071 bytes --]

On Fri, 02 Dec 2011 20:36:16 -0500
Mike Gilbert <floppym@gentoo.org> wrote:

> I've never thought of -mfpmath=sse as a "ricer" flag. If anything, it
> should make floating point calculations more consistent.

Not really.  It's it's extremely target processor dependent and generally the
defaults are the best settings.  It can vary a lot based on the SSE
instructions and number of registers available and the register allocator and
scheduler are optimized with that in mind.

> 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'd say it's still in flux.  The register allocator and instruction scheduler
were both rewritten for 4.4 and have seen a lot of work since then.


-- 
fonts, gcc-porting,                  it makes no sense how it makes no sense
toolchain, wxwidgets                           but i'll take it free anytime
@ gentoo.org                EFFD 380E 047A 4B51 D2BD C64F 8AA8 8346 F9A4 0662

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 198 bytes --]