drago01 (drago01(a)gmail.com) said:
> Way back when in February [1], FESCo decided that for Fedora 11,
i586 would
> be the default architecture, and for Fedora 12, it would be some variant of
> i686. It's time to follow through on that action item.
Moving to i686 is fine, non i686 chips are mostly dead (but the
perfomance gain from moving to i686 from i586 is questionable at
best).
... how so? It's consistently 1-2% in reasonable benchmarks (real-world
code, albeit cpu-specific).
This is going to far, it makes x86 no longer useable on anything but
P4, Pentium M and Atom.
The only chip which is worth optimizing for is the Atom but its not
worth killing support for a lot of older systems (ex: Athlon XP system
are still present and aren't much slower than the non 64bit cable P4)
Well, we could use the Atom tuning support and build with -march=i686
-mtune=atom. That could be fun.
> Why?
>
> - Faster and more consistent FP math by using SSE2 registers
Only in certain apps, and most of them have handwritten SSE routines anyway.
-fpmath=sse is faster in general, not just in specifc apps. (According
to all the toolchain people I've talked to.)
Bill