What is a difference between `-march=pentiumpro' and `-march=i686' ?

[Tim Prince]

IIRC, pentiumpro and i686 may be synonymous; -mcpu invokes the specified
scheduling parameters without going beyond the 486 instruction set,
and -march=pentiumpro both schedules and selects instructions (in
particular, conditional moves) for Pro/II/III.  I don't  believe there is
any better choice than that for P-III and newer in gcc-2.95.2.
----- Original Message -----
From: "Dmitry Antipov" <antipov@rosnet.ru>
To: <gcc@gcc.gnu.org>
Sent: Wednesday, October 25, 2000 9:03 AM
Subject: What is a difference between `-march=pentiumpro' and `-march=i686'
?


> Hello all,
>
> What is a difference between:
>  `-march=pentiumpro' and `-march=i686' ?
>  `-mcpu=pentiumpro' and `-mcpu=i686' ?
> And what are best optimization options (for code speed, of course)
> flags for PIII and Athlon processors in gcc 2.95.2 ?
>
> Thanks,
> --
> Dmitry Antipov <antipov@rosnet.ru>
> Rosnet JSC +7 (095) 7558560 (4304)
>