AMD K6-2s and the -mcpu=xxx switch.

Jason Gurtz flare at
Tue Aug 8 20:43:18 PDT 2000

> Reading the pgcc mailinglist one thing I learned is that the AMD-K6-2
> uses the same instruction set like the Pentium (in fact, it adds
> 3DNow! extension, but these instructions are not supported by gcc nor
> pgcc)

How about the SIMD instructions of the P3?

, but it's scheduling is more like the one from the PentiumPro,
> so one should use "-march=pentium -mcpu=pentiumpro" aka "-march=i586
> -mcpu=i686". You may of course play with the scheduling (which is
> specified with -mcpu=), but selecting anything higher than i586 aka
> pentium for code-creation (-march=) will sooner or later result in
> broken code or (more likely) error messages from the binutils about
> illegal instructions.
That makes sense as the K6 line has attained much higher clock speed than
can be attributed to die size alone (most recent is 600Mhz .18u) and the
integer performance _is_ impressive  :)
> >
> > ~Jason
> Tomislav

Mail archive:
IRC access: server: port: 6667 channel: #LFS
Unsubscribe: email lfs-discuss-request at and put
"unsubscribe" (without the quotation marks) in the body of the message
(no subject is required)

More information about the lfs-dev mailing list