[2.4] [2.5] [i386] Add support for GCC 3.1

Another processor config could be CONFIG_K62. gcc-3.1 -march=k6-2 benchmarks a little better than -march=k6. Adding CONFIG_XF86_USE_3DNOW=y seems to help a little too.

Based on grepping gcc-3.1 src, it appears:
k6-3 == k6-2
athlon-tbird == athlon
athlon-xp == athlon-4 == athlon-mp

Randy Hron

Make sure you benchmark FPU intensive use when testing USE_3DNOW. I've seen several situations where it looks marginally better until you actually measure two things - memory bandwidth available to user programs, and also FPU performance, especially of FPU heavy apps that schedule a lot (eg Quake)

Not quite...

   if (!ix86_arch_string)
                   ix86_arch_string = TARGET_64BIT ? "athlon-4" : "i386";

Discussion with Jan Hubicka reveals that this should be checking for "opteron", but as this was the closest match, it's not equivalent to athlon-xp or athlon-mp in current gcc.

| Dave Jones.        http://www.codemonkey.org.uk
| SuSE Labs

IIRC (not looking at the datasheets) there were some pretty nice improvements made to the core in the K6 to K6-2 update (not just and upclock and downsize, real changes(isn't this when they added MMX too?)).

However, the K6-3 is simply a K6-2 with the addition of a 256K L2 cache on die at full cpu clock. It was a great improvement performance wise for many uses (think 256K L2 @ 450Mhz, and then a 2M L3 on the mainboard) though.

I route, therefore you are.

original k6 had mmx. k6-2 brought 3dnow.

| Dave Jones.        http://www.codemonkey.org.uk
| SuSE Labs