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Re: SSE Level 3 drop in gemm
>2) What about other compilers? Anyone know if atlas is extensively
> used with other compilers, and whether those even accept __asm__
ATLAS is used with many other compilers, but gcc is clearly the best for
intel/linux. In the new work I'm doing, you can specify a particular
compiler and flags to go along with your kernel, so you can insist
on using gcc, even if ATLAS were to switch to pgcc, for instance . . .
>On a separate front, I've taken the optimally generated double
>precision matmul kernel and tried adding prefetch. Thus far, an
>inexplicable (to me at least) dramatic drop in performance,
>approaching a factor of 2! I thought some on this list might know
>what is going on.
For what it is worth, I had the same experience on adding 3DNow prefetch
to the Athlon kernel. I only messed with it one evening, so I never tracked
down what was going on . . .