Performance analysis of Mul algorithms in the same range

Torbjorn Granlund tg at
Sun Jan 4 16:39:22 CET 2009

"Lingchuan Meng" <lingchuanmeng at> writes:

  Thank you for the reply. The symlink is pointing to the 'gmp-mpara.h'
  located in /mpn/x86/k7/ in my case. And after editing,  both files in
  the build directory and  /mpn/x86/k7/ have been changed. I've compared
  the performances of untuned and tuned library by copying the
  thresholds from the tuning program to 'gmp-mpara.h' in the build
  folder, and it worked as expected. However, as mentioned in previous
  email, editing those thresholds manually to force certain algorithm to
  run doesn't deliver the expected result. And the new 'gmp-mpara.h' did
  survive the reconfigure and rebuild.

Since I don't know what result you expect, I don't think I can provide
much more assistance.  But perhaps a little debugger session would help

If you compile in MUL_KARATSUBA_THRESHOLD as 1, I'd expect crashes
and/or incorrect results.  If you don't get that, I doubt you have
compiled in that value.

  The speed program is great, but, in my case, I'm hoping to get more
  information by inserting PAPI codes.

I don't understand what you mean.


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