I've ported GMP to Mac Pro. GMPbench > 7700

Torbjorn Granlund tege at swox.com
Sat Oct 14 16:18:48 CEST 2006

"Jason Worth Martin" <martinjw at jmu.edu> writes:

  I've ported GMP to the Mac Pro (and it passes "make check").  I
  thought you might be interested since  I saw some archived posts on
  the poor Core 2 results.  I re-wrote add_n.asm and sub_n.asm and got a
  nice speed up by unrolling the loop and getting rid of the "inc"
  instruction.  I've attached a tarball with the relevant files and

I've made some experiments too, using the forgotten instruction jrcxz:

	jrcxz	exitloop
	lea	-1(%rcx), %rcx
	jmp	beginloop
  I believe that this code could be ported to Core 2 Linux machines, but
  the GNU assembler doesn't want to let me use the "sahf" and "lahf"
  instructions to save the flags between loop iterations.  The Apple
  assembler doesn't have a problem with it.  I'll see about replacing
  those instructions with a combitation of "bt" and "test" for a Linux
What sort of performance, as measured by tune/speed do you get for
your new functions?


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