[PATCH] T3/T4 sparc shifts, plus more timings

Torbjorn Granlund tg at gmplib.org
Mon Apr 1 19:34:11 CEST 2013

David Miller <davem at davemloft.net> writes:

  Yes, understood.  We have to transpose a few of the shifts with
  their neighbouring arithmetic ops in this loop to make it optimal
  for Ultra-I/II/IIi
I found a powered up US2 and run time timing tests.  No slowdown there
for the new generic functions.

I suppose mpn/sparc64/ultrasparc1234/[lr]shift.asm are now redundant.

Clearly, the new lshiftc code is not optimal for US1 through US4.  It
runs 0.5 c/l slower on them all, compared to what one would hope for
2-way unrolled code.


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