C implementation of mod_1_1

Torbjorn Granlund tg at gmplib.org
Tue Mar 1 12:23:01 CET 2011

nisse at lysator.liu.se (Niels Möller) writes:

  Can you add MOD_1_1P_METHOD to http://gmplib.org/devel/thresholds.html?


  I'm curious on where the new method 2 wins.

Almost everywhere, it seems.

  I might try to write add_mssaaaa for sparc32 and sparc64 (sparc is the
  only "obscure" architecture which both I and GMP understand to some

sparc32 should be piece of cake, sparc64 lacks a carry-generating insn,
making it somewhat hairy.  The asm code uses two approaches, one makes
use of a logical formula on the sign bits, the other (see
mpn/sparc64/ultrasparct1/add_n.asm) does some tricks using 32-bit and
64-bit addition operations.

  Or maybe m68k, but as far as I see there's no such machines in the
  test farm).

Unfortunately, the venerable mc68040 system of the GMP test array has a
dead PSU.  I got it to boot with a lab PSU setup, but I have not found
the time to repair the PSU yet...  Some may argue that GMP for m68k is
not critically important.


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