sysdeps/z8000/sub_n.s

   1 ! Z8000 __mpn_sub_n -- Subtract two limb vectors of the same length > 0 and
   2 ! store difference in a third limb vector.
   3
   4 ! Copyright (C) 1993, 1994 Free Software Foundation, Inc.
   5
   6 ! This file is part of the GNU MP Library.
   7
   8 ! The GNU MP Library is free software; you can redistribute it and/or modify
   9 ! it under the terms of the GNU Library General Public License as published by
  10 ! the Free Software Foundation; either version 2 of the License, or (at your
  11 ! option) any later version.
  12
  13 ! The GNU MP Library is distributed in the hope that it will be useful, but
  14 ! WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  15 ! or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
  16 ! License for more details.
  17
  18 ! You should have received a copy of the GNU Library General Public License
  19 ! along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
  20 ! the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  21 ! MA 02111-1307, USA.
  22
  23
  24 ! INPUT PARAMETERS
  25 ! res_ptr       r7
  26 ! s1_ptr        r6
  27 ! s2_ptr        r5
  28 ! size          r4
  29
  30 ! If we are really crazy, we can use push to write a few result words
  31 ! backwards, using push just because it is faster than reg+disp.  We'd
  32 ! then add 2x the number of words written to r7...
  33
  34         unseg
  35         .text
  36         even
  37         global ___mpn_sub_n
  38 ___mpn_sub_n:
  39         pop     r0,@r6
  40         pop     r1,@r5
  41         sub     r0,r1
  42         ld      @r7,r0
  43         dec     r4
  44         jr      eq,Lend
  45 Loop:   pop     r0,@r6
  46         pop     r1,@r5
  47         sbc     r0,r1
  48         inc     r7,#2
  49         ld      @r7,r0
  50         dec     r4
  51         jr      ne,Loop
  52 Lend:   ld      r2,r4           ! use 0 already in r4
  53         adc     r2,r2
  54         ret     t