sysdeps/sparc/sparc64/sub_n.S

   1 /* SPARC v9 __mpn_sub_n -- Subtract two limb vectors of the same length > 0
   2    and store difference in a third limb vector.
   3
   4    Copyright (C) 1995-2015 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 Lesser General Public License as published by
  10    the Free Software Foundation; either version 2.1 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 Lesser General Public
  16    License for more details.
  17
  18    You should have received a copy of the GNU Lesser General Public License
  19    along with the GNU MP Library; see the file COPYING.LIB.  If not,
  20    see <http://www.gnu.org/licenses/>.  */
  21
  22 #include <sysdep.h>
  23
  24 /* INPUT PARAMETERS
  25    res_ptr      %o0
  26    s1_ptr       %o1
  27    s2_ptr       %o2
  28    size         %o3  */
  29
  30 ENTRY(__mpn_sub_n)
  31
  32         sub %g0,%o3,%g5
  33         sllx %o3,3,%g1
  34         add %o1,%g1,%o1                 ! make s1_ptr point at end
  35         add %o2,%g1,%o2                 ! make s2_ptr point at end
  36         add %o0,%g1,%o0                 ! make res_ptr point at end
  37         mov 0,%o4                       ! clear carry variable
  38         sllx %g5,3,%o5                  ! compute initial address index
  39
  40 1:      ldx [%o2+%o5],%g1               ! load s2 limb
  41         add %g5,1,%g5                   ! increment loop count
  42         ldx [%o1+%o5],%o3               ! load s1 limb
  43         addcc %g1,%o4,%g1               ! add s2 limb and carry variable
  44         movcc %xcc,0,%o4                ! if carry-out, o4 was 1; clear it
  45         subcc %o3,%g1,%g1               ! subtract s1 limb from sum
  46         stx %g1,[%o0+%o5]               ! store result
  47         add %o5,8,%o5                   ! increment address index
  48         brnz,pt %g5,1b
  49          movcs %xcc,1,%o4               ! if s1 subtract gave carry, record it
  50
  51         retl
  52          mov %o4,%o0
  53
  54 END(__mpn_sub_n)