sysdeps/mips/submul_1.s

   1  # MIPS __mpn_submul_1 -- Multiply a limb vector with a single limb and
   2  # subtract the product from a second limb vector.
   3
   4  # Copyright (C) 1992, 1994, 1996 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      $4
  26  # s1_ptr       $5
  27  # size         $6
  28  # s2_limb      $7
  29
  30         .text
  31         .align   4
  32         .globl   __mpn_submul_1
  33         .ent    __mpn_submul_1
  34 __mpn_submul_1:
  35         .set    noreorder
  36         .set    nomacro
  37
  38  # warm up phase 0
  39         lw      $8,0($5)
  40
  41  # warm up phase 1
  42         addiu   $5,$5,4
  43         multu   $8,$7
  44
  45         addiu   $6,$6,-1
  46         beq     $6,$0,$LC0
  47          move   $2,$0           # zero cy2
  48
  49         addiu   $6,$6,-1
  50         beq     $6,$0,$LC1
  51         lw      $8,0($5)        # load new s1 limb as early as possible
  52
  53 Loop:   lw      $10,0($4)
  54         mflo    $3
  55         mfhi    $9
  56         addiu   $5,$5,4
  57         addu    $3,$3,$2        # add old carry limb to low product limb
  58         multu   $8,$7
  59         lw      $8,0($5)        # load new s1 limb as early as possible
  60         addiu   $6,$6,-1        # decrement loop counter
  61         sltu    $2,$3,$2        # carry from previous addition -> $2
  62         subu    $3,$10,$3
  63         sgtu    $10,$3,$10
  64         addu    $2,$2,$10
  65         sw      $3,0($4)
  66         addiu   $4,$4,4
  67         bne     $6,$0,Loop
  68          addu   $2,$9,$2        # add high product limb and carry from addition
  69
  70  # cool down phase 1
  71 $LC1:   lw      $10,0($4)
  72         mflo    $3
  73         mfhi    $9
  74         addu    $3,$3,$2
  75         sltu    $2,$3,$2
  76         multu   $8,$7
  77         subu    $3,$10,$3
  78         sgtu    $10,$3,$10
  79         addu    $2,$2,$10
  80         sw      $3,0($4)
  81         addiu   $4,$4,4
  82         addu    $2,$9,$2        # add high product limb and carry from addition
  83
  84  # cool down phase 0
  85 $LC0:   lw      $10,0($4)
  86         mflo    $3
  87         mfhi    $9
  88         addu    $3,$3,$2
  89         sltu    $2,$3,$2
  90         subu    $3,$10,$3
  91         sgtu    $10,$3,$10
  92         addu    $2,$2,$10
  93         sw      $3,0($4)
  94         j       $31
  95         addu    $2,$9,$2        # add high product limb and carry from addition
  96
  97         .end    __mpn_submul_1