source/libs/gmp/gmp-src/mpn/mips32/submul_1.asm

   1 dnl  MIPS32 mpn_submul_1 -- Multiply a limb vector with a single limb and
   2 dnl  subtract the product from a second limb vector.
   3
   4 dnl  Copyright 1992, 1994, 1996, 2000, 2002 Free Software Foundation, Inc.
   5
   6 dnl  This file is part of the GNU MP Library.
   7 dnl
   8 dnl  The GNU MP Library is free software; you can redistribute it and/or modify
   9 dnl  it under the terms of either:
  10 dnl
  11 dnl    * the GNU Lesser General Public License as published by the Free
  12 dnl      Software Foundation; either version 3 of the License, or (at your
  13 dnl      option) any later version.
  14 dnl
  15 dnl  or
  16 dnl
  17 dnl    * the GNU General Public License as published by the Free Software
  18 dnl      Foundation; either version 2 of the License, or (at your option) any
  19 dnl      later version.
  20 dnl
  21 dnl  or both in parallel, as here.
  22 dnl
  23 dnl  The GNU MP Library is distributed in the hope that it will be useful, but
  24 dnl  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  25 dnl  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  26 dnl  for more details.
  27 dnl
  28 dnl  You should have received copies of the GNU General Public License and the
  29 dnl  GNU Lesser General Public License along with the GNU MP Library.  If not,
  30 dnl  see https://www.gnu.org/licenses/.
  31
  32 include(`../config.m4')
  33
  34 C INPUT PARAMETERS
  35 C res_ptr       $4
  36 C s1_ptr        $5
  37 C size          $6
  38 C s2_limb       $7
  39
  40 ASM_START()
  41 PROLOGUE(mpn_submul_1)
  42
  43 C feed-in phase 0
  44         lw      $8,0($5)
  45
  46 C feed-in phase 1
  47         addiu   $5,$5,4
  48         multu   $8,$7
  49
  50         addiu   $6,$6,-1
  51         beq     $6,$0,$LC0
  52          move   $2,$0           C zero cy2
  53
  54         addiu   $6,$6,-1
  55         beq     $6,$0,$LC1
  56         lw      $8,0($5)        C load new s1 limb as early as possible
  57
  58 Loop:   lw      $10,0($4)
  59         mflo    $3
  60         mfhi    $9
  61         addiu   $5,$5,4
  62         addu    $3,$3,$2        C add old carry limb to low product limb
  63         multu   $8,$7
  64         lw      $8,0($5)        C load new s1 limb as early as possible
  65         addiu   $6,$6,-1        C decrement loop counter
  66         sltu    $2,$3,$2        C carry from previous addition -> $2
  67         subu    $3,$10,$3
  68         sgtu    $10,$3,$10
  69         addu    $2,$2,$10
  70         sw      $3,0($4)
  71         addiu   $4,$4,4
  72         bne     $6,$0,Loop
  73          addu   $2,$9,$2        C add high product limb and carry from addition
  74
  75 C wind-down phase 1
  76 $LC1:   lw      $10,0($4)
  77         mflo    $3
  78         mfhi    $9
  79         addu    $3,$3,$2
  80         sltu    $2,$3,$2
  81         multu   $8,$7
  82         subu    $3,$10,$3
  83         sgtu    $10,$3,$10
  84         addu    $2,$2,$10
  85         sw      $3,0($4)
  86         addiu   $4,$4,4
  87         addu    $2,$9,$2        C add high product limb and carry from addition
  88
  89 C wind-down phase 0
  90 $LC0:   lw      $10,0($4)
  91         mflo    $3
  92         mfhi    $9
  93         addu    $3,$3,$2
  94         sltu    $2,$3,$2
  95         subu    $3,$10,$3
  96         sgtu    $10,$3,$10
  97         addu    $2,$2,$10
  98         sw      $3,0($4)
  99         j       $31
 100         addu    $2,$9,$2        C add high product limb and carry from addition
 101 EPILOGUE(mpn_submul_1)