ports/sysdeps/mips/mips64/mul_1.S

   1 /* MIPS3 __mpn_mul_1 -- Multiply a limb vector with a single limb and
   2  * store the product in a second limb vector.
   3  *
   4  * Copyright (C) 1992-2013 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.  If not, see
  20  * <http://www.gnu.org/licenses/>.
  21  */
  22
  23 #include <sysdep.h>
  24 #include <sys/asm.h>
  25
  26 /* INPUT PARAMETERS
  27  * res_ptr      $4
  28  * s1_ptr       $5
  29  * size         $6
  30  * s2_limb      $7
  31  */
  32
  33 #ifdef __PIC__
  34         .option pic2
  35 #endif
  36 ENTRY (__mpn_mul_1)
  37 #ifdef __PIC__
  38         SETUP_GP /* ??? unused */
  39 #endif
  40         .set    noreorder
  41         .set    nomacro
  42
  43  # warm up phase 0
  44         ld      $8,0($5)
  45
  46  # warm up phase 1
  47         daddiu  $5,$5,8
  48         dmultu  $8,$7
  49
  50         daddiu  $6,$6,-1
  51         beq     $6,$0,L(LC0)
  52         move    $2,$0           # zero cy2
  53
  54         daddiu  $6,$6,-1
  55         beq     $6,$0,L(LC1)
  56         ld      $8,0($5)        # load new s1 limb as early as possible
  57
  58 L(Loop):        mflo    $10
  59         mfhi    $9
  60         daddiu  $5,$5,8
  61         daddu   $10,$10,$2      # add old carry limb to low product limb
  62         dmultu  $8,$7
  63         ld      $8,0($5)        # load new s1 limb as early as possible
  64         daddiu  $6,$6,-1        # decrement loop counter
  65         sltu    $2,$10,$2       # carry from previous addition -> $2
  66         sd      $10,0($4)
  67         daddiu  $4,$4,8
  68         bne     $6,$0,L(Loop)
  69         daddu   $2,$9,$2        # add high product limb and carry from addition
  70
  71  # cool down phase 1
  72 L(LC1): mflo    $10
  73         mfhi    $9
  74         daddu   $10,$10,$2
  75         sltu    $2,$10,$2
  76         dmultu  $8,$7
  77         sd      $10,0($4)
  78         daddiu  $4,$4,8
  79         daddu   $2,$9,$2        # add high product limb and carry from addition
  80
  81  # cool down phase 0
  82 L(LC0): mflo    $10
  83         mfhi    $9
  84         daddu   $10,$10,$2
  85         sltu    $2,$10,$2
  86         sd      $10,0($4)
  87         j       $31
  88         daddu   $2,$9,$2        # add high product limb and carry from addition
  89
  90 END (__mpn_mul_1)