sysdeps/alpha/alphaev5/add_n.s

   1  # Alpha __mpn_add_n -- Add two limb vectors of the same length > 0 and
   2  # store sum in a third limb vector.
   3
   4  # Copyright (C) 1995 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 <http://www.gnu.org/licenses/>.
  20
  21
  22  # INPUT PARAMETERS
  23  # res_ptr      $16
  24  # s1_ptr       $17
  25  # s2_ptr       $18
  26  # size         $19
  27
  28         .set    noreorder
  29         .set    noat
  30 .text
  31         .align  3
  32         .globl  __mpn_add_n
  33         .ent    __mpn_add_n
  34 __mpn_add_n:
  35         .frame  $30,0,$26,0
  36
  37         or      $31,$31,$25             # clear cy
  38         subq    $19,4,$19               # decr loop cnt
  39         blt     $19,.Lend2              # if less than 4 limbs, goto 2nd loop
  40  # Start software pipeline for 1st loop
  41         ldq     $0,0($18)
  42         ldq     $1,8($18)
  43         ldq     $4,0($17)
  44         ldq     $5,8($17)
  45         addq    $17,32,$17              # update s1_ptr
  46         ldq     $2,16($18)
  47         addq    $0,$4,$20               # 1st main add
  48         ldq     $3,24($18)
  49         subq    $19,4,$19               # decr loop cnt
  50         ldq     $6,-16($17)
  51         cmpult  $20,$0,$25              # compute cy from last add
  52         ldq     $7,-8($17)
  53         addq    $1,$25,$28              # cy add
  54         addq    $18,32,$18              # update s2_ptr
  55         addq    $5,$28,$21              # 2nd main add
  56         cmpult  $28,$25,$8              # compute cy from last add
  57         blt     $19,.Lend1              # if less than 4 limbs remain, jump
  58  # 1st loop handles groups of 4 limbs in a software pipeline
  59         .align  4
  60 .Loop:  cmpult  $21,$28,$25             # compute cy from last add
  61         ldq     $0,0($18)
  62         or      $8,$25,$25              # combine cy from the two adds
  63         ldq     $1,8($18)
  64         addq    $2,$25,$28              # cy add
  65         ldq     $4,0($17)
  66         addq    $28,$6,$22              # 3rd main add
  67         ldq     $5,8($17)
  68         cmpult  $28,$25,$8              # compute cy from last add
  69         cmpult  $22,$28,$25             # compute cy from last add
  70         stq     $20,0($16)
  71         or      $8,$25,$25              # combine cy from the two adds
  72         stq     $21,8($16)
  73         addq    $3,$25,$28              # cy add
  74         addq    $28,$7,$23              # 4th main add
  75         cmpult  $28,$25,$8              # compute cy from last add
  76         cmpult  $23,$28,$25             # compute cy from last add
  77         addq    $17,32,$17              # update s1_ptr
  78         or      $8,$25,$25              # combine cy from the two adds
  79         addq    $16,32,$16              # update res_ptr
  80         addq    $0,$25,$28              # cy add
  81         ldq     $2,16($18)
  82         addq    $4,$28,$20              # 1st main add
  83         ldq     $3,24($18)
  84         cmpult  $28,$25,$8              # compute cy from last add
  85         ldq     $6,-16($17)
  86         cmpult  $20,$28,$25             # compute cy from last add
  87         ldq     $7,-8($17)
  88         or      $8,$25,$25              # combine cy from the two adds
  89         subq    $19,4,$19               # decr loop cnt
  90         stq     $22,-16($16)
  91         addq    $1,$25,$28              # cy add
  92         stq     $23,-8($16)
  93         addq    $5,$28,$21              # 2nd main add
  94         addq    $18,32,$18              # update s2_ptr
  95         cmpult  $28,$25,$8              # compute cy from last add
  96         bge     $19,.Loop
  97  # Finish software pipeline for 1st loop
  98 .Lend1: cmpult  $21,$28,$25             # compute cy from last add
  99         or      $8,$25,$25              # combine cy from the two adds
 100         addq    $2,$25,$28              # cy add
 101         addq    $28,$6,$22              # 3rd main add
 102         cmpult  $28,$25,$8              # compute cy from last add
 103         cmpult  $22,$28,$25             # compute cy from last add
 104         stq     $20,0($16)
 105         or      $8,$25,$25              # combine cy from the two adds
 106         stq     $21,8($16)
 107         addq    $3,$25,$28              # cy add
 108         addq    $28,$7,$23              # 4th main add
 109         cmpult  $28,$25,$8              # compute cy from last add
 110         cmpult  $23,$28,$25             # compute cy from last add
 111         or      $8,$25,$25              # combine cy from the two adds
 112         addq    $16,32,$16              # update res_ptr
 113         stq     $22,-16($16)
 114         stq     $23,-8($16)
 115 .Lend2: addq    $19,4,$19               # restore loop cnt
 116         beq     $19,.Lret
 117  # Start software pipeline for 2nd loop
 118         ldq     $0,0($18)
 119         ldq     $4,0($17)
 120         subq    $19,1,$19
 121         beq     $19,.Lend0
 122  # 2nd loop handles remaining 1-3 limbs
 123         .align  4
 124 .Loop0: addq    $0,$25,$28              # cy add
 125         ldq     $0,8($18)
 126         addq    $4,$28,$20              # main add
 127         ldq     $4,8($17)
 128         addq    $18,8,$18
 129         cmpult  $28,$25,$8              # compute cy from last add
 130         addq    $17,8,$17
 131         stq     $20,0($16)
 132         cmpult  $20,$28,$25             # compute cy from last add
 133         subq    $19,1,$19               # decr loop cnt
 134         or      $8,$25,$25              # combine cy from the two adds
 135         addq    $16,8,$16
 136         bne     $19,.Loop0
 137 .Lend0: addq    $0,$25,$28              # cy add
 138         addq    $4,$28,$20              # main add
 139         cmpult  $28,$25,$8              # compute cy from last add
 140         cmpult  $20,$28,$25             # compute cy from last add
 141         stq     $20,0($16)
 142         or      $8,$25,$25              # combine cy from the two adds
 143
 144 .Lret:  or      $25,$31,$0              # return cy
 145         ret     $31,($26),1
 146         .end    __mpn_add_n