sysdeps/rs6000/lshift.s

   1 # IBM POWER __mpn_lshift --
   2
   3 # Copyright (C) 1992, 1994 Free Software Foundation, Inc.
   4
   5 # This file is part of the GNU MP Library.
   6
   7 # The GNU MP Library is free software; you can redistribute it and/or modify
   8 # it under the terms of the GNU Lesser General Public License as published by
   9 # the Free Software Foundation; either version 2.1 of the License, or (at your
  10 # option) any later version.
  11
  12 # The GNU MP Library is distributed in the hope that it will be useful, but
  13 # WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  14 # or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  15 # License for more details.
  16
  17 # You should have received a copy of the GNU Lesser General Public License
  18 # along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
  19 # the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  20 # MA 02111-1307, USA.
  21
  22
  23 # INPUT PARAMETERS
  24 # res_ptr       r3
  25 # s_ptr         r4
  26 # size          r5
  27 # cnt           r6
  28
  29         .toc
  30         .extern __mpn_lshift[DS]
  31         .extern .__mpn_lshift
  32 .csect [PR]
  33         .align 2
  34         .globl __mpn_lshift
  35         .globl .__mpn_lshift
  36         .csect __mpn_lshift[DS]
  37 __mpn_lshift:
  38         .long .__mpn_lshift, TOC[tc0], 0
  39         .csect [PR]
  40 .__mpn_lshift:
  41         sli     0,5,2
  42         cax     9,3,0
  43         cax     4,4,0
  44         sfi     8,6,32
  45         mtctr   5               # put limb count in CTR loop register
  46         lu      0,-4(4)         # read most significant limb
  47         sre     3,0,8           # compute carry out limb, and init MQ register
  48         bdz     Lend2           # if just one limb, skip loop
  49         lu      0,-4(4)         # read 2:nd most significant limb
  50         sreq    7,0,8           # compute most significant limb of result
  51         bdz     Lend            # if just two limb, skip loop
  52 Loop:   lu      0,-4(4)         # load next lower limb
  53         stu     7,-4(9)         # store previous result during read latency
  54         sreq    7,0,8           # compute result limb
  55         bdn     Loop            # loop back until CTR is zero
  56 Lend:   stu     7,-4(9)         # store 2:nd least significant limb
  57 Lend2:  sle     7,0,6           # compute least significant limb
  58         st      7,-4(9)         # store it"                             \
  59         br