grub-core/lib/libgcrypt/mpi/power/mpih-rshift.S

   1 /* IBM POWER rshift
   2  *
   3  *      Copyright (C) 1992, 1994, 1999, 2002 Free Software Foundation, Inc.
   4  *
   5  * This file is part of Libgcrypt.
   6  *
   7  * Libgcrypt is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU Lesser General Public License as
   9  * published by the Free Software Foundation; either version 2.1 of
  10  * the License, or (at your option) any later version.
  11  *
  12  * Libgcrypt is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  20  */
  21
  22 #include "sysdep.h"
  23 #include "asm-syntax.h"
  24
  25
  26 /*
  27 # INPUT PARAMETERS
  28 # res_ptr       r3
  29 # s_ptr         r4
  30 # size          r5
  31 # cnt           r6
  32 */
  33
  34         .toc
  35         .extern _gcry_mpih_rshift[DS]
  36         .extern ._gcry_mpih_rshift
  37 .csect [PR]
  38         .align 2
  39         .globl _gcry_mpih_rshift
  40         .globl ._gcry_mpih_rshift
  41         .csect _gcry_mpih_rshift[DS]
  42 _gcry_mpih_rshift:
  43         .long ._gcry_mpih_rshift, TOC[tc0], 0
  44         .csect [PR]
  45 ._gcry_mpih_rshift:
  46         sfi     8,6,32
  47         mtctr   5               # put limb count in CTR loop register
  48         l       0,0(4)          # read least significant limb
  49         ai      9,3,-4          # adjust res_ptr since it's offset in the stu:s
  50         sle     3,0,8           # compute carry limb, and init MQ register
  51         bdz     Lend2           # if just one limb, skip loop
  52         lu      0,4(4)          # read 2:nd least significant limb
  53         sleq    7,0,8           # compute least significant limb of result
  54         bdz     Lend            # if just two limb, skip loop
  55 Loop:   lu      0,4(4)          # load next higher limb
  56         stu     7,4(9)          # store previous result during read latency
  57         sleq    7,0,8           # compute result limb
  58         bdn     Loop            # loop back until CTR is zero
  59 Lend:   stu     7,4(9)          # store 2:nd most significant limb
  60 Lend2:  sre     7,0,6           # compute most significant limb
  61         st      7,4(9)          # store it
  62         br
  63
  64