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; 29000 __mpn_rshift --
; Copyright (C) 1992, 1994 Free Software Foundation, Inc.
; This file is part of the GNU MP Library.
; The GNU MP Library is free software; you can redistribute it and/or modify
; it under the terms of the GNU Library General Public License as published by
; the Free Software Foundation; either version 2 of the License, or (at your
; option) any later version.
; The GNU MP Library is distributed in the hope that it will be useful, but
; WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
; or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
; License for more details.
; You should have received a copy of the GNU Library General Public License
; along with the GNU MP Library; see the file COPYING.LIB. If not, write to
; the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
; MA 02111-1307, USA.
; INPUT PARAMETERS
; res_ptr lr2
; s1_ptr lr3
; s2_ptr lr4
; size lr5
; We use the loadm/storem instructions and operate on chunks of 8
; limbs/per iteration, until less than 8 limbs remain.
.sect .lit,lit
.text
.align 4
.global ___mpn_rshift
.word 0x60000
___mpn_rshift:
load 0,0,gr119,lr3
add lr3,lr3,4
subr gr116,lr5,32
sll gr96,gr119,gr116 ; return value
sub lr4,lr4,1 ; actual loop count is SIZE - 1
srl gr117,lr4,3 ; chuck count = (actual count) / 8
cpeq gr118,gr117,0
jmpt gr118,Ltail
mtsr fc,gr116
sub gr117,gr117,2 ; count for jmpfdec
; Main loop working 8 limbs/iteration.
Loop: mtsrim cr,(8-1)
loadm 0,0,gr100,lr3
add lr3,lr3,32
extract gr98,gr100,gr119
extract gr99,gr101,gr100
extract gr100,gr102,gr101
extract gr101,gr103,gr102
extract gr102,gr104,gr103
extract gr103,gr105,gr104
extract gr104,gr106,gr105
extract gr105,gr107,gr106
mtsrim cr,(8-1)
storem 0,0,gr98,lr2
add lr2,lr2,32
jmpfdec gr117,Loop
or gr119,gr107,0
; Code for the last up-to-7 limbs.
and lr4,lr4,(8-1)
Ltail: cpeq gr118,lr4,0
jmpt gr118,Lend
sub lr4,lr4,2 ; count for jmpfdec
Loop2: load 0,0,gr100,lr3
add lr3,lr3,4
extract gr117,gr100,gr119
store 0,0,gr117,lr2
add lr2,lr2,4
jmpfdec lr4,Loop2
or gr119,gr100,0
Lend: srl gr117,gr119,lr5
jmpi lr0
store 0,0,gr117,lr2
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