1/* IBM POWER lshift
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# INPUT PARAMETERS
27# res_ptr	r3
28# s_ptr 	r4
29# size		r5
30# cnt		r6
31 */
32
33	.toc
34	.extern _gcry_mpih_lshift[DS]
35	.extern ._gcry_mpih_lshift
36.csect [PR]
37	.align 2
38	.globl _gcry_mpih_lshift
39	.globl ._gcry_mpih_lshift
40	.csect _gcry_mpih_lshift[DS]
41_gcry_mpih_lshift:
42	.long ._gcry_mpih_lshift, TOC[tc0], 0
43	.csect [PR]
44._gcry_mpih_lshift:
45	sli	0,5,2
46	cax	9,3,0
47	cax	4,4,0
48	sfi	8,6,32
49	mtctr	5		# put limb count in CTR loop register
50	lu	0,-4(4) 	# read most significant limb
51	sre	3,0,8		# compute carry out limb, and init MQ register
52	bdz	Lend2		# if just one limb, skip loop
53	lu	0,-4(4) 	# read 2:nd most significant limb
54	sreq	7,0,8		# compute most significant limb of result
55	bdz	Lend		# if just two limb, skip loop
56Loop:	lu	0,-4(4) 	# load next lower limb
57	stu	7,-4(9) 	# store previous result during read latency
58	sreq	7,0,8		# compute result limb
59	bdn	Loop		# loop back until CTR is zero
60Lend:	stu	7,-4(9) 	# store 2:nd least significant limb
61Lend2:	sle	7,0,6		# compute least significant limb
62	st	7,-4(9) 	# store it
63	br
64
65