summaryrefslogtreecommitdiff
path: root/mpi/powerpc32/mpih-rshift.S
blob: 4a826b41af689d7fbc6bf34f3a131e058e5b0017 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
/* PowerPC-32 rshift
 *
 *      Copyright (C) 1995, 1998 Free Software Foundation, Inc.
 *
 * This file is part of GnuPG.
 *
 * GnuPG is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * GnuPG 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
 * USA.
 */


#include "sysdep.h"
#include "asm-syntax.h"


#ifndef USE_PPC_PATCHES

/*******************
 * mpi_limb_t
 * mpihelp_rshift( mpi_ptr_t wp,	(r3)
 *		   mpi_ptr_t up,	(r4)
 *		   mpi_size_t usize,	(r5)
 *		   unsigned cnt)	(r6)
 */

	.toc
.csect	.text[PR]
	.align	2
	.globl	mpihelp_rshift
	.globl	.mpihelp_rshift
	.csect	mpihelp_rshift[DS]
mpihelp_rshift:
	.long	.mpihelp_rshift,  TOC[tc0],	  0
	.csect	.text[PR]
.mpihelp_rshift:
	mtctr	5		# copy size into CTR
	addi	7,3,-4		# move adjusted res_ptr to free return reg
	subfic	8,6,32
	lwz	11,0(4) 	# load first s1 limb
	slw	3,11,8		# compute function return value
	bdz	Lend1

Loop:	lwzu	10,4(4)
	srw	9,11,6
	slw	12,10,8
	or	9,9,12
	stwu	9,4(7)
	bdz	Lend2
	lwzu	11,4(4)
	srw	9,10,6
	slw	12,11,8
	or	9,9,12
	stwu	9,4(7)
	bdnz	Loop

Lend1:	srw	0,11,6
	stw	0,4(7)
	blr

Lend2:	srw	0,10,6
	stw	0,4(7)
	blr

#else
/* Shift a limb right, low level routine.
   Copyright (C) 1995, 1997 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C 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 C 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 C Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
   Boston, MA 02110-1301, USA.	*/


/* INPUT PARAMETERS
   res_ptr     r3
   s1_ptr      r4
   size 	       r5
   cnt	       r6  */

ENTRY(mpihelp_rshift)
       mtctr   5	       # copy size into CTR
       addi    7,3,-4	       # move adjusted res_ptr to free return reg
       subfic  8,6,32
       lwz     11,0(4)	       # load first s1 limb
       slw     3,11,8	       # compute function return value
       bdz     1f

0:     lwzu    10,4(4)
       srw     9,11,6
       slw     12,10,8
       or      9,9,12
       stwu    9,4(7)
       bdz     2f
       lwzu    11,4(4)
       srw     9,10,6
       slw     12,11,8
       or      9,9,12
       stwu    9,4(7)
       bdnz    0b

1:     srw     0,11,6
       stw     0,4(7)
       blr

2:     srw     0,10,6
       stw     0,4(7)
       blr
END(mpihelp_rshift)
#endif