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
133
134
135
|
/* IBM POWER submul_1 -- Multiply a limb vector with a limb and subtract
* the result from a second limb vector.
*
* Copyright (C) 1992, 1994, 1999 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#include "sysdep.h"
#include "asm-syntax.h"
/*
# INPUT PARAMETERS
# res_ptr r3
# s1_ptr r4
# size r5
# s2_limb r6
# The RS/6000 has no unsigned 32x32->64 bit multiplication instruction. To
# obtain that operation, we have to use the 32x32->64 signed multiplication
# instruction, and add the appropriate compensation to the high limb of the
# result. We add the multiplicand if the multiplier has its most significant
# bit set, and we add the multiplier if the multiplicand has its most
# significant bit set. We need to preserve the carry flag between each
# iteration, so we have to compute the compensation carefully (the natural,
# srai+and doesn't work). Since the POWER architecture has a branch unit
# we can branch in zero cycles, so that's how we perform the additions.
*/
.toc
.csect .mpihelp_submul_1[PR]
.align 2
.globl mpihelp_submul_1
.globl .mpihelp_submul_1
.csect mpihelp_submul_1[DS]
mpihelp_submul_1:
.long .mpihelp_submul_1[PR], TOC[tc0], 0
.csect .mpihelp_submul_1[PR]
.mpihelp_submul_1:
cal 3,-4(3)
l 0,0(4)
cmpi 0,6,0
mtctr 5
mul 9,0,6
srai 7,0,31
and 7,7,6
mfmq 11
cax 9,9,7
l 7,4(3)
sf 8,11,7 # add res_limb
a 11,8,11 # invert cy (r11 is junk)
blt Lneg
Lpos: bdz Lend
Lploop: lu 0,4(4)
stu 8,4(3)
cmpi 0,0,0
mul 10,0,6
mfmq 0
ae 11,0,9 # low limb + old_cy_limb + old cy
l 7,4(3)
aze 10,10 # propagate cy to new cy_limb
sf 8,11,7 # add res_limb
a 11,8,11 # invert cy (r11 is junk)
bge Lp0
cax 10,10,6 # adjust high limb for negative limb from s1
Lp0: bdz Lend0
lu 0,4(4)
stu 8,4(3)
cmpi 0,0,0
mul 9,0,6
mfmq 0
ae 11,0,10
l 7,4(3)
aze 9,9
sf 8,11,7
a 11,8,11 # invert cy (r11 is junk)
bge Lp1
cax 9,9,6 # adjust high limb for negative limb from s1
Lp1: bdn Lploop
b Lend
Lneg: cax 9,9,0
bdz Lend
Lnloop: lu 0,4(4)
stu 8,4(3)
cmpi 0,0,0
mul 10,0,6
mfmq 7
ae 11,7,9
l 7,4(3)
ae 10,10,0 # propagate cy to new cy_limb
sf 8,11,7 # add res_limb
a 11,8,11 # invert cy (r11 is junk)
bge Ln0
cax 10,10,6 # adjust high limb for negative limb from s1
Ln0: bdz Lend0
lu 0,4(4)
stu 8,4(3)
cmpi 0,0,0
mul 9,0,6
mfmq 7
ae 11,7,10
l 7,4(3)
ae 9,9,0 # propagate cy to new cy_limb
sf 8,11,7 # add res_limb
a 11,8,11 # invert cy (r11 is junk)
bge Ln1
cax 9,9,6 # adjust high limb for negative limb from s1
Ln1: bdn Lnloop
b Lend
Lend0: cal 9,0(10)
Lend: st 8,4(3)
aze 3,9
br
|
