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
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
|
dnl PowerPC 750 mpn_rshift -- mpn right shift.
dnl Copyright 2002, 2003 Free Software Foundation, Inc.
dnl This file is part of the GNU MP Library.
dnl
dnl The GNU MP Library is free software; you can redistribute it and/or modify
dnl it under the terms of either:
dnl
dnl * the GNU Lesser General Public License as published by the Free
dnl Software Foundation; either version 3 of the License, or (at your
dnl option) any later version.
dnl
dnl or
dnl
dnl * the GNU General Public License as published by the Free Software
dnl Foundation; either version 2 of the License, or (at your option) any
dnl later version.
dnl
dnl or both in parallel, as here.
dnl
dnl The GNU MP Library is distributed in the hope that it will be useful, but
dnl WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
dnl or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
dnl for more details.
dnl
dnl You should have received copies of the GNU General Public License and the
dnl GNU Lesser General Public License along with the GNU MP Library. If not,
dnl see https://www.gnu.org/licenses/.
include(`../config.m4')
C cycles/limb
C 750: 3.0
C 7400: 3.0
C mp_limb_t mpn_rshift (mp_ptr dst, mp_srcptr src, mp_size_t size,
C unsigned shift);
C
C This code is the same per-limb speed as mpn/powerpc32/rshift.asm, but
C smaller and saving about 30 or so cycles of overhead.
ASM_START()
PROLOGUE(mpn_rshift)
C r3 dst
C r4 src
C r5 size
C r6 shift
mtctr r5 C size
lwz r8, 0(r4) C src[0]
subfic r7, r6, 32 C 32-shift
addi r5, r3, -4 C dst-4
slw r3, r8, r7 C return value
bdz L(one)
lwzu r9, 4(r4) C src[1]
srw r8, r8, r6 C src[0] >> shift
bdz L(two)
L(top):
C r3 return value
C r4 src, incrementing
C r5 dst, incrementing
C r6 shift
C r7 32-shift
C r8 src[i-1] >> shift
C r9 src[i]
C r10
lwzu r10, 4(r4)
slw r11, r9, r7
or r8, r8, r11
stwu r8, 4(r5)
srw r8, r9, r6
bdz L(odd)
C r8 src[i-1] >> shift
C r9
C r10 src[i]
lwzu r9, 4(r4)
slw r11, r10, r7
or r8, r8, r11
stwu r8, 4(r5)
srw r8, r10, r6
bdnz L(top)
L(two):
C r3 return value
C r4
C r5 &dst[size-2]
C r6 shift
C r7 32-shift
C r8 src[size-2] >> shift
C r9 src[size-1]
C r10
slw r11, r9, r7
srw r12, r9, r6 C src[size-1] >> shift
or r8, r8, r11
stw r12, 8(r5) C dst[size-1]
stw r8, 4(r5) C dst[size-2]
blr
L(odd):
C r3 return value
C r4
C r5 &dst[size-2]
C r6 shift
C r7 32-shift
C r8 src[size-2] >> shift
C r9
C r10 src[size-1]
slw r11, r10, r7
srw r12, r10, r6
or r8, r8, r11
stw r12, 8(r5) C dst[size-1]
stw r8, 4(r5) C dst[size-2]
blr
L(one):
C r3 return value
C r4
C r5 dst-4
C r6 shift
C r7
C r8 src[0]
srw r8, r8, r6
stw r8, 4(r5) C dst[0]
blr
EPILOGUE(mpn_rshift)
|
