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
|
/* dvdisaster: Additional error correction for optical media.
* Copyright (C) 2004-2015 Carsten Gnoerlich.
*
* Email: carsten@dvdisaster.org -or- cgnoerlich@fsfe.org
* Project homepage: http://www.dvdisaster.org
*
* This file is part of dvdisaster.
*
* dvdisaster 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 3 of the License, or
* (at your option) any later version.
*
* dvdisaster 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 dvdisaster. If not, see <http://www.gnu.org/licenses/>.
*/
#include "dvdisaster.h"
#ifdef HAVE_ALTIVEC
# include <altivec.h>
#endif
#include <signal.h>
#include <setjmp.h>
/***
*** Reed-Solomon encoding using AltiVec intrinsics
***
*** Based on rs-encoder-altivec.c
*** AltiVec version by michael.klein@puffin.lb.shuttle.de
***/
/* AltiVec version */
#ifdef HAVE_ALTIVEC
static volatile int AltiVecPresent;
static jmp_buf jmpbuf;
void sig_ill_handler(int sig)
{
AltiVecPresent = 0;
siglongjmp(jmpbuf, 0);
}
int ProbeAltiVec(void)
{
sig_t old_handler;
AltiVecPresent = 1;
old_handler = signal(SIGILL, sig_ill_handler);
if(!sigsetjmp(jmpbuf, 0))
{
vector unsigned char v;
asm volatile("vor %0, %0, %0": "=v"(v));
}
signal(SIGILL, old_handler);
return AltiVecPresent;
}
void encode_next_layer_altivec(ReedSolomonTables *rt, unsigned char *data, unsigned char *parity, guint64 layer_size, int shift)
{ gint32 *gf_index_of = rt->gfTables->indexOf;
gint32 *enc_alpha_to = rt->gfTables->encAlphaTo;
gint32 *rs_gpoly = rt->gpoly;
int nroots = rt->nroots;
int nroots_aligned = (nroots+15)&~15;
int nroots_full = nroots_aligned>>4;
int i,j;
for(i=0; i<layer_size; i++)
{ int feedback = gf_index_of[data[i] ^ parity[shift]];
int offset = nroots-shift-1;
if(feedback != GF_ALPHA0) /* non-zero feedback term */
{ guint8 *par_idx = (guint8*)parity;
guint8 *e_lut = rt->bLut[feedback]+offset;
vector unsigned char par, lut, out, msq, lsq, mask;
/* Process lut in 128 bit steps */
mask = vec_lvsl(0, e_lut);
for(j=nroots_full; j; j--)
{
par = vec_ld(0, par_idx);
msq = vec_ld(0, e_lut);
lsq = vec_ld(15, e_lut);
lut = vec_perm(msq, lsq, mask);
out = vec_xor(par, lut);
vec_st(out, 0, par_idx);
par_idx += 16;
e_lut += 16;
}
parity[shift] = enc_alpha_to[feedback + rs_gpoly[0]];
}
else /* zero feedback term */
parity[shift] = 0;
parity += nroots_aligned;
}
}
#else /* don't have ALTIVEC */
int ProbeAltiVec()
{ return 0;
}
void encode_next_layer_altivec(ReedSolomonTables *rt, unsigned char *data, unsigned char *parity, guint64 layer_size, int shift)
{
Stop("Mega borkage - EncodeNextLayerAltiVec() stub called.\n");
}
#endif /* HAVE_ALTIVEC */
|
