FFmpeg
svq1enc_altivec.c
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1 /*
2  * Copyright (c) 2007 Luca Barbato <lu_zero@gentoo.org>
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include "config.h"
22 
23 #include <stdint.h>
24 
25 #include "libavutil/attributes.h"
26 #include "libavutil/cpu.h"
27 #include "libavutil/ppc/cpu.h"
29 
30 #include "libavcodec/svq1enc.h"
31 
32 #if HAVE_ALTIVEC
33 static int ssd_int8_vs_int16_altivec(const int8_t *pix1, const int16_t *pix2,
34  intptr_t size)
35 {
36  int i, size16 = size >> 4;
37  vector signed char vpix1;
38  vector signed short vpix2, vdiff, vpix1l, vpix1h;
39  union {
40  vector signed int vscore;
41  int32_t score[4];
42  } u = { .vscore = vec_splat_s32(0) };
43 
44  while (size16) {
45  // score += (pix1[i] - pix2[i]) * (pix1[i] - pix2[i]);
46  // load pix1 and the first batch of pix2
47 
48  vpix1 = vec_unaligned_load(pix1);
49  vpix2 = vec_unaligned_load(pix2);
50  pix2 += 8;
51  // unpack
52  vpix1h = vec_unpackh(vpix1);
53  vdiff = vec_sub(vpix1h, vpix2);
54  vpix1l = vec_unpackl(vpix1);
55  // load another batch from pix2
56  vpix2 = vec_unaligned_load(pix2);
57  u.vscore = vec_msum(vdiff, vdiff, u.vscore);
58  vdiff = vec_sub(vpix1l, vpix2);
59  u.vscore = vec_msum(vdiff, vdiff, u.vscore);
60  pix1 += 16;
61  pix2 += 8;
62  size16--;
63  }
64  u.vscore = vec_sums(u.vscore, vec_splat_s32(0));
65 
66  size %= 16;
67  for (i = 0; i < size; i++)
68  u.score[3] += (pix1[i] - pix2[i]) * (pix1[i] - pix2[i]);
69 
70  return u.score[3];
71 }
72 #endif /* HAVE_ALTIVEC */
73 
75 {
76 #if HAVE_ALTIVEC
78  return;
79 
80  c->ssd_int8_vs_int16 = ssd_int8_vs_int16_altivec;
81 #endif /* HAVE_ALTIVEC */
82 }
Macro definitions for various function/variable attributes.
#define av_cold
Definition: attributes.h:82
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
#define u(width, name, range_min, range_max)
Definition: cbs_h2645.c:252
ptrdiff_t size
Definition: opengl_enc.c:100
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
#define PPC_ALTIVEC(flags)
Definition: cpu.h:25
int(* ssd_int8_vs_int16)(const int8_t *pix1, const int16_t *pix2, intptr_t size)
Definition: svq1enc.h:78
int32_t
av_cold void ff_svq1enc_init_ppc(SVQ1EncContext *c)
int av_get_cpu_flags(void)
Return the flags which specify extensions supported by the CPU.
Definition: cpu.c:93
Contains misc utility macros and inline functions.