FFmpeg
lossless_videodsp_altivec.c
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1 /*
2  * Copyright (c) 2002 Brian Foley
3  * Copyright (c) 2002 Dieter Shirley
4  * Copyright (c) 2003-2004 Romain Dolbeau <romain@dolbeau.org>
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 #include "config.h"
24 
25 #include "libavutil/attributes.h"
26 #include "libavutil/cpu.h"
27 #include "libavutil/ppc/cpu.h"
29 
31 
32 #if HAVE_ALTIVEC
33 static void add_bytes_altivec(uint8_t *dst, uint8_t *src, ptrdiff_t w)
34 {
35  register int i;
36  register vector unsigned char vdst, vsrc;
37 
38  /* dst and src are 16 bytes-aligned (guaranteed). */
39  for (i = 0; i + 15 < w; i += 16) {
40  vdst = vec_ld(i, (unsigned char *) dst);
41  vsrc = vec_ld(i, (unsigned char *) src);
42  vdst = vec_add(vsrc, vdst);
43  vec_st(vdst, i, (unsigned char *) dst);
44  }
45  /* If w is not a multiple of 16. */
46  for (; i < w; i++)
47  dst[i] = src[i];
48 }
49 #endif /* HAVE_ALTIVEC */
50 
52 {
53 #if HAVE_ALTIVEC
55  return;
56 
57  c->add_bytes = add_bytes_altivec;
58 #endif /* HAVE_ALTIVEC */
59 }
#define src
Definition: vp8dsp.c:254
Macro definitions for various function/variable attributes.
uint8_t
#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 i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
#define PPC_ALTIVEC(flags)
Definition: cpu.h:25
uint8_t w
Definition: llviddspenc.c:38
av_cold void ff_llviddsp_init_ppc(LLVidDSPContext *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.
void(* add_bytes)(uint8_t *dst, uint8_t *src, ptrdiff_t w)