FFmpeg
bswapdsp_init.c
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1 /*
2  * Copyright © 2022 Rémi Denis-Courmont.
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 <stdint.h>
22 
23 #include "config.h"
24 #include "libavutil/attributes.h"
25 #include "libavutil/cpu.h"
26 #include "libavcodec/bswapdsp.h"
27 
28 void ff_bswap32_buf_rvb(uint32_t *dst, const uint32_t *src, int len);
29 void ff_bswap16_buf_rvv(uint16_t *dst, const uint16_t *src, int len);
30 
32 {
33 #if HAVE_RV
34  int flags = av_get_cpu_flags();
35 
37 #if (__riscv_xlen >= 64)
39  c->bswap_buf = ff_bswap32_buf_rvb;
40 #endif
41 #if HAVE_RVV
43  c->bswap16_buf = ff_bswap16_buf_rvv;
44 #endif
45  }
46 #endif
47 }
bswapdsp.h
AV_CPU_FLAG_RVB_BASIC
#define AV_CPU_FLAG_RVB_BASIC
Basic bit-manipulations.
Definition: cpu.h:91
av_get_cpu_flags
int av_get_cpu_flags(void)
Return the flags which specify extensions supported by the CPU.
Definition: cpu.c:103
av_cold
#define av_cold
Definition: attributes.h:90
AV_CPU_FLAG_RVB_ADDR
#define AV_CPU_FLAG_RVB_ADDR
Address bit-manipulations.
Definition: cpu.h:92
ff_bswapdsp_init_riscv
av_cold void ff_bswapdsp_init_riscv(BswapDSPContext *c)
Definition: bswapdsp_init.c:31
ff_bswap16_buf_rvv
void ff_bswap16_buf_rvv(uint16_t *dst, const uint16_t *src, int len)
c
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
ff_bswap32_buf_rvb
void ff_bswap32_buf_rvb(uint32_t *dst, const uint32_t *src, int len)
cpu.h
attributes.h
AV_CPU_FLAG_RVV_I32
#define AV_CPU_FLAG_RVV_I32
Vectors of 8/16/32-bit int's *‍/.
Definition: cpu.h:87
len
int len
Definition: vorbis_enc_data.h:426
src
INIT_CLIP pixel * src
Definition: h264pred_template.c:418
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:482
BswapDSPContext
Definition: bswapdsp.h:24