FFmpeg
timer.h
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1 /*
2  * Copyright (c) 2023 Loongson Technology Corporation Limited
3  * Contributed by Hecai Yuan <yuanhecai@loongson.cn>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #ifndef AVUTIL_LOONGARCH_TIMER_H
23 #define AVUTIL_LOONGARCH_TIMER_H
24 
25 #include <stdint.h>
26 #include "config.h"
27 
28 #if HAVE_INLINE_ASM
29 
30 #define AV_READ_TIME read_time
31 
32 static inline uint64_t read_time(void)
33 {
34 
35 #if ARCH_LOONGARCH64
36  uint64_t a, id;
37  __asm__ volatile ( "rdtime.d %0, %1" : "=r"(a), "=r"(id) :: );
38  return a;
39 #else
40  uint32_t a, id;
41  __asm__ volatile ( "rdtimel.w %0, %1" : "=r"(a), "=r"(id) :: );
42  return (uint64_t)a;
43 #endif
44 }
45 
46 #endif /* HAVE_INLINE_ASM */
47 
48 #endif /* AVUTIL_LOONGARCH_TIMER_H */
read_time
static uint64_t read_time(void)
Definition: timer.h:30
a
The reader does not expect b to be semantically here and if the code is changed by maybe adding a a division or other the signedness will almost certainly be mistaken To avoid this confusion a new type was SUINT is the C unsigned type but it holds a signed int to use the same example SUINT a
Definition: undefined.txt:41
__asm__
__asm__(".macro parse_r var r\n\t" "\\var = -1\n\t" _IFC_REG(0) _IFC_REG(1) _IFC_REG(2) _IFC_REG(3) _IFC_REG(4) _IFC_REG(5) _IFC_REG(6) _IFC_REG(7) _IFC_REG(8) _IFC_REG(9) _IFC_REG(10) _IFC_REG(11) _IFC_REG(12) _IFC_REG(13) _IFC_REG(14) _IFC_REG(15) _IFC_REG(16) _IFC_REG(17) _IFC_REG(18) _IFC_REG(19) _IFC_REG(20) _IFC_REG(21) _IFC_REG(22) _IFC_REG(23) _IFC_REG(24) _IFC_REG(25) _IFC_REG(26) _IFC_REG(27) _IFC_REG(28) _IFC_REG(29) _IFC_REG(30) _IFC_REG(31) ".iflt \\var\n\t" ".error \"Unable to parse register name \\r\"\n\t" ".endif\n\t" ".endm")
id
enum AVCodecID id
Definition: dts2pts.c:364