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FFmpeg/libavutil/riscv/cpu.c
Rémi Denis-Courmont 1b2a925e94 lavc/riscv: drop probing for F & D extensions
F and D extensions are included in all RISC-V application profiles ever
made (so starting from RV64GC a.k.a. RVA20). Realistically they need to be
selected at compilation time.

Currently, there are no consumers for these two flags. If there is ever a
need to reintroduce F- or D-specific optimisations, we can always use
__riscv_f or __riscv_d compiler predefined macros respectively.
2024-08-01 22:56:50 +03:00

142 lines
4.2 KiB
C

/*
* Copyright © 2022 Rémi Denis-Courmont.
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#define _GNU_SOURCE
#include "libavutil/cpu.h"
#include "libavutil/cpu_internal.h"
#include "libavutil/macros.h"
#include "libavutil/log.h"
#include "config.h"
#if HAVE_GETAUXVAL
#include <sys/auxv.h>
#define HWCAP_RV(letter) (1ul << ((letter) - 'A'))
#endif
#if HAVE_SYS_HWPROBE_H
#include <sys/hwprobe.h>
#elif HAVE_ASM_HWPROBE_H
#include <asm/hwprobe.h>
#include <sys/syscall.h>
#include <unistd.h>
static int __riscv_hwprobe(struct riscv_hwprobe *pairs, size_t pair_count,
size_t cpu_count, unsigned long *cpus,
unsigned int flags)
{
return syscall(__NR_riscv_hwprobe, pairs, pair_count, cpu_count, cpus,
flags);
}
#endif
int ff_get_cpu_flags_riscv(void)
{
int ret = 0;
#if HAVE_SYS_HWPROBE_H || HAVE_ASM_HWPROBE_H
struct riscv_hwprobe pairs[] = {
{ RISCV_HWPROBE_KEY_BASE_BEHAVIOR, 0 },
{ RISCV_HWPROBE_KEY_IMA_EXT_0, 0 },
{ RISCV_HWPROBE_KEY_CPUPERF_0, 0 },
};
if (__riscv_hwprobe(pairs, FF_ARRAY_ELEMS(pairs), 0, NULL, 0) == 0) {
if (pairs[0].value & RISCV_HWPROBE_BASE_BEHAVIOR_IMA)
ret |= AV_CPU_FLAG_RVI;
#ifdef RISCV_HWPROBE_IMA_V
if (pairs[1].value & RISCV_HWPROBE_IMA_V)
ret |= AV_CPU_FLAG_RVV_I32 | AV_CPU_FLAG_RVV_I64
| AV_CPU_FLAG_RVV_F32 | AV_CPU_FLAG_RVV_F64;
#endif
#ifdef RISCV_HWPROBE_EXT_ZBA
if (pairs[1].value & RISCV_HWPROBE_EXT_ZBA)
ret |= AV_CPU_FLAG_RVB_ADDR;
#endif
#ifdef RISCV_HWPROBE_EXT_ZBB
if (pairs[1].value & RISCV_HWPROBE_EXT_ZBB)
ret |= AV_CPU_FLAG_RVB_BASIC;
#if defined (RISCV_HWPROBE_EXT_ZBA) && defined (RISCV_HWPROBE_EXT_ZBS)
if ((pairs[1].value & RISCV_HWPROBE_EXT_ZBA) &&
(pairs[1].value & RISCV_HWPROBE_EXT_ZBB) &&
(pairs[1].value & RISCV_HWPROBE_EXT_ZBS))
ret |= AV_CPU_FLAG_RVB;
#endif
#endif
#ifdef RISCV_HWPROBE_EXT_ZVBB
if (pairs[1].value & RISCV_HWPROBE_EXT_ZVBB)
ret |= AV_CPU_FLAG_RV_ZVBB;
#endif
switch (pairs[2].value & RISCV_HWPROBE_MISALIGNED_MASK) {
case RISCV_HWPROBE_MISALIGNED_FAST:
ret |= AV_CPU_FLAG_RV_MISALIGNED;
break;
default:
}
}
#elif HAVE_GETAUXVAL
{
const unsigned long hwcap = getauxval(AT_HWCAP);
if (hwcap & HWCAP_RV('I'))
ret |= AV_CPU_FLAG_RVI;
if (hwcap & HWCAP_RV('B'))
ret |= AV_CPU_FLAG_RVB_ADDR | AV_CPU_FLAG_RVB_BASIC |
AV_CPU_FLAG_RVB;
/* The V extension implies all Zve* functional subsets */
if (hwcap & HWCAP_RV('V'))
ret |= AV_CPU_FLAG_RVV_I32 | AV_CPU_FLAG_RVV_I64
| AV_CPU_FLAG_RVV_F32 | AV_CPU_FLAG_RVV_F64;
}
#endif
#ifdef __riscv_i
ret |= AV_CPU_FLAG_RVI;
#endif
#ifdef __riscv_zba
ret |= AV_CPU_FLAG_RVB_ADDR;
#endif
#ifdef __riscv_zbb
ret |= AV_CPU_FLAG_RVB_BASIC;
#endif
#if defined (__riscv_b) || \
(defined (__riscv_zba) && defined (__riscv_zbb) && defined (__riscv_zbs))
ret |= AV_CPU_FLAG_RVB;
#endif
/* If RV-V is enabled statically at compile-time, check the details. */
#ifdef __riscv_vector
ret |= AV_CPU_FLAG_RVV_I32;
#if __riscv_v_elen >= 64
ret |= AV_CPU_FLAG_RVV_I64;
#endif
#if __riscv_v_elen_fp >= 32
ret |= AV_CPU_FLAG_RVV_F32;
#if __riscv_v_elen_fp >= 64
ret |= AV_CPU_FLAG_RVV_F64;
#endif
#endif
#endif
#ifdef __riscv_zvbb
ret |= AV_CPU_FLAG_RV_ZVBB;
#endif
return ret;
}