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ffmpeg/libavutil/riscv/intmath.h

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lavu/riscv: add <intmath.h> optimisations This provides some micro-optimisations for signed integer clipping, and support for bit weight with the Zbb extension.
2022-09-12 15:53:20 +00:00
/*
* 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
*/
#ifndef AVUTIL_RISCV_INTMATH_H
#define AVUTIL_RISCV_INTMATH_H
#include <stdint.h>
#include "config.h"
#include "libavutil/attributes.h"
/*
* The compiler is forced to sign-extend the result anyhow, so it is faster to
* compute it explicitly and use it.
*/
#define av_clip_int8 av_clip_int8_rvi
static av_always_inline av_const int8_t av_clip_int8_rvi(int a)
{
union { uint8_t u; int8_t s; } u = { .u = a };
if (a != u.s)
a = ((a >> 31) ^ 0x7F);
return a;
}
#define av_clip_int16 av_clip_int16_rvi
static av_always_inline av_const int16_t av_clip_int16_rvi(int a)
{
lavu/riscv: fix av_clip_int16 Some serious copy-paste / squash / rebase mismanipulation here. Signed-off-by: James Almer <jamrial@gmail.com>
2022-09-14 17:34:19 +00:00
union { uint16_t u; int16_t s; } u = { .u = a };
lavu/riscv: add <intmath.h> optimisations This provides some micro-optimisations for signed integer clipping, and support for bit weight with the Zbb extension.
2022-09-12 15:53:20 +00:00
if (a != u.s)
lavu/riscv: fix av_clip_int16 Some serious copy-paste / squash / rebase mismanipulation here. Signed-off-by: James Almer <jamrial@gmail.com>
2022-09-14 17:34:19 +00:00
a = ((a >> 31) ^ 0x7FFF);
lavu/riscv: add <intmath.h> optimisations This provides some micro-optimisations for signed integer clipping, and support for bit weight with the Zbb extension.
2022-09-12 15:53:20 +00:00
return a;
}
#define av_clipl_int32 av_clipl_int32_rvi
static av_always_inline av_const int32_t av_clipl_int32_rvi(int64_t a)
{
union { uint32_t u; int32_t s; } u = { .u = a };
if (a != u.s)
a = ((a >> 63) ^ 0x7FFFFFFF);
return a;
}
#define av_clip_intp2 av_clip_intp2_rvi
static av_always_inline av_const int av_clip_intp2_rvi(int a, int p)
{
lavu/riscv: fix off-by-one in bit-magnitude clip
2022-09-15 18:26:48 +00:00
const int shift = 31 - p;
int b = ((int)(((unsigned)a) << shift)) >> shift;
lavu/riscv: add <intmath.h> optimisations This provides some micro-optimisations for signed integer clipping, and support for bit weight with the Zbb extension.
2022-09-12 15:53:20 +00:00
if (a != b)
b = (a >> 31) ^ ((1 << p) - 1);
return b;
}
riscv/intmath: use builtins for counting ones As with the earlier bswap change, all versions of GCC and Clang that support RISC-V support the popcount built-ins, so we can just use them instead of inline assembler.
2023-04-20 17:53:57 +00:00
#if defined (__GNUC__) || defined (__clang__)
#define av_popcount __builtin_popcount
lavu/riscv: add <intmath.h> optimisations This provides some micro-optimisations for signed integer clipping, and support for bit weight with the Zbb extension.
2022-09-12 15:53:20 +00:00
#if (__riscv_xlen >= 64)
riscv/intmath: use builtins for counting ones As with the earlier bswap change, all versions of GCC and Clang that support RISC-V support the popcount built-ins, so we can just use them instead of inline assembler.
2023-04-20 17:53:57 +00:00
#define av_popcount64 __builtin_popcountl
lavu/riscv: add <intmath.h> optimisations This provides some micro-optimisations for signed integer clipping, and support for bit weight with the Zbb extension.
2022-09-12 15:53:20 +00:00
#else
riscv/intmath: use builtins for counting ones As with the earlier bswap change, all versions of GCC and Clang that support RISC-V support the popcount built-ins, so we can just use them instead of inline assembler.
2023-04-20 17:53:57 +00:00
#define av_popcount64 __builtin_popcountll
lavu/riscv: add <intmath.h> optimisations This provides some micro-optimisations for signed integer clipping, and support for bit weight with the Zbb extension.
2022-09-12 15:53:20 +00:00
#endif
#endif
#endif /* AVUTIL_RISCV_INTMATH_H */