ffmpeg/libavutil/mem_internal.h
Zhao Zhili 6e49b86996 avutil/mem_internal: Don't use alignas for MSVC
MSVC messed up standard C features, again.

Signed-off-by: Zhao Zhili <zhilizhao@tencent.com>
Reviewed-by: James Almer <jamrial@gmail.com>
2024-12-02 20:37:47 +08:00

133 lines
4.2 KiB
C

/*
* Copyright (c) 2002 Fabrice Bellard
*
* 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_MEM_INTERNAL_H
#define AVUTIL_MEM_INTERNAL_H
#include "config.h"
#include <stdint.h>
#include <stdalign.h>
#include "attributes.h"
#include "macros.h"
/**
* @def DECLARE_ALIGNED(n,t,v)
* Declare a variable that is aligned in memory.
*
* @code{.c}
* DECLARE_ALIGNED(16, uint16_t, aligned_int) = 42;
* DECLARE_ALIGNED(32, uint8_t, aligned_array)[128];
*
* // The default-alignment equivalent would be
* uint16_t aligned_int = 42;
* uint8_t aligned_array[128];
* @endcode
*
* @param n Minimum alignment in bytes
* @param t Type of the variable (or array element)
* @param v Name of the variable
*/
/**
* @def DECLARE_ASM_ALIGNED(n,t,v)
* Declare an aligned variable appropriate for use in inline assembly code.
*
* @code{.c}
* DECLARE_ASM_ALIGNED(16, uint64_t, pw_08) = UINT64_C(0x0008000800080008);
* @endcode
*
* @param n Minimum alignment in bytes
* @param t Type of the variable (or array element)
* @param v Name of the variable
*/
/**
* @def DECLARE_ASM_CONST(n,t,v)
* Declare a static constant aligned variable appropriate for use in inline
* assembly code.
*
* @code{.c}
* DECLARE_ASM_CONST(16, uint64_t, pw_08) = UINT64_C(0x0008000800080008);
* @endcode
*
* @param n Minimum alignment in bytes
* @param t Type of the variable (or array element)
* @param v Name of the variable
*/
#if defined(__DJGPP__)
#define DECLARE_ALIGNED_T(n,t,v) alignas(FFMIN(n, 16)) t v
#define DECLARE_ASM_ALIGNED(n,t,v) alignas(FFMIN(n, 16)) t av_used v
#define DECLARE_ASM_CONST(n,t,v) alignas(FFMIN(n, 16)) static const t av_used v
#elif defined(_MSC_VER)
#define DECLARE_ALIGNED_T(n,t,v) __declspec(align(n)) t v
#define DECLARE_ASM_ALIGNED(n,t,v) __declspec(align(n)) t v
#define DECLARE_ASM_CONST(n,t,v) __declspec(align(n)) static const t v
#else
#define DECLARE_ALIGNED_T(n,t,v) alignas(n) t v
#define DECLARE_ASM_ALIGNED(n,t,v) alignas(n) t av_used v
#define DECLARE_ASM_CONST(n,t,v) alignas(n) static const t av_used v
#endif
#if HAVE_SIMD_ALIGN_64
#define ALIGN_64 64
#define ALIGN_32 32
#elif HAVE_SIMD_ALIGN_32
#define ALIGN_64 32
#define ALIGN_32 32
#else
#define ALIGN_64 16
#define ALIGN_32 16
#endif
#define DECLARE_ALIGNED(n,t,v) DECLARE_ALIGNED_V(n,t,v)
// Macro needs to be double-wrapped in order to expand
// possible other macros being passed for n.
#define DECLARE_ALIGNED_V(n,t,v) DECLARE_ALIGNED_##n(t,v)
#define DECLARE_ALIGNED_4(t,v) DECLARE_ALIGNED_T( 4, t, v)
#define DECLARE_ALIGNED_8(t,v) DECLARE_ALIGNED_T( 8, t, v)
#define DECLARE_ALIGNED_16(t,v) DECLARE_ALIGNED_T( 16, t, v)
#define DECLARE_ALIGNED_32(t,v) DECLARE_ALIGNED_T(ALIGN_32, t, v)
#define DECLARE_ALIGNED_64(t,v) DECLARE_ALIGNED_T(ALIGN_64, t, v)
// Some broken preprocessors need a second expansion
// to be forced to tokenize __VA_ARGS__
#define E1(x) x
#define LOCAL_ALIGNED_D(a, t, v, s, o, ...) \
DECLARE_ALIGNED(a, t, la_##v) s o; \
t (*v) o = la_##v
#define LOCAL_ALIGNED(a, t, v, ...) LOCAL_ALIGNED_##a(t, v, __VA_ARGS__)
#define LOCAL_ALIGNED_4(t, v, ...) E1(LOCAL_ALIGNED_D(4, t, v, __VA_ARGS__,,))
#define LOCAL_ALIGNED_8(t, v, ...) E1(LOCAL_ALIGNED_D(8, t, v, __VA_ARGS__,,))
#define LOCAL_ALIGNED_16(t, v, ...) E1(LOCAL_ALIGNED_D(16, t, v, __VA_ARGS__,,))
#define LOCAL_ALIGNED_32(t, v, ...) E1(LOCAL_ALIGNED_D(32, t, v, __VA_ARGS__,,))
#endif /* AVUTIL_MEM_INTERNAL_H */