[deb_ffmpeg.git] / ffmpeg / libavutil / intmath.h

/*
 * Copyright (c) 2010 Mans Rullgard <mans@mansr.com>
 *
 * 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_INTMATH_H
#define AVUTIL_INTMATH_H

#include <stdint.h>

#include "config.h"
#include "attributes.h"

#if ARCH_ARM
#   include "arm/intmath.h"
#endif

/**
 * @addtogroup lavu_internal
 * @{
 */

#if HAVE_FAST_CLZ && AV_GCC_VERSION_AT_LEAST(3,4)

#ifndef ff_log2
#   define ff_log2(x) (31 - __builtin_clz((x)|1))
#   ifndef ff_log2_16bit
#      define ff_log2_16bit av_log2
#   endif
#endif /* ff_log2 */

#endif /* AV_GCC_VERSION_AT_LEAST(3,4) */

extern const uint8_t ff_log2_tab[256];

#ifndef ff_log2
#define ff_log2 ff_log2_c
static av_always_inline av_const int ff_log2_c(unsigned int v)
{
    int n = 0;
    if (v & 0xffff0000) {
        v >>= 16;
        n += 16;
    }
    if (v & 0xff00) {
        v >>= 8;
        n += 8;
    }
    n += ff_log2_tab[v];

    return n;
}
#endif

#ifndef ff_log2_16bit
#define ff_log2_16bit ff_log2_16bit_c
static av_always_inline av_const int ff_log2_16bit_c(unsigned int v)
{
    int n = 0;
    if (v & 0xff00) {
        v >>= 8;
        n += 8;
    }
    n += ff_log2_tab[v];

    return n;
}
#endif

#define av_log2       ff_log2
#define av_log2_16bit ff_log2_16bit

/**
 * @}
 */

/**
 * @addtogroup lavu_math
 * @{
 */

#if HAVE_FAST_CLZ && AV_GCC_VERSION_AT_LEAST(3,4)
#ifndef ff_ctz
#define ff_ctz(v) __builtin_ctz(v)
#endif
#endif

#ifndef ff_ctz
#define ff_ctz ff_ctz_c
static av_always_inline av_const int ff_ctz_c(int v)
{
    int c;

    if (v & 0x1)
        return 0;

    c = 1;
    if (!(v & 0xffff)) {
        v >>= 16;
        c += 16;
    }
    if (!(v & 0xff)) {
        v >>= 8;
        c += 8;
    }
    if (!(v & 0xf)) {
        v >>= 4;
        c += 4;
    }
    if (!(v & 0x3)) {
        v >>= 2;
        c += 2;
    }
    c -= v & 0x1;

    return c;
}
#endif

/**
 * Trailing zero bit count.
 *
 * @param v  input value. If v is 0, the result is undefined.
 * @return   the number of trailing 0-bits
 */
int av_ctz(int v);

/**
 * @}
 */
#endif /* AVUTIL_INTMATH_H */
Commit	Line	Data
2ba45a60 DM	1	/*
	2	* Copyright (c) 2010 Mans Rullgard <mans@mansr.com>
	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	#ifndef AVUTIL_INTMATH_H
	22	#define AVUTIL_INTMATH_H
	23
	24	#include <stdint.h>
	25
	26	#include "config.h"
	27	#include "attributes.h"
	28
	29	#if ARCH_ARM
	30	# include "arm/intmath.h"
	31	#endif
	32
	33	/**
	34	* @addtogroup lavu_internal
	35	* @{
	36	*/
	37
	38	#if HAVE_FAST_CLZ && AV_GCC_VERSION_AT_LEAST(3,4)
	39
	40	#ifndef ff_log2
	41	# define ff_log2(x) (31 - __builtin_clz((x)\|1))
	42	# ifndef ff_log2_16bit
	43	# define ff_log2_16bit av_log2
	44	# endif
	45	#endif /* ff_log2 */
	46
	47	#endif /* AV_GCC_VERSION_AT_LEAST(3,4) */
	48
	49	extern const uint8_t ff_log2_tab[256];
	50
	51	#ifndef ff_log2
	52	#define ff_log2 ff_log2_c
	53	static av_always_inline av_const int ff_log2_c(unsigned int v)
	54	{
	55	int n = 0;
	56	if (v & 0xffff0000) {
	57	v >>= 16;
	58	n += 16;
	59	}
	60	if (v & 0xff00) {
	61	v >>= 8;
	62	n += 8;
	63	}
	64	n += ff_log2_tab[v];
65
66	return n;
67	}
68	#endif
69
70	#ifndef ff_log2_16bit
71	#define ff_log2_16bit ff_log2_16bit_c
72	static av_always_inline av_const int ff_log2_16bit_c(unsigned int v)
73	{
74	int n = 0;
75	if (v & 0xff00) {
76	v >>= 8;
77	n += 8;
78	}
79	n += ff_log2_tab[v];
80
81	return n;
82	}
83	#endif
84
85	#define av_log2 ff_log2
86	#define av_log2_16bit ff_log2_16bit
87
88	/**
89	* @}
90	*/
91
92	/**
93	* @addtogroup lavu_math
94	* @{
95	*/
96
97	#if HAVE_FAST_CLZ && AV_GCC_VERSION_AT_LEAST(3,4)
98	#ifndef ff_ctz
99	#define ff_ctz(v) __builtin_ctz(v)
100	#endif
101	#endif
102
103	#ifndef ff_ctz
104	#define ff_ctz ff_ctz_c
105	static av_always_inline av_const int ff_ctz_c(int v)
106	{
107	int c;
108
109	if (v & 0x1)
110	return 0;
111
112	c = 1;
113	if (!(v & 0xffff)) {
114	v >>= 16;
115	c += 16;
116	}
117	if (!(v & 0xff)) {
118	v >>= 8;
119	c += 8;
120	}
121	if (!(v & 0xf)) {
122	v >>= 4;
123	c += 4;
124	}
125	if (!(v & 0x3)) {
126	v >>= 2;
127	c += 2;
128	}
129	c -= v & 0x1;
130
131	return c;
132	}
133	#endif
134
135	/**
136	* Trailing zero bit count.
137	*
138	* @param v input value. If v is 0, the result is undefined.
139	* @return the number of trailing 0-bits
140	*/
141	int av_ctz(int v);
142
143	/**
144	* @}
145	*/
146	#endif /* AVUTIL_INTMATH_H */