1 /* libFLAC - Free Lossless Audio Codec library
2  * Copyright (C) 2012-2014  Xiph.org Foundation
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * - Redistributions of source code must retain the above copyright
9  * notice, this list of conditions and the following disclaimer.
10  *
11  * - Redistributions in binary form must reproduce the above copyright
12  * notice, this list of conditions and the following disclaimer in the
13  * documentation and/or other materials provided with the distribution.
14  *
15  * - Neither the name of the Xiph.org Foundation nor the names of its
16  * contributors may be used to endorse or promote products derived from
17  * this software without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22  * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
24  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
26  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
27  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
28  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
29  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /* It is assumed that this header will be included after "config.h". */
33 
34 #if HAVE_BSWAP32			/* GCC and Clang */
35 
36 /* GCC prior to 4.8 didn't provide bswap16 on x86_64 */
37 #if ! HAVE_BSWAP16
__builtin_bswap16(unsigned short a)38 static inline unsigned short __builtin_bswap16(unsigned short a)
39 {
40 	return (a<<8)|(a>>8);
41 }
42 #endif
43 
44 #define	ENDSWAP_16(x)		(__builtin_bswap16 (x))
45 #define	ENDSWAP_32(x)		(__builtin_bswap32 (x))
46 
47 #elif defined _MSC_VER		/* Windows. Apparently in <stdlib.h>. */
48 
49 #define	ENDSWAP_16(x)		(_byteswap_ushort (x))
50 #define	ENDSWAP_32(x)		(_byteswap_ulong (x))
51 
52 #elif defined HAVE_BYTESWAP_H		/* Linux */
53 
54 #include <byteswap.h>
55 
56 #define	ENDSWAP_16(x)		(bswap_16 (x))
57 #define	ENDSWAP_32(x)		(bswap_32 (x))
58 
59 #else
60 
61 #define	ENDSWAP_16(x)		((((x) >> 8) & 0xFF) | (((x) & 0xFF) << 8))
62 #define	ENDSWAP_32(x)		((((x) >> 24) & 0xFF) | (((x) >> 8) & 0xFF00) | (((x) & 0xFF00) << 8) | (((x) & 0xFF) << 24))
63 
64 #endif
65 
66 
67 /* Host to little-endian byte swapping. */
68 #if CPU_IS_BIG_ENDIAN
69 
70 #define H2LE_16(x)		ENDSWAP_16 (x)
71 #define H2LE_32(x)		ENDSWAP_32 (x)
72 
73 #else
74 
75 #define H2LE_16(x)		(x)
76 #define H2LE_32(x)		(x)
77 
78 #endif
79