libkern/libkern/i386/_OSByteOrder.h

   1 /*
   2  * Copyright (c) 2006 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 #ifndef _OS__OSBYTEORDERI386_H
  30 #define _OS__OSBYTEORDERI386_H
  31
  32 #if !defined(__DARWIN_OS_INLINE)
  33 # if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
  34 #        define __DARWIN_OS_INLINE static inline
  35 # elif defined(__MWERKS__) || defined(__cplusplus)
  36 #        define __DARWIN_OS_INLINE static inline
  37 # else
  38 #        define __DARWIN_OS_INLINE static __inline__
  39 # endif
  40 #endif
  41
  42 /* Generic byte swapping functions. */
  43
  44 __DARWIN_OS_INLINE
  45 __uint16_t
  46 _OSSwapInt16(
  47     __uint16_t        _data
  48 )
  49 {
  50     return ((_data << 8) | (_data >> 8));
  51 }
  52
  53 __DARWIN_OS_INLINE
  54 __uint32_t
  55 _OSSwapInt32(
  56     __uint32_t        _data
  57 )
  58 {
  59 #if defined(__llvm__)
  60     return __builtin_bswap32(_data);
  61 #else
  62     __asm__ ("bswap   %0" : "+r" (_data));
  63     return _data;
  64 #endif
  65 }
  66
  67 #if defined(__llvm__)
  68 __DARWIN_OS_INLINE
  69 __uint64_t
  70 _OSSwapInt64(
  71     __uint64_t        _data
  72 )
  73 {
  74     return __builtin_bswap64(_data);
  75 }
  76
  77 #elif defined(__i386__)
  78 __DARWIN_OS_INLINE
  79 __uint64_t
  80 _OSSwapInt64(
  81     __uint64_t        _data
  82 )
  83 {
  84     __asm__ ("bswap   %%eax\n\t"
  85              "bswap   %%edx\n\t"
  86              "xchgl   %%eax, %%edx"
  87              : "+A" (_data));
  88     return _data;
  89 }
  90 #elif defined(__x86_64__)
  91 __DARWIN_OS_INLINE
  92 __uint64_t
  93 _OSSwapInt64(
  94     __uint64_t        _data
  95 )
  96 {
  97     __asm__ ("bswap   %0" : "+r" (_data));
  98     return _data;
  99 }
 100 #else
 101 #error Unknown architecture
 102 #endif
 103
 104 #endif /* ! _OS__OSBYTEORDERI386_H */