libkern/libkern/i386/OSByteOrder.h

   1 /*
   2  * Copyright (c) 1999-2005 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_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
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30
  31 #ifndef _OS_OSBYTEORDERI386_H
  32 #define _OS_OSBYTEORDERI386_H
  33
  34 #include <stdint.h>
  35
  36 #if !defined(OS_INLINE)
  37 # if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
  38 #        define OS_INLINE static inline
  39 # elif defined(__MWERKS__) || defined(__cplusplus)
  40 #        define OS_INLINE static inline
  41 # else
  42 #        define OS_INLINE static __inline__
  43 # endif
  44 #endif
  45
  46 /* Generic byte swapping functions. */
  47
  48 OS_INLINE
  49 uint16_t
  50 _OSSwapInt16(
  51     uint16_t        data
  52 )
  53 {
  54     return ((data << 8) | (data >> 8));
  55 }
  56
  57 OS_INLINE
  58 uint32_t
  59 _OSSwapInt32(
  60     uint32_t        data
  61 )
  62 {
  63     __asm__ ("bswap   %0" : "+r" (data));
  64     return data;
  65 }
  66
  67 #if defined(__i386__)
  68 OS_INLINE
  69 uint64_t
  70 _OSSwapInt64(
  71     uint64_t        data
  72 )
  73 {
  74     __asm__ ("bswap   %%eax\n\t"
  75              "bswap   %%edx\n\t"
  76              "xchgl   %%eax, %%edx"
  77              : "+A" (data));
  78     return data;
  79 }
  80 #elif defined(__x86_64__)
  81 OS_INLINE
  82 uint64_t
  83 _OSSwapInt64(
  84     uint64_t        data
  85 )
  86 {
  87     __asm__ ("bswap   %0" : "+r" (data));
  88     return data;
  89 }
  90 #else
  91 #error Unknown architecture
  92 #endif
  93
  94 /* Functions for byte reversed loads. */
  95
  96 OS_INLINE
  97 uint16_t
  98 OSReadSwapInt16(
  99     const volatile void   * base,
 100     uintptr_t       byteOffset
 101 )
 102 {
 103     uint16_t result;
 104
 105     result = *(volatile uint16_t *)((uintptr_t)base + byteOffset);
 106     return _OSSwapInt16(result);
 107 }
 108
 109 OS_INLINE
 110 uint32_t
 111 OSReadSwapInt32(
 112     const volatile void   * base,
 113     uintptr_t       byteOffset
 114 )
 115 {
 116     uint32_t result;
 117
 118     result = *(volatile uint32_t *)((uintptr_t)base + byteOffset);
 119     return _OSSwapInt32(result);
 120 }
 121
 122 OS_INLINE
 123 uint64_t
 124 OSReadSwapInt64(
 125     const volatile void   * base,
 126     uintptr_t       byteOffset
 127 )
 128 {
 129     uint64_t result;
 130
 131     result = *(volatile uint64_t *)((uintptr_t)base + byteOffset);
 132     return _OSSwapInt64(result);
 133 }
 134
 135 /* Functions for byte reversed stores. */
 136
 137 OS_INLINE
 138 void
 139 OSWriteSwapInt16(
 140     volatile void   * base,
 141     uintptr_t       byteOffset,
 142     uint16_t        data
 143 )
 144 {
 145     *(volatile uint16_t *)((uintptr_t)base + byteOffset) = _OSSwapInt16(data);
 146 }
 147
 148 OS_INLINE
 149 void
 150 OSWriteSwapInt32(
 151     volatile void   * base,
 152     uintptr_t       byteOffset,
 153     uint32_t        data
 154 )
 155 {
 156     *(volatile uint32_t *)((uintptr_t)base + byteOffset) = _OSSwapInt32(data);
 157 }
 158
 159 OS_INLINE
 160 void
 161 OSWriteSwapInt64(
 162     volatile void    * base,
 163     uintptr_t        byteOffset,
 164     uint64_t         data
 165 )
 166 {
 167     *(volatile uint64_t *)((uintptr_t)base + byteOffset) = _OSSwapInt64(data);
 168 }
 169
 170 #endif /* ! _OS_OSBYTEORDERI386_H */