libkern/libkern/i386/OSByteOrder.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26  * Copyright (c) 1999 Apple Computer, Inc.  All rights reserved.
  27  *
  28  * HISTORY
  29  *
  30  */
  31
  32 #ifndef _OS_OSBYTEORDERI386_H
  33 #define _OS_OSBYTEORDERI386_H
  34
  35 #include <libkern/OSTypes.h>
  36
  37 /* Functions for byte reversed loads. */
  38
  39 OS_INLINE
  40 UInt16
  41 OSReadSwapInt16(
  42     volatile void               * base,
  43     UInt                          offset
  44 )
  45 {
  46     UInt16 result;
  47
  48     result = *(volatile UInt16 *)((UInt8 *)base + offset);
  49     __asm__ volatile("xchgb %b0,%h0"
  50                      : "=q" (result)
  51                      : "0"  (result));
  52     return result;
  53 }
  54
  55 OS_INLINE
  56 UInt32
  57 OSReadSwapInt32(
  58     volatile void               * base,
  59     UInt                          offset
  60 )
  61 {
  62     UInt32 result;
  63
  64     result = *(volatile UInt32 *)((UInt8 *)base + offset);
  65     __asm__ volatile("bswap %0"
  66                      : "=r" (result)
  67                      : "0"  (result));
  68     return result;
  69 }
  70
  71 OS_INLINE
  72 UInt64
  73 OSReadSwapInt64(
  74     volatile void               * base,
  75     UInt                          offset
  76 )
  77 {
  78     UInt64 * inp;
  79     union ullc {
  80         UInt64     ull;
  81         UInt       ul[2];
  82     } outv;
  83
  84     inp = (UInt64 *)base;
  85     outv.ul[0] = OSReadSwapInt32(inp, offset + 4);
  86     outv.ul[1] = OSReadSwapInt32(inp, offset);
  87     return outv.ull;
  88 }
  89
  90 OS_INLINE
  91 UInt
  92 OSReadSwapInt(
  93     volatile void               * base,
  94     UInt                          offset
  95 )
  96 {
  97     UInt result;
  98
  99     result = *(volatile UInt *)((UInt8 *)base + offset);
 100     __asm__ volatile("bswap %0"
 101                      : "=r" (result)
 102                      : "0"  (result));
 103     return result;
 104 }
 105
 106 /* Functions for byte reversed stores. */
 107
 108 OS_INLINE
 109 void
 110 OSWriteSwapInt16(
 111     volatile void               * base,
 112     UInt                          offset,
 113     UInt16                        data
 114 )
 115 {
 116     __asm__ volatile("xchgb %b0,%h0"
 117                      : "=q" (data)
 118                      : "0"  (data));
 119     *(volatile UInt16 *)((UInt8 *)base + offset) = data;
 120 }
 121
 122 OS_INLINE
 123 void
 124 OSWriteSwapInt32(
 125     volatile void               * base,
 126     UInt                          offset,
 127     UInt32                        data
 128 )
 129 {
 130     __asm__ volatile("bswap %0"
 131                      : "=r" (data)
 132                      : "0"  (data));
 133     *(volatile UInt32 *)((UInt8 *)base + offset) = data;
 134 }
 135
 136 OS_INLINE
 137 void
 138 OSWriteSwapInt64(
 139     volatile void               * base,
 140     UInt                          offset,
 141     UInt64                        data
 142 )
 143 {
 144     UInt64 * outp;
 145     union ullc {
 146         UInt64     ull;
 147         UInt       ul[2];
 148     } *inp;
 149
 150     outp = (UInt64 *)base;
 151     inp  = (union ullc *)&data;
 152     OSWriteSwapInt32(outp, offset, inp->ul[1]);
 153     OSWriteSwapInt32(outp, offset + 4, inp->ul[0]);
 154 }
 155
 156 OS_INLINE
 157 void
 158 OSWriteSwapInt(
 159     volatile void               * base,
 160     UInt                          offset,
 161     UInt                          data
 162 )
 163 {
 164     __asm__ volatile("bswap %0"
 165                      : "=r" (data)
 166                      : "0"  (data));
 167     *(volatile UInt *)((UInt8 *)base + offset) = data;
 168 }
 169
 170 /* Generic byte swapping functions. */
 171
 172 OS_INLINE
 173 UInt16
 174 OSSwapInt16(
 175     UInt16                        data
 176 )
 177 {
 178     UInt16 temp = data;
 179     return OSReadSwapInt16(&temp, 0);
 180 }
 181
 182 OS_INLINE
 183 UInt32
 184 OSSwapInt32(
 185     UInt32                        data
 186 )
 187 {
 188     UInt32 temp = data;
 189     return OSReadSwapInt32(&temp, 0);
 190 }
 191
 192 OS_INLINE
 193 UInt64
 194 OSSwapInt64(
 195     UInt64                        data
 196 )
 197 {
 198     UInt64 temp = data;
 199     return OSReadSwapInt64(&temp, 0);
 200 }
 201
 202 OS_INLINE
 203 UInt
 204 OSSwapInt(
 205     UInt                          data
 206 )
 207 {
 208     UInt temp = data;
 209     return OSReadSwapInt(&temp, 0);
 210 }
 211
 212 #endif /* ! _OS_OSBYTEORDERI386_H */