EXTERNAL_HEADERS/architecture/i386/byte_order.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * Copyright (c) 1992 NeXT Computer, Inc.
  24  *
  25  * Byte ordering conversion (for i386).
  26  *
  27  * HISTORY
  28  *
  29  * 8 October 1992 ? at NeXT
  30  *      Converted to NXxxx versions.  Condensed history.
  31  *
  32  * 18 May 1992 ? at NeXT
  33  *      Created.
  34  */
  35
  36 static __inline__
  37 unsigned short
  38 NXSwapShort(
  39     unsigned short      inv
  40 )
  41 {
  42     register unsigned short value = inv;
  43
  44     __asm__ volatile( "xchgb %h1, %b1" : "=q" (value) : "0" (value));
  45
  46     return (value);
  47 }
  48
  49 static __inline__
  50 unsigned long
  51 NXSwapInt(
  52     unsigned long inv
  53 )
  54 {
  55     register unsigned int outv = inv;
  56
  57     __asm__ volatile( "bswap %0" : "=r" (outv) : "0" (outv));
  58
  59     return (outv);
  60 }
  61
  62 static __inline__
  63 unsigned long
  64 NXSwapLong(
  65     unsigned long       inv
  66 )
  67 {
  68     unsigned long       outv;
  69
  70     __asm__ volatile(
  71         "bswap %0"
  72
  73         : "=r"  (outv)
  74         : "0"   (inv));
  75
  76     return (outv);
  77 }
  78
  79 static __inline__
  80 unsigned long long
  81 NXSwapLongLong(
  82     unsigned long long  inv
  83 )
  84 {
  85     union llconv {
  86         unsigned long long      ull;
  87         unsigned long           ul[2];
  88     } *inp, outv;
  89
  90     inp = (union llconv *)&inv;
  91
  92     outv.ul[0] = NXSwapLong(inp->ul[1]);
  93     outv.ul[1] = NXSwapLong(inp->ul[0]);
  94
  95     return (outv.ull);
  96 }
  97
  98 static __inline__ NXSwappedFloat
  99 NXConvertHostFloatToSwapped(float x)
 100 {
 101     union fconv {
 102         float number;
 103         NXSwappedFloat sf;
 104     };
 105     return ((union fconv *)&x)->sf;
 106 }
 107
 108 static __inline__ float
 109 NXConvertSwappedFloatToHost(NXSwappedFloat x)
 110 {
 111     union fconv {
 112         float number;
 113         NXSwappedFloat sf;
 114     };
 115     return ((union fconv *)&x)->number;
 116 }
 117
 118 static __inline__ NXSwappedDouble
 119 NXConvertHostDoubleToSwapped(double x)
 120 {
 121     union dconv {
 122         double number;
 123         NXSwappedDouble sd;
 124     };
 125     return ((union dconv *)&x)->sd;
 126 }
 127
 128 static __inline__ double
 129 NXConvertSwappedDoubleToHost(NXSwappedDouble x)
 130 {
 131     union dconv {
 132         double number;
 133         NXSwappedDouble sd;
 134     };
 135     return ((union dconv *)&x)->number;
 136 }
 137
 138 static __inline__ NXSwappedFloat
 139 NXSwapFloat(NXSwappedFloat x)
 140 {
 141     return NXSwapLong(x);
 142 }
 143
 144 static __inline__ NXSwappedDouble
 145 NXSwapDouble(NXSwappedDouble x)
 146 {
 147     return NXSwapLongLong(x);
 148 }