mono/metadata/mono-endian.c

   1 /**
   2  * \file
   3  *
   4  * Author:
   5  *      Mono Project (http://www.mono-project.com)
   6  *
   7  * Copyright 2001-2003 Ximian, Inc (http://www.ximian.com)
   8  * Copyright 2004-2009 Novell, Inc (http://www.novell.com)
   9  * Licensed under the MIT license. See LICENSE file in the project root for full license information.
  10  */
  11 #include <config.h>
  12 #include <mono/utils/mono-compiler.h>
  13 #include "mono-endian.h"
  14
  15 #if NO_UNALIGNED_ACCESS
  16
  17 typedef union {
  18         char c [2];
  19         guint16 i;
  20 } mono_rint16;
  21
  22 typedef union {
  23         char c [4];
  24         guint32 i;
  25 } mono_rint32;
  26
  27 typedef union {
  28         char c [8];
  29         guint64 i;
  30 } mono_rint64;
  31
  32 guint16
  33 mono_read16 (const unsigned char *x)
  34 {
  35         mono_rint16 r;
  36 #if G_BYTE_ORDER == G_LITTLE_ENDIAN
  37         r.c [0] = x [0];
  38         r.c [1] = x [1];
  39 #else
  40         r.c [1] = x [0];
  41         r.c [0] = x [1];
  42 #endif
  43         return r.i;
  44 }
  45
  46 guint32
  47 mono_read32 (const unsigned char *x)
  48 {
  49         mono_rint32 r;
  50 #if G_BYTE_ORDER == G_LITTLE_ENDIAN
  51         r.c [0] = x [0];
  52         r.c [1] = x [1];
  53         r.c [2] = x [2];
  54         r.c [3] = x [3];
  55 #else
  56         r.c [3] = x [0];
  57         r.c [2] = x [1];
  58         r.c [1] = x [2];
  59         r.c [0] = x [3];
  60 #endif
  61         return r.i;
  62 }
  63
  64 guint64
  65 mono_read64 (const unsigned char *x)
  66 {
  67         mono_rint64 r;
  68 #if G_BYTE_ORDER == G_LITTLE_ENDIAN
  69         r.c [0] = x [0];
  70         r.c [1] = x [1];
  71         r.c [2] = x [2];
  72         r.c [3] = x [3];
  73         r.c [4] = x [4];
  74         r.c [5] = x [5];
  75         r.c [6] = x [6];
  76         r.c [7] = x [7];
  77 #else
  78         r.c [7] = x [0];
  79         r.c [6] = x [1];
  80         r.c [5] = x [2];
  81         r.c [4] = x [3];
  82         r.c [3] = x [4];
  83         r.c [2] = x [5];
  84         r.c [1] = x [6];
  85         r.c [0] = x [7];
  86 #endif
  87         return r.i;
  88 }
  89
  90 #else /* NO_UNALIGNED_ACCESS */
  91
  92 MONO_EMPTY_SOURCE_FILE (mono_endian);
  93
  94 #endif