include/asterisk/unaligned.h

   1 /*
   2  * Asterisk -- An open source telephony toolkit.
   3  *
   4  * Copyright (C) 1999 - 2005, Digium, Inc.
   5  *
   6  * Mark Spencer <markster@digium.com>
   7  *
   8  * See http://www.asterisk.org for more information about
   9  * the Asterisk project. Please do not directly contact
  10  * any of the maintainers of this project for assistance;
  11  * the project provides a web site, mailing lists and IRC
  12  * channels for your use.
  13  *
  14  * This program is free software, distributed under the terms of
  15  * the GNU General Public License Version 2. See the LICENSE file
  16  * at the top of the source tree.
  17  */
  18
  19 /*! \file
  20  * \brief Handle unaligned data access
  21  */
  22
  23 #ifndef _ASTERISK_UNALIGNED_H
  24 #define _ASTERISK_UNALIGNED_H
  25
  26 #if defined(__cplusplus) || defined(c_plusplus)
  27 extern "C" {
  28 #endif
  29
  30 #ifdef __GNUC__
  31 /* If we just tell GCC what's going on, we can trust it to behave optimally */
  32 static inline unsigned int get_unaligned_uint32(void *p)
  33 {
  34         struct { unsigned int d; } __attribute__((packed)) *pp = (void *)p;
  35
  36         return pp->d;
  37 }
  38 static inline unsigned short get_unaligned_uint16(void *p)
  39 {
  40         struct { unsigned short d; } __attribute__((packed)) *pp = (void *)p;
  41
  42         return pp->d;
  43 }
  44
  45 static inline void put_unaligned_uint32(void *p, unsigned int datum)
  46 {
  47         struct { unsigned int d; } __attribute__((packed)) *pp = (void *)p;
  48
  49         pp->d = datum;
  50 }
  51
  52 static inline void put_unaligned_uint16(void *p, unsigned short datum)
  53 {
  54         struct { unsigned short d; } __attribute__((packed)) *pp = (void *)p;
  55
  56         pp->d = datum;
  57 }
  58 #elif defined(SOLARIS) && defined(__sparc__)
  59 static inline unsigned int get_unaligned_uint32(void *p)
  60 {
  61         unsigned char *cp = p;
  62
  63         return (cp[0] << 24) | (cp[1] << 16) | (cp[2] << 8) | cp[3];
  64 }
  65
  66 static inline unsigned short get_unaligned_uint16(void *p)
  67 {
  68         unsigned char *cp = p;
  69
  70         return (cp[0] << 8) | cp[1] ;
  71 }
  72
  73 static inline void put_unaligned_uint32(void *p, unsigned int datum)
  74 {
  75         unsigned char *cp = p;
  76
  77         cp[0] = datum >> 24;
  78         cp[1] = datum >> 16;
  79         cp[2] = datum >> 8;
  80         cp[3] = datum;
  81 }
  82
  83 static inline void put_unaligned_uint16(void *p, unsigned int datum)
  84 {
  85         unsigned char *cp = p;
  86
  87         cp[0] = datum >> 8;
  88         cp[1] = datum;
  89 }
  90 #else /* Not GCC, not Solaris/SPARC. Assume we can handle direct load/store. */
  91 #define get_unaligned_uint32(p) (*((unsigned int *)(p)))
  92 #define get_unaligned_uint16(p) (*((unsigned short *)(p)))
  93 #define put_unaligned_uint32(p,d) do { unsigned int *__P = (p); *__P = d; } while(0)
  94 #define put_unaligned_uint16(p,d) do { unsigned short *__P = (p); *__P = d; } while(0)
  95 #endif
  96
  97 #if defined(__cplusplus) || defined(c_plusplus)
  98 }
  99 #endif
 100
 101
 102 #endif /* _ASTERISK_UNALIGNED_H */