vpx_ports/mem_ops.h

   1 /*
   2  *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
   3  *
   4  *  Use of this source code is governed by a BSD-style license
   5  *  that can be found in the LICENSE file in the root of the source
   6  *  tree. An additional intellectual property rights grant can be found
   7  *  in the file PATENTS.  All contributing project authors may
   8  *  be found in the AUTHORS file in the root of the source tree.
   9  */
  10
  11 #ifndef VPX_PORTS_MEM_OPS_H_
  12 #define VPX_PORTS_MEM_OPS_H_
  13
  14 /* \file
  15  * \brief Provides portable memory access primitives
  16  *
  17  * This function provides portable primitives for getting and setting of
  18  * signed and unsigned integers in 16, 24, and 32 bit sizes. The operations
  19  * can be performed on unaligned data regardless of hardware support for
  20  * unaligned accesses.
  21  *
  22  * The type used to pass the integral values may be changed by defining
  23  * MEM_VALUE_T with the appropriate type. The type given must be an integral
  24  * numeric type.
  25  *
  26  * The actual functions instantiated have the MEM_VALUE_T type name pasted
  27  * on to the symbol name. This allows the developer to instantiate these
  28  * operations for multiple types within the same translation unit. This is
  29  * of somewhat questionable utility, but the capability exists nonetheless.
  30  * Users not making use of this functionality should call the functions
  31  * without the type name appended, and the preprocessor will take care of
  32  * it.
  33  *
  34  * NOTE: This code is not supported on platforms where char > 1 octet ATM.
  35  */
  36
  37 #ifndef MAU_T
  38 /* Minimum Access Unit for this target */
  39 #define MAU_T unsigned char
  40 #endif
  41
  42 #ifndef MEM_VALUE_T
  43 #define MEM_VALUE_T int
  44 #endif
  45
  46 #undef MEM_VALUE_T_SZ_BITS
  47 #define MEM_VALUE_T_SZ_BITS (sizeof(MEM_VALUE_T) << 3)
  48
  49 #undef  mem_ops_wrap_symbol
  50 #define mem_ops_wrap_symbol(fn) mem_ops_wrap_symbol2(fn, MEM_VALUE_T)
  51 #undef  mem_ops_wrap_symbol2
  52 #define mem_ops_wrap_symbol2(fn,typ) mem_ops_wrap_symbol3(fn,typ)
  53 #undef  mem_ops_wrap_symbol3
  54 #define mem_ops_wrap_symbol3(fn,typ) fn##_as_##typ
  55
  56 /*
  57  * Include aligned access routines
  58  */
  59 #define INCLUDED_BY_MEM_OPS_H
  60 #include "mem_ops_aligned.h"
  61 #undef  INCLUDED_BY_MEM_OPS_H
  62
  63 #undef  mem_get_be16
  64 #define mem_get_be16 mem_ops_wrap_symbol(mem_get_be16)
  65 static unsigned MEM_VALUE_T mem_get_be16(const void *vmem) {
  66   unsigned MEM_VALUE_T  val;
  67   const MAU_T          *mem = (const MAU_T *)vmem;
  68
  69   val = mem[0] << 8;
  70   val |= mem[1];
  71   return val;
  72 }
  73
  74 #undef  mem_get_be24
  75 #define mem_get_be24 mem_ops_wrap_symbol(mem_get_be24)
  76 static unsigned MEM_VALUE_T mem_get_be24(const void *vmem) {
  77   unsigned MEM_VALUE_T  val;
  78   const MAU_T          *mem = (const MAU_T *)vmem;
  79
  80   val = mem[0] << 16;
  81   val |= mem[1] << 8;
  82   val |= mem[2];
  83   return val;
  84 }
  85
  86 #undef  mem_get_be32
  87 #define mem_get_be32 mem_ops_wrap_symbol(mem_get_be32)
  88 static unsigned MEM_VALUE_T mem_get_be32(const void *vmem) {
  89   unsigned MEM_VALUE_T  val;
  90   const MAU_T          *mem = (const MAU_T *)vmem;
  91
  92   val = mem[0] << 24;
  93   val |= mem[1] << 16;
  94   val |= mem[2] << 8;
  95   val |= mem[3];
  96   return val;
  97 }
  98
  99 #undef  mem_get_le16
 100 #define mem_get_le16 mem_ops_wrap_symbol(mem_get_le16)
 101 static unsigned MEM_VALUE_T mem_get_le16(const void *vmem) {
 102   unsigned MEM_VALUE_T  val;
 103   const MAU_T          *mem = (const MAU_T *)vmem;
 104
 105   val = mem[1] << 8;
 106   val |= mem[0];
 107   return val;
 108 }
 109
 110 #undef  mem_get_le24
 111 #define mem_get_le24 mem_ops_wrap_symbol(mem_get_le24)
 112 static unsigned MEM_VALUE_T mem_get_le24(const void *vmem) {
 113   unsigned MEM_VALUE_T  val;
 114   const MAU_T          *mem = (const MAU_T *)vmem;
 115
 116   val = mem[2] << 16;
 117   val |= mem[1] << 8;
 118   val |= mem[0];
 119   return val;
 120 }
 121
 122 #undef  mem_get_le32
 123 #define mem_get_le32 mem_ops_wrap_symbol(mem_get_le32)
 124 static unsigned MEM_VALUE_T mem_get_le32(const void *vmem) {
 125   unsigned MEM_VALUE_T  val;
 126   const MAU_T          *mem = (const MAU_T *)vmem;
 127
 128   val = mem[3] << 24;
 129   val |= mem[2] << 16;
 130   val |= mem[1] << 8;
 131   val |= mem[0];
 132   return val;
 133 }
 134
 135 #define mem_get_s_generic(end,sz) \
 136   static signed MEM_VALUE_T mem_get_s##end##sz(const void *vmem) {\
 137     const MAU_T *mem = (const MAU_T*)vmem;\
 138     signed MEM_VALUE_T val = mem_get_##end##sz(mem);\
 139     return (val << (MEM_VALUE_T_SZ_BITS - sz)) >> (MEM_VALUE_T_SZ_BITS - sz);\
 140   }
 141
 142 #undef  mem_get_sbe16
 143 #define mem_get_sbe16 mem_ops_wrap_symbol(mem_get_sbe16)
 144 mem_get_s_generic(be, 16)
 145
 146 #undef  mem_get_sbe24
 147 #define mem_get_sbe24 mem_ops_wrap_symbol(mem_get_sbe24)
 148 mem_get_s_generic(be, 24)
 149
 150 #undef  mem_get_sbe32
 151 #define mem_get_sbe32 mem_ops_wrap_symbol(mem_get_sbe32)
 152 mem_get_s_generic(be, 32)
 153
 154 #undef  mem_get_sle16
 155 #define mem_get_sle16 mem_ops_wrap_symbol(mem_get_sle16)
 156 mem_get_s_generic(le, 16)
 157
 158 #undef  mem_get_sle24
 159 #define mem_get_sle24 mem_ops_wrap_symbol(mem_get_sle24)
 160 mem_get_s_generic(le, 24)
 161
 162 #undef  mem_get_sle32
 163 #define mem_get_sle32 mem_ops_wrap_symbol(mem_get_sle32)
 164 mem_get_s_generic(le, 32)
 165
 166 #undef  mem_put_be16
 167 #define mem_put_be16 mem_ops_wrap_symbol(mem_put_be16)
 168 static void mem_put_be16(void *vmem, MEM_VALUE_T val) {
 169   MAU_T *mem = (MAU_T *)vmem;
 170
 171   mem[0] = (val >> 8) & 0xff;
 172   mem[1] = (val >> 0) & 0xff;
 173 }
 174
 175 #undef  mem_put_be24
 176 #define mem_put_be24 mem_ops_wrap_symbol(mem_put_be24)
 177 static void mem_put_be24(void *vmem, MEM_VALUE_T val) {
 178   MAU_T *mem = (MAU_T *)vmem;
 179
 180   mem[0] = (val >> 16) & 0xff;
 181   mem[1] = (val >>  8) & 0xff;
 182   mem[2] = (val >>  0) & 0xff;
 183 }
 184
 185 #undef  mem_put_be32
 186 #define mem_put_be32 mem_ops_wrap_symbol(mem_put_be32)
 187 static void mem_put_be32(void *vmem, MEM_VALUE_T val) {
 188   MAU_T *mem = (MAU_T *)vmem;
 189
 190   mem[0] = (val >> 24) & 0xff;
 191   mem[1] = (val >> 16) & 0xff;
 192   mem[2] = (val >>  8) & 0xff;
 193   mem[3] = (val >>  0) & 0xff;
 194 }
 195
 196 #undef  mem_put_le16
 197 #define mem_put_le16 mem_ops_wrap_symbol(mem_put_le16)
 198 static void mem_put_le16(void *vmem, MEM_VALUE_T val) {
 199   MAU_T *mem = (MAU_T *)vmem;
 200
 201   mem[0] = (val >>  0) & 0xff;
 202   mem[1] = (val >>  8) & 0xff;
 203 }
 204
 205 #undef  mem_put_le24
 206 #define mem_put_le24 mem_ops_wrap_symbol(mem_put_le24)
 207 static void mem_put_le24(void *vmem, MEM_VALUE_T val) {
 208   MAU_T *mem = (MAU_T *)vmem;
 209
 210   mem[0] = (val >>  0) & 0xff;
 211   mem[1] = (val >>  8) & 0xff;
 212   mem[2] = (val >> 16) & 0xff;
 213 }
 214
 215 #undef  mem_put_le32
 216 #define mem_put_le32 mem_ops_wrap_symbol(mem_put_le32)
 217 static void mem_put_le32(void *vmem, MEM_VALUE_T val) {
 218   MAU_T *mem = (MAU_T *)vmem;
 219
 220   mem[0] = (val >>  0) & 0xff;
 221   mem[1] = (val >>  8) & 0xff;
 222   mem[2] = (val >> 16) & 0xff;
 223   mem[3] = (val >> 24) & 0xff;
 224 }
 225
 226 #endif  // VPX_PORTS_MEM_OPS_H_