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
  12 /* \file
  13  * \brief Provides portable memory access primitives
  14  *
  15  * This function provides portable primitives for getting and setting of
  16  * signed and unsigned integers in 16, 24, and 32 bit sizes. The operations
  17  * can be performed on unaligned data regardless of hardware support for
  18  * unaligned accesses.
  19  *
  20  * The type used to pass the integral values may be changed by defining
  21  * MEM_VALUE_T with the appropriate type. The type given must be an integral
  22  * numeric type.
  23  *
  24  * The actual functions instantiated have the MEM_VALUE_T type name pasted
  25  * on to the symbol name. This allows the developer to instantiate these
  26  * operations for multiple types within the same translation unit. This is
  27  * of somewhat questionable utility, but the capability exists nonetheless.
  28  * Users not making use of this functionality should call the functions
  29  * without the type name appended, and the preprocessor will take care of
  30  * it.
  31  *
  32  * NOTE: This code is not supported on platforms where char > 1 octet ATM.
  33  */
  34
  35 #ifndef MAU_T
  36 /* Minimum Access Unit for this target */
  37 #define MAU_T unsigned char
  38 #endif
  39
  40 #ifndef MEM_VALUE_T
  41 #define MEM_VALUE_T int
  42 #endif
  43
  44 #undef MEM_VALUE_T_SZ_BITS
  45 #define MEM_VALUE_T_SZ_BITS (sizeof(MEM_VALUE_T) << 3)
  46
  47 #undef  mem_ops_wrap_symbol
  48 #define mem_ops_wrap_symbol(fn) mem_ops_wrap_symbol2(fn, MEM_VALUE_T)
  49 #undef  mem_ops_wrap_symbol2
  50 #define mem_ops_wrap_symbol2(fn,typ) mem_ops_wrap_symbol3(fn,typ)
  51 #undef  mem_ops_wrap_symbol3
  52 #define mem_ops_wrap_symbol3(fn,typ) fn##_as_##typ
  53
  54 /*
  55  * Include aligned access routines
  56  */
  57 #define INCLUDED_BY_MEM_OPS_H
  58 #include "mem_ops_aligned.h"
  59 #undef  INCLUDED_BY_MEM_OPS_H
  60
  61 #undef  mem_get_be16
  62 #define mem_get_be16 mem_ops_wrap_symbol(mem_get_be16)
  63 static unsigned MEM_VALUE_T mem_get_be16(const void *vmem)
  64 {
  65     unsigned MEM_VALUE_T  val;
  66     const MAU_T          *mem = (const MAU_T *)vmem;
  67
  68     val = mem[0] << 8;
  69     val |= mem[1];
  70     return val;
  71 }
  72
  73 #undef  mem_get_be24
  74 #define mem_get_be24 mem_ops_wrap_symbol(mem_get_be24)
  75 static unsigned MEM_VALUE_T mem_get_be24(const void *vmem)
  76 {
  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 {
  90     unsigned MEM_VALUE_T  val;
  91     const MAU_T          *mem = (const MAU_T *)vmem;
  92
  93     val = mem[0] << 24;
  94     val |= mem[1] << 16;
  95     val |= mem[2] << 8;
  96     val |= mem[3];
  97     return val;
  98 }
  99
 100 #undef  mem_get_le16
 101 #define mem_get_le16 mem_ops_wrap_symbol(mem_get_le16)
 102 static unsigned MEM_VALUE_T mem_get_le16(const void *vmem)
 103 {
 104     unsigned MEM_VALUE_T  val;
 105     const MAU_T          *mem = (const MAU_T *)vmem;
 106
 107     val = mem[1] << 8;
 108     val |= mem[0];
 109     return val;
 110 }
 111
 112 #undef  mem_get_le24
 113 #define mem_get_le24 mem_ops_wrap_symbol(mem_get_le24)
 114 static unsigned MEM_VALUE_T mem_get_le24(const void *vmem)
 115 {
 116     unsigned MEM_VALUE_T  val;
 117     const MAU_T          *mem = (const MAU_T *)vmem;
 118
 119     val = mem[2] << 16;
 120     val |= mem[1] << 8;
 121     val |= mem[0];
 122     return val;
 123 }
 124
 125 #undef  mem_get_le32
 126 #define mem_get_le32 mem_ops_wrap_symbol(mem_get_le32)
 127 static unsigned MEM_VALUE_T mem_get_le32(const void *vmem)
 128 {
 129     unsigned MEM_VALUE_T  val;
 130     const MAU_T          *mem = (const MAU_T *)vmem;
 131
 132     val = mem[3] << 24;
 133     val |= mem[2] << 16;
 134     val |= mem[1] << 8;
 135     val |= mem[0];
 136     return val;
 137 }
 138
 139 #define mem_get_s_generic(end,sz) \
 140     static signed MEM_VALUE_T mem_get_s##end##sz(const void *vmem) {\
 141         const MAU_T *mem = (const MAU_T*)vmem;\
 142         signed MEM_VALUE_T val = mem_get_##end##sz(mem);\
 143         return (val << (MEM_VALUE_T_SZ_BITS - sz)) >> (MEM_VALUE_T_SZ_BITS - sz);\
 144     }
 145
 146 #undef  mem_get_sbe16
 147 #define mem_get_sbe16 mem_ops_wrap_symbol(mem_get_sbe16)
 148 mem_get_s_generic(be, 16);
 149
 150 #undef  mem_get_sbe24
 151 #define mem_get_sbe24 mem_ops_wrap_symbol(mem_get_sbe24)
 152 mem_get_s_generic(be, 24);
 153
 154 #undef  mem_get_sbe32
 155 #define mem_get_sbe32 mem_ops_wrap_symbol(mem_get_sbe32)
 156 mem_get_s_generic(be, 32);
 157
 158 #undef  mem_get_sle16
 159 #define mem_get_sle16 mem_ops_wrap_symbol(mem_get_sle16)
 160 mem_get_s_generic(le, 16);
 161
 162 #undef  mem_get_sle24
 163 #define mem_get_sle24 mem_ops_wrap_symbol(mem_get_sle24)
 164 mem_get_s_generic(le, 24);
 165
 166 #undef  mem_get_sle32
 167 #define mem_get_sle32 mem_ops_wrap_symbol(mem_get_sle32)
 168 mem_get_s_generic(le, 32);
 169
 170 #undef  mem_put_be16
 171 #define mem_put_be16 mem_ops_wrap_symbol(mem_put_be16)
 172 static void mem_put_be16(void *vmem, MEM_VALUE_T val)
 173 {
 174     MAU_T *mem = (MAU_T *)vmem;
 175
 176     mem[0] = (val >> 8) & 0xff;
 177     mem[1] = (val >> 0) & 0xff;
 178 }
 179
 180 #undef  mem_put_be24
 181 #define mem_put_be24 mem_ops_wrap_symbol(mem_put_be24)
 182 static void mem_put_be24(void *vmem, MEM_VALUE_T val)
 183 {
 184     MAU_T *mem = (MAU_T *)vmem;
 185
 186     mem[0] = (val >> 16) & 0xff;
 187     mem[1] = (val >>  8) & 0xff;
 188     mem[2] = (val >>  0) & 0xff;
 189 }
 190
 191 #undef  mem_put_be32
 192 #define mem_put_be32 mem_ops_wrap_symbol(mem_put_be32)
 193 static void mem_put_be32(void *vmem, MEM_VALUE_T val)
 194 {
 195     MAU_T *mem = (MAU_T *)vmem;
 196
 197     mem[0] = (val >> 24) & 0xff;
 198     mem[1] = (val >> 16) & 0xff;
 199     mem[2] = (val >>  8) & 0xff;
 200     mem[3] = (val >>  0) & 0xff;
 201 }
 202
 203 #undef  mem_put_le16
 204 #define mem_put_le16 mem_ops_wrap_symbol(mem_put_le16)
 205 static void mem_put_le16(void *vmem, MEM_VALUE_T val)
 206 {
 207     MAU_T *mem = (MAU_T *)vmem;
 208
 209     mem[0] = (val >>  0) & 0xff;
 210     mem[1] = (val >>  8) & 0xff;
 211 }
 212
 213 #undef  mem_put_le24
 214 #define mem_put_le24 mem_ops_wrap_symbol(mem_put_le24)
 215 static void mem_put_le24(void *vmem, MEM_VALUE_T val)
 216 {
 217     MAU_T *mem = (MAU_T *)vmem;
 218
 219     mem[0] = (val >>  0) & 0xff;
 220     mem[1] = (val >>  8) & 0xff;
 221     mem[2] = (val >> 16) & 0xff;
 222 }
 223
 224 #undef  mem_put_le32
 225 #define mem_put_le32 mem_ops_wrap_symbol(mem_put_le32)
 226 static void mem_put_le32(void *vmem, MEM_VALUE_T val)
 227 {
 228     MAU_T *mem = (MAU_T *)vmem;
 229
 230     mem[0] = (val >>  0) & 0xff;
 231     mem[1] = (val >>  8) & 0xff;
 232     mem[2] = (val >> 16) & 0xff;
 233     mem[3] = (val >> 24) & 0xff;
 234 }