2 * Copyright (c) 2010 The WebM project authors. All Rights Reserved.
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.
13 * \brief Provides portable memory access primitives
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
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
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
32 * NOTE: This code is not supported on platforms where char > 1 octet ATM.
36 /* Minimum Access Unit for this target */
37 #define MAU_T unsigned char
41 #define MEM_VALUE_T int
44 #undef MEM_VALUE_T_SZ_BITS
45 #define MEM_VALUE_T_SZ_BITS (sizeof(MEM_VALUE_T) << 3)
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
55 * Include aligned access routines
57 #define INCLUDED_BY_MEM_OPS_H
58 #include "mem_ops_aligned.h"
59 #undef INCLUDED_BY_MEM_OPS_H
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 unsigned MEM_VALUE_T val;
65 const MAU_T *mem = (const MAU_T *)vmem;
73 #define mem_get_be24 mem_ops_wrap_symbol(mem_get_be24)
74 static unsigned MEM_VALUE_T mem_get_be24(const void *vmem) {
75 unsigned MEM_VALUE_T val;
76 const MAU_T *mem = (const MAU_T *)vmem;
85 #define mem_get_be32 mem_ops_wrap_symbol(mem_get_be32)
86 static unsigned MEM_VALUE_T mem_get_be32(const void *vmem) {
87 unsigned MEM_VALUE_T val;
88 const MAU_T *mem = (const MAU_T *)vmem;
98 #define mem_get_le16 mem_ops_wrap_symbol(mem_get_le16)
99 static unsigned MEM_VALUE_T mem_get_le16(const void *vmem) {
100 unsigned MEM_VALUE_T val;
101 const MAU_T *mem = (const MAU_T *)vmem;
109 #define mem_get_le24 mem_ops_wrap_symbol(mem_get_le24)
110 static unsigned MEM_VALUE_T mem_get_le24(const void *vmem) {
111 unsigned MEM_VALUE_T val;
112 const MAU_T *mem = (const MAU_T *)vmem;
121 #define mem_get_le32 mem_ops_wrap_symbol(mem_get_le32)
122 static unsigned MEM_VALUE_T mem_get_le32(const void *vmem) {
123 unsigned MEM_VALUE_T val;
124 const MAU_T *mem = (const MAU_T *)vmem;
133 #define mem_get_s_generic(end,sz) \
134 static signed MEM_VALUE_T mem_get_s##end##sz(const void *vmem) {\
135 const MAU_T *mem = (const MAU_T*)vmem;\
136 signed MEM_VALUE_T val = mem_get_##end##sz(mem);\
137 return (val << (MEM_VALUE_T_SZ_BITS - sz)) >> (MEM_VALUE_T_SZ_BITS - sz);\
141 #define mem_get_sbe16 mem_ops_wrap_symbol(mem_get_sbe16)
142 mem_get_s_generic(be, 16)
145 #define mem_get_sbe24 mem_ops_wrap_symbol(mem_get_sbe24)
146 mem_get_s_generic(be, 24)
149 #define mem_get_sbe32 mem_ops_wrap_symbol(mem_get_sbe32)
150 mem_get_s_generic(be, 32)
153 #define mem_get_sle16 mem_ops_wrap_symbol(mem_get_sle16)
154 mem_get_s_generic(le, 16)
157 #define mem_get_sle24 mem_ops_wrap_symbol(mem_get_sle24)
158 mem_get_s_generic(le, 24)
161 #define mem_get_sle32 mem_ops_wrap_symbol(mem_get_sle32)
162 mem_get_s_generic(le, 32)
165 #define mem_put_be16 mem_ops_wrap_symbol(mem_put_be16)
166 static void mem_put_be16(void *vmem, MEM_VALUE_T val) {
167 MAU_T *mem = (MAU_T *)vmem;
169 mem[0] = (val >> 8) & 0xff;
170 mem[1] = (val >> 0) & 0xff;
174 #define mem_put_be24 mem_ops_wrap_symbol(mem_put_be24)
175 static void mem_put_be24(void *vmem, MEM_VALUE_T val) {
176 MAU_T *mem = (MAU_T *)vmem;
178 mem[0] = (val >> 16) & 0xff;
179 mem[1] = (val >> 8) & 0xff;
180 mem[2] = (val >> 0) & 0xff;
184 #define mem_put_be32 mem_ops_wrap_symbol(mem_put_be32)
185 static void mem_put_be32(void *vmem, MEM_VALUE_T val) {
186 MAU_T *mem = (MAU_T *)vmem;
188 mem[0] = (val >> 24) & 0xff;
189 mem[1] = (val >> 16) & 0xff;
190 mem[2] = (val >> 8) & 0xff;
191 mem[3] = (val >> 0) & 0xff;
195 #define mem_put_le16 mem_ops_wrap_symbol(mem_put_le16)
196 static void mem_put_le16(void *vmem, MEM_VALUE_T val) {
197 MAU_T *mem = (MAU_T *)vmem;
199 mem[0] = (val >> 0) & 0xff;
200 mem[1] = (val >> 8) & 0xff;
204 #define mem_put_le24 mem_ops_wrap_symbol(mem_put_le24)
205 static void mem_put_le24(void *vmem, MEM_VALUE_T val) {
206 MAU_T *mem = (MAU_T *)vmem;
208 mem[0] = (val >> 0) & 0xff;
209 mem[1] = (val >> 8) & 0xff;
210 mem[2] = (val >> 16) & 0xff;
214 #define mem_put_le32 mem_ops_wrap_symbol(mem_put_le32)
215 static void mem_put_le32(void *vmem, MEM_VALUE_T val) {
216 MAU_T *mem = (MAU_T *)vmem;
218 mem[0] = (val >> 0) & 0xff;
219 mem[1] = (val >> 8) & 0xff;
220 mem[2] = (val >> 16) & 0xff;
221 mem[3] = (val >> 24) & 0xff;