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)
65static 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)
76static 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)
88static 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)
101static 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)
112static 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)
124static 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 VPX_INLINE 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)
144mem_get_s_generic(be, 16)
145
146#undef  mem_get_sbe24
147#define mem_get_sbe24 mem_ops_wrap_symbol(mem_get_sbe24)
148mem_get_s_generic(be, 24)
149
150#undef  mem_get_sbe32
151#define mem_get_sbe32 mem_ops_wrap_symbol(mem_get_sbe32)
152mem_get_s_generic(be, 32)
153
154#undef  mem_get_sle16
155#define mem_get_sle16 mem_ops_wrap_symbol(mem_get_sle16)
156mem_get_s_generic(le, 16)
157
158#undef  mem_get_sle24
159#define mem_get_sle24 mem_ops_wrap_symbol(mem_get_sle24)
160mem_get_s_generic(le, 24)
161
162#undef  mem_get_sle32
163#define mem_get_sle32 mem_ops_wrap_symbol(mem_get_sle32)
164mem_get_s_generic(le, 32)
165
166#undef  mem_put_be16
167#define mem_put_be16 mem_ops_wrap_symbol(mem_put_be16)
168static VPX_INLINE 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)
177static VPX_INLINE 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)
187static VPX_INLINE 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)
198static VPX_INLINE 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)
207static VPX_INLINE 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)
217static VPX_INLINE 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_
227