1 /*
2  * Copyright (c) 2016, Alliance for Open Media. All rights reserved
3  *
4  * This source code is subject to the terms of the BSD 2 Clause License and
5  * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
6  * was not distributed with this source code in the LICENSE file, you can
7  * obtain it at www.aomedia.org/license/software. If the Alliance for Open
8  * Media Patent License 1.0 was not distributed with this source code in the
9  * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
10  */
11 
12 #ifndef AOM_AOM_PORTS_MEM_OPS_H_
13 #define AOM_AOM_PORTS_MEM_OPS_H_
14 
15 /* \file
16  * \brief Provides portable memory access primitives
17  *
18  * This function provides portable primitives for getting and setting of
19  * signed and unsigned integers in 16, 24, and 32 bit sizes. The operations
20  * can be performed on unaligned data regardless of hardware support for
21  * unaligned accesses.
22  *
23  * The type used to pass the integral values may be changed by defining
24  * MEM_VALUE_T with the appropriate type. The type given must be an integral
25  * numeric type.
26  *
27  * The actual functions instantiated have the MEM_VALUE_T type name pasted
28  * on to the symbol name. This allows the developer to instantiate these
29  * operations for multiple types within the same translation unit. This is
30  * of somewhat questionable utility, but the capability exists nonetheless.
31  * Users not making use of this functionality should call the functions
32  * without the type name appended, and the preprocessor will take care of
33  * it.
34  *
35  * NOTE: This code is not supported on platforms where char > 1 octet ATM.
36  */
37 
38 #ifndef MAU_T
39 /* Minimum Access Unit for this target */
40 #define MAU_T unsigned char
41 #endif
42 
43 #ifndef MEM_VALUE_T
44 #define MEM_VALUE_T int
45 #endif
46 
47 #undef MEM_VALUE_T_SZ_BITS
48 #define MEM_VALUE_T_SZ_BITS (sizeof(MEM_VALUE_T) << 3)
49 
50 #undef mem_ops_wrap_symbol
51 #define mem_ops_wrap_symbol(fn) mem_ops_wrap_symbol2(fn, MEM_VALUE_T)
52 #undef mem_ops_wrap_symbol2
53 #define mem_ops_wrap_symbol2(fn, typ) mem_ops_wrap_symbol3(fn, typ)
54 #undef mem_ops_wrap_symbol3
55 #define mem_ops_wrap_symbol3(fn, typ) fn##_as_##typ
56 
57 /*
58  * Include aligned access routines
59  */
60 #define INCLUDED_BY_MEM_OPS_H
61 #include "mem_ops_aligned.h"
62 #undef INCLUDED_BY_MEM_OPS_H
63 
64 #undef mem_get_be16
65 #define mem_get_be16 mem_ops_wrap_symbol(mem_get_be16)
mem_get_be16(const void * vmem)66 static unsigned MEM_VALUE_T mem_get_be16(const void *vmem) {
67   unsigned MEM_VALUE_T val;
68   const MAU_T *mem = (const MAU_T *)vmem;
69 
70   val = mem[0] << 8;
71   val |= mem[1];
72   return val;
73 }
74 
75 #undef mem_get_be24
76 #define mem_get_be24 mem_ops_wrap_symbol(mem_get_be24)
mem_get_be24(const void * vmem)77 static unsigned MEM_VALUE_T mem_get_be24(const void *vmem) {
78   unsigned MEM_VALUE_T val;
79   const MAU_T *mem = (const MAU_T *)vmem;
80 
81   val = mem[0] << 16;
82   val |= mem[1] << 8;
83   val |= mem[2];
84   return val;
85 }
86 
87 #undef mem_get_be32
88 #define mem_get_be32 mem_ops_wrap_symbol(mem_get_be32)
mem_get_be32(const void * vmem)89 static unsigned MEM_VALUE_T mem_get_be32(const void *vmem) {
90   unsigned MEM_VALUE_T val;
91   const MAU_T *mem = (const MAU_T *)vmem;
92 
93   val = ((unsigned MEM_VALUE_T)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)
mem_get_le16(const void * vmem)102 static unsigned MEM_VALUE_T mem_get_le16(const void *vmem) {
103   unsigned MEM_VALUE_T val;
104   const MAU_T *mem = (const MAU_T *)vmem;
105 
106   val = mem[1] << 8;
107   val |= mem[0];
108   return val;
109 }
110 
111 #undef mem_get_le24
112 #define mem_get_le24 mem_ops_wrap_symbol(mem_get_le24)
mem_get_le24(const void * vmem)113 static unsigned MEM_VALUE_T mem_get_le24(const void *vmem) {
114   unsigned MEM_VALUE_T val;
115   const MAU_T *mem = (const MAU_T *)vmem;
116 
117   val = mem[2] << 16;
118   val |= mem[1] << 8;
119   val |= mem[0];
120   return val;
121 }
122 
123 #undef mem_get_le32
124 #define mem_get_le32 mem_ops_wrap_symbol(mem_get_le32)
mem_get_le32(const void * vmem)125 static unsigned MEM_VALUE_T mem_get_le32(const void *vmem) {
126   unsigned MEM_VALUE_T val;
127   const MAU_T *mem = (const MAU_T *)vmem;
128 
129   val = ((unsigned MEM_VALUE_T)mem[3]) << 24;
130   val |= mem[2] << 16;
131   val |= mem[1] << 8;
132   val |= mem[0];
133   return val;
134 }
135 
136 #define mem_get_s_generic(end, sz)                                            \
137   static AOM_INLINE signed MEM_VALUE_T mem_get_s##end##sz(const void *vmem) { \
138     const MAU_T *mem = (const MAU_T *)vmem;                                   \
139     signed MEM_VALUE_T val = mem_get_##end##sz(mem);                          \
140     return (val << (MEM_VALUE_T_SZ_BITS - sz)) >> (MEM_VALUE_T_SZ_BITS - sz); \
141   }
142 
143 /* clang-format off */
144 #undef  mem_get_sbe16
145 #define mem_get_sbe16 mem_ops_wrap_symbol(mem_get_sbe16)
146 mem_get_s_generic(be, 16)
147 
148 #undef  mem_get_sbe24
149 #define mem_get_sbe24 mem_ops_wrap_symbol(mem_get_sbe24)
150 mem_get_s_generic(be, 24)
151 
152 #undef  mem_get_sbe32
153 #define mem_get_sbe32 mem_ops_wrap_symbol(mem_get_sbe32)
154 mem_get_s_generic(be, 32)
155 
156 #undef  mem_get_sle16
157 #define mem_get_sle16 mem_ops_wrap_symbol(mem_get_sle16)
158 mem_get_s_generic(le, 16)
159 
160 #undef  mem_get_sle24
161 #define mem_get_sle24 mem_ops_wrap_symbol(mem_get_sle24)
162 mem_get_s_generic(le, 24)
163 
164 #undef  mem_get_sle32
165 #define mem_get_sle32 mem_ops_wrap_symbol(mem_get_sle32)
166 mem_get_s_generic(le, 32)
167 
168 #undef  mem_put_be16
169 #define mem_put_be16 mem_ops_wrap_symbol(mem_put_be16)
mem_put_be16(void * vmem,MEM_VALUE_T val)170 static AOM_INLINE void mem_put_be16(void *vmem, MEM_VALUE_T val) {
171   MAU_T *mem = (MAU_T *)vmem;
172 
173   mem[0] = (MAU_T)((val >> 8) & 0xff);
174   mem[1] = (MAU_T)((val >> 0) & 0xff);
175 }
176 
177 #undef  mem_put_be24
178 #define mem_put_be24 mem_ops_wrap_symbol(mem_put_be24)
mem_put_be24(void * vmem,MEM_VALUE_T val)179 static AOM_INLINE void mem_put_be24(void *vmem, MEM_VALUE_T val) {
180   MAU_T *mem = (MAU_T *)vmem;
181 
182   mem[0] = (MAU_T)((val >> 16) & 0xff);
183   mem[1] = (MAU_T)((val >>  8) & 0xff);
184   mem[2] = (MAU_T)((val >>  0) & 0xff);
185 }
186 
187 #undef  mem_put_be32
188 #define mem_put_be32 mem_ops_wrap_symbol(mem_put_be32)
mem_put_be32(void * vmem,MEM_VALUE_T val)189 static AOM_INLINE void mem_put_be32(void *vmem, MEM_VALUE_T val) {
190   MAU_T *mem = (MAU_T *)vmem;
191 
192   mem[0] = (MAU_T)((val >> 24) & 0xff);
193   mem[1] = (MAU_T)((val >> 16) & 0xff);
194   mem[2] = (MAU_T)((val >>  8) & 0xff);
195   mem[3] = (MAU_T)((val >>  0) & 0xff);
196 }
197 
198 #undef  mem_put_le16
199 #define mem_put_le16 mem_ops_wrap_symbol(mem_put_le16)
mem_put_le16(void * vmem,MEM_VALUE_T val)200 static AOM_INLINE void mem_put_le16(void *vmem, MEM_VALUE_T val) {
201   MAU_T *mem = (MAU_T *)vmem;
202 
203   mem[0] = (MAU_T)((val >> 0) & 0xff);
204   mem[1] = (MAU_T)((val >> 8) & 0xff);
205 }
206 
207 #undef  mem_put_le24
208 #define mem_put_le24 mem_ops_wrap_symbol(mem_put_le24)
mem_put_le24(void * vmem,MEM_VALUE_T val)209 static AOM_INLINE void mem_put_le24(void *vmem, MEM_VALUE_T val) {
210   MAU_T *mem = (MAU_T *)vmem;
211 
212   mem[0] = (MAU_T)((val >>  0) & 0xff);
213   mem[1] = (MAU_T)((val >>  8) & 0xff);
214   mem[2] = (MAU_T)((val >> 16) & 0xff);
215 }
216 
217 #undef  mem_put_le32
218 #define mem_put_le32 mem_ops_wrap_symbol(mem_put_le32)
mem_put_le32(void * vmem,MEM_VALUE_T val)219 static AOM_INLINE void mem_put_le32(void *vmem, MEM_VALUE_T val) {
220   MAU_T *mem = (MAU_T *)vmem;
221 
222   mem[0] = (MAU_T)((val >>  0) & 0xff);
223   mem[1] = (MAU_T)((val >>  8) & 0xff);
224   mem[2] = (MAU_T)((val >> 16) & 0xff);
225   mem[3] = (MAU_T)((val >> 24) & 0xff);
226 }
227 /* clang-format on */
228 #endif  // AOM_AOM_PORTS_MEM_OPS_H_
229