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)
mem_get_be16(const void * vmem)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)
mem_get_be24(const void * vmem)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)
mem_get_be32(const void * vmem)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)
mem_get_le16(const void * vmem)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)
mem_get_le24(const void * vmem)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)
mem_get_le32(const void * vmem)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 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)
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)
mem_put_be16(void * vmem,MEM_VALUE_T val)168 static 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)
mem_put_be24(void * vmem,MEM_VALUE_T val)177 static 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)
mem_put_be32(void * vmem,MEM_VALUE_T val)187 static 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)
mem_put_le16(void * vmem,MEM_VALUE_T val)198 static 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)
mem_put_le24(void * vmem,MEM_VALUE_T val)207 static 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)
mem_put_le32(void * vmem,MEM_VALUE_T val)217 static 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