1 /*
2  * Copyright 2011 Google Inc. All Rights Reserved.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef SFNTLY_CPP_SRC_SFNTLY_PORT_ENDIAN_H_
18 #define SFNTLY_CPP_SRC_SFNTLY_PORT_ENDIAN_H_
19 
20 #include "sfntly/port/config.h"
21 #include "sfntly/port/type.h"
22 
23 namespace sfntly {
24 
EndianSwap16(uint16_t value)25 static inline uint16_t EndianSwap16(uint16_t value) {
26   return (uint16_t)((value >> 8) | (value << 8));
27 }
28 
EndianSwap32(int32_t value)29 static inline int32_t EndianSwap32(int32_t value) {
30   return (((value & 0x000000ff) << 24) |
31           ((value & 0x0000ff00) <<  8) |
32           ((value & 0x00ff0000) >>  8) |
33           ((value & 0xff000000) >> 24));
34 }
35 
EndianSwap64(uint64_t value)36 static inline uint64_t EndianSwap64(uint64_t value) {
37   return (((value & 0x00000000000000ffLL) << 56) |
38           ((value & 0x000000000000ff00LL) << 40) |
39           ((value & 0x0000000000ff0000LL) << 24) |
40           ((value & 0x00000000ff000000LL) << 8)  |
41           ((value & 0x000000ff00000000LL) >> 8)  |
42           ((value & 0x0000ff0000000000LL) >> 24) |
43           ((value & 0x00ff000000000000LL) >> 40) |
44           ((value & 0xff00000000000000LL) >> 56));
45 }
46 
47 #ifdef SFNTLY_LITTLE_ENDIAN
48   #define ToBE16(n) EndianSwap16(n)
49   #define ToBE32(n) EndianSwap32(n)
50   #define ToBE64(n) EndianSwap64(n)
51   #define ToLE16(n) (n)
52   #define ToLE32(n) (n)
53   #define ToLE64(n) (n)
54   #define FromBE16(n) EndianSwap16(n)
55   #define FromBE32(n) EndianSwap32(n)
56   #define FromBE64(n) EndianSwap64(n)
57   #define FromLE16(n) (n)
58   #define FromLE32(n) (n)
59   #define FromLE64(n) (n)
60 #else  // SFNTLY_BIG_ENDIAN
61   #define ToBE16(n) (n)
62   #define ToBE32(n) (n)
63   #define ToBE64(n) (n)
64   #define ToLE16(n) EndianSwap16(n)
65   #define ToLE32(n) EndianSwap32(n)
66   #define ToLE64(n) EndianSwap64(n)
67   #define FromBE16(n) (n)
68   #define FromBE32(n) (n)
69   #define FromBE64(n) (n)
70   #define FromLE16(n) EndianSwap16(n)
71   #define FromLE32(n) EndianSwap32(n)
72   #define FromLE64(n) EndianSwap64(n)
73 #endif
74 
75 }  // namespace sfntly
76 
77 #endif  // SFNTLY_CPP_SRC_SFNTLY_PORT_ENDIAN_H_
78