1 2 /* 3 * Copyright 2006 The Android Open Source Project 4 * 5 * Use of this source code is governed by a BSD-style license that can be 6 * found in the LICENSE file. 7 */ 8 9 10 #ifndef SkEndian_DEFINED 11 #define SkEndian_DEFINED 12 13 #include "SkTypes.h" 14 15 /** \file SkEndian.h 16 17 Macros and helper functions for handling 16 and 32 bit values in 18 big and little endian formats. 19 */ 20 21 #if defined(SK_CPU_LENDIAN) && defined(SK_CPU_BENDIAN) 22 #error "can't have both LENDIAN and BENDIAN defined" 23 #endif 24 25 #if !defined(SK_CPU_LENDIAN) && !defined(SK_CPU_BENDIAN) 26 #error "need either LENDIAN or BENDIAN defined" 27 #endif 28 29 /** Swap the two bytes in the low 16bits of the parameters. 30 e.g. 0x1234 -> 0x3412 31 */ 32 static inline uint16_t SkEndianSwap16(U16CPU value) { 33 SkASSERT(value == (uint16_t)value); 34 return static_cast<uint16_t>((value >> 8) | (value << 8)); 35 } 36 template<uint16_t N> struct SkTEndianSwap16 { 37 static const uint16_t value = static_cast<uint16_t>((N >> 8) | ((N & 0xFF) << 8)); 38 }; 39 40 /** Vector version of SkEndianSwap16(), which swaps the 41 low two bytes of each value in the array. 42 */ 43 static inline void SkEndianSwap16s(uint16_t array[], int count) { 44 SkASSERT(count == 0 || array != NULL); 45 46 while (--count >= 0) { 47 *array = SkEndianSwap16(*array); 48 array += 1; 49 } 50 } 51 52 /** Reverse all 4 bytes in a 32bit value. 53 e.g. 0x12345678 -> 0x78563412 54 */ 55 static inline uint32_t SkEndianSwap32(uint32_t value) { 56 return ((value & 0xFF) << 24) | 57 ((value & 0xFF00) << 8) | 58 ((value & 0xFF0000) >> 8) | 59 (value >> 24); 60 } 61 template<uint32_t N> struct SkTEndianSwap32 { 62 static const uint32_t value = ((N & 0xFF) << 24) | 63 ((N & 0xFF00) << 8) | 64 ((N & 0xFF0000) >> 8) | 65 (N >> 24); 66 }; 67 68 /** Vector version of SkEndianSwap32(), which swaps the 69 bytes of each value in the array. 70 */ 71 static inline void SkEndianSwap32s(uint32_t array[], int count) { 72 SkASSERT(count == 0 || array != NULL); 73 74 while (--count >= 0) { 75 *array = SkEndianSwap32(*array); 76 array += 1; 77 } 78 } 79 80 /** Reverse all 8 bytes in a 64bit value. 81 e.g. 0x1122334455667788 -> 0x8877665544332211 82 */ 83 static inline uint64_t SkEndianSwap64(uint64_t value) { 84 return (((value & 0x00000000000000FFULL) << (8*7)) | 85 ((value & 0x000000000000FF00ULL) << (8*5)) | 86 ((value & 0x0000000000FF0000ULL) << (8*3)) | 87 ((value & 0x00000000FF000000ULL) << (8*1)) | 88 ((value & 0x000000FF00000000ULL) >> (8*1)) | 89 ((value & 0x0000FF0000000000ULL) >> (8*3)) | 90 ((value & 0x00FF000000000000ULL) >> (8*5)) | 91 ((value) >> (8*7))); 92 } 93 template<uint64_t N> struct SkTEndianSwap64 { 94 static const uint64_t value = (((N & 0x00000000000000FFULL) << (8*7)) | 95 ((N & 0x000000000000FF00ULL) << (8*5)) | 96 ((N & 0x0000000000FF0000ULL) << (8*3)) | 97 ((N & 0x00000000FF000000ULL) << (8*1)) | 98 ((N & 0x000000FF00000000ULL) >> (8*1)) | 99 ((N & 0x0000FF0000000000ULL) >> (8*3)) | 100 ((N & 0x00FF000000000000ULL) >> (8*5)) | 101 ((N) >> (8*7))); 102 }; 103 104 /** Vector version of SkEndianSwap64(), which swaps the 105 bytes of each value in the array. 106 */ 107 static inline void SkEndianSwap64s(uint64_t array[], int count) { 108 SkASSERT(count == 0 || array != NULL); 109 110 while (--count >= 0) { 111 *array = SkEndianSwap64(*array); 112 array += 1; 113 } 114 } 115 116 #ifdef SK_CPU_LENDIAN 117 #define SkEndian_SwapBE16(n) SkEndianSwap16(n) 118 #define SkEndian_SwapBE32(n) SkEndianSwap32(n) 119 #define SkEndian_SwapBE64(n) SkEndianSwap64(n) 120 #define SkEndian_SwapLE16(n) (n) 121 #define SkEndian_SwapLE32(n) (n) 122 #define SkEndian_SwapLE64(n) (n) 123 124 #define SkTEndian_SwapBE16(n) SkTEndianSwap16<n>::value 125 #define SkTEndian_SwapBE32(n) SkTEndianSwap32<n>::value 126 #define SkTEndian_SwapBE64(n) SkTEndianSwap64<n>::value 127 #define SkTEndian_SwapLE16(n) (n) 128 #define SkTEndian_SwapLE32(n) (n) 129 #define SkTEndian_SwapLE64(n) (n) 130 #else // SK_CPU_BENDIAN 131 #define SkEndian_SwapBE16(n) (n) 132 #define SkEndian_SwapBE32(n) (n) 133 #define SkEndian_SwapBE64(n) (n) 134 #define SkEndian_SwapLE16(n) SkEndianSwap16(n) 135 #define SkEndian_SwapLE32(n) SkEndianSwap32(n) 136 #define SkEndian_SwapLE64(n) SkEndianSwap64(n) 137 138 #define SkTEndian_SwapBE16(n) (n) 139 #define SkTEndian_SwapBE32(n) (n) 140 #define SkTEndian_SwapBE64(n) (n) 141 #define SkTEndian_SwapLE16(n) SkTEndianSwap16<n>::value 142 #define SkTEndian_SwapLE32(n) SkTEndianSwap32<n>::value 143 #define SkTEndian_SwapLE64(n) SkTEndianSwap64<n>::value 144 #endif 145 146 // When a bytestream is embedded in a 32-bit word, how far we need to 147 // shift the word to extract each byte from the low 8 bits by anding with 0xff. 148 #ifdef SK_CPU_LENDIAN 149 #define SkEndian_Byte0Shift 0 150 #define SkEndian_Byte1Shift 8 151 #define SkEndian_Byte2Shift 16 152 #define SkEndian_Byte3Shift 24 153 #else // SK_CPU_BENDIAN 154 #define SkEndian_Byte0Shift 24 155 #define SkEndian_Byte1Shift 16 156 #define SkEndian_Byte2Shift 8 157 #define SkEndian_Byte3Shift 0 158 #endif 159 160 161 #if defined(SK_UINT8_BITFIELD_LENDIAN) && defined(SK_UINT8_BITFIELD_BENDIAN) 162 #error "can't have both bitfield LENDIAN and BENDIAN defined" 163 #endif 164 165 #if !defined(SK_UINT8_BITFIELD_LENDIAN) && !defined(SK_UINT8_BITFIELD_BENDIAN) 166 #ifdef SK_CPU_LENDIAN 167 #define SK_UINT8_BITFIELD_LENDIAN 168 #else 169 #define SK_UINT8_BITFIELD_BENDIAN 170 #endif 171 #endif 172 173 #ifdef SK_UINT8_BITFIELD_LENDIAN 174 #define SK_UINT8_BITFIELD(f0, f1, f2, f3, f4, f5, f6, f7) \ 175 SK_OT_BYTE f0 : 1; \ 176 SK_OT_BYTE f1 : 1; \ 177 SK_OT_BYTE f2 : 1; \ 178 SK_OT_BYTE f3 : 1; \ 179 SK_OT_BYTE f4 : 1; \ 180 SK_OT_BYTE f5 : 1; \ 181 SK_OT_BYTE f6 : 1; \ 182 SK_OT_BYTE f7 : 1; 183 #else 184 #define SK_UINT8_BITFIELD(f0, f1, f2, f3, f4, f5, f6, f7) \ 185 SK_OT_BYTE f7 : 1; \ 186 SK_OT_BYTE f6 : 1; \ 187 SK_OT_BYTE f5 : 1; \ 188 SK_OT_BYTE f4 : 1; \ 189 SK_OT_BYTE f3 : 1; \ 190 SK_OT_BYTE f2 : 1; \ 191 SK_OT_BYTE f1 : 1; \ 192 SK_OT_BYTE f0 : 1; 193 #endif 194 195 #endif 196
