1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/skia/trunk/include/core/SkEndian.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,195 @@
1.4 +
1.5 +/*
1.6 + * Copyright 2006 The Android Open Source Project
1.7 + *
1.8 + * Use of this source code is governed by a BSD-style license that can be
1.9 + * found in the LICENSE file.
1.10 + */
1.11 +
1.12 +
1.13 +#ifndef SkEndian_DEFINED
1.14 +#define SkEndian_DEFINED
1.15 +
1.16 +#include "SkTypes.h"
1.17 +
1.18 +/** \file SkEndian.h
1.19 +
1.20 + Macros and helper functions for handling 16 and 32 bit values in
1.21 + big and little endian formats.
1.22 +*/
1.23 +
1.24 +#if defined(SK_CPU_LENDIAN) && defined(SK_CPU_BENDIAN)
1.25 + #error "can't have both LENDIAN and BENDIAN defined"
1.26 +#endif
1.27 +
1.28 +#if !defined(SK_CPU_LENDIAN) && !defined(SK_CPU_BENDIAN)
1.29 + #error "need either LENDIAN or BENDIAN defined"
1.30 +#endif
1.31 +
1.32 +/** Swap the two bytes in the low 16bits of the parameters.
1.33 + e.g. 0x1234 -> 0x3412
1.34 +*/
1.35 +static inline uint16_t SkEndianSwap16(U16CPU value) {
1.36 + SkASSERT(value == (uint16_t)value);
1.37 + return static_cast<uint16_t>((value >> 8) | (value << 8));
1.38 +}
1.39 +template<uint16_t N> struct SkTEndianSwap16 {
1.40 + static const uint16_t value = static_cast<uint16_t>((N >> 8) | ((N & 0xFF) << 8));
1.41 +};
1.42 +
1.43 +/** Vector version of SkEndianSwap16(), which swaps the
1.44 + low two bytes of each value in the array.
1.45 +*/
1.46 +static inline void SkEndianSwap16s(uint16_t array[], int count) {
1.47 + SkASSERT(count == 0 || array != NULL);
1.48 +
1.49 + while (--count >= 0) {
1.50 + *array = SkEndianSwap16(*array);
1.51 + array += 1;
1.52 + }
1.53 +}
1.54 +
1.55 +/** Reverse all 4 bytes in a 32bit value.
1.56 + e.g. 0x12345678 -> 0x78563412
1.57 +*/
1.58 +static inline uint32_t SkEndianSwap32(uint32_t value) {
1.59 + return ((value & 0xFF) << 24) |
1.60 + ((value & 0xFF00) << 8) |
1.61 + ((value & 0xFF0000) >> 8) |
1.62 + (value >> 24);
1.63 +}
1.64 +template<uint32_t N> struct SkTEndianSwap32 {
1.65 + static const uint32_t value = ((N & 0xFF) << 24) |
1.66 + ((N & 0xFF00) << 8) |
1.67 + ((N & 0xFF0000) >> 8) |
1.68 + (N >> 24);
1.69 +};
1.70 +
1.71 +/** Vector version of SkEndianSwap32(), which swaps the
1.72 + bytes of each value in the array.
1.73 +*/
1.74 +static inline void SkEndianSwap32s(uint32_t array[], int count) {
1.75 + SkASSERT(count == 0 || array != NULL);
1.76 +
1.77 + while (--count >= 0) {
1.78 + *array = SkEndianSwap32(*array);
1.79 + array += 1;
1.80 + }
1.81 +}
1.82 +
1.83 +/** Reverse all 8 bytes in a 64bit value.
1.84 + e.g. 0x1122334455667788 -> 0x8877665544332211
1.85 +*/
1.86 +static inline uint64_t SkEndianSwap64(uint64_t value) {
1.87 + return (((value & 0x00000000000000FFULL) << (8*7)) |
1.88 + ((value & 0x000000000000FF00ULL) << (8*5)) |
1.89 + ((value & 0x0000000000FF0000ULL) << (8*3)) |
1.90 + ((value & 0x00000000FF000000ULL) << (8*1)) |
1.91 + ((value & 0x000000FF00000000ULL) >> (8*1)) |
1.92 + ((value & 0x0000FF0000000000ULL) >> (8*3)) |
1.93 + ((value & 0x00FF000000000000ULL) >> (8*5)) |
1.94 + ((value) >> (8*7)));
1.95 +}
1.96 +template<uint64_t N> struct SkTEndianSwap64 {
1.97 + static const uint64_t value = (((N & 0x00000000000000FFULL) << (8*7)) |
1.98 + ((N & 0x000000000000FF00ULL) << (8*5)) |
1.99 + ((N & 0x0000000000FF0000ULL) << (8*3)) |
1.100 + ((N & 0x00000000FF000000ULL) << (8*1)) |
1.101 + ((N & 0x000000FF00000000ULL) >> (8*1)) |
1.102 + ((N & 0x0000FF0000000000ULL) >> (8*3)) |
1.103 + ((N & 0x00FF000000000000ULL) >> (8*5)) |
1.104 + ((N) >> (8*7)));
1.105 +};
1.106 +
1.107 +/** Vector version of SkEndianSwap64(), which swaps the
1.108 + bytes of each value in the array.
1.109 +*/
1.110 +static inline void SkEndianSwap64s(uint64_t array[], int count) {
1.111 + SkASSERT(count == 0 || array != NULL);
1.112 +
1.113 + while (--count >= 0) {
1.114 + *array = SkEndianSwap64(*array);
1.115 + array += 1;
1.116 + }
1.117 +}
1.118 +
1.119 +#ifdef SK_CPU_LENDIAN
1.120 + #define SkEndian_SwapBE16(n) SkEndianSwap16(n)
1.121 + #define SkEndian_SwapBE32(n) SkEndianSwap32(n)
1.122 + #define SkEndian_SwapBE64(n) SkEndianSwap64(n)
1.123 + #define SkEndian_SwapLE16(n) (n)
1.124 + #define SkEndian_SwapLE32(n) (n)
1.125 + #define SkEndian_SwapLE64(n) (n)
1.126 +
1.127 + #define SkTEndian_SwapBE16(n) SkTEndianSwap16<n>::value
1.128 + #define SkTEndian_SwapBE32(n) SkTEndianSwap32<n>::value
1.129 + #define SkTEndian_SwapBE64(n) SkTEndianSwap64<n>::value
1.130 + #define SkTEndian_SwapLE16(n) (n)
1.131 + #define SkTEndian_SwapLE32(n) (n)
1.132 + #define SkTEndian_SwapLE64(n) (n)
1.133 +#else // SK_CPU_BENDIAN
1.134 + #define SkEndian_SwapBE16(n) (n)
1.135 + #define SkEndian_SwapBE32(n) (n)
1.136 + #define SkEndian_SwapBE64(n) (n)
1.137 + #define SkEndian_SwapLE16(n) SkEndianSwap16(n)
1.138 + #define SkEndian_SwapLE32(n) SkEndianSwap32(n)
1.139 + #define SkEndian_SwapLE64(n) SkEndianSwap64(n)
1.140 +
1.141 + #define SkTEndian_SwapBE16(n) (n)
1.142 + #define SkTEndian_SwapBE32(n) (n)
1.143 + #define SkTEndian_SwapBE64(n) (n)
1.144 + #define SkTEndian_SwapLE16(n) SkTEndianSwap16<n>::value
1.145 + #define SkTEndian_SwapLE32(n) SkTEndianSwap32<n>::value
1.146 + #define SkTEndian_SwapLE64(n) SkTEndianSwap64<n>::value
1.147 +#endif
1.148 +
1.149 +// When a bytestream is embedded in a 32-bit word, how far we need to
1.150 +// shift the word to extract each byte from the low 8 bits by anding with 0xff.
1.151 +#ifdef SK_CPU_LENDIAN
1.152 + #define SkEndian_Byte0Shift 0
1.153 + #define SkEndian_Byte1Shift 8
1.154 + #define SkEndian_Byte2Shift 16
1.155 + #define SkEndian_Byte3Shift 24
1.156 +#else // SK_CPU_BENDIAN
1.157 + #define SkEndian_Byte0Shift 24
1.158 + #define SkEndian_Byte1Shift 16
1.159 + #define SkEndian_Byte2Shift 8
1.160 + #define SkEndian_Byte3Shift 0
1.161 +#endif
1.162 +
1.163 +
1.164 +#if defined(SK_UINT8_BITFIELD_LENDIAN) && defined(SK_UINT8_BITFIELD_BENDIAN)
1.165 + #error "can't have both bitfield LENDIAN and BENDIAN defined"
1.166 +#endif
1.167 +
1.168 +#if !defined(SK_UINT8_BITFIELD_LENDIAN) && !defined(SK_UINT8_BITFIELD_BENDIAN)
1.169 + #ifdef SK_CPU_LENDIAN
1.170 + #define SK_UINT8_BITFIELD_LENDIAN
1.171 + #else
1.172 + #define SK_UINT8_BITFIELD_BENDIAN
1.173 + #endif
1.174 +#endif
1.175 +
1.176 +#ifdef SK_UINT8_BITFIELD_LENDIAN
1.177 + #define SK_UINT8_BITFIELD(f0, f1, f2, f3, f4, f5, f6, f7) \
1.178 + SK_OT_BYTE f0 : 1; \
1.179 + SK_OT_BYTE f1 : 1; \
1.180 + SK_OT_BYTE f2 : 1; \
1.181 + SK_OT_BYTE f3 : 1; \
1.182 + SK_OT_BYTE f4 : 1; \
1.183 + SK_OT_BYTE f5 : 1; \
1.184 + SK_OT_BYTE f6 : 1; \
1.185 + SK_OT_BYTE f7 : 1;
1.186 +#else
1.187 + #define SK_UINT8_BITFIELD(f0, f1, f2, f3, f4, f5, f6, f7) \
1.188 + SK_OT_BYTE f7 : 1; \
1.189 + SK_OT_BYTE f6 : 1; \
1.190 + SK_OT_BYTE f5 : 1; \
1.191 + SK_OT_BYTE f4 : 1; \
1.192 + SK_OT_BYTE f3 : 1; \
1.193 + SK_OT_BYTE f2 : 1; \
1.194 + SK_OT_BYTE f1 : 1; \
1.195 + SK_OT_BYTE f0 : 1;
1.196 +#endif
1.197 +
1.198 +#endif
