| /* |
| * Copyright 2006 The Android Open Source Project |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef SkEndian_DEFINED |
| #define SkEndian_DEFINED |
| |
| #include "include/private/base/SkAssert.h" |
| #include "include/private/base/SkFeatures.h" |
| |
| #include <cstdint> |
| |
| /** \file SkEndian.h |
| |
| Macros and helper functions for handling 16 and 32 bit values in |
| big and little endian formats. |
| */ |
| |
| #if defined(SK_CPU_LENDIAN) && defined(SK_CPU_BENDIAN) |
| #error "can't have both LENDIAN and BENDIAN defined" |
| #endif |
| |
| #if !defined(SK_CPU_LENDIAN) && !defined(SK_CPU_BENDIAN) |
| #error "need either LENDIAN or BENDIAN defined" |
| #endif |
| |
| /** Swap the two bytes in the low 16bits of the parameters. |
| e.g. 0x1234 -> 0x3412 |
| */ |
| static inline uint16_t SkEndianSwap16(uint16_t value) { |
| return static_cast<uint16_t>((value >> 8) | ((value & 0xFF) << 8)); |
| } |
| |
| template<uint16_t N> struct SkTEndianSwap16 { |
| static const uint16_t value = static_cast<uint16_t>((N >> 8) | ((N & 0xFF) << 8)); |
| }; |
| |
| /** Vector version of SkEndianSwap16(), which swaps the |
| low two bytes of each value in the array. |
| */ |
| static inline void SkEndianSwap16s(uint16_t array[], int count) { |
| SkASSERT(count == 0 || array != nullptr); |
| |
| while (--count >= 0) { |
| *array = SkEndianSwap16(*array); |
| array += 1; |
| } |
| } |
| |
| /** Reverse all 4 bytes in a 32bit value. |
| e.g. 0x12345678 -> 0x78563412 |
| */ |
| static constexpr uint32_t SkEndianSwap32(uint32_t value) { |
| return ((value & 0xFF) << 24) | |
| ((value & 0xFF00) << 8) | |
| ((value & 0xFF0000) >> 8) | |
| (value >> 24); |
| } |
| |
| template<uint32_t N> struct SkTEndianSwap32 { |
| static const uint32_t value = ((N & 0xFF) << 24) | |
| ((N & 0xFF00) << 8) | |
| ((N & 0xFF0000) >> 8) | |
| (N >> 24); |
| }; |
| |
| /** Vector version of SkEndianSwap32(), which swaps the |
| bytes of each value in the array. |
| */ |
| static inline void SkEndianSwap32s(uint32_t array[], int count) { |
| SkASSERT(count == 0 || array != nullptr); |
| |
| while (--count >= 0) { |
| *array = SkEndianSwap32(*array); |
| array += 1; |
| } |
| } |
| |
| /** Reverse all 8 bytes in a 64bit value. |
| e.g. 0x1122334455667788 -> 0x8877665544332211 |
| */ |
| static inline uint64_t SkEndianSwap64(uint64_t value) { |
| return (((value & 0x00000000000000FFULL) << (8*7)) | |
| ((value & 0x000000000000FF00ULL) << (8*5)) | |
| ((value & 0x0000000000FF0000ULL) << (8*3)) | |
| ((value & 0x00000000FF000000ULL) << (8*1)) | |
| ((value & 0x000000FF00000000ULL) >> (8*1)) | |
| ((value & 0x0000FF0000000000ULL) >> (8*3)) | |
| ((value & 0x00FF000000000000ULL) >> (8*5)) | |
| ((value) >> (8*7))); |
| } |
| template<uint64_t N> struct SkTEndianSwap64 { |
| static const uint64_t value = (((N & 0x00000000000000FFULL) << (8*7)) | |
| ((N & 0x000000000000FF00ULL) << (8*5)) | |
| ((N & 0x0000000000FF0000ULL) << (8*3)) | |
| ((N & 0x00000000FF000000ULL) << (8*1)) | |
| ((N & 0x000000FF00000000ULL) >> (8*1)) | |
| ((N & 0x0000FF0000000000ULL) >> (8*3)) | |
| ((N & 0x00FF000000000000ULL) >> (8*5)) | |
| ((N) >> (8*7))); |
| }; |
| |
| /** Vector version of SkEndianSwap64(), which swaps the |
| bytes of each value in the array. |
| */ |
| static inline void SkEndianSwap64s(uint64_t array[], int count) { |
| SkASSERT(count == 0 || array != nullptr); |
| |
| while (--count >= 0) { |
| *array = SkEndianSwap64(*array); |
| array += 1; |
| } |
| } |
| |
| // Static casts are used here for otherwise no-op macros to make sure they return the same type as |
| // SkEndianSwap* functions. |
| #ifdef SK_CPU_LENDIAN |
| #define SkEndian_SwapBE16(n) SkEndianSwap16(n) |
| #define SkEndian_SwapBE32(n) SkEndianSwap32(n) |
| #define SkEndian_SwapBE64(n) SkEndianSwap64(n) |
| #define SkEndian_SwapLE16(n) static_cast<uint16_t>(n) |
| #define SkEndian_SwapLE32(n) static_cast<uint32_t>(n) |
| #define SkEndian_SwapLE64(n) static_cast<uint64_t>(n) |
| |
| #define SkTEndian_SwapBE16(n) SkTEndianSwap16<n>::value |
| #define SkTEndian_SwapBE32(n) SkTEndianSwap32<n>::value |
| #define SkTEndian_SwapBE64(n) SkTEndianSwap64<n>::value |
| #define SkTEndian_SwapLE16(n) (n) |
| #define SkTEndian_SwapLE32(n) (n) |
| #define SkTEndian_SwapLE64(n) (n) |
| #else // SK_CPU_BENDIAN |
| #define SkEndian_SwapBE16(n) static_cast<uint16_t>(n) |
| #define SkEndian_SwapBE32(n) static_cast<uint32_t>(n) |
| #define SkEndian_SwapBE64(n) static_cast<uint64_t>(n) |
| #define SkEndian_SwapLE16(n) SkEndianSwap16(n) |
| #define SkEndian_SwapLE32(n) SkEndianSwap32(n) |
| #define SkEndian_SwapLE64(n) SkEndianSwap64(n) |
| |
| #define SkTEndian_SwapBE16(n) (n) |
| #define SkTEndian_SwapBE32(n) (n) |
| #define SkTEndian_SwapBE64(n) (n) |
| #define SkTEndian_SwapLE16(n) SkTEndianSwap16<n>::value |
| #define SkTEndian_SwapLE32(n) SkTEndianSwap32<n>::value |
| #define SkTEndian_SwapLE64(n) SkTEndianSwap64<n>::value |
| #endif |
| |
| // When a bytestream is embedded in a 32-bit word, how far we need to |
| // shift the word to extract each byte from the low 8 bits by anding with 0xff. |
| #ifdef SK_CPU_LENDIAN |
| #define SkEndian_Byte0Shift 0 |
| #define SkEndian_Byte1Shift 8 |
| #define SkEndian_Byte2Shift 16 |
| #define SkEndian_Byte3Shift 24 |
| #else // SK_CPU_BENDIAN |
| #define SkEndian_Byte0Shift 24 |
| #define SkEndian_Byte1Shift 16 |
| #define SkEndian_Byte2Shift 8 |
| #define SkEndian_Byte3Shift 0 |
| #endif |
| |
| |
| #if defined(SK_UINT8_BITFIELD_LENDIAN) && defined(SK_UINT8_BITFIELD_BENDIAN) |
| #error "can't have both bitfield LENDIAN and BENDIAN defined" |
| #endif |
| |
| #if !defined(SK_UINT8_BITFIELD_LENDIAN) && !defined(SK_UINT8_BITFIELD_BENDIAN) |
| #ifdef SK_CPU_LENDIAN |
| #define SK_UINT8_BITFIELD_LENDIAN |
| #else |
| #define SK_UINT8_BITFIELD_BENDIAN |
| #endif |
| #endif |
| |
| #ifdef SK_UINT8_BITFIELD_LENDIAN |
| #define SK_UINT8_BITFIELD(f0, f1, f2, f3, f4, f5, f6, f7) \ |
| SK_OT_BYTE f0 : 1; \ |
| SK_OT_BYTE f1 : 1; \ |
| SK_OT_BYTE f2 : 1; \ |
| SK_OT_BYTE f3 : 1; \ |
| SK_OT_BYTE f4 : 1; \ |
| SK_OT_BYTE f5 : 1; \ |
| SK_OT_BYTE f6 : 1; \ |
| SK_OT_BYTE f7 : 1; |
| #else |
| #define SK_UINT8_BITFIELD(f0, f1, f2, f3, f4, f5, f6, f7) \ |
| SK_OT_BYTE f7 : 1; \ |
| SK_OT_BYTE f6 : 1; \ |
| SK_OT_BYTE f5 : 1; \ |
| SK_OT_BYTE f4 : 1; \ |
| SK_OT_BYTE f3 : 1; \ |
| SK_OT_BYTE f2 : 1; \ |
| SK_OT_BYTE f1 : 1; \ |
| SK_OT_BYTE f0 : 1; |
| #endif |
| |
| #endif |