| |
| /* |
| * 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 "SkTypes.h" |
| |
| /** \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(U16CPU value) { |
| SkASSERT(value == (uint16_t)value); |
| return (uint16_t)((value >> 8) | (value << 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 != NULL); |
| |
| while (--count >= 0) { |
| *array = SkEndianSwap16(*array); |
| array += 1; |
| } |
| } |
| |
| /** Reverse all 4 bytes in a 32bit value. |
| e.g. 0x12345678 -> 0x78563412 |
| */ |
| static inline uint32_t SkEndianSwap32(uint32_t value) { |
| return ((value & 0xFF) << 24) | |
| ((value & 0xFF00) << 8) | |
| ((value & 0xFF0000) >> 8) | |
| (value >> 24); |
| } |
| |
| /** Vector version of SkEndianSwap16(), which swaps the |
| bytes of each value in the array. |
| */ |
| static inline void SkEndianSwap32s(uint32_t array[], int count) { |
| SkASSERT(count == 0 || array != NULL); |
| |
| while (--count >= 0) { |
| *array = SkEndianSwap32(*array); |
| array += 1; |
| } |
| } |
| |
| #ifdef SK_CPU_LENDIAN |
| #define SkEndian_SwapBE16(n) SkEndianSwap16(n) |
| #define SkEndian_SwapBE32(n) SkEndianSwap32(n) |
| #define SkEndian_SwapLE16(n) (n) |
| #define SkEndian_SwapLE32(n) (n) |
| #else // SK_CPU_BENDIAN |
| #define SkEndian_SwapBE16(n) (n) |
| #define SkEndian_SwapBE32(n) (n) |
| #define SkEndian_SwapLE16(n) SkEndianSwap16(n) |
| #define SkEndian_SwapLE32(n) SkEndianSwap32(n) |
| #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 |
| |
| #endif |
| |