1 /* 2 * Copyright (C) 2006 The Android Open Source Project 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 SkEndian_DEFINED 18 #define SkEndian_DEFINED 19 20 #include "SkTypes.h" 21 22 /** \file SkEndian.h 23 24 Macros and helper functions for handling 16 and 32 bit values in 25 big and little endian formats. 26 */ 27 28 #if defined(SK_CPU_LENDIAN) && defined(SK_CPU_BENDIAN) 29 #error "can't have both LENDIAN and BENDIAN defined" 30 #endif 31 32 #if !defined(SK_CPU_LENDIAN) && !defined(SK_CPU_BENDIAN) 33 #error "need either LENDIAN or BENDIAN defined" 34 #endif 35 36 /** Swap the two bytes in the low 16bits of the parameters. 37 e.g. 0x1234 -> 0x3412 38 */ 39 static inline uint16_t SkEndianSwap16(U16CPU value) { 40 SkASSERT(value == (uint16_t)value); 41 return (uint16_t)((value >> 8) | (value << 8)); 42 } 43 44 /** Vector version of SkEndianSwap16(), which swaps the 45 low two bytes of each value in the array. 46 */ 47 static inline void SkEndianSwap16s(uint16_t array[], int count) { 48 SkASSERT(count == 0 || array != NULL); 49 50 while (--count >= 0) { 51 *array = SkEndianSwap16(*array); 52 array += 1; 53 } 54 } 55 56 /** Reverse all 4 bytes in a 32bit value. 57 e.g. 0x12345678 -> 0x78563412 58 */ 59 static inline uint32_t SkEndianSwap32(uint32_t value) { 60 return ((value & 0xFF) << 24) | 61 ((value & 0xFF00) << 8) | 62 ((value & 0xFF0000) >> 8) | 63 (value >> 24); 64 } 65 66 /** Vector version of SkEndianSwap16(), which swaps the 67 bytes of each value in the array. 68 */ 69 static inline void SkEndianSwap32s(uint32_t array[], int count) { 70 SkASSERT(count == 0 || array != NULL); 71 72 while (--count >= 0) { 73 *array = SkEndianSwap32(*array); 74 array += 1; 75 } 76 } 77 78 #ifdef SK_CPU_LENDIAN 79 #define SkEndian_SwapBE16(n) SkEndianSwap16(n) 80 #define SkEndian_SwapBE32(n) SkEndianSwap32(n) 81 #define SkEndian_SwapLE16(n) (n) 82 #define SkEndian_SwapLE32(n) (n) 83 #else // SK_CPU_BENDIAN 84 #define SkEndian_SwapBE16(n) (n) 85 #define SkEndian_SwapBE32(n) (n) 86 #define SkEndian_SwapLE16(n) SkEndianSwap16(n) 87 #define SkEndian_SwapLE32(n) SkEndianSwap32(n) 88 #endif 89 90 91 #endif 92 93
