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/*
* 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
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