michael@0: 
michael@0: /*
michael@0:  * Copyright 2006 The Android Open Source Project
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: 
michael@0: #ifndef SkEndian_DEFINED
michael@0: #define SkEndian_DEFINED
michael@0: 
michael@0: #include "SkTypes.h"
michael@0: 
michael@0: /** \file SkEndian.h
michael@0: 
michael@0:     Macros and helper functions for handling 16 and 32 bit values in
michael@0:     big and little endian formats.
michael@0: */
michael@0: 
michael@0: #if defined(SK_CPU_LENDIAN) && defined(SK_CPU_BENDIAN)
michael@0:     #error "can't have both LENDIAN and BENDIAN defined"
michael@0: #endif
michael@0: 
michael@0: #if !defined(SK_CPU_LENDIAN) && !defined(SK_CPU_BENDIAN)
michael@0:     #error "need either LENDIAN or BENDIAN defined"
michael@0: #endif
michael@0: 
michael@0: /** Swap the two bytes in the low 16bits of the parameters.
michael@0:     e.g. 0x1234 -> 0x3412
michael@0: */
michael@0: static inline uint16_t SkEndianSwap16(U16CPU value) {
michael@0:     SkASSERT(value == (uint16_t)value);
michael@0:     return static_cast<uint16_t>((value >> 8) | (value << 8));
michael@0: }
michael@0: template<uint16_t N> struct SkTEndianSwap16 {
michael@0:     static const uint16_t value = static_cast<uint16_t>((N >> 8) | ((N & 0xFF) << 8));
michael@0: };
michael@0: 
michael@0: /** Vector version of SkEndianSwap16(), which swaps the
michael@0:     low two bytes of each value in the array.
michael@0: */
michael@0: static inline void SkEndianSwap16s(uint16_t array[], int count) {
michael@0:     SkASSERT(count == 0 || array != NULL);
michael@0: 
michael@0:     while (--count >= 0) {
michael@0:         *array = SkEndianSwap16(*array);
michael@0:         array += 1;
michael@0:     }
michael@0: }
michael@0: 
michael@0: /** Reverse all 4 bytes in a 32bit value.
michael@0:     e.g. 0x12345678 -> 0x78563412
michael@0: */
michael@0: static inline uint32_t SkEndianSwap32(uint32_t value) {
michael@0:     return  ((value & 0xFF) << 24) |
michael@0:             ((value & 0xFF00) << 8) |
michael@0:             ((value & 0xFF0000) >> 8) |
michael@0:             (value >> 24);
michael@0: }
michael@0: template<uint32_t N> struct SkTEndianSwap32 {
michael@0:     static const uint32_t value = ((N & 0xFF) << 24) |
michael@0:                                   ((N & 0xFF00) << 8) |
michael@0:                                   ((N & 0xFF0000) >> 8) |
michael@0:                                   (N >> 24);
michael@0: };
michael@0: 
michael@0: /** Vector version of SkEndianSwap32(), which swaps the
michael@0:     bytes of each value in the array.
michael@0: */
michael@0: static inline void SkEndianSwap32s(uint32_t array[], int count) {
michael@0:     SkASSERT(count == 0 || array != NULL);
michael@0: 
michael@0:     while (--count >= 0) {
michael@0:         *array = SkEndianSwap32(*array);
michael@0:         array += 1;
michael@0:     }
michael@0: }
michael@0: 
michael@0: /** Reverse all 8 bytes in a 64bit value.
michael@0:     e.g. 0x1122334455667788 -> 0x8877665544332211
michael@0: */
michael@0: static inline uint64_t SkEndianSwap64(uint64_t value) {
michael@0:     return (((value & 0x00000000000000FFULL) << (8*7)) |
michael@0:             ((value & 0x000000000000FF00ULL) << (8*5)) |
michael@0:             ((value & 0x0000000000FF0000ULL) << (8*3)) |
michael@0:             ((value & 0x00000000FF000000ULL) << (8*1)) |
michael@0:             ((value & 0x000000FF00000000ULL) >> (8*1)) |
michael@0:             ((value & 0x0000FF0000000000ULL) >> (8*3)) |
michael@0:             ((value & 0x00FF000000000000ULL) >> (8*5)) |
michael@0:             ((value)                         >> (8*7)));
michael@0: }
michael@0: template<uint64_t N> struct SkTEndianSwap64 {
michael@0:     static const uint64_t value = (((N & 0x00000000000000FFULL) << (8*7)) |
michael@0:                                    ((N & 0x000000000000FF00ULL) << (8*5)) |
michael@0:                                    ((N & 0x0000000000FF0000ULL) << (8*3)) |
michael@0:                                    ((N & 0x00000000FF000000ULL) << (8*1)) |
michael@0:                                    ((N & 0x000000FF00000000ULL) >> (8*1)) |
michael@0:                                    ((N & 0x0000FF0000000000ULL) >> (8*3)) |
michael@0:                                    ((N & 0x00FF000000000000ULL) >> (8*5)) |
michael@0:                                    ((N)                         >> (8*7)));
michael@0: };
michael@0: 
michael@0: /** Vector version of SkEndianSwap64(), which swaps the
michael@0:     bytes of each value in the array.
michael@0: */
michael@0: static inline void SkEndianSwap64s(uint64_t array[], int count) {
michael@0:     SkASSERT(count == 0 || array != NULL);
michael@0: 
michael@0:     while (--count >= 0) {
michael@0:         *array = SkEndianSwap64(*array);
michael@0:         array += 1;
michael@0:     }
michael@0: }
michael@0: 
michael@0: #ifdef SK_CPU_LENDIAN
michael@0:     #define SkEndian_SwapBE16(n)    SkEndianSwap16(n)
michael@0:     #define SkEndian_SwapBE32(n)    SkEndianSwap32(n)
michael@0:     #define SkEndian_SwapBE64(n)    SkEndianSwap64(n)
michael@0:     #define SkEndian_SwapLE16(n)    (n)
michael@0:     #define SkEndian_SwapLE32(n)    (n)
michael@0:     #define SkEndian_SwapLE64(n)    (n)
michael@0: 
michael@0:     #define SkTEndian_SwapBE16(n)    SkTEndianSwap16<n>::value
michael@0:     #define SkTEndian_SwapBE32(n)    SkTEndianSwap32<n>::value
michael@0:     #define SkTEndian_SwapBE64(n)    SkTEndianSwap64<n>::value
michael@0:     #define SkTEndian_SwapLE16(n)    (n)
michael@0:     #define SkTEndian_SwapLE32(n)    (n)
michael@0:     #define SkTEndian_SwapLE64(n)    (n)
michael@0: #else   // SK_CPU_BENDIAN
michael@0:     #define SkEndian_SwapBE16(n)    (n)
michael@0:     #define SkEndian_SwapBE32(n)    (n)
michael@0:     #define SkEndian_SwapBE64(n)    (n)
michael@0:     #define SkEndian_SwapLE16(n)    SkEndianSwap16(n)
michael@0:     #define SkEndian_SwapLE32(n)    SkEndianSwap32(n)
michael@0:     #define SkEndian_SwapLE64(n)    SkEndianSwap64(n)
michael@0: 
michael@0:     #define SkTEndian_SwapBE16(n)    (n)
michael@0:     #define SkTEndian_SwapBE32(n)    (n)
michael@0:     #define SkTEndian_SwapBE64(n)    (n)
michael@0:     #define SkTEndian_SwapLE16(n)    SkTEndianSwap16<n>::value
michael@0:     #define SkTEndian_SwapLE32(n)    SkTEndianSwap32<n>::value
michael@0:     #define SkTEndian_SwapLE64(n)    SkTEndianSwap64<n>::value
michael@0: #endif
michael@0: 
michael@0: // When a bytestream is embedded in a 32-bit word, how far we need to
michael@0: // shift the word to extract each byte from the low 8 bits by anding with 0xff.
michael@0: #ifdef SK_CPU_LENDIAN
michael@0:     #define SkEndian_Byte0Shift 0
michael@0:     #define SkEndian_Byte1Shift 8
michael@0:     #define SkEndian_Byte2Shift 16
michael@0:     #define SkEndian_Byte3Shift 24
michael@0: #else   // SK_CPU_BENDIAN
michael@0:     #define SkEndian_Byte0Shift 24
michael@0:     #define SkEndian_Byte1Shift 16
michael@0:     #define SkEndian_Byte2Shift 8
michael@0:     #define SkEndian_Byte3Shift 0
michael@0: #endif
michael@0: 
michael@0: 
michael@0: #if defined(SK_UINT8_BITFIELD_LENDIAN) && defined(SK_UINT8_BITFIELD_BENDIAN)
michael@0:     #error "can't have both bitfield LENDIAN and BENDIAN defined"
michael@0: #endif
michael@0: 
michael@0: #if !defined(SK_UINT8_BITFIELD_LENDIAN) && !defined(SK_UINT8_BITFIELD_BENDIAN)
michael@0:     #ifdef SK_CPU_LENDIAN
michael@0:         #define SK_UINT8_BITFIELD_LENDIAN
michael@0:     #else
michael@0:         #define SK_UINT8_BITFIELD_BENDIAN
michael@0:     #endif
michael@0: #endif
michael@0: 
michael@0: #ifdef SK_UINT8_BITFIELD_LENDIAN
michael@0:     #define SK_UINT8_BITFIELD(f0, f1, f2, f3, f4, f5, f6, f7) \
michael@0:         SK_OT_BYTE f0 : 1; \
michael@0:         SK_OT_BYTE f1 : 1; \
michael@0:         SK_OT_BYTE f2 : 1; \
michael@0:         SK_OT_BYTE f3 : 1; \
michael@0:         SK_OT_BYTE f4 : 1; \
michael@0:         SK_OT_BYTE f5 : 1; \
michael@0:         SK_OT_BYTE f6 : 1; \
michael@0:         SK_OT_BYTE f7 : 1;
michael@0: #else
michael@0:     #define SK_UINT8_BITFIELD(f0, f1, f2, f3, f4, f5, f6, f7) \
michael@0:         SK_OT_BYTE f7 : 1; \
michael@0:         SK_OT_BYTE f6 : 1; \
michael@0:         SK_OT_BYTE f5 : 1; \
michael@0:         SK_OT_BYTE f4 : 1; \
michael@0:         SK_OT_BYTE f3 : 1; \
michael@0:         SK_OT_BYTE f2 : 1; \
michael@0:         SK_OT_BYTE f1 : 1; \
michael@0:         SK_OT_BYTE f0 : 1;
michael@0: #endif
michael@0: 
michael@0: #endif