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Diffstat (limited to 'third_party/jpeg-xl/lib/jxl/base/byte_order.h')
| -rw-r--r-- | third_party/jpeg-xl/lib/jxl/base/byte_order.h | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/third_party/jpeg-xl/lib/jxl/base/byte_order.h b/third_party/jpeg-xl/lib/jxl/base/byte_order.h new file mode 100644 index 0000000000..8966834e08 --- /dev/null +++ b/third_party/jpeg-xl/lib/jxl/base/byte_order.h @@ -0,0 +1,274 @@ +// Copyright (c) the JPEG XL Project Authors. All rights reserved. +// +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +#ifndef LIB_JXL_BASE_BYTE_ORDER_H_ +#define LIB_JXL_BASE_BYTE_ORDER_H_ + +#include <jxl/types.h> +#include <stdint.h> +#include <string.h> // memcpy + +#include "lib/jxl/base/compiler_specific.h" + +#if JXL_COMPILER_MSVC +#include <intrin.h> // _byteswap_* +#endif + +#if (defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)) +#define JXL_BYTE_ORDER_LITTLE 1 +#else +// This means that we don't know that the byte order is little endian, in +// this case we use endian-neutral code that works for both little- and +// big-endian. +#define JXL_BYTE_ORDER_LITTLE 0 +#endif + +// Returns whether the system is little-endian (least-significant byte first). +#if JXL_BYTE_ORDER_LITTLE +static constexpr bool IsLittleEndian() { return true; } +#else +static inline bool IsLittleEndian() { + const uint32_t multibyte = 1; + uint8_t byte; + memcpy(&byte, &multibyte, 1); + return byte == 1; +} +#endif + +static inline bool SwapEndianness(JxlEndianness endianness) { + return ((endianness == JXL_BIG_ENDIAN && IsLittleEndian()) || + (endianness == JXL_LITTLE_ENDIAN && !IsLittleEndian())); +} + +#if JXL_COMPILER_MSVC +#define JXL_BSWAP16(x) _byteswap_ushort(x) +#define JXL_BSWAP32(x) _byteswap_ulong(x) +#define JXL_BSWAP64(x) _byteswap_uint64(x) +#else +#define JXL_BSWAP16(x) __builtin_bswap16(x) +#define JXL_BSWAP32(x) __builtin_bswap32(x) +#define JXL_BSWAP64(x) __builtin_bswap64(x) +#endif + +static JXL_INLINE uint32_t LoadBE16(const uint8_t* p) { + const uint32_t byte1 = p[0]; + const uint32_t byte0 = p[1]; + return (byte1 << 8) | byte0; +} + +static JXL_INLINE uint32_t LoadLE16(const uint8_t* p) { + const uint32_t byte0 = p[0]; + const uint32_t byte1 = p[1]; + return (byte1 << 8) | byte0; +} + +static JXL_INLINE uint32_t LoadBE32(const uint8_t* p) { +#if JXL_BYTE_ORDER_LITTLE + uint32_t big; + memcpy(&big, p, 4); + return JXL_BSWAP32(big); +#else + // Byte-order-independent - can't assume this machine is big endian. + const uint32_t byte3 = p[0]; + const uint32_t byte2 = p[1]; + const uint32_t byte1 = p[2]; + const uint32_t byte0 = p[3]; + return (byte3 << 24) | (byte2 << 16) | (byte1 << 8) | byte0; +#endif +} + +static JXL_INLINE uint64_t LoadBE64(const uint8_t* p) { +#if JXL_BYTE_ORDER_LITTLE + uint64_t big; + memcpy(&big, p, 8); + return JXL_BSWAP64(big); +#else + // Byte-order-independent - can't assume this machine is big endian. + const uint64_t byte7 = p[0]; + const uint64_t byte6 = p[1]; + const uint64_t byte5 = p[2]; + const uint64_t byte4 = p[3]; + const uint64_t byte3 = p[4]; + const uint64_t byte2 = p[5]; + const uint64_t byte1 = p[6]; + const uint64_t byte0 = p[7]; + return (byte7 << 56ull) | (byte6 << 48ull) | (byte5 << 40ull) | + (byte4 << 32ull) | (byte3 << 24ull) | (byte2 << 16ull) | + (byte1 << 8ull) | byte0; +#endif +} + +static JXL_INLINE uint32_t LoadLE32(const uint8_t* p) { +#if JXL_BYTE_ORDER_LITTLE + uint32_t little; + memcpy(&little, p, 4); + return little; +#else + // Byte-order-independent - can't assume this machine is big endian. + const uint32_t byte0 = p[0]; + const uint32_t byte1 = p[1]; + const uint32_t byte2 = p[2]; + const uint32_t byte3 = p[3]; + return (byte3 << 24) | (byte2 << 16) | (byte1 << 8) | byte0; +#endif +} + +static JXL_INLINE uint64_t LoadLE64(const uint8_t* p) { +#if JXL_BYTE_ORDER_LITTLE + uint64_t little; + memcpy(&little, p, 8); + return little; +#else + // Byte-order-independent - can't assume this machine is big endian. + const uint64_t byte0 = p[0]; + const uint64_t byte1 = p[1]; + const uint64_t byte2 = p[2]; + const uint64_t byte3 = p[3]; + const uint64_t byte4 = p[4]; + const uint64_t byte5 = p[5]; + const uint64_t byte6 = p[6]; + const uint64_t byte7 = p[7]; + return (byte7 << 56) | (byte6 << 48) | (byte5 << 40) | (byte4 << 32) | + (byte3 << 24) | (byte2 << 16) | (byte1 << 8) | byte0; +#endif +} + +// Loads a Big-Endian float +static JXL_INLINE float LoadBEFloat(const uint8_t* p) { + uint32_t u = LoadBE32(p); + float result; + memcpy(&result, &u, 4); + return result; +} + +// Loads a Little-Endian float +static JXL_INLINE float LoadLEFloat(const uint8_t* p) { + uint32_t u = LoadLE32(p); + float result; + memcpy(&result, &u, 4); + return result; +} + +static JXL_INLINE void StoreBE16(const uint32_t native, uint8_t* p) { + p[0] = (native >> 8) & 0xFF; + p[1] = native & 0xFF; +} + +static JXL_INLINE void StoreLE16(const uint32_t native, uint8_t* p) { + p[1] = (native >> 8) & 0xFF; + p[0] = native & 0xFF; +} + +static JXL_INLINE void StoreBE32(const uint32_t native, uint8_t* p) { +#if JXL_BYTE_ORDER_LITTLE + const uint32_t big = JXL_BSWAP32(native); + memcpy(p, &big, 4); +#else + // Byte-order-independent - can't assume this machine is big endian. + p[0] = native >> 24; + p[1] = (native >> 16) & 0xFF; + p[2] = (native >> 8) & 0xFF; + p[3] = native & 0xFF; +#endif +} + +static JXL_INLINE void StoreBE64(const uint64_t native, uint8_t* p) { +#if JXL_BYTE_ORDER_LITTLE + const uint64_t big = JXL_BSWAP64(native); + memcpy(p, &big, 8); +#else + // Byte-order-independent - can't assume this machine is big endian. + p[0] = native >> 56ull; + p[1] = (native >> 48ull) & 0xFF; + p[2] = (native >> 40ull) & 0xFF; + p[3] = (native >> 32ull) & 0xFF; + p[4] = (native >> 24ull) & 0xFF; + p[5] = (native >> 16ull) & 0xFF; + p[6] = (native >> 8ull) & 0xFF; + p[7] = native & 0xFF; +#endif +} + +static JXL_INLINE void StoreLE32(const uint32_t native, uint8_t* p) { +#if JXL_BYTE_ORDER_LITTLE + const uint32_t little = native; + memcpy(p, &little, 4); +#else + // Byte-order-independent - can't assume this machine is big endian. + p[3] = native >> 24; + p[2] = (native >> 16) & 0xFF; + p[1] = (native >> 8) & 0xFF; + p[0] = native & 0xFF; +#endif +} + +static JXL_INLINE void StoreLE64(const uint64_t native, uint8_t* p) { +#if JXL_BYTE_ORDER_LITTLE + const uint64_t little = native; + memcpy(p, &little, 8); +#else + // Byte-order-independent - can't assume this machine is big endian. + p[7] = native >> 56; + p[6] = (native >> 48) & 0xFF; + p[5] = (native >> 40) & 0xFF; + p[4] = (native >> 32) & 0xFF; + p[3] = (native >> 24) & 0xFF; + p[2] = (native >> 16) & 0xFF; + p[1] = (native >> 8) & 0xFF; + p[0] = native & 0xFF; +#endif +} + +static JXL_INLINE float BSwapFloat(float x) { + uint32_t u; + memcpy(&u, &x, 4); + uint32_t uswap = JXL_BSWAP32(u); + float xswap; + memcpy(&xswap, &uswap, 4); + return xswap; +} + +// Big/Little Endian order. +struct OrderBE {}; +struct OrderLE {}; + +// Wrappers for calling from generic code. +static JXL_INLINE void Store16(OrderBE /*tag*/, const uint32_t native, + uint8_t* p) { + return StoreBE16(native, p); +} + +static JXL_INLINE void Store16(OrderLE /*tag*/, const uint32_t native, + uint8_t* p) { + return StoreLE16(native, p); +} + +static JXL_INLINE void Store32(OrderBE /*tag*/, const uint32_t native, + uint8_t* p) { + return StoreBE32(native, p); +} + +static JXL_INLINE void Store32(OrderLE /*tag*/, const uint32_t native, + uint8_t* p) { + return StoreLE32(native, p); +} + +static JXL_INLINE uint32_t Load16(OrderBE /*tag*/, const uint8_t* p) { + return LoadBE16(p); +} + +static JXL_INLINE uint32_t Load16(OrderLE /*tag*/, const uint8_t* p) { + return LoadLE16(p); +} + +static JXL_INLINE uint32_t Load32(OrderBE /*tag*/, const uint8_t* p) { + return LoadBE32(p); +} + +static JXL_INLINE uint32_t Load32(OrderLE /*tag*/, const uint8_t* p) { + return LoadLE32(p); +} + +#endif // LIB_JXL_BASE_BYTE_ORDER_H_ |