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phosit
170 lines
6.0 KiB
C++
170 lines
6.0 KiB
C++
/* Copyright (C) 2026 Wildfire Games.
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*
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* Permission is hereby granted, free of charge, to any person obtaining
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* a copy of this software and associated documentation files (the
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* "Software"), to deal in the Software without restriction, including
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* without limitation the rights to use, copy, modify, merge, publish,
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* distribute, sublicense, and/or sell copies of the Software, and to
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* permit persons to whom the Software is furnished to do so, subject to
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* the following conditions:
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*
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* The above copyright notice and this permission notice shall be included
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* in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
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* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
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* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
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* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*/
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/*
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* byte order (endianness) support routines.
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*/
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#ifndef INCLUDED_BYTE_ORDER
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#define INCLUDED_BYTE_ORDER
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#include "lib/sysdep/compiler.h"
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#include <cstddef>
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// detect byte order via predefined macros.
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#ifndef BYTE_ORDER
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# define LITTLE_ENDIAN 0x4321
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# define BIG_ENDIAN 0x1234
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# if ARCH_IA32 || ARCH_IA64 || ARCH_AMD64 || ARCH_ALPHA || ARCH_ARM || ARCH_AARCH64 || ARCH_MIPS || ARCH_E2K || ARCH_PPC64 || defined(__LITTLE_ENDIAN__)
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# define BYTE_ORDER LITTLE_ENDIAN
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# else
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# define BYTE_ORDER BIG_ENDIAN
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# endif
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#endif
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/**
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* convert 4 characters to std::uint32_t (at compile time) for easy comparison.
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* output is in native byte order; e.g. FOURCC_LE can be used instead.
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**/
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#define FOURCC(a,b,c,d) // real definition is below
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#undef FOURCC
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// implementation rationale:
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// - can't pass code as string, and use s[0]..s[3], because
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// VC6/7 don't realize the macro is constant
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// (it should be usable as a switch{} expression)
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// - the casts are ugly but necessary. std::uint32_t is required because
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// std::uint8_t << 8 == 0; the additional std::uint8_t cast ensures each
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// character is treated as unsigned (otherwise, they'd be promoted to signed
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// int before the std::uint32_t cast, which would break things).
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/// big-endian version of FOURCC
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#define FOURCC_BE(a,b,c,d) ( static_cast<std::uint32_t>(static_cast<std::uint8_t>(a)) << 24 | \
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static_cast<std::uint32_t>(static_cast<std::uint8_t>(b)) << 16 | \
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static_cast<std::uint32_t>(static_cast<std::uint8_t>(c)) << 8 | \
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static_cast<std::uint32_t>(static_cast<std::uint8_t>(d)) << 0 )
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/// little-endian version of FOURCC
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#define FOURCC_LE(a,b,c,d) ( static_cast<std::uint32_t>(static_cast<std::uint8_t>(a)) << 0 | \
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static_cast<std::uint32_t>(static_cast<std::uint8_t>(b)) << 8 | \
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static_cast<std::uint32_t>(static_cast<std::uint8_t>(c)) << 16 | \
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static_cast<std::uint32_t>(static_cast<std::uint8_t>(d)) << 24 )
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#if BYTE_ORDER == BIG_ENDIAN
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# define FOURCC FOURCC_BE
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#else
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# define FOURCC FOURCC_LE
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#endif
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#if BYTE_ORDER == BIG_ENDIAN
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// convert a little-endian number to/from native byte order.
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# define to_le16(x) swap16(x)
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# define to_le32(x) swap32(x)
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# define to_le64(x) swap64(x)
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// convert a big-endian number to/from native byte order.
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# define to_be16(x) (x)
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# define to_be32(x) (x)
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# define to_be64(x) (x)
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#else // LITTLE_ENDIAN
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// convert a little-endian number to/from native byte order.
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# define to_le16(x) (x)
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# define to_le32(x) (x)
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# define to_le64(x) (x)
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// convert a big-endian number to/from native byte order.
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# define to_be16(x) swap16(x)
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# define to_be32(x) swap32(x)
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# define to_be64(x) swap64(x)
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#endif
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/// read a little-endian number from memory into native byte order.
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std::uint16_t read_le16(const void* p);
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std::uint32_t read_le32(const void* p); /// see read_le16
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std::uint64_t read_le64(const void* p); /// see read_le16
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/// read a big-endian number from memory into native byte order.
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std::uint16_t read_be16(const void* p);
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std::uint32_t read_be32(const void* p); /// see read_be16
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std::uint64_t read_be64(const void* p); /// see read_be16
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/// write a little-endian number to memory in native byte order.
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void write_le16(void* p, std::uint16_t x);
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void write_le32(void* p, std::uint32_t x); /// see write_le16
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void write_le64(void* p, std::uint64_t x); /// see write_le16
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/// write a big-endian number to memory in native byte order.
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void write_be16(void* p, std::uint16_t x);
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void write_be32(void* p, std::uint32_t x); /// see write_be16
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void write_be64(void* p, std::uint64_t x); /// see write_be16
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/**
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* zero-extend \<size\> (truncated to 8) bytes of little-endian data to
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* std::uint64_t, starting at address \<p\> (need not be aligned).
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**/
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std::uint64_t movzx_le64(const std::uint8_t* p, size_t size);
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std::uint64_t movzx_be64(const std::uint8_t* p, size_t size);
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/**
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* sign-extend \<size\> (truncated to 8) bytes of little-endian data to
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* std::int64_t, starting at address \<p\> (need not be aligned).
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**/
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std::int64_t movsx_le64(const std::uint8_t* p, size_t size);
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std::int64_t movsx_be64(const std::uint8_t* p, size_t size);
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#if MSC_VERSION
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extern unsigned short _byteswap_ushort(unsigned short);
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extern unsigned long _byteswap_ulong(unsigned long);
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extern unsigned __int64 _byteswap_uint64(unsigned __int64);
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#pragma intrinsic(_byteswap_ushort)
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#pragma intrinsic(_byteswap_ulong)
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#pragma intrinsic(_byteswap_uint64)
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# define swap16 _byteswap_ushort
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# define swap32 _byteswap_ulong
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# define swap64 _byteswap_uint64
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#elif defined(linux)
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# include <asm/byteorder.h>
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# if defined(__arch__swab16) && !defined(swap16)
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# define swap16 __arch__swab16
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# endif
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# if defined(__arch__swab32) && !defined(swap32)
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# define swap32 __arch__swab32
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# endif
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# if defined(__arch__swab64) && !defined(swap64)
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# define swap64 __arch__swab64
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# endif
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#endif
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#ifndef swap16
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std::uint16_t swap16(const std::uint16_t x);
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#endif
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#ifndef swap32
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std::uint32_t swap32(const std::uint32_t x);
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#endif
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#ifndef swap64
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std::uint64_t swap64(const std::uint64_t x);
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#endif
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#endif // #ifndef INCLUDED_BYTE_ORDER
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