Improve readability of endianness detection

This commit is contained in:
Martchus 2018-12-29 23:48:01 +01:00
parent 22795dac8a
commit fe4d2b5778
1 changed files with 24 additions and 15 deletions

View File

@ -5,7 +5,8 @@
#include "../global.h"
#ifdef __BYTE_ORDER__
// detect byte order according to __BYTE_ORDER__
#if defined(__BYTE_ORDER__)
#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
#define CONVERSION_UTILITIES_IS_BYTE_ORDER_LITTLE_ENDIAN false
#define CONVERSION_UTILITIES_IS_BYTE_ORDER_BIG_ENDIAN true
@ -19,8 +20,10 @@
#define CONVERSION_UTILITIES_IS_BYTE_ORDER_BIG_ENDIAN false
#define CONVERSION_UTILITIES_BYTE_ORDER_LITTLE_ENDIAN
#endif
#endif
#ifdef __FLOAT_WORD_ORDER__
#endif // defined(__BYTE_ORDER__)
// detect float byte order according to __FLOAT_WORD_ORDER__
#if defined(__FLOAT_WORD_ORDER__)
#if __FLOAT_WORD_ORDER__ == __ORDER_BIG_ENDIAN__
#define CONVERSION_UTILITIES_FLOAT_BYTE_ORDER_BIG_ENDIAN
#elif __FLOAT_WORD_ORDER__ == __ORDER_PDP_ENDIAN__
@ -28,37 +31,43 @@
#elif __FLOAT_WORD_ORDER__ == __ORDER_LITTLE_ENDIAN__
#define CONVERSION_UTILITIES_FLOAT_BYTE_ORDER_LITTLE_ENDIAN
#endif
#endif
#if defined(__BYTE_ORDER__) && defined(__FLOAT_WORD_ORDER__)
#else
#endif // defined(__FLOAT_WORD_ORDER__)
// detect (float) byte order according to other macros
#if !defined(__BYTE_ORDER__) || !defined(__FLOAT_WORD_ORDER__)
// assume little endian from the precense of several macros
#if defined(__i386) || defined(__i386__) || defined(_M_IX86) || defined(__x86_64) || defined(__x86_64__) || defined(__amd64) || defined(_M_X64) \
|| defined(__LITTLE_ENDIAN__) || defined(_little_endian__) || defined(_LITTLE_ENDIAN) || defined(_WIN32_WCE) || defined(WINAPI_FAMILY)
#ifndef __BYTE_ORDER__
#if !defined(__BYTE_ORDER__)
#define CONVERSION_UTILITIES_IS_BYTE_ORDER_LITTLE_ENDIAN true
#define CONVERSION_UTILITIES_IS_BYTE_ORDER_BIG_ENDIAN false
#define CONVERSION_UTILITIES_BYTE_ORDER_LITTLE_ENDIAN
#endif
#ifndef __FLOAT_WORD_ORDER__
#if !defined(__FLOAT_WORD_ORDER__)
#define CONVERSION_UTILITIES_FLOAT_BYTE_ORDER_LITTLE_ENDIAN
#endif
// assume big endian from the precense of several macros
#elif defined(__MIPSEB__) || defined(__s390__) || defined(__BIG_ENDIAN__) || defined(_big_endian__) || defined(_BIG_ENDIAN)
#ifndef __BYTE_ORDER__
#if !defined(__BYTE_ORDER__)
#define CONVERSION_UTILITIES_IS_BYTE_ORDER_LITTLE_ENDIAN false
#define CONVERSION_UTILITIES_IS_BYTE_ORDER_BIG_ENDIAN true
#define CONVERSION_UTILITIES_BYTE_ORDER_BIG_ENDIAN
#endif
#ifndef __FLOAT_WORD_ORDER__
#if !defined(__FLOAT_WORD_ORDER__)
#define CONVERSION_UTILITIES_FLOAT_BYTE_ORDER_BIG_ENDIAN
#endif
// fail if unable to detect endianness
#else
#error "Unable to determine byte order!"
#endif
#endif
#if defined(CONVERSION_UTILITIES_BYTE_ORDER_MIDDLE_ENDIAN)
#error "Middle endian byte order is not supported!"
#endif
#if defined(CONVERSION_UTILITIES_FLOAT_BYTE_ORDER_MIDDLE_ENDIAN)
#endif // !defined(__BYTE_ORDER__) || !defined(__FLOAT_WORD_ORDER__)
// fail if middle endian detected
#if defined(CONVERSION_UTILITIES_BYTE_ORDER_MIDDLE_ENDIAN) || defined(CONVERSION_UTILITIES_FLOAT_BYTE_ORDER_MIDDLE_ENDIAN)
#error "Middle endian byte order is not supported!"
#endif