编译器中和64位编程有关的预定义宏

本文对分别测试VC，MinGW，GCC 三种编译器，32位和64位模式，共6种情况下，和64位编程有关的与预定义宏的值。对跨平台编程具有参考意义。

Agner Fog 在他的《Calling conventions for different C++ compilers and operating systems》提到一些预订宏。这里摘录如下。

注：下面的内容来自《Calling conventions for different C++ compilers and operating systems》,Last updated 2012-02-29，作者：By Agner Fog. Copenhagen University College .如何原文内容不符，以原文为准。

Most C++ compilers have a predefined macro containing the version number of the

problems with incompatible compilers.

Table 23. Compiler version predefined macros

Unfortunately, not all compilers have well-documented macros telling which hardware

Table 24. Hardware platform predefined macros

Table 25. Operating system predefined macros

下面的代码主要测试和64编程有关的宏

void test()
{
	int len=sizeof(int)*8;
	printf("sizeof(int)=%d\n",len);

	len=sizeof(int *)*8;
	printf("sizeof(int*)=%d\n",len);

#ifdef _MSC_VER
	printf("_MSC_VER is defined\n");
#endif

#ifdef __GNUC__
	printf("__GNUC__ is defined\n");
#endif

#ifdef __INTEL__
	printf("__INTEL__  is defined\n");
#endif

#ifdef __i386__
	printf("__i386__  is defined\n");
#endif

#ifdef __x86_64__
	printf("__x86_64__  is defined\n");
#endif

#ifdef _WIN32
	printf("_WIN32 is defined\n");
#endif

#ifdef _WIN64
	printf("_WIN64 is defined\n");
#endif

#ifdef __linux__
	printf("__linux__ is defined\n");
#endif

#ifdef __LP64__
	printf("__LP64__ is defined\n");
#endif

#ifdef __amd64
	printf("__amd64 is defined\n");
#endif
}

int main(int argc, char* argv[])
{
	test();
	return 0;
}

最后给出结果.

1. 在VC2010， 32位模式下编译，输出下面的信息

sizeof(int)=32

sizeof(int*)=32

_MSC_VER is defined

_WIN32 is defined

2. 在MinGW下编译 输出下面的信息

sizeof(int)=32

sizeof(int*)=32

__GNUC__ is defined

__i386__  is defined

_WIN32 is defined

3. 在64位Fedora19, 使用gcc -m32 编译，输出下面的信息

sizeof(int)=32

sizeof(int*)=32

__GNUC__ is defined

__i386__  is defined

__linux__ is defined

4. 在VC2010， 64位模式下编译，输出下面的信息

sizeof(int)=32

sizeof(int*)=64

_MSC_VER is defined

_WIN32 is defined

_WIN64 is defined

5. 在MinGW64下编译 输出下面的信息

sizeof(int)=32

sizeof(int*)=64

__GNUC__ is defined

__x86_64__  is defined

_WIN32 is defined

_WIN64 is defined

__amd64 is defined

6.  在64位Fedora19, 使用gcc -m64 编译，输出下面的信息

sizeof(int)=32

sizeof(int*)=64

__GNUC__ is defined

__x86_64__  is defined

__linux__ is defined

__LP64__ is defined

__amd64 is defined

注：在VC下直接用集成环境编译，在MinGW和Linux下直接使用 gcc来编译。

编译器中和64位编程有关的预定义宏