Hi all,
This is a neat trick to find out what is pre defined for your compiler.
For example on you can see the differences between mingw32 and mingw64 gcc compilers here:
--------------- mingw64 ---------------------------
woodbri@imaptools /c/ming64/projects/pgrouting
$ touch test.c
woodbri@imaptools /c/ming64/projects/pgrouting
$ gcc -E -dM test.c | grep -i win
#define _WIN32 1
#define _WIN64 1
#define __WINT_MAX__ 65535
#define __WINT_MIN__ 0
#define __WIN32 1
#define __WIN64 1
#define __WINNT 1
#define __WINNT__ 1
#define __WIN32__ 1
#define __SIZEOF_WINT_T__ 2
#define WIN32 1
#define WIN64 1
#define __WINT_TYPE__ short unsigned int
#define WINNT 1
#define __WIN64__ 1
woodbri@imaptools /c/ming64/projects/pgrouting
$ gcc -E -dM test.c | grep -i ming
#define __MINGW32__ 1
#define __VERSION__ "4.5.4 20111030 (prerelease) [svn/rev.180676 - mingw-w64/oz]"
#define __MINGW64__ 1
--------------- mingw32 ---------------------------
woodbri@imaptools /c/ming32/projects/pgrouting
$ touch test.c
woodbri@imaptools /c/ming32/projects/pgrouting
$ gcc -E -dM test.c | grep -i win
#define _WIN32 1
#define __WINT_MAX__ 65535
#define __WINT_MIN__ 0
#define __WIN32 1
#define __WINNT 1
#define __WINNT__ 1
#define __WIN32__ 1
#define __SIZEOF_WINT_T__ 2
#define WIN32 1
#define __WINT_TYPE__ short unsigned int
#define WINNT 1
woodbri@imaptools /c/ming32/projects/pgrouting
$ gcc -E -dM test.c | grep -i ming
#define __MINGW32__ 1
#define __VERSION__ "4.5.4 20111030 (prerelease) [svn/rev.180676 - mingw-w64/oz]"