http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47175
--- Comment #4 from Jan <jan.rauberg at gmx dot de> 2011-01-05 15:13:23 UTC --- (In reply to comment #3) > (In reply to comment #2) > > (In reply to comment #1) > > > Checking __amd64, __amd64__, __x86_64 __x86_64__ for > > > pointer size is wrong since pointer size may be > > > 32bit on x86-64. > > No, it can't be. The macros are set in dependence of the target platform > > (m32 > > or m64). That means, if m32 is given the macro __i686 is set instead of > > __amd64. On the other hand, if m64 is given the macro __amd64 is set. I > > don't > > want to know the really underlying platform. I (or Matlab) want to know the > > target platform. So it is right to check the __amd64 macro. You can try it > > with > > the gcc-4.4. Only with gfortran-4.4 the macro is missed. > > See > > http://www.kernel.org/pub/linux/devel/binutils/ilp32/abi.pdf > > where pointer size is 32bit. As far as I understood means ILP32 a 32bit application in a 64bit environment and LP64 a 64bit application in 64bit environment. Am I Right? The predefined preprocessor macro __amd64 is true if I compile with -m64 (default on Linux) and it is not true if I compile with -m32. So why I can't check against this macro, as far it is supported (as in gcc)? Please correct me if I'm totally wrong. Or do you want to tell me that a 64bit application could use 32bit pointers, or the other way round? If so, how is it possible? Jan
