AIX

gcc -m64 isnt working,says no such option
and for xlc -q64 it says
xlc: cannot retrieve message number 1501-221
any idea?

Vishal,
Your nls path is not set, that is why your not able to see message.
I did porting a application on AIX 5.3. I used

xlc_r -q64 -qwarn64

try to use these options.

hey great,
can you tell me some points on porting application to 64 bit.It is a combination of 32-bit and 64-bit executables,was running fine on 32-bit AIX but we need to run that on 64 bit.What are the main changes we need to make.

how do i differentiate between an AIX 64 bit and AIX 32 bit using a single command.
I tried versions of uname but it only gives some arbitrary results.for other OS uname -m did work but for AIX it aint working.
any help?

Not in the same process, in a single process all loaded binaries have to be either 32bit or 64bit.

Other than that, operating systems like Irix and Solaris use a differenet lib path variable in 64 bit compared to 32 bit. What AIX does is have both 32 bit and 64 bit code in a single shared library, the shared library is actually a normal archive file with a "shr.o" for 32 bit, and a "shr64.o" for 64 bit, both the linker and loader are supposed to sort out what is expected based on the current "mode".

You can always check what compilation environment is available to you by means of the sysconf() function.

_SC_XBS5_ILP32_OFF32 Implementation provides a C-language compilation environment
with 32-bit int, long, pointer and off_t types.
_SC_XBS5_ILP32_OFFBIG Implementation provides a C-language compilation environment
with 32-bit int, long and pointer types and an off_t type
using at least 64 bits.
_SC_XBS5_LP64_OFF64 Implementation provides a C-language compilation environment
with 32-bit int and 64-bit long, pointer and off_t types.
_SC_XBS5_LPBIG_OFFBIG Implementation provides a C-language compilation environment
with an int type using at least 32 bits and long, pointer
and off_t types using at least 64 bits.

Man sysconf for further information.

use following command

#bootinfo -K, if it is 64-bit kernel it will give you 64.

further you can run #file <filename> command on AIX to see whether
the binary it 32-bit or 64-bit. If you have both in one library ared
with ar command then try following commands

dump <binaryfilename>
nm <binaryfilename>

use man pages to learn more about these commands, there are options to
see the symbols too (i.e. 32-bit symbols and 64-bit symbols)