On AIX Version 4.3.3 with the POSIX 1003.1-1996 standard pthreads API, XL Fortran, beginning with Version 5.1.1, supports 64-bit thread programming. You can specify the -q64 compiler option with the xlf_r, xlf_r7, xlf90_r, xlf90_r7, xlf95_r, and xlf95_r7 commands. For example, you can specify the following command to compile and then link a program in 64-bit object mode:
xlf90_r -q64 -qsmp test.f
AIX Version 4.3.3 supports the POSIX 1003.1-1996 standard interface in both 32-bit and 64-bit object mode but supports the Draft 7 interface in 32-bit object mode only. That is, the libpthreads.a library has a 32-bit and a 64-bit part, while the libpthreads_compat.a and libxlfpthrds_compat.a libraries have 32-bit parts only.