[cffi-devel] detecting int size used by library

Hi, Is there a way to detect the size of integers (ie 32 or 64 bit) used by a library? I am using LAPACK/BLAS (ATLAS) libraries via CFFI. Recently, my tests failed, and to my surprise, the solution was to use 32-bit ints. Note that I am on a 64-bit platform, using the Ubuntu libraries, so why this happens is a mystery. But it would be great if I could detect it somehow from within Lisp. Thanks, Tamas