using getconf in autoconf macro to find 64 bit compile options?

[Ed Hartnett]

Howdy all!

I'm working on netCDF, a freeware scientific data format for Earth
Science work. 

(http://my.unidata.ucar.edu/content/software/netcdf/index.html).

We compile on a lot of platforms, and use autoconf to do so.

I wonder if there is any autoconf macro for running getconf to find
the compile flags needed for 64-bit compilation on platforms that
support it. For example, both the AIX and solaris platforms have
special compile options to get 64 bit pointers. 

I'm trying to avoid reinventing the wheel here.

Does anyone here know of any such macros?

Thanks!

Ed Hartnett
Unidata