Re: determining 32 v. 64 bit compilatio

[Bob Friesenhahn]

On Tue, 29 Jun 2010, Wesley Smith wrote:

> What's the appropriate way to determine 32 v. 64 bit compilation?
> I've looked into using:
>
> AC_CANONICAL_BUILD
>
> with the $build_cpu $build_vendor $build_os variables, but it doesn't
> give the right info (in my case i686 pc linux-gnu).  I'm essentially
> looking for something in autoconf land equivalent to:

It is much more useful and reliable to test the size of the relevant 
types.  For example, my package includes tests like this in 
configure.ac:

# Obtain size of a 'unsigned long' and define as SIZEOF_UNSIGNED_LONG
AC_CHECK_SIZEOF(unsigned long)

# Obtain size of size_t and define as SIZEOF_SIZE_T
AC_CHECK_SIZEOF(size_t)

# Obtain size of an unsigned int pointer and define as SIZEOF_UNSIGNED_INTP
AC_CHECK_SIZEOF(unsigned int*)

Bob
--
Bob Friesenhahn
address@hidden, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/