Under IRIX OS all code is generally compiled at least with the -n32 option.
Since more than one object format exists SGI states that a portable lib/app would be compiled with the -n32 option. Moreover this is a de facto standard when you need to link toghether more libs (from separate vendors) because different object abi does not link togheter.
Under newer platform this is the default but on older you must specify the option above NOT ONLY to the compiler but to the linker too (if as you do do not let the compiler to invoke the linker).
I do not known the GNU libtool but to overcome the problem i simply set the following environment variables before run the configure script:
setenv CFLAGS '-n32 -INLINE -O2 -OPT:Olimit=0'
setenv LDFLAGS -n32
apart from the csh syntax note that the -INLINE directive is given to ensure proper inlining and the -O2 and following Olimit is for ensure that optimization is turned on without memory limit