scion+gmp@webrelay.net writes:
configure:8781: gcc -o conftest -g -O2 conftest.c -lgmp >&5 ld: warning: file /usr/local/lib/gcc-lib/sparc-sun-solaris2.8/3.3.2/../../../libgmp.a(getlimbn.o): wrong ELF class: ELFCLASS64
...
./configure --disable-shared ABI=64
"ABI and ISA" in the manual describes the options you need to add to application compiles if you want to use the 64-bit ABI.