Why did you add HAVE_NATIVE_ around the C mpn_gcd_11 function? #if !HAVE_NATIVE_mpn_gcd_11 mp_limb_t mpn_gcd_11 (mp_limb_t u, mp_limb_t v) . . . I would assume configure does its magic for this file just as with any other file, i.e., exclude it when there is a definition earlier in the mpn path. -- Torbjörn Please encrypt, key id 0xC8601622