https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67728
--- Comment #5 from joseph at codesourcery dot com <joseph at codesourcery dot com> --- GMP does, or did, select an ABI at configuration time that may not be the same as that used by default by the compiler used to build it. For example, if building on an x86_64 processor it might select a 64-bit ABI even if you have configured GCC for a 32-bit host. If your goal is to make multiple-precision computations as fast as possible, choosing the ABI for that purpose makes sense - but for GCC's uses the requirement is to choose the same ABI as for the selected host, even if that's slower than some other ABI available on the processor.
