(Related, I wonder what the effect would be of redefining umul_ppmm as C expressions involving __uint128_t on compilers that support that). We do that already for some CPUs, but this has proven to be somewhat fragile, and in unexpected cases lead to libgcc calls.
We brave to do that for at least PowerPC-64, MIPS-64, s390x, Arm64. For alpha, gcc provides an _int_mult_upper which we use instead. Apart from better scheduling, making gcc aware of the semantics allows for algebraic optimisations and various foldings. -- Torbjörn Please encrypt, key id 0xC8601622 _______________________________________________ gmp-bugs mailing list gmp-bugs@gmplib.org https://gmplib.org/mailman/listinfo/gmp-bugs