"Marco Bodrato" <bodr...@mail.dm.unipi.it> writes: > If you pass NULL, you'll not avoid any pesky branch :-D > > If you pass a static "1", and do not branch, you will end up allocating > space and loosing time to multiply NUM(op1) by one...
Depends on whether or not we want to recognize the integer case also for mpq_cmp. I think it would make some sense to do that. And if so, passing a static "1" for mpq_cmp_z seems right, because then no additional branch is needed for that case. As I understand tail call machinery, to really get a tail call, the calling functions (mpq_cmp and mpq_cmp_z) mustn't pass any stack-allocated pointers to mpq_cmp_helper. > If we want to share code and we don't want to penalise the _z flavour too > much, some branches are needed. Is there a lot shared logic? For the integer case, we compare A/B to C, by first checking signs and sizes, and for close sizes, compare B*C to A (or ideally, only one or two of the high limbs of the product). While for the non-integer case, A/B vs C/D, it seems to me that sign logic would be the same, but size comparisons are different (limb size of A known exactly, while limb size of A*D has one unit of uncertainty). Regards, /Niels -- Niels Möller. PGP-encrypted email is preferred. Keyid C0B98E26. Internet email is subject to wholesale government surveillance. _______________________________________________ gmp-devel mailing list gmp-devel@gmplib.org https://gmplib.org/mailman/listinfo/gmp-devel
