Small toom43 cleanup

Niels Möller nisse at
Tue Oct 20 22:19:04 CEST 2009

Torbjorn Granlund <tg at> writes:

> mp_size_t is a signed type, for various reasons.  size_t is an unsigned
> type.  Unsigned division by constants is a few cycles faster.

How are these divisions by constants implemented? I guess it depends
on the compiler, but this is precisely the type of application your
and Montgomery's paper is about, right? IIRC, it should be a multiply,
possibly some shifting, and unlike udiv_qrnn_preinv, one may even get
away without any adjustment steps.


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