A question on mpn_aorslsh1_n function pairs
tg at gmplib.org
Wed Dec 25 10:58:05 UTC 2013
Anil Singhar <anil.singhar at linaro.org> writes:
Could someone please help me understand the return values of the following
i) mpn_addlsh1_n : rp = up + (vp << 1)
- is the return value = (vp[num_limbs -1] >> 63) + carry from the above
ii) mpn_sublsh1_n : rp = up - (vp << 1)
- Is the return value = "Borrow from the above subtraction" - (vp[num_limbs
-1] >> 63) ?
These functions are internal, and as such we don't have much
documentation for them. An idea of their current behaviour could be
gathered by the current implementations, and by tests/refmpn.c.
We may of course change the behaviour of internal functions at any time,
or for that matter remove them.
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