paul zimmermann writes:
> you might be interested by Algorithms DivApprox1 and DivApprox2
> from https://hal.inria.fr/hal-01502326.
Thanks. I'm looking for something in between, single limb quotient based
on double limb inputs.
Regards,
/Niels
--
Niels Möller. PGP-encrypted email is preferred
Ciao,
Il Dom, 29 Aprile 2018 8:24 pm, Bradley Lucier ha scritto:
> On 04/28/2018 04:16 AM, Marco Bodrato wrote:
>> Finally, the mini-mpq code is in the development library.
>> https://gmplib.org/repo/gmp/file/tip/mini-gmp
> I haven't tested the code, but I have examined it.
Thank you!
> I would
On 04/28/2018 04:16 AM, Marco Bodrato wrote:
Finally, the mini-mpq code is in the development library.
https://gmplib.org/repo/gmp/file/tip/mini-gmp
I'll be happy if you want to test it or write any comment about it.
I haven't tested the code, but I have examined it.
I would suggest testing
Niels,
> static inline mp_limb_t
> divappr_2 (mp_limb_t n2, mp_limb_t n1,
>mp_limb_t d1, mp_limb_t d0, mp_limb_t dinv)
> This needs more analysis. [...]
you might be interested by Algorithms DivApprox1 and DivApprox2
from https://hal.inria.fr/hal-01502326.
Best regards,
Paul
_
Ciao Niels,
Il Dom, 29 Aprile 2018 10:52 am, Niels Möller ha scritto:
> #if 0
> q1 += (r1 >= d1);
> #else
> /* FIXME: Take care of this case more efficiently,
> need analysis of the case n1 == d1. */
> if (r1 >= d1 && q1 != GMP_NUMB_MAX)
> q1++;
> #endif
On some CPU saturating arit
ni...@lysator.liu.se (Niels Möller) writes:
The first failure was for an input with n2 == d1, n1 == d1-1.
static void test_divappr_2(void)
{
mp_limb_t q = divappr_2(0x8001ULL, 0xbfffULL,
0x8001ULL, 0xc000ULL,
ni...@lysator.liu.se (Niels Möller) writes:
> ni...@lysator.liu.se (Niels Möller) writes:
>
>> If we can get away with that, it gets a lot
>> simpler,
>>
>> if (r >= q_0) /* Needs to be branch free */
>> {
>> q--;
>> r += d_1;
>> }
>> return q + (r >= d_1);
>
> I've given it a try.
