[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: seg fault in mpz_root
From: |
Kevin Ryde |
Subject: |
Re: seg fault in mpz_root |
Date: |
Fri, 13 Dec 2002 10:12:47 +1000 |
User-agent: |
Gnus/5.090008 (Oort Gnus v0.08) Emacs/21.1 (i386-debian-linux-gnu) |
Jason Moxham <address@hidden> writes:
>
> the fn mpn_rootrem , calculates an approx root which can be one unit too
> large
> , and then it powers it to see if it is too large , if the approx root is 3 ,
> whereas the real root is 2 then after powering a lot more space is required
Ah, beaut.
> 1) would to be allocate enough space for the worst case eg (3/2)^k more
> limbs
Yes, better do that. Can you come up with a good change for the 4.1.1
code?
> ,assuming mpn_rootrem is only called when root>=2
True currently I think.
> 2) identified these worst cases (these cases can be identified fairly
> quickly(see my code for example)) and call a mpn_pow_1 which checks for
> overflow
That might be better for the future. Unless we change to Paul Z.'s
discrete variant, which if I understand it keeps intermediates below
the true root.
- seg fault in mpz_root, Jason Moxham, 2002/12/10
- Re: seg fault in mpz_root, Kevin Ryde, 2002/12/10
- Re: seg fault in mpz_root, Jason Moxham, 2002/12/10
- Re: seg fault in mpz_root patch, Jason Moxham, 2002/12/12
- Re: seg fault in mpz_root patch, Kevin Ryde, 2002/12/16
- Re: seg fault in mpz_root patch, Kevin Ryde, 2002/12/16
- Re: seg fault in mpz_root patch, Jason Moxham, 2002/12/16
- Re: seg fault in mpz_root patch, Kevin Ryde, 2002/12/17
- Re: seg fault in mpz_root patch, Torbjorn Granlund, 2002/12/18