20130225, 15:57  #1 
"Ben"
Feb 2007
3,361 Posts 
YAFU1.34
There is a lot of new stuff in this version, highlights include:
Fully automated SNFS factorization. Polynomial selection is supported for a variety of special forms: N = a*b^n +/ c, for b < 100, c < 2^30, N < 1024 bits N = b^n +/ 1, for b > 100, N < 1024 bits N = a^n +/ b^n, for gcd(a,b) = 1, a,b <= 12, N < 1024 bits N = x^y + y^x, for 1 < x < y < 151, N < 1024 bits There are two ways to run it. "nfs(number)" will autodetect any of the above forms, and proceed with the primitive factor of the input  but only in "pure" form (i.e., the number can't have been reduced by any known large factors). Use "snfs(number, cofactor)", where "number" is the pure form (i.e. 2^10391) and "cofactor" is the number reduced by any known large factors. Next, WraithX contributed his port of APRCL to YAFU, so now every factor found will be automatically proved prime. A couple new options control when it is run and how verbose the output is: aprcl_p <num> and aprcl_d <num>. The defaults are: below 500 digits are automatically proved (the upper end of that range can take a minute or two) and above 200 digits extra verbosity is enabled. 1.34 also contains the first real speedup of my SIQS code in a while. New SSE2 code gives a 23% speedup, or, on supported systems, SSE4.1 code gives about a 10% speedup. SSE4.1 is automatically detected and used if found. Finally, there are quite a few bugfixes and minor updates. Check the changelog for details. May thanks to all bug reporters and developers that contributed to this version! Very much appreciated! Happy factoring,  ben. Last fiddled with by bsquared on 20130225 at 15:59 Reason: add link 
20130225, 18:43  #2 
Romulan Interpreter
Jun 2011
Thailand
23C6_{16} Posts 
Now, THAT's news....
Thanks a billion! 
20130225, 22:43  #3 
Basketry That Evening!
"Bunslow the Bold"
Jun 2011
40<A<43 89<O<88
3×29×83 Posts 
Sweet!
Can we see your Msieve patch? As it is then, YAFU using Msieve and GMPECM is now the best way to automagically factor about any number that can be handled by modern algorithms. Thanks a billion Ben! 
20130225, 22:48  #4 
"Ben"
Feb 2007
3,361 Posts 
Sure, I'll post it sometime soon.
Also, there appears to be a problem with factoring certain small inputs with siqs that missed my (woefully insufficient) testing process... somewhere around 130 bits or so. I'm looking into it. 
20130226, 00:47  #5 
Apr 2012
2×47 Posts 
Great job, thanks
though I've just posted a possible bug (related with compilation?) Last fiddled with by skan on 20130226 at 01:38 
20130226, 01:14  #6 
Jun 2012
2^{7}·23 Posts 
Great news! Thanks for all the work.

20130226, 04:19  #7 
"Ben"
Feb 2007
3,361 Posts 

20130226, 06:05  #8 
Basketry That Evening!
"Bunslow the Bold"
Jun 2011
40<A<43 89<O<88
7221_{10} Posts 
Fun fact: Somewhere between 25003000 lines of new NFS code were added, written almost entirely by Ben

20130226, 12:47  #9 
Mar 2010
5·11 Posts 
Does the factor() function automatically invoke snfs if it finishes ECM with a cofactor that requires NFS and the original form meets the proper criteria?

20130226, 17:30  #10 
"Ben"
Feb 2007
3,361 Posts 
It turns out the Win32 executable was linked against the wrong ecm library, which was causing it to crash. I've now corrected this (and another unrelated bug). Please redownload (version 1.34.2). Sorry for the churn everyone ... like I said, there was a lot of new stuff in this release . Let me know if there are any other problems.

20130226, 17:33  #11 
"Ben"
Feb 2007
3,361 Posts 
I actually wasn't sure, so I tested it out and no, it won't. If ecm doesn't find a factor, then it should start snfs, but if it does then the snfs detection code might not recognize it as a special form. You'd have to kill the gnfs poly selection (or run ecm only) and restart with snfs(form, cofactor). Sorry, an oversight on my part.

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