YAFU 2.0

[NyanCat]

According to the source code, it always chooses the yafu.ini in the working directory. There are three ways to solve this:
1. cd to the yafu directory before running it
2. Copy the default yafu.ini to your directory
3. Change the source code to always find yafu.ini in your directory
To be exact, you can change the path in top/driver.c Line 110
ini_success = readINI("yafu.ini", options);

[kotenok2000]

Sometimes yafu gets stuck siqs sieving on repeat and I have to kill yafu.exe
It reports

08/27/22 01:31:03, trial division touched 0 sieve locations out of 0
08/27/22 01:31:03, total reports = 0, total surviving reports = 0
08/27/22 01:31:03, total blocks sieved = 0, avg surviving reports per block = -nan(ind)
08/27/22 01:31:03, dlp-ecm: 0 failures, 0 attempts, 0 outside range, 0 prp, 0 useful

I use fdb_comp_evaluator.pl from https://github.com/AntonioPK/Fdb

[EdH]

Another member asked me to test a failure and I can replicate it with both 2.07 and 2.09. The composite is 9649340769776349618630915417390658987772498722136713669954798667326094136661 and it has the short form (8^85-2)/6 per factordb:

YAFU Version 2.09
Built with GCC 9
Using GMP-ECM 7.0.5-dev, Powered by GMP 6.2.0
Detected         Intel(R) Core(TM) i7-2600 CPU @ 3.40GHz
Detected L1 = 32768 bytes, L2 = 8388608 bytes, CL = 64 bytes
Using 1 random witness for Rabin-Miller PRP checks
Cached 664579 primes; max prime is 9999991
Parsed yafu.ini from /home/math96/Math/yafu

===============================================================
======= Welcome to YAFU (Yet Another Factoring Utility) =======
=======             bbuhrow@gmail.com                   =======
=======     Type help at any time, or quit to quit      =======
===============================================================

>> factor(9649340769776349618630915417390658987772498722136713669954798667326094136661)
fac: factoring 9649340769776349618630915417390658987772498722136713669954798667326094136661
fac: using pretesting plan: normal
fac: using specified qs/gnfs crossover of 100 digits
fac: using specified qs/snfs crossover of 75 digits
div: primes less than 10000
fmt: 1000000 iterations
rho: x^2 + 3, starting 1000 iterations on C76 
rho: x^2 + 2, starting 1000 iterations on C76 
rho: x^2 + 1, starting 1000 iterations on C76 
nfs: searching for brent special forms...
nfs: input divides 2^254 - 1
nfs: snfs form detection took 0.000103 seconds
nfs: snfs form detection took 0.000061 seconds
gen: found primitive cofactor < input number:
gen: 170141183460469231731687303715884105727
fac: ecm effort reduced from 23.38 to 18.19: input has snfs form
pm1: starting B1 = 150K, B2 = gmp-ecm default on C76
nfs: snfs form detection took 0.000109 seconds
gen: found primitive cofactor < input number:
gen: 170141183460469231731687303715884105727
fac: ecm effort reduced from 23.38 to 18.19: input has snfs form
ecm: 30/30 curves on C76, B1=2k, B2=gmp-ecm default
nfs: snfs form detection took 0.000069 seconds
gen: found primitive cofactor < input number:
gen: 170141183460469231731687303715884105727
fac: ecm effort reduced from 23.38 to 18.19: input has snfs form
ecm: 45/45 curves on C76, B1=11k, B2=gmp-ecm default
nfs: snfs form detection took 0.000073 seconds
gen: found primitive cofactor < input number:
gen: 170141183460469231731687303715884105727
fac: ecm effort reduced from 23.38 to 18.19: input has snfs form
nfs: commencing nfs on c76: 9649340769776349618630915417390658987772498722136713669954798667326094136661
nfs: searching for brent special forms...
nfs: input divides 2^254 - 1
nfs: snfs form detection took 0.000091 seconds
gen: found primitive cofactor < input number:
gen: 170141183460469231731687303715884105727
nfs: found 4 polynomials, selecting best
nfs: using provided snfs difficulty 38.230809
nfs: using provided snfs difficulty 38.531839
nfs: using provided snfs difficulty 38.230809
nfs: commencing algebraic side lattice sieving over range: 155000 - 160000
nfs: commencing algebraic side lattice sieving over range: 180000 - 185000
nfs: commencing algebraic side lattice sieving over range: 160000 - 165000
nfs: commencing algebraic side lattice sieving over range: 170000 - 175000
nfs: commencing algebraic side lattice sieving over range: 150000 - 155000
nfs: commencing algebraic side lattice sieving over range: 175000 - 180000
nfs: commencing algebraic side lattice sieving over range: 165000 - 170000
nfs: commencing algebraic side lattice sieving over range: 185000 - 190000
*** Error in `../ggnfs/bin/gnfs-lasieve4I11e': realloc(): invalid next size: 0x00000000010b52f0 ***
======= Backtrace: =========
[0x47fc21]
[0x48b166]
[0x48c489]
[0x40bb25]
[0x40acf9]
[0x406167]
[0x467ba6]
[0x467d9a]
[0x4083f9]
======= Memory map: ========
00400000-0055e000 r-xp 00000000 08:01 6693409                            /home/math96/Math/ggnfs/bin/gnfs-lasieve4I11e
0075d000-00760000 rwxp 0015d000 08:01 6693409                            /home/math96/Math/ggnfs/bin/gnfs-lasieve4I11e
00760000-007f5000 rwxp 00000000 00:00 0 
00d3d000-01355000 rwxp 00000000 00:00 0                                  [heap]
7f37dc000000-7f37dc024000 rwxp 00000000 00:00 0 
7f37dc024000-7f37e0000000 ---p 00000000 00:00 0 
7f37e1f5f000-7f37e45a2000 rwxp 00000000 00:00 0 
7fff9ca0d000-7fff9ca2e000 rwxp 00000000 00:00 0                          [stack]
7fff9cad1000-7fff9cad4000 r--p 00000000 00:00 0                          [vvar]
7fff9cad4000-7fff9cad5000 r-xp 00000000 00:00 0                          [vdso]
ffffffffff600000-ffffffffff601000 --xp 00000000 00:00 0                  [vsyscall]
*** Error in `../ggnfs/bin/gnfs-lasieve4I11e': realloc(): invalid next size: 0x0000000002672610 ***
======= Backtrace: =========
[0x47fc21]
[0x48b166]
[0x48c489]
[0x40bb25]
[0x40acf9]
[0x406167]
[0x467ba6]
[0x467d9a]
[0x4083f9]
======= Memory map: ========
00400000-0055e000 r-xp 00000000 08:01 6693409                            /home/math96/Math/ggnfs/bin/gnfs-lasieve4I11e
0075d000-00760000 rwxp 0015d000 08:01 6693409                            /home/math96/Math/ggnfs/bin/gnfs-lasieve4I11e
00760000-007f5000 rwxp 00000000 00:00 0 
022f8000-02913000 rwxp 00000000 00:00 0                                  [heap]
7f8240000000-7f8240024000 rwxp 00000000 00:00 0 
7f8240024000-7f8244000000 ---p 00000000 00:00 0 
7f8245874000-7f8247ec1000 rwxp 00000000 00:00 0 
7ffcaa002000-7ffcaa023000 rwxp 00000000 00:00 0                          [stack]
7ffcaa1b7000-7ffcaa1ba000 r--p 00000000 00:00 0                          [vvar]
7ffcaa1ba000-7ffcaa1bb000 r-xp 00000000 00:00 0                          [vdso]
ffffffffff600000-ffffffffff601000 --xp 00000000 00:00 0                  [vsyscall]
Aborted (core dumped)
Aborted (core dumped)
*** Error in `../ggnfs/bin/gnfs-lasieve4I11e': realloc(): invalid next size: 0x0000000001c42f20 ***
======= Backtrace: =========
[0x47fc21]
[0x48b166]
[0x48c489]
[0x40bb25]
[0x40acf9]
[0x406167]
[0x467ba6]
[0x467d9a]
[0x4083f9]
======= Memory map: ========
00400000-0055e000 r-xp 00000000 08:01 6693409                            /home/math96/Math/ggnfs/bin/gnfs-lasieve4I11e
0075d000-00760000 rwxp 0015d000 08:01 6693409                            /home/math96/Math/ggnfs/bin/gnfs-lasieve4I11e
00760000-007f5000 rwxp 00000000 00:00 0 
01853000-01f59000 rwxp 00000000 00:00 0                                  [heap]
7f4d38000000-7f4d38024000 rwxp 00000000 00:00 0 
7f4d38024000-7f4d3c000000 ---p 00000000 00:00 0 
7f4d3c1b3000-7f4d3e7ec000 rwxp 00000000 00:00 0 
7ffc33d13000-7ffc33d34000 rwxp 00000000 00:00 0                          [stack]
7ffc33d82000-7ffc33d85000 r--p 00000000 00:00 0                          [vvar]
7ffc33d85000-7ffc33d86000 r-xp 00000000 00:00 0                          [vdso]
ffffffffff600000-ffffffffff601000 --xp 00000000 00:00 0                  [vsyscall]
*** Error in `../ggnfs/bin/gnfs-lasieve4I11e': realloc(): invalid next size: 0x0000000001960e50 ***
======= Backtrace: =========
[0x47fc21]
[0x48b166]
[0x48c489]
[0x40bb25]
[0x40acf9]
[0x406167]
[0x467ba6]
[0x467d9a]
[0x4083f9]
======= Memory map: ========
00400000-0055e000 r-xp 00000000 08:01 6693409                            /home/math96/Math/ggnfs/bin/gnfs-lasieve4I11e
0075d000-00760000 rwxp 0015d000 08:01 6693409                            /home/math96/Math/ggnfs/bin/gnfs-lasieve4I11e
00760000-007f5000 rwxp 00000000 00:00 0 
01431000-01b71000 rwxp 00000000 00:00 0                                  [heap]
7ff054000000-7ff054024000 rwxp 00000000 00:00 0 
7ff054024000-7ff058000000 ---p 00000000 00:00 0 
7ff05ae9a000-7ff05d4b4000 rwxp 00000000 00:00 0 
7ffc503c6000-7ffc503e7000 rwxp 00000000 00:00 0                          [stack]
7ffc503ef000-7ffc503f2000 r--p 00000000 00:00 0                          [vvar]
7ffc503f2000-7ffc503f3000 r-xp 00000000 00:00 0                          [vdso]
ffffffffff600000-ffffffffff601000 --xp 00000000 00:00 0                  [vsyscall]
Aborted (core dumped)
Aborted (core dumped)
*** Error in `../ggnfs/bin/gnfs-lasieve4I11e': realloc(): invalid next size: 0x00000000021c9770 ***
======= Backtrace: =========
[0x47fc21]
[0x48b166]
[0x48c489]
[0x40bb25]
[0x40acf9]
[0x406167]
[0x467ba6]
[0x467d9a]
[0x4083f9]
======= Memory map: ========
00400000-0055e000 r-xp 00000000 08:01 6693409                            /home/math96/Math/ggnfs/bin/gnfs-lasieve4I11e
0075d000-00760000 rwxp 0015d000 08:01 6693409                            /home/math96/Math/ggnfs/bin/gnfs-lasieve4I11e
00760000-007f5000 rwxp 00000000 00:00 0 
01b3b000-02488000 rwxp 00000000 00:00 0                                  [heap]
7f2928000000-7f2928024000 rwxp 00000000 00:00 0 
7f2928024000-7f292c000000 ---p 00000000 00:00 0 
7f292e8cb000-7f2930f21000 rwxp 00000000 00:00 0 
7fff6ad49000-7fff6ad6a000 rwxp 00000000 00:00 0                          [stack]
7fff6ad8e000-7fff6ad91000 r--p 00000000 00:00 0                          [vvar]
7fff6ad91000-7fff6ad92000 r-xp 00000000 00:00 0                          [vdso]
ffffffffff600000-ffffffffff601000 --xp 00000000 00:00 0                  [vsyscall]
Aborted (core dumped)
total yield: 169943, q=160031 (0.00002 sec/rel) 
total yield: 179959, q=150193 (0.00002 sec/rel) 
total yield: 171864, q=165049 (0.00002 sec/rel) 


***factors found***


***co-factor***
C76 = 9649340769776349618630915417390658987772498722136713669954798667326094136661

Due to residual files, subsequent runs provide one factor, but not both:

YAFU Version 2.09
 Built with GCC 9
Using GMP-ECM 7.0.5-dev, Powered by GMP 6.2.0
Detected         Intel(R) Core(TM) i7-2600 CPU @ 3.40GHz
Detected L1 = 32768 bytes, L2 = 8388608 bytes, CL = 64 bytes
Using 1 random witness for Rabin-Miller PRP checks
Cached 664579 primes; max prime is 9999991
Parsed yafu.ini from /home/math96/Math/yafu

===============================================================
======= Welcome to YAFU (Yet Another Factoring Utility) =======
=======             bbuhrow@gmail.com                   =======
=======     Type help at any time, or quit to quit      =======
===============================================================

>> factor(9649340769776349618630915417390658987772498722136713669954798667326094136661)
fac: factoring 9649340769776349618630915417390658987772498722136713669954798667326094136661
fac: using pretesting plan: normal
fac: using specified qs/gnfs crossover of 100 digits
fac: using specified qs/snfs crossover of 75 digits
nfs: searching for brent special forms...
nfs: input divides 2^254 - 1
nfs: snfs form detection took 0.000082 seconds

starting SIQS on c39: 170141183460469231731687303715884105727
Total factoring time = 0.1513 seconds


***factors found***

P39 = 170141183460469231731687303715884105727

 ans = 1

I tested the siever that was reported faulty (with a separate test poly) and it ran fine.

Thanks for all your work.

[James Heinrich]

Originally Posted by EdH

Another member asked me to test a failure and I can replicate it with both 2.07 and 2.09

For what it's worth, it works fine on v1.34.5:

Starting factorization of 9649340769776349618630915417390658987772498722136713669954798667326094136661
starting SIQS on c76: 9649340769776349618630915417390658987772498722136713669954798667326094136661
commencing Lanczos iteration
memory use: 2.5 MB
lanczos halted after 344 iterations (dim = 21633)
recovered 16 nontrivial dependencies
prp39 = 170141183460469231731687303715884105727
prp38 = 56713727820156410577229101238628035243
Lanczos elapsed time = 1.2290 seconds.
Sqrt elapsed time = 0.0180 seconds.
SIQS elapsed time = 10.4296 seconds.
Total factoring time = 22.3813 seconds

[kotenok2000]

Maybe you compiled gnfs incorrectly?
What if you copy gnfs-lasieve files from yafu boinc project slot directory?
They have linux compiled executables. https://yafu.myfirewall.org/yafu/apps.php

[EdH]

Originally Posted by James Heinrich

For what it's worth, it works fine on v1.34.5:

Thanks! I hadn't tried version 1.

Originally Posted by kotenok2000

Maybe you compiled gnfs incorrectly?. . .

Thanks, but it also fails with the siever that bsquared compiled.

[chris2be8]

(8^85-2)/6 simplifies to (2^254-1)/3 which factors to (2^127-1)*(2^127+1)/3.

The problem was probably caused by the fact the expression had algebraic factors.

[bsquared]

If you look closely at EdH's post of the output you'll see:

nfs: commencing nfs on c76: 9649340769776349618630915417390658987772498722136713669954798667326094136661
nfs: searching for brent special forms...
nfs: input divides 2^254 - 1
nfs: snfs form detection took 0.000091 seconds
gen: found primitive cofactor < input number:
gen: 170141183460469231731687303715884105727

Which shows that it recognizes the form 2^254-1 and that it found the algebraic factor (2^127-1). What I guess I hadn't anticipated is that this would complete the factorization. I can patch that up. The ggnfs sievers must have issues when asked to factor a small prime number, or the parameters are crazy because the input (a p38) is so small.

1.34.5 works because the siqs/snfs crossovers are apparently set differently so it proceeds immediately to siqs without doing the algebraic factor detection.

[LaurV]

In yafu.ini from git, there is no B1pp1 nor B1pp2, but the B1pm1 and B1pm2 appear two times.

Intentional, or copy/paste error?

[storm5510]

For some reason, the latest release of YAFU will run on my i7 system, but not a Xeon I have. Both Windows 10 and 16 GB of RAM.

It displays its title screen and some other info then drops back to the command prompt. No error messages.

[James Heinrich]

Originally Posted by storm5510

i7 system, but not a Xeon I have

"i7" and "Xeon" are both nebulous descriptors that could describe any number of CPUs over decades. Perhaps specific model numbers would provide more of a clue as to perhaps which features are not supported on your "Xeon".