mtsieve

[rogue]

Originally Posted by ryanp

I'm also seeing a segfault with an existing build of xyyxsievecl:

$ ./xyyxsievecl -i ./cand.txt  -o newterms.txt -P 1e11 -G 16 -g 16 -M 1000000
xyyxsieve v1.8.1, a program to find factors numbers of the form x^y+y^x or x^y-y^x
Segmentation fault (core dumped)

I have committed a code change and an update to the makefile. So if you are interesting in "giving it a spin", please do so. I think it should be faster than the version you are using now. The main difference is that since the range of x and y exceed the number of actual candidates, it will store the list of candidates differently and iterate thru them differently. Unfortunately there is no great way to optimize the sieving based upon the input.

[rogue]

Originally Posted by storm5510

The issue I mentioned with v1.7 of srsieve2 seems to continue. I can create a new sieve by using the -s switch in the proper form. If I use that output as in input using -i to elevate the levels of P, then it will drop out to the prompt. I should be able to work up a sample, if you would like.

Edit: This happens on the Riesel side only.

This will run properly:

srsieve2 -n100e3 -N250e3 -p3 -P1e9 -W7 -r -s"2444*45^n+1" -o1e9.abcd
srsieve2 -p1e9 -P5e9 -W7 -r -i1e9.abcd -o5e9.abcd

This will not:

srsieve2 -n3 -N100e3 -p3 -P1e9 -W7 -s"22*173^n-1" -o1e9.abcd

I will stick with v1.6.9 for now.

I cannot reproduce this. Did you use the version in the mtsieve 2.4.7 or the stand-alone one?

srsieve2 -n3 -N100e3 -p3 -P1e9 -W7 -s"22*173^n-1" -o1e9.abcd
srsieve2 v1.7, a program to find factors of k*b^n+c numbers for fixed b and variable k and n
Sieving with generic logic for p >= 3
Sieve started: 3 < p < 1e9 with 99998 terms (3 <= n <= 100000, k*173^n-1) (expecting 94697 factors)
Sieving with single sequence c=1 logic for p >= 257
BASE_MULTIPLE = 30, POWER_RESIDUE_LCM = 720, LIMIT_BASE = 720
Split 1 base 173 sequence into 15 base 173^60 sequences.
Legendre summary:  Approximately 952 bytes needed for Legendre tables
         ... removed ...
Increasing worksize to 2000000 since each chunk is tested in less than a second
Sieve completed at p=1026219533.
CPU time: 48.14 sec. (0.47 sieving) (4.84 cores)
3384 terms written to 1e9.abcd
Primes tested: 50847327.  Factors found: 96614.  Remaining terms: 3384.  Time: 9.95 seconds.

srsieve2 -n3 -N100e3 -p3 -P1e9 -W7 -s"22*173^n+1" -o1e9.abcd
srsieve2 v1.7, a program to find factors of k*b^n+c numbers for fixed b and variable k and n
Sieving with generic logic for p >= 3
Sieve started: 3 < p < 1e9 with 99998 terms (3 <= n <= 100000, k*173^n+1) (expecting 94697 factors)
Sieving with single sequence c=1 logic for p >= 257
BASE_MULTIPLE = 30, POWER_RESIDUE_LCM = 720, LIMIT_BASE = 720
Split 1 base 173 sequence into 27 base 173^60 sequences.
Legendre summary:  Approximately 6 bytes needed for Legendre tables
         ... removed ...
Increasing worksize to 2000000 since each chunk is tested in less than a second
Sieve completed at p=1000000007.
CPU time: 57.88 sec. (0.48 sieving) (4.91 cores)
7644 terms written to 1e9.abcd
Primes tested: 50847326.  Factors found: 92354.  Remaining terms: 7644.  Time: 11.79 seconds.

[storm5510]

Originally Posted by rogue

I cannot reproduce this. Did you use the version in the mtsieve 2.4.7 or the stand-alone one?

It is the one packaged with the srbsieve archive with an internal date of 5/24/2023. The one within mtsieve 2.4.7 has an internal date of 4/13/2023. I look at these with the file properties. Extracting them changes the visible date stamp in the file explorer. I honestly can't say if I ever tried the latter.

[rogue]

There is mtsieve_2.4.6.7z and mtsieve_2.4.7.7z. 2.4.7 is the latest and is the one I ran without an issue.

[storm5510]

Originally Posted by rogue

There is mtsieve_2.4.6.7z and mtsieve_2.4.7.7z. 2.4.7 is the latest and is the one I ran without an issue.

Now, I cannot reproduce it.

The one I mentioned from April is v1.6.9, so scrap that one.

An srbsieve_1.3 archive containing 21 files and mtsieve v2.4.7 both have srsieve2 in them. The date stamps are one day apart even though the file lengths are the same.

I think I will just wait and see if this happens again.

[rogue]

Originally Posted by storm5510

Now, I cannot reproduce it.

The one I mentioned from April is v1.6.9, so scrap that one.

An srbsieve_1.3 archive containing 21 files and mtsieve v2.4.7 both have srsieve2 in them. The date stamps are one day apart even though the file lengths are the same.

I think I will just wait and see if this happens again.

I removed the standalone one. I released separately because it wasn't fully ready.

[storm5510]

Originally Posted by rogue

I removed the standalone one. I released separately because it wasn't fully ready.

The standalone? You mean the one in the mtsieve package?

I started a new sieve yesterday evening. I have been using the v1.7 from the srbsieve_1.3 archive. No problems whatsoever.

[rogue]

Originally Posted by storm5510

The standalone? You mean the one in the mtsieve package?

I started a new sieve yesterday evening. I have been using the v1.7 from the srbsieve_1.3 archive. No problems whatsoever.

That srsieve2 is current. If I included in the srbsieve package, then I made a mistake.

[rogue]

mtsieve 2.4.8 is released. Here are the changes:

fbncsieve: version 1.7
   No longer remove even k for base 2.
   Ensure that odd bases only report even k that are removed.
   Ignore factors for terms where k is outside of specified range.
   
xyyxsieve/xyyxsievecl: version 2.0
   If the range of x or the range of y is greater than the number of candidates,
   then different logic is used to manage the candidates and iterate over them.

Various bugs where reported with fbncsieve 1.6.x. Don't use that version.

[pepi37]

Can you write ( inside mtsieve package) small program that will show is alg factors in specific sequence ( that user choose) and write small report like number of alg factors?
That can be used for confirming there is no alg factors left in seqeunce

[pepi37]

srsieve2 ( from last package 2.4.8)
If I try to apply factors I got error

Fatal Error: Invalid factor: 16*767^504684+1 mod 10994911890479476681 = 8563234858453284832
Fatal Error: Invalid factor: 4*767^500350+1 mod 18446744073709551615 = 2

Factor are confirmed
(16*767^504684+1)%10994911890479476681 is Zero (0)
(4*767^500350+1)%367677432715278443521 is Zero (0)