20160525, 18:30  #133 
Sep 2013
2^{3}×7 Posts 
No disagreement here. I do not really want or need a start_string=<huge>.
In the absence of an offset I tried it as (non working) workaround. So waiting for lmin it is. 
20160525, 19:02  #134 
"Mark"
Apr 2003
Between here and the
2^{2}×5×17×19 Posts 
Hopefully I can get around to testing tonight, but I had to make a number of changes to the asm code, which I probably broke because I'm not an x86 asm expert. All I can say is that it compiles right now. My first attempt to test will be to make sure that I didn't break what it does right now. Then I get to test the harder stuff.
Last fiddled with by rogue on 20160525 at 19:03 
20160526, 00:27  #135 
"Mark"
Apr 2003
Between here and the
2^{2}·5·17·19 Posts 
Here is the latest, with source. I know this doesn't work because it crashes somewhere in the asm code. I do not know how easy the problem is to fix. Maybe someone with more asm experience than me can point out what I'm doing wrong.

20160527, 22:26  #136 
"Mark"
Apr 2003
Between here and the
1100100111100_{2} Posts 
I believe that I have found and fixed the bug. You can find the latest executable and source here. Although only a Windows build is included, it should build and run on Linux and OS X. Unfortunately it crashes on OS X and I don't know why yet, so I'm still investigating.
I have added the l parameter and I have added a N parameter to start a new sieve. Previously it used the existence of the index file to determine if a new sieve would be started. An example of the usage would be: Code:
pixsieve l40000 L50000 S20 P1e9 spi.txt iterms.txt Rterms.pfgw N Why pfgw 3.8? Previous versions of pfgw had a limit of 5000 characters for input strings. This means that it could not verify factors of numbers longer than that. I upped that limit to 5000000 characters. 
20160528, 00:41  #137 
"Mark"
Apr 2003
Between here and the
193C_{16} Posts 
The bug will affect linux too. It is no longer crashing as I found the cause, but the OS X build is missing factors where as the Windows build does not (based upon the testing I have done).

20160528, 10:06  #138 
Sep 2013
111000_{2} Posts 
Did some quick tests, found some bugs, unfortunately not
only cosmetic ones. pixs1 is old version (v0.1), pixs2 new one (v1.1), result file were deleted between runs. repeated runs with same input produce different results, multithreaded both versions, singlethreaded v1.1 too, not sure if v0.1 singlethreaded too sometime there are lines like p=30523395, 598.5K p/sec, 496 terms left, 61.0% done p=36397059, 1.573M p/sec, 490 terms left, 72.8% done Shouldn't p be prime? writing intermediate file, v0.1 to _idx (i), v1.1 to _NoF (R) v1.1 incorrect updates '...terms left', probably same bug as the one above v1.1 crashes without N, if there are no other files to continue from Sample outputs: Code:
t:\test>pixs1 sPi1M.txt S10 i_idx R_NoF f_fac L20000 P1e8 m1e9 r20 pixsieve version 0.1.0 (testing) Compiled May 14 2016 with GCC 4.9.2 Starting with 20000 terms 5285 terms remaining after removing terms divisible by 2, 3, and 5 Primes in X sieve initialized: n <= 20000 Sieve started: 3 <= p < 100000000 Thread 0 starting p=2019331, 100.9K p/sec, 1128 terms left, 2.0% done p=7032835, 250.5K p/sec, 1043 terms left, 7.0% done ... Wrote 899 terms to output file `_idx' p=85895171, 316.4K p/sec, 899 terms left, 85.9% done p=92274691, 318.7K p/sec, 895 terms left, 92.3% done p=98678787, 320.0K p/sec, 892 terms left, 98.7% done Thread 0 completed Waiting for threads to exit Wrote 890 terms to output file `_idx' Sieve complete: 3 <= p < 100000000 Found factors for 19110 terms, 890 remain count=5761454,sum=0x0000fdf0985fb44a Elapsed time: 344.53 sec. (0.02 init + 344.51 sieve) at 290272 p/sec. Processor time: 336.57 sec. (0.02 init + 336.56 sieve) at 297132 p/sec. Average processor utilization: 1.00 (init), 0.98 (sieve) t:\test>dir _* 28.05.2016 10:45 43.998.817 _fac 28.05.2016 10:45 5.743 _idx 28.05.2016 10:45 8.889.704 _NoF t:\test>pixs2 sPi1M.txt S10 i_idx R_NoF f_fac L20000 P1e8 m1e9 r20 N pixsieve version 1.1 (testing) Compiled May 27 2016 with GCC 4.9.2 Starting with 20000 terms 5285 terms remaining after removing ones divisible by 2, 3, and 5 Sieve started: 3 <= p < 100000000 Thread 0 starting p=1370115, 68.50K p/sec, 949 terms left, 1.4% done p=5648387, 213.8K p/sec, 943 terms left, 5.6% done ... Wrote 943 terms to output file `_NoF' p=67943427, 244.7K p/sec, 943 terms left, 67.9% done ... p=98286595, 254.8K p/sec, 943 terms left, 98.3% done Thread 0 completed Waiting for threads to exit Wrote 943 terms to output file `_NoF' Sieve complete: 3 <= p < 100000000 Found factors for 19057 terms, 943 remain count=5761454,sum=0x0000fdf0985fb44a Elapsed time: 427.01 sec. (0.01 init + 427.00 sieve) at 234195 p/sec. Processor time: 378.15 sec. (0.02 init + 378.13 sieve) at 264461 p/sec. Average processor utilization: 2.23 (init), 0.89 (sieve) t:\test>dir _* 28.05.2016 10:56 43.249.631 _fac 28.05.2016 11:03 6.095 _idx 28.05.2016 11:03 9.635.005 _NoF t:\test>pixs2 sPi1M.txt S10 i_idx R_NoF f_fac L20000 P1e8 m1e9 r20 N t4 pixsieve version 1.1 (testing) Compiled May 27 2016 with GCC 4.9.2 Starting with 20000 terms 5285 terms remaining after removing ones divisible by 2, 3, and 5 Sieve started: 3 <= p < 100000000 Thread 3 starting Thread 2 starting Thread 1 starting Thread 0 starting p=6845443, 342.2K p/sec, 946 terms left, 6.8% done p=24364035, 875.9K p/sec, 945 terms left, 24.4% done p=43248643, 944.2K p/sec, 945 terms left, 43.2% done p=63548419, 1.015M p/sec, 945 terms left, 63.5% done p=84314115, 1.038M p/sec, 945 terms left, 84.3% done Thread 3 completed Thread 0 completed Waiting for threads to exit Thread 2 completed Thread 1 completed Wrote 945 terms to output file `_NoF' Sieve complete: 3 <= p < 100000000 Found factors for 19055 terms, 945 remain count=5761454,sum=0x0000fdf0985fb44a Elapsed time: 114.96 sec. (0.01 init + 114.95 sieve) at 869931 p/sec. Processor time: 397.16 sec. (0.02 init + 397.15 sieve) at 251798 p/sec. Average processor utilization: 1.73 (init), 3.45 (sieve) t:\test>dir _* 28.05.2016 11:16 43.273.849 _fac 28.05.2016 11:17 6.108 _idx 28.05.2016 11:17 9.611.857 _NoF t:\test>pixs2 sPi1M.txt S10 i_idx R_NoF f_fac L20000 P1e8 m1e9 r20 N t4 pixsieve version 1.1 (testing) Compiled May 27 2016 with GCC 4.9.2 Starting with 20000 terms 5285 terms remaining after removing ones divisible by 2, 3, and 5 Sieve started: 3 <= p < 100000000 Thread 1 starting Thread 0 starting Thread 3 starting Thread 2 starting p=5359619, 267.7K p/sec, 943 terms left, 5.4% done p=22938627, 878.7K p/sec, 943 terms left, 22.9% done p=41423875, 923.2K p/sec, 943 terms left, 41.4% done p=60315651, 944.6K p/sec, 943 terms left, 60.3% done p=79875075, 977.9K p/sec, 943 terms left, 79.9% done p=99307523, 971.6K p/sec, 943 terms left, 99.3% done Thread 0 completed Thread 3 completed Thread 2 completed Waiting for threads to exit Thread 1 completed Wrote 943 terms to output file `_NoF' Sieve complete: 3 <= p < 100000000 Found factors for 19057 terms, 943 remain count=5761454,sum=0x0000fdf0985fb44a Elapsed time: 120.86 sec. (0.02 init + 120.84 sieve) at 827534 p/sec. Processor time: 397.05 sec. (0.00 init + 397.05 sieve) at 251857 p/sec. Average processor utilization: 0.00 (init), 3.29 (sieve) t:\test>dir _* 28.05.2016 11:46 43.301.860 _fac 28.05.2016 11:48 6.093 _idx 28.05.2016 11:48 9.583.830 _NoF 
20160528, 13:19  #139 
"Mark"
Apr 2003
Between here and the
2^{2}×5×17×19 Posts 
Very odd. I don't know how it could be testing p that are not prime, but I see that the original version did as well. I am uncertain how it could be missing factors. Maybe the old one was removing terms incorrectly. I'll have to do some runs. I'm also surprised that it is slower. It should be much faster. It was in the runs I did.

20160528, 14:18  #140  
Sep 2013
70_{8} Posts 
Quote:
runs, I'm not suprised that speed differs. Also, I guess changing background load (which I had) would mess with timings to some degree too. (I admit, I don't know how the runtime measurement works exactly, whether it's counting only that cpu cycles when the threads are really doing something, or to what extent it includes things like wait cycles for data from higher lvl cache/RAM etc.) 

20160528, 14:57  #141 
"Mark"
Apr 2003
Between here and the
193C_{16} Posts 
In doing some testing I found that the older version also misses factors. For that range you tested, there should only be 627 remaining terms. I remember yesterday fixing a bug with the original code that caused that, but the prime sieve issues might be just as big. Is it possible that some primes aren't being tested at all? Probably not, but I wonder how many numbers are being tested as divisors that aren't truly prime.
When I have some time I'm going to replace the prime number sieve with one that I know works. The one in this program originated years ago and was used by the original fpsieve. That leaves a bug in the new code that was intended to speed up testing of ranges when using the new l option. That code is likely responsible for the issues on the OS X build. When testing on Windows I ran into a very weird bug with gcc that I was able to work around, but maybe it doesn't work in all cases. Fortunately I have enough good data that I should be able to squash that bug when I have some time. 
20160531, 01:46  #142 
"Mark"
Apr 2003
Between here and the
2^{2}×5×17×19 Posts 
This is odd. I was reviewing the asm code and found that it was making some unnecessary comparisons. On the plus side, removing that code improved the performance of the application. In fact, it seems to be finding all of the factors on OS X right now, although I still have more testing to do. On the minus side, that same code does not behave in the same way on Windows and I don't know why, so it misses factors. Also on the minus side the OS X code crashes when it finishes the run, although I think that I figured that one out.

20160531, 16:53  #143 
"Serge"
Mar 2008
Phi(4,2^7658614+1)/2
2^{3}×1,201 Posts 
Incidentally, an interesting entry was added to PRPtop last month.
PIPrime(613373) (613373 digits, ...obviously)  Adrian Bondrescu 05/2016 
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