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 Showing results 1 to 25 of 1000 Search took 0.42 seconds. Search: Posts Made By: bsquared
 Forum: Puzzles 2020-08-06, 20:42 Replies: 27 Views: 885 Posted By bsquared I see that you are finding a short addition chain... I see that you are finding a short addition chain using the x^(2^k) elements that will be computed anyway during the test. That's a very nice approach. As mentioned, the short addition chain...
 Forum: Puzzles 2020-08-06, 18:59 Replies: 27 Views: 885 Posted By bsquared Maybe also relevant to mention that the problem... Maybe also relevant to mention that the problem of finding the shortest addition chain for a given binary string is known to be NP-hard (section 14.102 in HOAC). But you'd only have to do it once...
 Forum: Puzzles 2020-08-06, 18:44 Replies: 27 Views: 885 Posted By bsquared I'm just looking for ways to minimize the number... I'm just looking for ways to minimize the number of multiplications in a modular exponentiation x^N mod M. In the handbook of applied cryptography (http://cacr.uwaterloo.ca/hac/about/chap14.pdf),...
 Forum: Hardware 2020-08-06, 18:13 Replies: 31 Views: 609 Posted By bsquared Maybe not as cheap as you think :smile:. If... Maybe not as cheap as you think :smile:. If the sand is mosly quartz with a density of 2.65 g/cm^3, then you have around 9433 cm^3 of sand. With a 250 micron grain size you'd only have around 600...
 Forum: Puzzles 2020-08-06, 17:11 Replies: 27 Views: 885 Posted By bsquared If it is possible/cheap to compute 3^-1 mod M,... If it is possible/cheap to compute 3^-1 mod M, then it is possible to do even a little better by first recoding the exponent in signed representation {-1, 0, 1}. powersmooth(1000000) has 1442080...
 Forum: Lounge 2020-07-27, 15:03 Replies: 16 Views: 377 Posted By bsquared I ran into this luna moth while camping last... I ran into this luna moth while camping last month. I'd never seen one this close up before. It was pretty big - maybe 5 inches wingtip to wingtip.
 Forum: Lounge 2020-07-23, 12:44 Replies: 91 Views: 5,827 Posted By bsquared Congratulations, and nice pictures! I hope to do... Congratulations, and nice pictures! I hope to do that also someday.
 Forum: Programming 2020-07-23, 02:42 Replies: 14 Views: 588 Posted By bsquared Agreed, it's not a good benchmark. The OP asked... Agreed, it's not a good benchmark. The OP asked for a way to multiply 64-bit unsigned ints and he now has several things to try. I assumed he will use them in his application to figure out which is...
 Forum: Programming 2020-07-22, 15:48 Replies: 14 Views: 588 Posted By bsquared As far as I can see from objdump, yes (except the... As far as I can see from objdump, yes (except the one usage of mulx).
 Forum: Programming 2020-07-22, 14:56 Replies: 14 Views: 588 Posted By bsquared Yeah, macros may integrate better into the rest... Yeah, macros may integrate better into the rest of the code. However, for this simple benchmark loop: for (i = 0; i < 1000000000; i++) { c = mulx64(a, b, &d); a = c; b = d; }
 Forum: Programming 2020-07-22, 13:25 Replies: 14 Views: 588 Posted By bsquared Try: __inline uint64_t mul64(uint64_t x,... Try: __inline uint64_t mul64(uint64_t x, uint64_t y, uint64_t* hi) { __asm__( "mulq %3 \n\t" : "=&a"(x), "=&d"(y) : "0"(x), "1"(y) : "cc" ); *hi...
 Forum: YAFU 2020-07-10, 01:14 Replies: 2 Views: 274 Posted By bsquared Yes, use -pretest Yes, use -pretest
 Forum: Factoring 2020-06-29, 23:11 Replies: 10 Views: 800 Posted By bsquared For the C100, this is not true; or at least, it... For the C100, this is not true; or at least, it is close enough to be worth discussing. For the others, of course you're right. But everyone discussing here knows that already; we are optimizing...
 Forum: Factoring 2020-06-29, 14:10 Replies: 10 Views: 800 Posted By bsquared Thanks! I have also been tinkering with the... Thanks! I have also been tinkering with the three large prime variation during this pandemic. I've mostly been focused on seeing if I can make QS faster in the upper end of the size range where...
 Forum: Factoring 2020-06-28, 03:06 Replies: 10 Views: 800 Posted By bsquared Congratulations, that's quite a feat! Can... Congratulations, that's quite a feat! Can you give a few more details? What were the large prime bounds? Do you have any more statistics on the cycles, e.g., the percentage that used a TLP? ...
 Forum: Puzzles 2020-06-25, 19:21 Replies: 16 Views: 1,678 Posted By bsquared It is yafu starting from a r381 (wip-branch). It is yafu starting from a r381 (wip-branch).
 Forum: Puzzles 2020-06-25, 13:25 Replies: 16 Views: 1,678 Posted By bsquared >> x=2^7* 5 * 23 * 127 * 659 * 53323 * 1876187 *... >> x=2^7* 5 * 23 * 127 * 659 * 53323 * 1876187 * 97544836889 * 665320793909 7998766649128898059663516612687535453720960 >> totient(x) 3031634148236289733373855928919180891127808 >> sigma(x,1)-x...
 Forum: Miscellaneous Math 2020-06-23, 20:48 Replies: 59 Views: 1,312 Posted By bsquared I agree with the first but my take on his... I agree with the first but my take on his "explanation" so far is that BillyB(x,0) = x. i.e., a thing of size x cut zero times remains size x. So BillyB(0,0) = 0 by that definition.  but...
 Forum: Msieve 2020-06-16, 19:52 Replies: 2 Views: 224 Posted By bsquared Yeah, I ran across this and came up with this... Yeah, I ran across this and came up with this fix: https://www.mersenneforum.org/showpost.php?p=540947&postcount=81 I suspect the problem comes about because of this from the gmp changelog: ...
 Forum: YAFU 2020-06-16, 16:08 Replies: 14 Views: 1,031 Posted By bsquared The CADO-as-a-black-box approach might not be too... The CADO-as-a-black-box approach might not be too bad to add to yafu... I really don't want to have to deal with param files, managing different stages, etc. But if someone already has good params...
 Forum: Factoring 2020-06-15, 20:28 Replies: 22 Views: 1,293 Posted By bsquared Yes, exactly. But I'm using 16-bit containers... Yes, exactly. But I'm using 16-bit containers for everything so overflow is a little trickier to handle. There are actually several different k's used in the p/2^k approximations as primes grow in...
 Forum: YAFU 2020-06-15, 19:04 Replies: 14 Views: 1,031 Posted By bsquared I saw this too. I think it has to do with blank... I saw this too. I think it has to do with blank lines in the .ini. I changed the ReadINI function to ignore these but the writeINI function that is called as part of tune did not get changed and...
 Forum: YAFU 2020-06-15, 18:51 Replies: 14 Views: 1,031 Posted By bsquared In my mind, the .ini file should be used to set... In my mind, the .ini file should be used to set *permanent* parameters. Things that you always need (for example the ecm path, ggnfs binary folder, and ecm pretesting preferences). Anything in the...
 Forum: Factoring 2020-06-15, 17:14 Replies: 22 Views: 1,293 Posted By bsquared By the way, I would recommend ignoring most of... By the way, I would recommend ignoring most of the optimization stuff I talked about until you address other things. I posted them mostly for reference. Till's list of things in post 15 and 16 are...
 Forum: Factoring 2020-06-15, 16:14 Replies: 22 Views: 1,293 Posted By bsquared Yafu uses a similar method, with the following... Yafu uses a similar method, with the following optimizations: 1) small primes (less than 256) are not sieved. A "zeroth" pass trial divides candidates by these small primes and there is a second...
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