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Old 2006-05-06, 18:10   #34
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Quote:
Originally Posted by ewmayer
OK, let's move on to Master's level:

M12160287649628674460477464915995054973742562690104903778198683593

M24247014121478057345510500801908699603302763478708108175450119307
Hmmm... I got the previous results on a Win32 system. Mfactor compiled for Win32 (March 22nd 2006) doesn't seem to reach such versatility in fact it breaks apart with such numbers.

I got a
Code:
ERROR: Mul-by-10 overflows in convert_base10_char_uint64: Offending input string
 = 6402474964732639141992726042699227967823547816360093417216412199
ERROR: At line 1698 of file \Documents and Settings\mayer\Mlucas\util.c
Assertion failed: 0
Also, there are problems with exponents greater than 78 bits:

Code:
ERROR: log2(max factor) exceeds allowable limit of 78. Offending entry = 79.0000
00.
ERROR: At line 723 of file \Documents and Settings\mayer\Mlucas\factor.c
Assertion failed: 0
Maybe you already knew about this, anyway I'm tightened to Factor4 as long as a 32-bit fully functional version of Mfactor is out (hint! hint!).

Luigi (your best fan)
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Old 2006-05-06, 21:04   #35
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The release binaries of Mfactor only allow TF up to 96 bits (78 bits for the floating-point-based-mod versions built for Win32). There are build flags available to us developers (well, just me actually) that allow going deeper. I posted the above "challenges" as a way for you to exercise your code (and if you happened to find any factors in addition to the ones I posted, that would indicate a problem with one of codes.) I plan to release binaries of the multiword versions of Mfactor sometime this month, but need to do some code cleanup and additional tuning first.
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Old 2006-05-06, 21:36   #36
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Quote:
Originally Posted by ewmayer
The release binaries of Mfactor only allow TF up to 96 bits (78 bits for the floating-point-based-mod versions built for Win32). There are build flags available to us developers (well, just me actually) that allow going deeper. I posted the above "challenges" as a way for you to exercise your code (and if you happened to find any factors in addition to the ones I posted, that would indicate a problem with one of codes.) I plan to release binaries of the multiword versions of Mfactor sometime this month, but need to do some code cleanup and additional tuning first.
Thank you for the "challenge", in fact I found the last factor testing my new build with GMP 4.2.1, and the last Mersenne number is at 249.92 bits.

Don't feel pressed, Factor4 is far from your highly optimized code (it is written in plain C with no ASM macros, no tight loops and generalized in the choice of the variables length). it's slower but maybe a bit more "general purpose".

Could you point me to some links dealing with writing inline assembler with GCC? I just can't find out a good AT&T asm manual over the Internet...

Luigi
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Old 2006-05-07, 15:05   #37
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M24247014121478057345510500801908699603302763478708108175450119307 has a factor: 2079083331892761004876676951418337621569030224230467189523407626117207889809

Exponent tested up to k=50,073,599,652.

Luigi
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Old 2006-05-08, 16:01   #38
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Quote:
Originally Posted by ET_
Exponent tested up to k=50,073,599,652.
How long did that take, and on what kind of hardware?

Re. your question about gcc inline asm - I've only dabbled in that to the minimal extent necessary, and could use a good (and hopefully not too bloated - e.g. more along the lines of Kernighan/Ritchie and less like Stroustrup, by way of example) reference myself. Try googling "gcc inline assembly reference guide" and see if anything turns up (preferably in online-manual form) that seems to fit the bill.
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Old 2006-05-08, 18:51   #39
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Quote:
Originally Posted by ewmayer
Try googling "gcc inline assembly reference guide" and see if anything turns up (preferably in online-manual form) that seems to fit the bill.
Ditch the "reference guide" and this is the first link that comes up
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Old 2006-05-11, 18:27   #40
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Quote:
Originally Posted by ewmayer
How long did that take, and on what kind of hardware?
I didn't write it down, IIRC between 60 and 66 hours on an AMD64 3700+ with Windows XP 32-bit and GMP 4.2.1.

BTW, my sieve routines leave me with more trial divides than Mfactor. I think there should be some space for enhancements...

Quote:
Originally Posted by ewmayer
Re. your question about gcc inline asm [...] Try googling "gcc inline assembly reference guide" and see if anything turns up (preferably in online-manual form) that seems to fit the bill.
I found some documents and working on them... thanks!

Luigi

Last fiddled with by ET_ on 2006-05-11 at 18:29
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