Integer maths > 16 bits

[MathMan]

...

In the interim, I've put this at the top of int128.pas to decouple the checks it uses internally from the rest of the project.

Code: Pascal  [Select][+][-]

1. {$ifdef CHECK_INT128 }
2.   {$rangechecks on}
3.   {$overflowchecks on }
4. {$else }
5.   {$rangechecks off}
6.   {$overflowchecks off }
7. {$endif }
8.  

I'd also note that I'm defining USE_FPC64 and USE_INT128 at the project level. I might remove the first of those after I've checked the situation on the RPi Pico etc., although that definitely won't be this week.

MarkMLl

My current estimate is ~4 weeks to integrate all we discussed so far

 - implement the missing signed stuff
 - replicate everything for the unchecked types
 - add DivMod, MulMod & PwrMod
 - tidy everything, improve comments & add a short manual

If I shuffle a bit and start with adding the unchecked unsigned type for +, -, *, div and mod I may be able to provide an interim around next week, fitting to your schedule. Pls let me know if you'd like to have that - otherwise I'll stick to the sequence above.

MathMan

[MarkMLl]

/Definitely/ stick to your own time. I've found a few glitches in my code which I'm in the middle of fixing (including one place where the compiler was going recursive on my 128-bit implementation of HexStr(), even if the parameter was cast to a qword) and will post an update over the next day or so, but after that I've got plenty else to get on with.

MarkMLl

[MarkMLl]

Updated version attached. 16-, 32-, 64- and 128-bit words work, obviously turning off runtime checks and increasing the optimisation level (although the RTL I'm using is unoptimised) speeds things up:

Code: Text  [Select][+][-]

1. $ time ./Hash16Demo-x86_64-linux
2. Internal check: primality tests passed
3. Internal check: passphrase hashing passed
4. Difference: DD7B 1101110101111011 12
5. real    0m0.001s
6. user    0m0.001s
7. sys     0m0.000s
8.  
9. $ time ./Hash32Demo-x86_64-linux
10. Internal check: primality tests passed
11. Internal check: passphrase hashing passed
12. Difference: 8EBB1617 10001110101110110001011000010111 17
13. real    0m0.001s
14. user    0m0.001s
15. sys     0m0.000s
16.  
17. $ time ./Hash64Demo-x86_64-linux
18. Internal check: primality tests passed
19. Internal check: passphrase hashing passed
20. Difference: 4A450DE35FE54A5F 0100101001000101000011011110001101011111111001010100101001011111 34
21. real    0m9.346s
22. user    0m9.341s
23. sys     0m0.004s
24.  
25. $ time ./Hash128Demo-x86_64-linux
26. Internal check: primality tests passed
27. Internal check: passphrase hashing passed
28. Difference: F020AB06A60C27202257A1C7AEB1D5C9 11110000001000001010101100000110101001100000110000100111001000000010001001010111101000011100011110101110101100011101010111001001 56
29. real    227m22.372s
30. user    227m16.241s
31. sys     0m1.208s
32.  

If assertions are enabled there are internal tests of prime number handling, followed by hashing a short password and looking for the nearest prime: predictably, it is there that the time is being spent (and I am /not/ complaining about that, since the prime checker is fairly naive and there are obvious ways it could be improved).

If INTERNALTEST is defined and there are no commandline parameters the program will hash two passphrases and find the number of bits by which they differ (Hamming distance?) which is what's being displayed above; ideally that would be half the wordsize.

Contributed as test code with the hope that it is useful to somebody, or at least a source of mirth :-)

MarkMLl