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Just a test

A project log for PEAC Pisano with End-Around Carry algorithm

Add X to Y and Y to X, says the song. And carry on.

Yann Guidon / YGDESYann Guidon / YGDES 07/18/2021 at 02:210 Comments

While trying to estimate the size of the complete set of arc data for w32, I wrote dispatch_02.c and let it run for a minute or so...

$ gcc -Wall -DWIDTH=32 -Os dispatch_02.c -o dispatch && ./dispatch
Run on W32 from 42 to 1500
   42 -> X=2656939159   N=5996278162 l=5
   43 -> X=2529572078   N=1751451951 l=5
   44 -> X=4217682635   N=9651841000 l=5
   45 -> X= 528636580   N=9545525216 l=5
   46 -> X= 626411012   N=855984539 l=5
   47 -> X=1331873985   N=1897705442 l=5
   48 -> X=3644464132   N=2553832670 l=5
   49 -> X= 955492511   N=2834782532 l=5
   50 -> X=2905244640   N=10158815173 l=5
   51 -> X=3977561810   N=570944009 l=5
   52 -> X=1285427445   N=1916254633 l=5
   53 -> X=2722001243   N=8057574457 l=5
   54 -> X=1572286052   N=2556104354 l=5
   55 -> X=1183375166   N=3596834417 l=5
   56 -> X=1423688005   N=2467949744 l=5
   57 -> X=1992353645   N=1488849858 l=5
   58 -> X= 208628631   N=3750365940 l=5
   59 -> X=3057416295   N=269839798 l=5
   60 -> X=3795627370   N=5996278162 l=5
   61 -> X=2510464790   N=251891606 l=4
   62 -> X=1770417005   N=8459247511 l=5
   63 -> X= 740091212   N=9545525216 l=5
   64 -> X=3908705066   N=691897578 l=5
   65 -> X=2100730390   N=3511641358 l=5
   66 -> X=4175190107   N=5996278162 l=5
   67 -> X=3476866509   N=1904497197 l=5
   68 -> X=1024457701   N=3162422531 l=5
   69 -> X= 939616518   N=855984539 l=5
   70 -> X=1593588803   N=5245804944 l=5
   71 -> X=  21251938   N=1049143365 l=5
   72 -> X=  53655981   N=5873919413 l=5
^C

Using a MIDI-like "variable length code", I see an average of 5 bytes of the size of an arc.

This means that 4Gi arcs × (4+5 bytes) = about 40GB, not including duplicates for verifications. The file(s) may be streamed, but the tabulation will require more than 64GB of RAM.

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