Mirror/aicodix___code
1
0
Fork 0
mirror of https://github.com/aicodix/code.git synced 2026-04-27 14:30:36 +00:00
Code Issues Projects Releases Packages Wiki Activity

added tool to find xorshift parameters

Browse source
This commit is contained in:
Ahmet Inan 2025-06-14 08:20:28 +02:00
commit 31458c0f56
1 changed files with 34 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

34
tools/xorshift.c Normal file
View file

@ -0,0 +1,34 @@
/*
Exhaustive search of xorshift parameters
Copyright 2025 Ahmet Inan <inan@aicodix.de>
*/
#include <stdio.h>
#include <stdlib.h>
int main(int argc, char **argv) {
if (argc != 2)
return 1;
int bits = atoi(argv[1]);
int mask = (1 << bits) - 1;
int seed = 1;
for (int a = 1; a < bits; ++a) {
for (int b = 1; b < bits; ++b) {
for (int c = 1; c < bits; ++c) {
int good = 1;
for (int y = seed, i = mask; good && i; --i) {
y ^= y << a;
y &= mask;
y ^= y >> b;
y ^= y << c;
y &= mask;
good &= (i == 1) == (y == seed);
}
if (good)
printf("%d %d %d\n", a, b, c);
}
}
}
return 0;
}