xorshift32 matrix demo

xorshift32.py

import numpy as np

M = None

def xorshift32(x):
    x ^= (x << 13) & 0xFFFFFFFF
    x ^= x >> 17
    x ^= (x << 5) & 0xFFFFFFFF
    return x


def int_to_bitvec(x, n=32):
    """
    [低位, ..., 高位]
    """
    return np.array([(x >> i) & 1 for i in range(n)], dtype=np.uint8)


def bitvec_to_int(v):
    return sum([v[i] << i for i in range(len(v))])


def get_M():
    """
    k < 0, left shift, top change 0 means Little -> 0
    k > 0, right shift, bottom change 0 High -> 0
    """
    I = np.eye(32, dtype=np.uint32)
    M_a = np.diag(I.diagonal()[:19], k=-13)

    M_b = np.diag(I.diagonal()[:15], k=17)
    M_c = np.diag(I.diagonal()[:27], k=-5)
    Ma = (I + M_a) % 2
    Mb = (I + M_b) % 2
    Mc = (I + M_c) % 2
    return np.mod(Mc @ np.mod(Mb @ Ma, 2), 2)


def matrix_demo_xorshift32(x):
    global M
    if M is None:
        M = get_M()
    x_vec = int_to_bitvec(x)
    x_next_vec = np.mod(M @ x_vec, 2)
    return bitvec_to_int(x_next_vec)


if __name__ == "__main__":
    for i in range(100, 1000):
        print(matrix_demo_xorshift32(i) == xorshift32(i))