pcg.jl

@inline function rotr(x,y)
    s = sizeof(x) << 3
    (x >> (y % s)) | (x << (-y % s))
end


function foo(state, n)   
    s = sizeof(state) << 3
    t = trailing_zeros(s)-1 # log2(s)-1
    p1 = (s>>1 + t)>>1
    p2 = s>>1 - t
    p3 = s-t
    
    y = UInt64(0)
    for i = 1:n
        x = rotr(
                 (((state >> p1) $ state) >> p2) % UInt32,
                 (state >> p3) % UInt32
                 )        

        state = state * 0x5851f42d4c957f2d + 0x000000000000006d

        y += x
    end
    return y
end

@time foo(0x185706b82c2e03f8, 10_000_000)


using RNG.PCG
r = PermutedCongruentialGenerator(PCGStateSetseq, PCG_XSH_RR, UInt64)

function bar(r,n)
    y = UInt64(0)
    for i = 1:n
        y += UInt64(rand(r,UInt32))
    end
    y
end

srand(r, (42 % UInt64, 54 % UInt64))
@time bar(r,10_000_000)