[i2om3r]

> The same [1] claims in "Visual Summary" that the "cycles/byte" is 1 for various PRNGs but http://xoshiro.di.unimi.it/ seems to show that the reason splitmix64 is not preferred everywhere is that xoroshiro128+ is roughly two times faster than splitmix64 .

I have tested xoroshiro128+ vs splitmix64 in several procedural generation & simulation code bases in C and Swift. I could never confirm the numbers on http://xoshiro.di.unimi.it/. In fact, splitmix64 was slightly faster in all my tests with different optimizations enabled. I always assumed that's because its state only occupies a single register which certainly matters in practical applications (especially in C with its restricted calling conventions). I am not absolutely sure whether that was always the reason, though.