aboutsummaryrefslogtreecommitdiff
path: root/rand/rand_xoshiro/src/xoshiro512plus.rs
diff options
context:
space:
mode:
Diffstat (limited to 'rand/rand_xoshiro/src/xoshiro512plus.rs')
-rw-r--r--rand/rand_xoshiro/src/xoshiro512plus.rs122
1 files changed, 0 insertions, 122 deletions
diff --git a/rand/rand_xoshiro/src/xoshiro512plus.rs b/rand/rand_xoshiro/src/xoshiro512plus.rs
deleted file mode 100644
index 4b589f2..0000000
--- a/rand/rand_xoshiro/src/xoshiro512plus.rs
+++ /dev/null
@@ -1,122 +0,0 @@
-// Copyright 2018 Developers of the Rand project.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-#[cfg(feature="serde1")] use serde::{Serialize, Deserialize};
-use rand_core::impls::fill_bytes_via_next;
-use rand_core::le::read_u64_into;
-use rand_core::{SeedableRng, RngCore, Error};
-
-use crate::Seed512;
-
-/// A xoshiro512+ random number generator.
-///
-/// The xoshiro512+ algorithm is not suitable for cryptographic purposes, but
-/// is very fast and has good statistical properties, besides a low linear
-/// complexity in the lowest bits.
-///
-/// The algorithm used here is translated from [the `xoshiro512plus.c`
-/// reference source code](http://xoshiro.di.unimi.it/xoshiro512plus.c) by
-/// David Blackman and Sebastiano Vigna.
-#[derive(Debug, Clone)]
-#[cfg_attr(feature="serde1", derive(Serialize, Deserialize))]
-pub struct Xoshiro512Plus {
- s: [u64; 8],
-}
-
-impl Xoshiro512Plus {
- /// Jump forward, equivalently to 2^256 calls to `next_u64()`.
- ///
- /// This can be used to generate 2^256 non-overlapping subsequences for
- /// parallel computations.
- ///
- /// ```
- /// use rand_xoshiro::rand_core::SeedableRng;
- /// use rand_xoshiro::Xoshiro512Plus;
- ///
- /// let rng1 = Xoshiro512Plus::seed_from_u64(0);
- /// let mut rng2 = rng1.clone();
- /// rng2.jump();
- /// let mut rng3 = rng2.clone();
- /// rng3.jump();
- /// ```
- pub fn jump(&mut self) {
- impl_jump!(u64, self, [
- 0x33ed89b6e7a353f9, 0x760083d7955323be, 0x2837f2fbb5f22fae,
- 0x4b8c5674d309511c, 0xb11ac47a7ba28c25, 0xf1be7667092bcc1c,
- 0x53851efdb6df0aaf, 0x1ebbc8b23eaf25db
- ]);
- }
-}
-
-impl SeedableRng for Xoshiro512Plus {
- type Seed = Seed512;
-
- /// Create a new `Xoshiro512Plus`. If `seed` is entirely 0, it will be
- /// mapped to a different seed.
- #[inline]
- fn from_seed(seed: Seed512) -> Xoshiro512Plus {
- deal_with_zero_seed!(seed, Self);
- let mut state = [0; 8];
- read_u64_into(&seed.0, &mut state);
- Xoshiro512Plus { s: state }
- }
-
- /// Seed a `Xoshiro512Plus` from a `u64` using `SplitMix64`.
- fn seed_from_u64(seed: u64) -> Xoshiro512Plus {
- from_splitmix!(seed)
- }
-}
-
-impl RngCore for Xoshiro512Plus {
- #[inline]
- fn next_u32(&mut self) -> u32 {
- self.next_u64() as u32
- }
-
- #[inline]
- fn next_u64(&mut self) -> u64 {
- let result_plus = self.s[0].wrapping_add(self.s[2]);
- impl_xoshiro_large!(self);
- result_plus
- }
-
- #[inline]
- fn fill_bytes(&mut self, dest: &mut [u8]) {
- fill_bytes_via_next(self, dest);
- }
-
- #[inline]
- fn try_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), Error> {
- self.fill_bytes(dest);
- Ok(())
- }
-}
-
-#[cfg(test)]
-mod tests {
- use super::*;
-
- #[test]
- fn reference() {
- let mut rng = Xoshiro512Plus::from_seed(Seed512(
- [1, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0,
- 3, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0, 0,
- 5, 0, 0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 0,
- 7, 0, 0, 0, 0, 0, 0, 0, 8, 0, 0, 0, 0, 0, 0, 0]));
- // These values were produced with the reference implementation:
- // http://xoshiro.di.unimi.it/xoshiro512plus.c
- let expected = [
- 4, 8, 4113, 25169936, 52776585412635, 57174648719367,
- 9223482039571869716, 9331471677901559830, 9340533895746033672,
- 14078399799840753678,
- ];
- for &e in &expected {
- assert_eq!(rng.next_u64(), e);
- }
- }
-}