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+// 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.
+
+/// Initialize a RNG from a `u64` seed using `SplitMix64`.
+macro_rules! from_splitmix {
+ ($seed:expr) => { {
+ let mut rng = ::SplitMix64::seed_from_u64($seed);
+ Self::from_rng(&mut rng).unwrap()
+ } }
+}
+
+/// Apply the ** scrambler used by some RNGs from the xoshiro family.
+macro_rules! starstar_u64 {
+ ($x:expr) => {
+ $x.wrapping_mul(5).rotate_left(7).wrapping_mul(9)
+ }
+}
+
+/// Apply the ** scrambler used by some RNGs from the xoshiro family.
+macro_rules! starstar_u32 {
+ ($x:expr) => {
+ $x.wrapping_mul(0x9E3779BB).rotate_left(5).wrapping_mul(5)
+ }
+}
+
+/// Implement a jump function for an RNG from the xoshiro family.
+macro_rules! impl_jump {
+ (u32, $self:expr, [$j0:expr, $j1:expr]) => {
+ const JUMP: [u32; 2] = [$j0, $j1];
+ let mut s0 = 0;
+ let mut s1 = 0;
+ for j in &JUMP {
+ for b in 0..32 {
+ if (j & 1 << b) != 0 {
+ s0 ^= $self.s0;
+ s1 ^= $self.s1;
+ }
+ $self.next_u32();
+ }
+ }
+ $self.s0 = s0;
+ $self.s1 = s1;
+ };
+ (u64, $self:expr, [$j0:expr, $j1:expr]) => {
+ const JUMP: [u64; 2] = [$j0, $j1];
+ let mut s0 = 0;
+ let mut s1 = 0;
+ for j in &JUMP {
+ for b in 0..64 {
+ if (j & 1 << b) != 0 {
+ s0 ^= $self.s0;
+ s1 ^= $self.s1;
+ }
+ $self.next_u64();
+ }
+ }
+ $self.s0 = s0;
+ $self.s1 = s1;
+ };
+ (u32, $self:expr, [$j0:expr, $j1:expr, $j2:expr, $j3:expr]) => {
+ const JUMP: [u32; 4] = [$j0, $j1, $j2, $j3];
+ let mut s0 = 0;
+ let mut s1 = 0;
+ let mut s2 = 0;
+ let mut s3 = 0;
+ for j in &JUMP {
+ for b in 0..32 {
+ if (j & 1 << b) != 0 {
+ s0 ^= $self.s[0];
+ s1 ^= $self.s[1];
+ s2 ^= $self.s[2];
+ s3 ^= $self.s[3];
+ }
+ $self.next_u32();
+ }
+ }
+ $self.s[0] = s0;
+ $self.s[1] = s1;
+ $self.s[2] = s2;
+ $self.s[3] = s3;
+ };
+ (u64, $self:expr, [$j0:expr, $j1:expr, $j2:expr, $j3:expr]) => {
+ const JUMP: [u64; 4] = [$j0, $j1, $j2, $j3];
+ let mut s0 = 0;
+ let mut s1 = 0;
+ let mut s2 = 0;
+ let mut s3 = 0;
+ for j in &JUMP {
+ for b in 0..64 {
+ if (j & 1 << b) != 0 {
+ s0 ^= $self.s[0];
+ s1 ^= $self.s[1];
+ s2 ^= $self.s[2];
+ s3 ^= $self.s[3];
+ }
+ $self.next_u64();
+ }
+ }
+ $self.s[0] = s0;
+ $self.s[1] = s1;
+ $self.s[2] = s2;
+ $self.s[3] = s3;
+ };
+ (u64, $self:expr, [$j0:expr, $j1:expr, $j2:expr, $j3:expr,
+ $j4:expr, $j5:expr, $j6:expr, $j7:expr]) => {
+ const JUMP: [u64; 8] = [$j0, $j1, $j2, $j3, $j4, $j5, $j6, $j7];
+ let mut s = [0; 8];
+ for j in &JUMP {
+ for b in 0..64 {
+ if (j & 1 << b) != 0 {
+ s[0] ^= $self.s[0];
+ s[1] ^= $self.s[1];
+ s[2] ^= $self.s[2];
+ s[3] ^= $self.s[3];
+ s[4] ^= $self.s[4];
+ s[5] ^= $self.s[5];
+ s[6] ^= $self.s[6];
+ s[7] ^= $self.s[7];
+ }
+ $self.next_u64();
+ }
+ }
+ $self.s = s;
+ };
+}
+
+/// Implement the xoroshiro iteration.
+macro_rules! impl_xoroshiro_u32 {
+ ($self:expr) => {
+ $self.s1 ^= $self.s0;
+ $self.s0 = $self.s0.rotate_left(26) ^ $self.s1 ^ ($self.s1 << 9);
+ $self.s1 = $self.s1.rotate_left(13);
+ }
+}
+
+/// Implement the xoroshiro iteration.
+macro_rules! impl_xoroshiro_u64 {
+ ($self:expr) => {
+ $self.s1 ^= $self.s0;
+ $self.s0 = $self.s0.rotate_left(24) ^ $self.s1 ^ ($self.s1 << 16);
+ $self.s1 = $self.s1.rotate_left(37);
+ }
+}
+
+/// Implement the xoshiro iteration for `u32` output.
+macro_rules! impl_xoshiro_u32 {
+ ($self:expr) => {
+ let t = $self.s[1] << 9;
+
+ $self.s[2] ^= $self.s[0];
+ $self.s[3] ^= $self.s[1];
+ $self.s[1] ^= $self.s[2];
+ $self.s[0] ^= $self.s[3];
+
+ $self.s[2] ^= t;
+
+ $self.s[3] = $self.s[3].rotate_left(11);
+ }
+}
+
+/// Implement the xoshiro iteration for `u64` output.
+macro_rules! impl_xoshiro_u64 {
+ ($self:expr) => {
+ let t = $self.s[1] << 17;
+
+ $self.s[2] ^= $self.s[0];
+ $self.s[3] ^= $self.s[1];
+ $self.s[1] ^= $self.s[2];
+ $self.s[0] ^= $self.s[3];
+
+ $self.s[2] ^= t;
+
+ $self.s[3] = $self.s[3].rotate_left(45);
+ }
+}
+
+/// Implement the large-state xoshiro iteration.
+macro_rules! impl_xoshiro_large {
+ ($self:expr) => {
+ let t = $self.s[1] << 11;
+
+ $self.s[2] ^= $self.s[0];
+ $self.s[5] ^= $self.s[1];
+ $self.s[1] ^= $self.s[2];
+ $self.s[7] ^= $self.s[3];
+ $self.s[3] ^= $self.s[4];
+ $self.s[4] ^= $self.s[5];
+ $self.s[0] ^= $self.s[6];
+ $self.s[6] ^= $self.s[7];
+
+ $self.s[6] ^= t;
+
+ $self.s[7] = $self.s[7].rotate_left(21);
+ }
+}
+
+/// Map an all-zero seed to a different one.
+macro_rules! deal_with_zero_seed {
+ ($seed:expr, $Self:ident) => {
+ if $seed.iter().all(|&x| x == 0) {
+ return $Self::seed_from_u64(0);
+ }
+ }
+}
+
+/// 512-bit seed for a generator.
+///
+/// This wrapper is necessary, because some traits required for a seed are not
+/// implemented on large arrays.
+#[derive(Clone)]
+pub struct Seed512(pub [u8; 64]);
+
+use core;
+impl Seed512 {
+ /// Return an iterator over the seed.
+ pub fn iter(&self) -> core::slice::Iter<u8> {
+ self.0.iter()
+ }
+}
+
+impl core::fmt::Debug for Seed512 {
+ fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
+ self.0[..].fmt(f)
+ }
+}
+
+impl Default for Seed512 {
+ fn default() -> Seed512 {
+ Seed512([0; 64])
+ }
+}
+
+impl AsMut<[u8]> for Seed512 {
+ fn as_mut(&mut self) -> &mut [u8] {
+ &mut self.0
+ }
+}
+
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