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Diffstat (limited to 'rand/rand_pcg/src/pcg64.rs')
-rw-r--r--rand/rand_pcg/src/pcg64.rs26
1 files changed, 6 insertions, 20 deletions
diff --git a/rand/rand_pcg/src/pcg64.rs b/rand/rand_pcg/src/pcg64.rs
index 9177ec2..fadc6dc 100644
--- a/rand/rand_pcg/src/pcg64.rs
+++ b/rand/rand_pcg/src/pcg64.rs
@@ -11,8 +11,8 @@
//! PCG random number generators
use core::fmt;
-use core::mem::transmute;
use rand_core::{RngCore, SeedableRng, Error, le, impls};
+#[cfg(feature="serde1")] use serde::{Serialize, Deserialize};
// This is the default multiplier used by PCG for 64-bit state.
const MULTIPLIER: u64 = 6364136223846793005;
@@ -45,7 +45,8 @@ impl Lcg64Xsh32 {
/// Note that PCG specifies default values for both parameters:
///
/// - `state = 0xcafef00dd15ea5e5`
- /// - `stream = 721347520444481703`
+ /// - `stream = 0xa02bdbf7bb3c0a7`
+ // Note: stream is 1442695040888963407u64 >> 1
pub fn new(state: u64, stream: u64) -> Self {
// The increment must be odd, hence we discard one bit:
let increment = (stream << 1) | 1;
@@ -115,27 +116,12 @@ impl RngCore for Lcg64Xsh32 {
#[inline]
fn fill_bytes(&mut self, dest: &mut [u8]) {
- // specialisation of impls::fill_bytes_via_next; approx 40% faster
- let mut left = dest;
- while left.len() >= 4 {
- let (l, r) = {left}.split_at_mut(4);
- left = r;
- let chunk: [u8; 4] = unsafe {
- transmute(self.next_u32().to_le())
- };
- l.copy_from_slice(&chunk);
- }
- let n = left.len();
- if n > 0 {
- let chunk: [u8; 4] = unsafe {
- transmute(self.next_u32().to_le())
- };
- left.copy_from_slice(&chunk[..n]);
- }
+ impls::fill_bytes_via_next(self, dest)
}
#[inline]
fn try_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), Error> {
- Ok(self.fill_bytes(dest))
+ self.fill_bytes(dest);
+ Ok(())
}
}