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-rw-r--r--third_party/rust/rand/src/distributions/integer.rs274
1 files changed, 274 insertions, 0 deletions
diff --git a/third_party/rust/rand/src/distributions/integer.rs b/third_party/rust/rand/src/distributions/integer.rs
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+++ b/third_party/rust/rand/src/distributions/integer.rs
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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.
+
+//! The implementations of the `Standard` distribution for integer types.
+
+use crate::distributions::{Distribution, Standard};
+use crate::Rng;
+#[cfg(all(target_arch = "x86", feature = "simd_support"))]
+use core::arch::x86::{__m128i, __m256i};
+#[cfg(all(target_arch = "x86_64", feature = "simd_support"))]
+use core::arch::x86_64::{__m128i, __m256i};
+use core::num::{NonZeroU16, NonZeroU32, NonZeroU64, NonZeroU8, NonZeroUsize,
+ NonZeroU128};
+#[cfg(feature = "simd_support")] use packed_simd::*;
+
+impl Distribution<u8> for Standard {
+ #[inline]
+ fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> u8 {
+ rng.next_u32() as u8
+ }
+}
+
+impl Distribution<u16> for Standard {
+ #[inline]
+ fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> u16 {
+ rng.next_u32() as u16
+ }
+}
+
+impl Distribution<u32> for Standard {
+ #[inline]
+ fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> u32 {
+ rng.next_u32()
+ }
+}
+
+impl Distribution<u64> for Standard {
+ #[inline]
+ fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> u64 {
+ rng.next_u64()
+ }
+}
+
+impl Distribution<u128> for Standard {
+ #[inline]
+ fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> u128 {
+ // Use LE; we explicitly generate one value before the next.
+ let x = u128::from(rng.next_u64());
+ let y = u128::from(rng.next_u64());
+ (y << 64) | x
+ }
+}
+
+impl Distribution<usize> for Standard {
+ #[inline]
+ #[cfg(any(target_pointer_width = "32", target_pointer_width = "16"))]
+ fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> usize {
+ rng.next_u32() as usize
+ }
+
+ #[inline]
+ #[cfg(target_pointer_width = "64")]
+ fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> usize {
+ rng.next_u64() as usize
+ }
+}
+
+macro_rules! impl_int_from_uint {
+ ($ty:ty, $uty:ty) => {
+ impl Distribution<$ty> for Standard {
+ #[inline]
+ fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> $ty {
+ rng.gen::<$uty>() as $ty
+ }
+ }
+ };
+}
+
+impl_int_from_uint! { i8, u8 }
+impl_int_from_uint! { i16, u16 }
+impl_int_from_uint! { i32, u32 }
+impl_int_from_uint! { i64, u64 }
+impl_int_from_uint! { i128, u128 }
+impl_int_from_uint! { isize, usize }
+
+macro_rules! impl_nzint {
+ ($ty:ty, $new:path) => {
+ impl Distribution<$ty> for Standard {
+ fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> $ty {
+ loop {
+ if let Some(nz) = $new(rng.gen()) {
+ break nz;
+ }
+ }
+ }
+ }
+ };
+}
+
+impl_nzint!(NonZeroU8, NonZeroU8::new);
+impl_nzint!(NonZeroU16, NonZeroU16::new);
+impl_nzint!(NonZeroU32, NonZeroU32::new);
+impl_nzint!(NonZeroU64, NonZeroU64::new);
+impl_nzint!(NonZeroU128, NonZeroU128::new);
+impl_nzint!(NonZeroUsize, NonZeroUsize::new);
+
+#[cfg(feature = "simd_support")]
+macro_rules! simd_impl {
+ ($(($intrinsic:ident, $vec:ty),)+) => {$(
+ impl Distribution<$intrinsic> for Standard {
+ #[inline]
+ fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> $intrinsic {
+ $intrinsic::from_bits(rng.gen::<$vec>())
+ }
+ }
+ )+};
+
+ ($bits:expr,) => {};
+ ($bits:expr, $ty:ty, $($ty_more:ty,)*) => {
+ simd_impl!($bits, $($ty_more,)*);
+
+ impl Distribution<$ty> for Standard {
+ #[inline]
+ fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> $ty {
+ let mut vec: $ty = Default::default();
+ unsafe {
+ let ptr = &mut vec;
+ let b_ptr = &mut *(ptr as *mut $ty as *mut [u8; $bits/8]);
+ rng.fill_bytes(b_ptr);
+ }
+ vec.to_le()
+ }
+ }
+ };
+}
+
+#[cfg(feature = "simd_support")]
+simd_impl!(16, u8x2, i8x2,);
+#[cfg(feature = "simd_support")]
+simd_impl!(32, u8x4, i8x4, u16x2, i16x2,);
+#[cfg(feature = "simd_support")]
+simd_impl!(64, u8x8, i8x8, u16x4, i16x4, u32x2, i32x2,);
+#[cfg(feature = "simd_support")]
+simd_impl!(128, u8x16, i8x16, u16x8, i16x8, u32x4, i32x4, u64x2, i64x2,);
+#[cfg(feature = "simd_support")]
+simd_impl!(256, u8x32, i8x32, u16x16, i16x16, u32x8, i32x8, u64x4, i64x4,);
+#[cfg(feature = "simd_support")]
+simd_impl!(512, u8x64, i8x64, u16x32, i16x32, u32x16, i32x16, u64x8, i64x8,);
+#[cfg(all(
+ feature = "simd_support",
+ any(target_arch = "x86", target_arch = "x86_64")
+))]
+simd_impl!((__m128i, u8x16), (__m256i, u8x32),);
+
+#[cfg(test)]
+mod tests {
+ use super::*;
+
+ #[test]
+ fn test_integers() {
+ let mut rng = crate::test::rng(806);
+
+ rng.sample::<isize, _>(Standard);
+ rng.sample::<i8, _>(Standard);
+ rng.sample::<i16, _>(Standard);
+ rng.sample::<i32, _>(Standard);
+ rng.sample::<i64, _>(Standard);
+ rng.sample::<i128, _>(Standard);
+
+ rng.sample::<usize, _>(Standard);
+ rng.sample::<u8, _>(Standard);
+ rng.sample::<u16, _>(Standard);
+ rng.sample::<u32, _>(Standard);
+ rng.sample::<u64, _>(Standard);
+ rng.sample::<u128, _>(Standard);
+ }
+
+ #[test]
+ fn value_stability() {
+ fn test_samples<T: Copy + core::fmt::Debug + PartialEq>(zero: T, expected: &[T])
+ where Standard: Distribution<T> {
+ let mut rng = crate::test::rng(807);
+ let mut buf = [zero; 3];
+ for x in &mut buf {
+ *x = rng.sample(Standard);
+ }
+ assert_eq!(&buf, expected);
+ }
+
+ test_samples(0u8, &[9, 247, 111]);
+ test_samples(0u16, &[32265, 42999, 38255]);
+ test_samples(0u32, &[2220326409, 2575017975, 2018088303]);
+ test_samples(0u64, &[
+ 11059617991457472009,
+ 16096616328739788143,
+ 1487364411147516184,
+ ]);
+ test_samples(0u128, &[
+ 296930161868957086625409848350820761097,
+ 145644820879247630242265036535529306392,
+ 111087889832015897993126088499035356354,
+ ]);
+ #[cfg(any(target_pointer_width = "32", target_pointer_width = "16"))]
+ test_samples(0usize, &[2220326409, 2575017975, 2018088303]);
+ #[cfg(target_pointer_width = "64")]
+ test_samples(0usize, &[
+ 11059617991457472009,
+ 16096616328739788143,
+ 1487364411147516184,
+ ]);
+
+ test_samples(0i8, &[9, -9, 111]);
+ // Skip further i* types: they are simple reinterpretation of u* samples
+
+ #[cfg(feature = "simd_support")]
+ {
+ // We only test a sub-set of types here and make assumptions about the rest.
+
+ test_samples(u8x2::default(), &[
+ u8x2::new(9, 126),
+ u8x2::new(247, 167),
+ u8x2::new(111, 149),
+ ]);
+ test_samples(u8x4::default(), &[
+ u8x4::new(9, 126, 87, 132),
+ u8x4::new(247, 167, 123, 153),
+ u8x4::new(111, 149, 73, 120),
+ ]);
+ test_samples(u8x8::default(), &[
+ u8x8::new(9, 126, 87, 132, 247, 167, 123, 153),
+ u8x8::new(111, 149, 73, 120, 68, 171, 98, 223),
+ u8x8::new(24, 121, 1, 50, 13, 46, 164, 20),
+ ]);
+
+ test_samples(i64x8::default(), &[
+ i64x8::new(
+ -7387126082252079607,
+ -2350127744969763473,
+ 1487364411147516184,
+ 7895421560427121838,
+ 602190064936008898,
+ 6022086574635100741,
+ -5080089175222015595,
+ -4066367846667249123,
+ ),
+ i64x8::new(
+ 9180885022207963908,
+ 3095981199532211089,
+ 6586075293021332726,
+ 419343203796414657,
+ 3186951873057035255,
+ 5287129228749947252,
+ 444726432079249540,
+ -1587028029513790706,
+ ),
+ i64x8::new(
+ 6075236523189346388,
+ 1351763722368165432,
+ -6192309979959753740,
+ -7697775502176768592,
+ -4482022114172078123,
+ 7522501477800909500,
+ -1837258847956201231,
+ -586926753024886735,
+ ),
+ ]);
+ }
+ }
+}
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