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Diffstat (limited to 'vendor/rand-0.7.3/src/distributions/integer.rs')
-rw-r--r-- | vendor/rand-0.7.3/src/distributions/integer.rs | 279 |
1 files changed, 279 insertions, 0 deletions
diff --git a/vendor/rand-0.7.3/src/distributions/integer.rs b/vendor/rand-0.7.3/src/distributions/integer.rs new file mode 100644 index 000000000..f2db1f1c6 --- /dev/null +++ b/vendor/rand-0.7.3/src/distributions/integer.rs @@ -0,0 +1,279 @@ +// 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 = "nightly"))] use core::arch::x86::*; +#[cfg(all(target_arch = "x86_64", feature = "nightly"))] +use core::arch::x86_64::*; +#[cfg(not(target_os = "emscripten"))] use core::num::NonZeroU128; +use core::num::{NonZeroU16, NonZeroU32, NonZeroU64, NonZeroU8, NonZeroUsize}; +#[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() + } +} + +#[cfg(not(target_os = "emscripten"))] +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 $ty + } + } + }; +} + +impl_int_from_uint! { i8, u8 } +impl_int_from_uint! { i16, u16 } +impl_int_from_uint! { i32, u32 } +impl_int_from_uint! { i64, u64 } +#[cfg(not(target_os = "emscripten"))] +impl_int_from_uint! { i128, u128 } +impl_int_from_uint! { isize, usize } + +macro_rules! impl_nzint { + ($ty:ty, $new:path) => { + impl Distribution<$ty> for Standard { + fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> $ty { + loop { + if let Some(nz) = $new(rng.gen()) { + break nz; + } + } + } + } + }; +} + +impl_nzint!(NonZeroU8, NonZeroU8::new); +impl_nzint!(NonZeroU16, NonZeroU16::new); +impl_nzint!(NonZeroU32, NonZeroU32::new); +impl_nzint!(NonZeroU64, NonZeroU64::new); +#[cfg(not(target_os = "emscripten"))] +impl_nzint!(NonZeroU128, NonZeroU128::new); +impl_nzint!(NonZeroUsize, NonZeroUsize::new); + +#[cfg(feature = "simd_support")] +macro_rules! simd_impl { + ($(($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", + feature = "nightly", + any(target_arch = "x86", target_arch = "x86_64") +))] +simd_impl!((__m64, u8x8), (__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); + #[cfg(not(target_os = "emscripten"))] + rng.sample::<i128, _>(Standard); + + rng.sample::<usize, _>(Standard); + rng.sample::<u8, _>(Standard); + rng.sample::<u16, _>(Standard); + rng.sample::<u32, _>(Standard); + rng.sample::<u64, _>(Standard); + #[cfg(not(target_os = "emscripten"))] + 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, + ), + ]); + } + } +} |