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Diffstat (limited to 'third_party/rust/num-integer/benches/average.rs')
-rw-r--r-- | third_party/rust/num-integer/benches/average.rs | 414 |
1 files changed, 414 insertions, 0 deletions
diff --git a/third_party/rust/num-integer/benches/average.rs b/third_party/rust/num-integer/benches/average.rs new file mode 100644 index 0000000000..649078c39d --- /dev/null +++ b/third_party/rust/num-integer/benches/average.rs @@ -0,0 +1,414 @@ +//! Benchmark sqrt and cbrt + +#![feature(test)] + +extern crate num_integer; +extern crate num_traits; +extern crate test; + +use num_integer::Integer; +use num_traits::{AsPrimitive, PrimInt, WrappingAdd, WrappingMul}; +use std::cmp::{max, min}; +use std::fmt::Debug; +use test::{black_box, Bencher}; + +// --- Utilities for RNG ---------------------------------------------------- + +trait BenchInteger: Integer + PrimInt + WrappingAdd + WrappingMul + 'static {} + +impl<T> BenchInteger for T where T: Integer + PrimInt + WrappingAdd + WrappingMul + 'static {} + +// Simple PRNG so we don't have to worry about rand compatibility +fn lcg<T>(x: T) -> T +where + u32: AsPrimitive<T>, + T: BenchInteger, +{ + // LCG parameters from Numerical Recipes + // (but we're applying it to arbitrary sizes) + const LCG_A: u32 = 1664525; + const LCG_C: u32 = 1013904223; + x.wrapping_mul(&LCG_A.as_()).wrapping_add(&LCG_C.as_()) +} + +// --- Alt. Implementations ------------------------------------------------- + +trait NaiveAverage { + fn naive_average_ceil(&self, other: &Self) -> Self; + fn naive_average_floor(&self, other: &Self) -> Self; +} + +trait UncheckedAverage { + fn unchecked_average_ceil(&self, other: &Self) -> Self; + fn unchecked_average_floor(&self, other: &Self) -> Self; +} + +trait ModuloAverage { + fn modulo_average_ceil(&self, other: &Self) -> Self; + fn modulo_average_floor(&self, other: &Self) -> Self; +} + +macro_rules! naive_average { + ($T:ident) => { + impl super::NaiveAverage for $T { + fn naive_average_floor(&self, other: &$T) -> $T { + match self.checked_add(*other) { + Some(z) => Integer::div_floor(&z, &2), + None => { + if self > other { + let diff = self - other; + other + Integer::div_floor(&diff, &2) + } else { + let diff = other - self; + self + Integer::div_floor(&diff, &2) + } + } + } + } + fn naive_average_ceil(&self, other: &$T) -> $T { + match self.checked_add(*other) { + Some(z) => Integer::div_ceil(&z, &2), + None => { + if self > other { + let diff = self - other; + self - Integer::div_floor(&diff, &2) + } else { + let diff = other - self; + other - Integer::div_floor(&diff, &2) + } + } + } + } + } + }; +} + +macro_rules! unchecked_average { + ($T:ident) => { + impl super::UncheckedAverage for $T { + fn unchecked_average_floor(&self, other: &$T) -> $T { + self.wrapping_add(*other) / 2 + } + fn unchecked_average_ceil(&self, other: &$T) -> $T { + (self.wrapping_add(*other) / 2).wrapping_add(1) + } + } + }; +} + +macro_rules! modulo_average { + ($T:ident) => { + impl super::ModuloAverage for $T { + fn modulo_average_ceil(&self, other: &$T) -> $T { + let (q1, r1) = self.div_mod_floor(&2); + let (q2, r2) = other.div_mod_floor(&2); + q1 + q2 + (r1 | r2) + } + fn modulo_average_floor(&self, other: &$T) -> $T { + let (q1, r1) = self.div_mod_floor(&2); + let (q2, r2) = other.div_mod_floor(&2); + q1 + q2 + (r1 * r2) + } + } + }; +} + +// --- Bench functions ------------------------------------------------------ + +fn bench_unchecked<T, F>(b: &mut Bencher, v: &[(T, T)], f: F) +where + T: Integer + Debug + Copy, + F: Fn(&T, &T) -> T, +{ + b.iter(|| { + for (x, y) in v { + black_box(f(x, y)); + } + }); +} + +fn bench_ceil<T, F>(b: &mut Bencher, v: &[(T, T)], f: F) +where + T: Integer + Debug + Copy, + F: Fn(&T, &T) -> T, +{ + for &(i, j) in v { + let rt = f(&i, &j); + let (a, b) = (min(i, j), max(i, j)); + // if both number are the same sign, check rt is in the middle + if (a < T::zero()) == (b < T::zero()) { + if (b - a).is_even() { + assert_eq!(rt - a, b - rt); + } else { + assert_eq!(rt - a, b - rt + T::one()); + } + // if both number have a different sign, + } else { + if (a + b).is_even() { + assert_eq!(rt, (a + b) / (T::one() + T::one())) + } else { + assert_eq!(rt, (a + b + T::one()) / (T::one() + T::one())) + } + } + } + bench_unchecked(b, v, f); +} + +fn bench_floor<T, F>(b: &mut Bencher, v: &[(T, T)], f: F) +where + T: Integer + Debug + Copy, + F: Fn(&T, &T) -> T, +{ + for &(i, j) in v { + let rt = f(&i, &j); + let (a, b) = (min(i, j), max(i, j)); + // if both number are the same sign, check rt is in the middle + if (a < T::zero()) == (b < T::zero()) { + if (b - a).is_even() { + assert_eq!(rt - a, b - rt); + } else { + assert_eq!(rt - a + T::one(), b - rt); + } + // if both number have a different sign, + } else { + if (a + b).is_even() { + assert_eq!(rt, (a + b) / (T::one() + T::one())) + } else { + assert_eq!(rt, (a + b - T::one()) / (T::one() + T::one())) + } + } + } + bench_unchecked(b, v, f); +} + +// --- Bench implementation ------------------------------------------------- + +macro_rules! bench_average { + ($($T:ident),*) => {$( + mod $T { + use test::Bencher; + use num_integer::{Average, Integer}; + use super::{UncheckedAverage, NaiveAverage, ModuloAverage}; + use super::{bench_ceil, bench_floor, bench_unchecked}; + + naive_average!($T); + unchecked_average!($T); + modulo_average!($T); + + const SIZE: $T = 30; + + fn overflowing() -> Vec<($T, $T)> { + (($T::max_value()-SIZE)..$T::max_value()) + .flat_map(|x| -> Vec<_> { + (($T::max_value()-100)..($T::max_value()-100+SIZE)) + .map(|y| (x, y)) + .collect() + }) + .collect() + } + + fn small() -> Vec<($T, $T)> { + (0..SIZE) + .flat_map(|x| -> Vec<_> {(0..SIZE).map(|y| (x, y)).collect()}) + .collect() + } + + fn rand() -> Vec<($T, $T)> { + small() + .into_iter() + .map(|(x, y)| (super::lcg(x), super::lcg(y))) + .collect() + } + + mod ceil { + + use super::*; + + mod small { + + use super::*; + + #[bench] + fn optimized(b: &mut Bencher) { + let v = small(); + bench_ceil(b, &v, |x: &$T, y: &$T| x.average_ceil(y)); + } + + #[bench] + fn naive(b: &mut Bencher) { + let v = small(); + bench_ceil(b, &v, |x: &$T, y: &$T| x.naive_average_ceil(y)); + } + + #[bench] + fn unchecked(b: &mut Bencher) { + let v = small(); + bench_unchecked(b, &v, |x: &$T, y: &$T| x.unchecked_average_ceil(y)); + } + + #[bench] + fn modulo(b: &mut Bencher) { + let v = small(); + bench_ceil(b, &v, |x: &$T, y: &$T| x.modulo_average_ceil(y)); + } + } + + mod overflowing { + + use super::*; + + #[bench] + fn optimized(b: &mut Bencher) { + let v = overflowing(); + bench_ceil(b, &v, |x: &$T, y: &$T| x.average_ceil(y)); + } + + #[bench] + fn naive(b: &mut Bencher) { + let v = overflowing(); + bench_ceil(b, &v, |x: &$T, y: &$T| x.naive_average_ceil(y)); + } + + #[bench] + fn unchecked(b: &mut Bencher) { + let v = overflowing(); + bench_unchecked(b, &v, |x: &$T, y: &$T| x.unchecked_average_ceil(y)); + } + + #[bench] + fn modulo(b: &mut Bencher) { + let v = overflowing(); + bench_ceil(b, &v, |x: &$T, y: &$T| x.modulo_average_ceil(y)); + } + } + + mod rand { + + use super::*; + + #[bench] + fn optimized(b: &mut Bencher) { + let v = rand(); + bench_ceil(b, &v, |x: &$T, y: &$T| x.average_ceil(y)); + } + + #[bench] + fn naive(b: &mut Bencher) { + let v = rand(); + bench_ceil(b, &v, |x: &$T, y: &$T| x.naive_average_ceil(y)); + } + + #[bench] + fn unchecked(b: &mut Bencher) { + let v = rand(); + bench_unchecked(b, &v, |x: &$T, y: &$T| x.unchecked_average_ceil(y)); + } + + #[bench] + fn modulo(b: &mut Bencher) { + let v = rand(); + bench_ceil(b, &v, |x: &$T, y: &$T| x.modulo_average_ceil(y)); + } + } + + } + + mod floor { + + use super::*; + + mod small { + + use super::*; + + #[bench] + fn optimized(b: &mut Bencher) { + let v = small(); + bench_floor(b, &v, |x: &$T, y: &$T| x.average_floor(y)); + } + + #[bench] + fn naive(b: &mut Bencher) { + let v = small(); + bench_floor(b, &v, |x: &$T, y: &$T| x.naive_average_floor(y)); + } + + #[bench] + fn unchecked(b: &mut Bencher) { + let v = small(); + bench_unchecked(b, &v, |x: &$T, y: &$T| x.unchecked_average_floor(y)); + } + + #[bench] + fn modulo(b: &mut Bencher) { + let v = small(); + bench_floor(b, &v, |x: &$T, y: &$T| x.modulo_average_floor(y)); + } + } + + mod overflowing { + + use super::*; + + #[bench] + fn optimized(b: &mut Bencher) { + let v = overflowing(); + bench_floor(b, &v, |x: &$T, y: &$T| x.average_floor(y)); + } + + #[bench] + fn naive(b: &mut Bencher) { + let v = overflowing(); + bench_floor(b, &v, |x: &$T, y: &$T| x.naive_average_floor(y)); + } + + #[bench] + fn unchecked(b: &mut Bencher) { + let v = overflowing(); + bench_unchecked(b, &v, |x: &$T, y: &$T| x.unchecked_average_floor(y)); + } + + #[bench] + fn modulo(b: &mut Bencher) { + let v = overflowing(); + bench_floor(b, &v, |x: &$T, y: &$T| x.modulo_average_floor(y)); + } + } + + mod rand { + + use super::*; + + #[bench] + fn optimized(b: &mut Bencher) { + let v = rand(); + bench_floor(b, &v, |x: &$T, y: &$T| x.average_floor(y)); + } + + #[bench] + fn naive(b: &mut Bencher) { + let v = rand(); + bench_floor(b, &v, |x: &$T, y: &$T| x.naive_average_floor(y)); + } + + #[bench] + fn unchecked(b: &mut Bencher) { + let v = rand(); + bench_unchecked(b, &v, |x: &$T, y: &$T| x.unchecked_average_floor(y)); + } + + #[bench] + fn modulo(b: &mut Bencher) { + let v = rand(); + bench_floor(b, &v, |x: &$T, y: &$T| x.modulo_average_floor(y)); + } + } + + } + + } + )*} +} + +bench_average!(i8, i16, i32, i64, i128, isize); +bench_average!(u8, u16, u32, u64, u128, usize); |