Added int_pow micro-benchmarks

This commit is contained in:
Nicholas Thompson 2023-12-28 00:54:45 -05:00
parent 7c28a50a3a
commit 33a47df84a
2 changed files with 551 additions and 0 deletions

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@ -0,0 +1,550 @@
#![allow(unused_macros)] // TODO
use rand::Rng;
use test::{black_box, Bencher};
const ITERATIONS: usize = 128;
const SMALL_EXPONENT_MAX: u32 = 6;
macro_rules! pow_bench_template {
($name:ident, $t:ty, $inner_macro:ident, $base_macro:ident, $exp_macro:ident, $attribute:meta) => {
#[$attribute] // cfg(all()) makes a nice no-op.
#[bench]
fn $name(bench: &mut Bencher) {
// Frequent black_box calls can add latency and prevent optimizations, so for
// variable parameters we premake an array and pass the
// reference through black_box outside of the loop.
$base_macro!(1, $t, base_ident);
$exp_macro!(1, $t, exp_ident);
bench.iter(|| {
(0..ITERATIONS).fold((0 as $t, false), |acc, _| {
// Sometimes constants don't propogate all the way to the
// inside of the loop, so we call a custom expression every cycle.
// This allows us to use literals and `const` variables.
let base: $t = $base_macro!(2, $t, base_ident, acc);
let exp: u32 = $exp_macro!(2, $t, exp_ident, acc);
let r: ($t, bool) = $inner_macro!($t, base, exp);
(acc.0 | r.0, acc.1 | r.1)
})
});
}
};
}
// This may panic if it overflows.
// Consider running this bench along with an equivalent pow_unwrapped.
macro_rules! inner_pow {
($t:ty, $base:ident, $exp:ident) => {
($base.pow($exp), false)
};
}
macro_rules! inner_wrapping_pow {
($t:ty, $base:ident, $exp:ident) => {
($base.wrapping_pow($exp), false)
};
}
macro_rules! inner_overflowing_pow {
($t:ty, $base:ident, $exp:ident) => {
$base.overflowing_pow($exp)
};
}
macro_rules! inner_overflowing_pow_value {
($t:ty, $base:ident, $exp:ident) => {
($base.overflowing_pow($exp).0, false)
};
}
macro_rules! inner_overflowing_pow_overflow {
($t:ty, $base:ident, $exp:ident) => {
(0 as $t, $base.overflowing_pow($exp).1)
};
}
macro_rules! inner_checked_pow_option {
($t:ty, $base:ident, $exp:ident) => {
match $base.checked_pow($exp) {
Some(x) => (x, false),
None => (0 as $t, true),
}
};
}
macro_rules! inner_checked_value {
($t:ty, $base:ident, $exp:ident) => {
match $base.checked_pow($exp) {
Some(x) => (x, false),
None => (0 as $t, false),
}
};
}
macro_rules! inner_checked_pow_overflow {
($t:ty, $base:ident, $exp:ident) => {
(0 as $t, $base.checked_pow($exp).ok())
};
}
// This panics if it overflows.
macro_rules! inner_checked_pow_unwrapped {
($t:ty, $base:ident, $exp:ident) => {
($base.checked_pow($exp).unwrap(), false)
};
}
// This has undefined behavior if it overflows.
// Consider running this bench along with an equivalent pow_unwrapped.
macro_rules! inner_checked_pow_unwrapped_unchecked {
($t:ty, $base:ident, $exp:ident) => {
// SAFETY: Macro caller must ensure there is never an overflow.
unsafe { ($base.checked_pow($exp).unwrap_unchecked(), false) }
};
}
macro_rules! inner_saturating_pow {
($t:ty, $base:ident, $exp:ident) => {
($base.saturating_pow($exp), false)
};
}
// ***
macro_rules! make_const_base {
($name:ident, $x:literal) => {
macro_rules! $name {
(1, $t:ty, $ident:ident) => {};
(2, $t:ty, $ident:ident, $acc:ident) => {
$x
};
}
};
}
make_const_base!(base_const_2, 2);
make_const_base!(base_const_3, 3);
macro_rules! make_invariant_base {
($name:ident, $x:literal) => {
macro_rules! $name {
(1, $t:ty, $ident:ident) => {
let $ident: $t = black_box($x);
};
(2, $t:ty, $ident:ident, $acc:ident) => {
$ident
};
}
};
}
macro_rules! make_repeated_base {
($name:ident, $x:literal) => {
macro_rules! $name {
(1, $t:ty, $ident:ident) => {
let mut rng = crate::bench_rng();
let mut exp_array = [$x as $t; ITERATIONS];
let array_ref: &[$t; ITERATIONS] = black_box(&exp_array);
let mut $ident = std::iter::repeat(array_ref.into_iter()).flatten();
};
(2, $t:ty, $ident:ident, $acc:ident) => {
*$ident.next().unwrap()
};
}
};
}
macro_rules! base_small_sequential {
(1, $t:ty, $ident:ident) => {
let mut rng = crate::bench_rng();
let mut base_array = [0 as $t; ITERATIONS];
#[allow(unused_comparisons)]
const SIG_BITS: u32 = (<$t>::BITS - (<$t>::MIN < 0) as u32) / SMALL_EXPONENT_MAX;
const BASE_MAX: $t = ((1 as $t) << SIG_BITS) - 1;
const BASE_MIN: $t = (0 as $t).saturating_sub(BASE_MAX);
for i in 0..base_array.len() {
base_array[i] = rng.gen_range(BASE_MIN..=BASE_MAX);
}
let array_ref: &[$t; ITERATIONS] = black_box(&base_array);
let mut $ident = std::iter::repeat(array_ref.into_iter()).flatten();
};
(2, $t:ty, $ident:ident, $acc:ident) => {
*$ident.next().unwrap() ^ ($acc.0 & 1)
// Worst case this changes -1 to -2 for i8
};
}
macro_rules! base_exponential {
(1, $t:ty, $ident:ident) => {
let mut rng = crate::bench_rng();
let mut base_array = [0 as $t; ITERATIONS];
for i in 0..base_array.len() {
base_array[i] = rng.gen::<$t>() >> rng.gen_range(0..<$t>::BITS);
}
let array_ref: &[$t; ITERATIONS] = black_box(&base_array);
let mut $ident = std::iter::repeat(array_ref.into_iter()).flatten();
};
(2, $t:ty, $ident:ident, $acc:ident) => {
*$ident.next().unwrap()
};
}
macro_rules! make_const_exp {
($name:ident, $x:literal) => {
macro_rules! $name {
(1, $t:ty, $ident:ident) => {};
(2, $t:ty, $ident:ident, $acc:ident) => {
$x
};
}
};
}
make_const_exp!(exp_const_6, 6);
macro_rules! make_invariant_exp {
($name:ident, $x:literal) => {
macro_rules! $name {
(1, $t:ty, $ident:ident) => {
let $ident: u32 = black_box($x);
};
(2, $t:ty, $ident:ident, $acc:ident) => {
$ident
};
}
};
}
macro_rules! make_repeated_exp {
($name:ident, $x:literal) => {
macro_rules! $name {
(1, $t:ty, $ident:ident) => {
let mut rng = crate::bench_rng();
let mut exp_array = [$x as u32; ITERATIONS];
let array_ref: &[u32; ITERATIONS] = black_box(&exp_array);
let mut $ident = std::iter::repeat(array_ref.into_iter()).flatten();
};
(2, $t:ty, $ident:ident, $acc:ident) => {
*$ident.next().unwrap()
};
}
};
}
macro_rules! exp_small {
(1, $t:ty, $ident:ident) => {
let mut rng = crate::bench_rng();
let mut exp_array = [0u32; ITERATIONS];
for i in 0..exp_array.len() {
exp_array[i] = rng.gen_range(0..=SMALL_EXPONENT_MAX);
}
let array_ref: &[u32; ITERATIONS] = black_box(&exp_array);
let mut $ident = std::iter::repeat(array_ref.into_iter()).flatten();
};
(2, $t:ty, $ident:ident, $acc:ident) => {
*$ident.next().unwrap()
};
}
macro_rules! exp_exponential {
(1, $t:ty, $ident:ident) => {
let mut rng = crate::bench_rng();
let mut exp_array = [0u32; ITERATIONS];
for i in 0..exp_array.len() {
exp_array[i] = rng.gen::<u32>() >> rng.gen_range(0..u32::BITS);
}
let array_ref: &[u32; ITERATIONS] = black_box(&exp_array);
let mut $ident = std::iter::repeat(array_ref.into_iter()).flatten();
};
(2, $t:ty, $ident:ident, $acc:ident) => {
*$ident.next().unwrap()
};
}
macro_rules! exp_full {
(1, $t:ty, $ident:ident) => {
let mut rng = crate::bench_rng();
let mut exp_array = [0u32; ITERATIONS];
for i in 0..exp_array.len() {
exp_array[i] = rng.gen() & (1 << 31);
}
let array_ref: &[u32; ITERATIONS] = black_box(&exp_array);
let mut $ident = std::iter::repeat(array_ref.into_iter()).flatten();
};
(2, $t:ty, $ident:ident, $acc:ident) => {
*$ident.next().unwrap()
};
}
// ***
macro_rules! default_benches {
(
$t:ty,
$ignored:meta,
$pow_small_name:ident,
$wrapping_small_name:ident,
$overflowing_small_name:ident,
$unwrapped_small_name:ident,
$saturating_small_name:ident,
$wrapping_exponential_name:ident,
$overflowing_exponential_name:ident,
$pow_const_2_name:ident,
$overflowing_const_2_name:ident,
$overflowing_const_3_name:ident,
$pow_const_6_name:ident
) => {
pow_bench_template!(
$pow_small_name,
$t,
inner_pow,
base_small_sequential,
exp_small,
$ignored
);
pow_bench_template!(
$wrapping_small_name,
$t,
inner_wrapping_pow,
base_small_sequential,
exp_small,
$ignored
);
pow_bench_template!(
$overflowing_small_name,
$t,
inner_overflowing_pow,
base_small_sequential,
exp_small,
$ignored
);
pow_bench_template!(
$unwrapped_small_name,
$t,
inner_checked_pow_unwrapped,
base_small_sequential,
exp_small,
$ignored
);
pow_bench_template!(
$saturating_small_name,
$t,
inner_saturating_pow,
base_small_sequential,
exp_small,
$ignored
);
pow_bench_template!(
$wrapping_exponential_name,
$t,
inner_wrapping_pow,
base_small_sequential,
exp_exponential,
$ignored
);
pow_bench_template!(
$overflowing_exponential_name,
$t,
inner_overflowing_pow,
base_small_sequential,
exp_exponential,
$ignored
);
pow_bench_template!(
$pow_const_2_name,
$t,
inner_pow,
base_const_2,
exp_exponential,
$ignored
);
pow_bench_template!(
$overflowing_const_2_name,
$t,
inner_overflowing_pow,
base_const_2,
exp_exponential,
$ignored
);
pow_bench_template!(
$overflowing_const_3_name,
$t,
inner_overflowing_pow,
base_const_2,
exp_exponential,
$ignored
);
pow_bench_template!(
$pow_const_6_name,
$t,
inner_pow,
base_small_sequential,
exp_const_6,
$ignored
);
};
}
default_benches!(
u8,
ignore,
u8_pow_small,
u8_wrapping_pow_small,
u8_overflowing_pow_small,
u8_checked_unwrapped_pow_small,
u8_staurating_pow_small,
u8_wrapping_pow_base_small_exp_exponential,
u8_overflowing_pow_base_small_exp_exponential,
u8_pow_base_const_2_exp_small,
u8_overfowing_pow_base_const_2_exp_exponential,
u8_overfowing_pow_base_const_3_exp_exponential,
u8_pow_base_small_exp_const_6
);
default_benches!(
i8,
ignore,
i8_pow_small,
i8_wrapping_pow_small,
i8_overflowing_pow_small,
i8_checked_unwrapped_pow_small,
i8_staurating_pow_small,
i8_wrapping_pow_base_small_exp_exponential,
i8_overflowing_pow_base_small_exp_exponential,
i8_pow_base_const_2_exp_small,
i8_overfowing_pow_base_const_2_exp_exponential,
i8_overfowing_pow_base_const_3_exp_exponential,
i8_pow_base_small_exp_const_6
);
default_benches!(
u16,
ignore,
u16_pow_small,
u16_wrapping_pow_small,
u16_overflowing_pow_small,
u16_checked_unwrapped_pow_small,
u16_staurating_pow_small,
u16_wrapping_pow_base_small_exp_exponential,
u16_overflowing_pow_base_small_exp_exponential,
u16_pow_base_const_2_exp_small,
u16_overfowing_pow_base_const_2_exp_exponential,
u16_overfowing_pow_base_const_3_exp_exponential,
u16_pow_base_small_exp_const_6
);
default_benches!(
i16,
ignore,
i16_pow_small,
i16_wrapping_pow_small,
i16_overflowing_pow_small,
i16_checked_unwrapped_pow_small,
i16_staurating_pow_small,
i16_wrapping_pow_base_small_exp_exponential,
i16_overflowing_pow_base_small_exp_exponential,
i16_pow_base_const_2_exp_small,
i16_overfowing_pow_base_const_2_exp_exponential,
i16_overfowing_pow_base_const_3_exp_exponential,
i16_pow_base_small_exp_const_6
);
default_benches!(
u32,
ignore,
u32_pow_small,
u32_wrapping_pow_small,
u32_overflowing_pow_small,
u32_checked_unwrapped_pow_small,
u32_staurating_pow_small,
u32_wrapping_pow_base_small_exp_exponential,
u32_overflowing_pow_base_small_exp_exponential,
u32_pow_base_const_2_exp_small,
u32_overfowing_pow_base_const_2_exp_exponential,
u32_overfowing_pow_base_const_3_exp_exponential,
u32_pow_base_small_exp_const_6
);
default_benches!(
i32,
cfg(all()),
i32_pow_small,
i32_wrapping_pow_small,
i32_overflowing_pow_small,
i32_checked_unwrapped_pow_small,
i32_staurating_pow_small,
i32_wrapping_pow_base_small_exp_exponential,
i32_overflowing_pow_base_small_exp_exponential,
i32_pow_base_const_2_exp_small,
i32_overfowing_pow_base_const_2_exp_exponential,
i32_overfowing_pow_base_const_3_exp_exponential,
i32_pow_base_small_exp_const_6
);
default_benches!(
u64,
cfg(all()),
u64_pow_small,
u64_wrapping_pow_small,
u64_overflowing_pow_small,
u64_checked_unwrapped_pow_small,
u64_staurating_pow_small,
u64_wrapping_pow_base_small_exp_exponential,
u64_overflowing_pow_base_small_exp_exponential,
u64_pow_base_const_2_exp_small,
u64_overfowing_pow_base_const_2_exp_exponential,
u64_overfowing_pow_base_const_3_exp_exponential,
u64_pow_base_small_exp_const_6
);
default_benches!(
i64,
ignore,
i64_pow_small,
i64_wrapping_pow_small,
i64_overflowing_pow_small,
i64_checked_unwrapped_pow_small,
i64_staurating_pow_small,
i64_wrapping_pow_base_small_exp_exponential,
i64_overflowing_pow_base_small_exp_exponential,
i64_pow_base_const_2_exp_small,
i64_overfowing_pow_base_const_2_exp_exponential,
i64_overfowing_pow_base_const_3_exp_exponential,
i64_pow_base_small_exp_const_6
);
default_benches!(
u128,
ignore,
u128_pow_small,
u128_wrapping_pow_small,
u128_overflowing_pow_small,
u128_checked_unwrapped_pow_small,
u128_staurating_pow_small,
u128_wrapping_pow_base_small_exp_exponential,
u128_overflowing_pow_base_small_exp_exponential,
u128_pow_base_const_2_exp_small,
u128_overfowing_pow_base_const_2_exp_exponential,
u128_overfowing_pow_base_const_3_exp_exponential,
u128_pow_base_small_exp_const_6
);
default_benches!(
i128,
ignore,
i128_pow_small,
i128_wrapping_pow_small,
i128_overflowing_pow_small,
i128_checked_unwrapped_pow_small,
i128_staurating_pow_small,
i128_wrapping_pow_base_small_exp_exponential,
i128_overflowing_pow_base_small_exp_exponential,
i128_pow_base_const_2_exp_small,
i128_overfowing_pow_base_const_2_exp_exponential,
i128_overfowing_pow_base_const_3_exp_exponential,
i128_pow_base_small_exp_const_6
);

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@ -1,6 +1,7 @@
mod dec2flt; mod dec2flt;
mod flt2dec; mod flt2dec;
mod int_log; mod int_log;
mod int_pow;
use std::str::FromStr; use std::str::FromStr;
use test::{black_box, Bencher}; use test::{black_box, Bencher};