Yi Kong | c1a6315 | 2021-02-03 15:04:59 +0800 | [diff] [blame^] | 1 | //! Benchmark sqrt and cbrt |
| 2 | |
| 3 | #![feature(test)] |
| 4 | |
| 5 | extern crate num_integer; |
| 6 | extern crate num_traits; |
| 7 | extern crate test; |
| 8 | |
| 9 | use num_integer::Integer; |
| 10 | use num_traits::{AsPrimitive, PrimInt, WrappingAdd, WrappingMul}; |
| 11 | use std::cmp::{max, min}; |
| 12 | use std::fmt::Debug; |
| 13 | use test::{black_box, Bencher}; |
| 14 | |
| 15 | // --- Utilities for RNG ---------------------------------------------------- |
| 16 | |
| 17 | trait BenchInteger: Integer + PrimInt + WrappingAdd + WrappingMul + 'static {} |
| 18 | |
| 19 | impl<T> BenchInteger for T where T: Integer + PrimInt + WrappingAdd + WrappingMul + 'static {} |
| 20 | |
| 21 | // Simple PRNG so we don't have to worry about rand compatibility |
| 22 | fn lcg<T>(x: T) -> T |
| 23 | where |
| 24 | u32: AsPrimitive<T>, |
| 25 | T: BenchInteger, |
| 26 | { |
| 27 | // LCG parameters from Numerical Recipes |
| 28 | // (but we're applying it to arbitrary sizes) |
| 29 | const LCG_A: u32 = 1664525; |
| 30 | const LCG_C: u32 = 1013904223; |
| 31 | x.wrapping_mul(&LCG_A.as_()).wrapping_add(&LCG_C.as_()) |
| 32 | } |
| 33 | |
| 34 | // --- Alt. Implementations ------------------------------------------------- |
| 35 | |
| 36 | trait NaiveAverage { |
| 37 | fn naive_average_ceil(&self, other: &Self) -> Self; |
| 38 | fn naive_average_floor(&self, other: &Self) -> Self; |
| 39 | } |
| 40 | |
| 41 | trait UncheckedAverage { |
| 42 | fn unchecked_average_ceil(&self, other: &Self) -> Self; |
| 43 | fn unchecked_average_floor(&self, other: &Self) -> Self; |
| 44 | } |
| 45 | |
| 46 | trait ModuloAverage { |
| 47 | fn modulo_average_ceil(&self, other: &Self) -> Self; |
| 48 | fn modulo_average_floor(&self, other: &Self) -> Self; |
| 49 | } |
| 50 | |
| 51 | macro_rules! naive_average { |
| 52 | ($T:ident) => { |
| 53 | impl super::NaiveAverage for $T { |
| 54 | fn naive_average_floor(&self, other: &$T) -> $T { |
| 55 | match self.checked_add(*other) { |
| 56 | Some(z) => z.div_floor(&2), |
| 57 | None => { |
| 58 | if self > other { |
| 59 | let diff = self - other; |
| 60 | other + diff.div_floor(&2) |
| 61 | } else { |
| 62 | let diff = other - self; |
| 63 | self + diff.div_floor(&2) |
| 64 | } |
| 65 | } |
| 66 | } |
| 67 | } |
| 68 | fn naive_average_ceil(&self, other: &$T) -> $T { |
| 69 | match self.checked_add(*other) { |
| 70 | Some(z) => z.div_ceil(&2), |
| 71 | None => { |
| 72 | if self > other { |
| 73 | let diff = self - other; |
| 74 | self - diff.div_floor(&2) |
| 75 | } else { |
| 76 | let diff = other - self; |
| 77 | other - diff.div_floor(&2) |
| 78 | } |
| 79 | } |
| 80 | } |
| 81 | } |
| 82 | } |
| 83 | }; |
| 84 | } |
| 85 | |
| 86 | macro_rules! unchecked_average { |
| 87 | ($T:ident) => { |
| 88 | impl super::UncheckedAverage for $T { |
| 89 | fn unchecked_average_floor(&self, other: &$T) -> $T { |
| 90 | self.wrapping_add(*other) / 2 |
| 91 | } |
| 92 | fn unchecked_average_ceil(&self, other: &$T) -> $T { |
| 93 | (self.wrapping_add(*other) / 2).wrapping_add(1) |
| 94 | } |
| 95 | } |
| 96 | }; |
| 97 | } |
| 98 | |
| 99 | macro_rules! modulo_average { |
| 100 | ($T:ident) => { |
| 101 | impl super::ModuloAverage for $T { |
| 102 | fn modulo_average_ceil(&self, other: &$T) -> $T { |
| 103 | let (q1, r1) = self.div_mod_floor(&2); |
| 104 | let (q2, r2) = other.div_mod_floor(&2); |
| 105 | q1 + q2 + (r1 | r2) |
| 106 | } |
| 107 | fn modulo_average_floor(&self, other: &$T) -> $T { |
| 108 | let (q1, r1) = self.div_mod_floor(&2); |
| 109 | let (q2, r2) = other.div_mod_floor(&2); |
| 110 | q1 + q2 + (r1 * r2) |
| 111 | } |
| 112 | } |
| 113 | }; |
| 114 | } |
| 115 | |
| 116 | // --- Bench functions ------------------------------------------------------ |
| 117 | |
| 118 | fn bench_unchecked<T, F>(b: &mut Bencher, v: &[(T, T)], f: F) |
| 119 | where |
| 120 | T: Integer + Debug + Copy, |
| 121 | F: Fn(&T, &T) -> T, |
| 122 | { |
| 123 | b.iter(|| { |
| 124 | for (x, y) in v { |
| 125 | black_box(f(x, y)); |
| 126 | } |
| 127 | }); |
| 128 | } |
| 129 | |
| 130 | fn bench_ceil<T, F>(b: &mut Bencher, v: &[(T, T)], f: F) |
| 131 | where |
| 132 | T: Integer + Debug + Copy, |
| 133 | F: Fn(&T, &T) -> T, |
| 134 | { |
| 135 | for &(i, j) in v { |
| 136 | let rt = f(&i, &j); |
| 137 | let (a, b) = (min(i, j), max(i, j)); |
| 138 | // if both number are the same sign, check rt is in the middle |
| 139 | if (a < T::zero()) == (b < T::zero()) { |
| 140 | if (b - a).is_even() { |
| 141 | assert_eq!(rt - a, b - rt); |
| 142 | } else { |
| 143 | assert_eq!(rt - a, b - rt + T::one()); |
| 144 | } |
| 145 | // if both number have a different sign, |
| 146 | } else { |
| 147 | if (a + b).is_even() { |
| 148 | assert_eq!(rt, (a + b) / (T::one() + T::one())) |
| 149 | } else { |
| 150 | assert_eq!(rt, (a + b + T::one()) / (T::one() + T::one())) |
| 151 | } |
| 152 | } |
| 153 | } |
| 154 | bench_unchecked(b, v, f); |
| 155 | } |
| 156 | |
| 157 | fn bench_floor<T, F>(b: &mut Bencher, v: &[(T, T)], f: F) |
| 158 | where |
| 159 | T: Integer + Debug + Copy, |
| 160 | F: Fn(&T, &T) -> T, |
| 161 | { |
| 162 | for &(i, j) in v { |
| 163 | let rt = f(&i, &j); |
| 164 | let (a, b) = (min(i, j), max(i, j)); |
| 165 | // if both number are the same sign, check rt is in the middle |
| 166 | if (a < T::zero()) == (b < T::zero()) { |
| 167 | if (b - a).is_even() { |
| 168 | assert_eq!(rt - a, b - rt); |
| 169 | } else { |
| 170 | assert_eq!(rt - a + T::one(), b - rt); |
| 171 | } |
| 172 | // if both number have a different sign, |
| 173 | } else { |
| 174 | if (a + b).is_even() { |
| 175 | assert_eq!(rt, (a + b) / (T::one() + T::one())) |
| 176 | } else { |
| 177 | assert_eq!(rt, (a + b - T::one()) / (T::one() + T::one())) |
| 178 | } |
| 179 | } |
| 180 | } |
| 181 | bench_unchecked(b, v, f); |
| 182 | } |
| 183 | |
| 184 | // --- Bench implementation ------------------------------------------------- |
| 185 | |
| 186 | macro_rules! bench_average { |
| 187 | ($($T:ident),*) => {$( |
| 188 | mod $T { |
| 189 | use test::Bencher; |
| 190 | use num_integer::{Average, Integer}; |
| 191 | use super::{UncheckedAverage, NaiveAverage, ModuloAverage}; |
| 192 | use super::{bench_ceil, bench_floor, bench_unchecked}; |
| 193 | |
| 194 | naive_average!($T); |
| 195 | unchecked_average!($T); |
| 196 | modulo_average!($T); |
| 197 | |
| 198 | const SIZE: $T = 30; |
| 199 | |
| 200 | fn overflowing() -> Vec<($T, $T)> { |
| 201 | (($T::max_value()-SIZE)..$T::max_value()) |
| 202 | .flat_map(|x| -> Vec<_> { |
| 203 | (($T::max_value()-100)..($T::max_value()-100+SIZE)) |
| 204 | .map(|y| (x, y)) |
| 205 | .collect() |
| 206 | }) |
| 207 | .collect() |
| 208 | } |
| 209 | |
| 210 | fn small() -> Vec<($T, $T)> { |
| 211 | (0..SIZE) |
| 212 | .flat_map(|x| -> Vec<_> {(0..SIZE).map(|y| (x, y)).collect()}) |
| 213 | .collect() |
| 214 | } |
| 215 | |
| 216 | fn rand() -> Vec<($T, $T)> { |
| 217 | small() |
| 218 | .into_iter() |
| 219 | .map(|(x, y)| (super::lcg(x), super::lcg(y))) |
| 220 | .collect() |
| 221 | } |
| 222 | |
| 223 | mod ceil { |
| 224 | |
| 225 | use super::*; |
| 226 | |
| 227 | mod small { |
| 228 | |
| 229 | use super::*; |
| 230 | |
| 231 | #[bench] |
| 232 | fn optimized(b: &mut Bencher) { |
| 233 | let v = small(); |
| 234 | bench_ceil(b, &v, |x: &$T, y: &$T| x.average_ceil(y)); |
| 235 | } |
| 236 | |
| 237 | #[bench] |
| 238 | fn naive(b: &mut Bencher) { |
| 239 | let v = small(); |
| 240 | bench_ceil(b, &v, |x: &$T, y: &$T| x.naive_average_ceil(y)); |
| 241 | } |
| 242 | |
| 243 | #[bench] |
| 244 | fn unchecked(b: &mut Bencher) { |
| 245 | let v = small(); |
| 246 | bench_unchecked(b, &v, |x: &$T, y: &$T| x.unchecked_average_ceil(y)); |
| 247 | } |
| 248 | |
| 249 | #[bench] |
| 250 | fn modulo(b: &mut Bencher) { |
| 251 | let v = small(); |
| 252 | bench_ceil(b, &v, |x: &$T, y: &$T| x.modulo_average_ceil(y)); |
| 253 | } |
| 254 | } |
| 255 | |
| 256 | mod overflowing { |
| 257 | |
| 258 | use super::*; |
| 259 | |
| 260 | #[bench] |
| 261 | fn optimized(b: &mut Bencher) { |
| 262 | let v = overflowing(); |
| 263 | bench_ceil(b, &v, |x: &$T, y: &$T| x.average_ceil(y)); |
| 264 | } |
| 265 | |
| 266 | #[bench] |
| 267 | fn naive(b: &mut Bencher) { |
| 268 | let v = overflowing(); |
| 269 | bench_ceil(b, &v, |x: &$T, y: &$T| x.naive_average_ceil(y)); |
| 270 | } |
| 271 | |
| 272 | #[bench] |
| 273 | fn unchecked(b: &mut Bencher) { |
| 274 | let v = overflowing(); |
| 275 | bench_unchecked(b, &v, |x: &$T, y: &$T| x.unchecked_average_ceil(y)); |
| 276 | } |
| 277 | |
| 278 | #[bench] |
| 279 | fn modulo(b: &mut Bencher) { |
| 280 | let v = overflowing(); |
| 281 | bench_ceil(b, &v, |x: &$T, y: &$T| x.modulo_average_ceil(y)); |
| 282 | } |
| 283 | } |
| 284 | |
| 285 | mod rand { |
| 286 | |
| 287 | use super::*; |
| 288 | |
| 289 | #[bench] |
| 290 | fn optimized(b: &mut Bencher) { |
| 291 | let v = rand(); |
| 292 | bench_ceil(b, &v, |x: &$T, y: &$T| x.average_ceil(y)); |
| 293 | } |
| 294 | |
| 295 | #[bench] |
| 296 | fn naive(b: &mut Bencher) { |
| 297 | let v = rand(); |
| 298 | bench_ceil(b, &v, |x: &$T, y: &$T| x.naive_average_ceil(y)); |
| 299 | } |
| 300 | |
| 301 | #[bench] |
| 302 | fn unchecked(b: &mut Bencher) { |
| 303 | let v = rand(); |
| 304 | bench_unchecked(b, &v, |x: &$T, y: &$T| x.unchecked_average_ceil(y)); |
| 305 | } |
| 306 | |
| 307 | #[bench] |
| 308 | fn modulo(b: &mut Bencher) { |
| 309 | let v = rand(); |
| 310 | bench_ceil(b, &v, |x: &$T, y: &$T| x.modulo_average_ceil(y)); |
| 311 | } |
| 312 | } |
| 313 | |
| 314 | } |
| 315 | |
| 316 | mod floor { |
| 317 | |
| 318 | use super::*; |
| 319 | |
| 320 | mod small { |
| 321 | |
| 322 | use super::*; |
| 323 | |
| 324 | #[bench] |
| 325 | fn optimized(b: &mut Bencher) { |
| 326 | let v = small(); |
| 327 | bench_floor(b, &v, |x: &$T, y: &$T| x.average_floor(y)); |
| 328 | } |
| 329 | |
| 330 | #[bench] |
| 331 | fn naive(b: &mut Bencher) { |
| 332 | let v = small(); |
| 333 | bench_floor(b, &v, |x: &$T, y: &$T| x.naive_average_floor(y)); |
| 334 | } |
| 335 | |
| 336 | #[bench] |
| 337 | fn unchecked(b: &mut Bencher) { |
| 338 | let v = small(); |
| 339 | bench_unchecked(b, &v, |x: &$T, y: &$T| x.unchecked_average_floor(y)); |
| 340 | } |
| 341 | |
| 342 | #[bench] |
| 343 | fn modulo(b: &mut Bencher) { |
| 344 | let v = small(); |
| 345 | bench_floor(b, &v, |x: &$T, y: &$T| x.modulo_average_floor(y)); |
| 346 | } |
| 347 | } |
| 348 | |
| 349 | mod overflowing { |
| 350 | |
| 351 | use super::*; |
| 352 | |
| 353 | #[bench] |
| 354 | fn optimized(b: &mut Bencher) { |
| 355 | let v = overflowing(); |
| 356 | bench_floor(b, &v, |x: &$T, y: &$T| x.average_floor(y)); |
| 357 | } |
| 358 | |
| 359 | #[bench] |
| 360 | fn naive(b: &mut Bencher) { |
| 361 | let v = overflowing(); |
| 362 | bench_floor(b, &v, |x: &$T, y: &$T| x.naive_average_floor(y)); |
| 363 | } |
| 364 | |
| 365 | #[bench] |
| 366 | fn unchecked(b: &mut Bencher) { |
| 367 | let v = overflowing(); |
| 368 | bench_unchecked(b, &v, |x: &$T, y: &$T| x.unchecked_average_floor(y)); |
| 369 | } |
| 370 | |
| 371 | #[bench] |
| 372 | fn modulo(b: &mut Bencher) { |
| 373 | let v = overflowing(); |
| 374 | bench_floor(b, &v, |x: &$T, y: &$T| x.modulo_average_floor(y)); |
| 375 | } |
| 376 | } |
| 377 | |
| 378 | mod rand { |
| 379 | |
| 380 | use super::*; |
| 381 | |
| 382 | #[bench] |
| 383 | fn optimized(b: &mut Bencher) { |
| 384 | let v = rand(); |
| 385 | bench_floor(b, &v, |x: &$T, y: &$T| x.average_floor(y)); |
| 386 | } |
| 387 | |
| 388 | #[bench] |
| 389 | fn naive(b: &mut Bencher) { |
| 390 | let v = rand(); |
| 391 | bench_floor(b, &v, |x: &$T, y: &$T| x.naive_average_floor(y)); |
| 392 | } |
| 393 | |
| 394 | #[bench] |
| 395 | fn unchecked(b: &mut Bencher) { |
| 396 | let v = rand(); |
| 397 | bench_unchecked(b, &v, |x: &$T, y: &$T| x.unchecked_average_floor(y)); |
| 398 | } |
| 399 | |
| 400 | #[bench] |
| 401 | fn modulo(b: &mut Bencher) { |
| 402 | let v = rand(); |
| 403 | bench_floor(b, &v, |x: &$T, y: &$T| x.modulo_average_floor(y)); |
| 404 | } |
| 405 | } |
| 406 | |
| 407 | } |
| 408 | |
| 409 | } |
| 410 | )*} |
| 411 | } |
| 412 | |
| 413 | bench_average!(i8, i16, i32, i64, i128, isize); |
| 414 | bench_average!(u8, u16, u32, u64, u128, usize); |