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| 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); |
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