1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
|
#![feature(test)]
#![cfg(feature = "rand")]
extern crate test;
use num_bigint::{BigUint, RandBigInt};
use test::Bencher;
mod rng;
use rng::get_rng;
// The `big64` cases demonstrate the speed of cases where the value
// can be converted to a `u64` primitive for faster calculation.
//
// The `big1k` cases demonstrate those that can convert to `f64` for
// a better initial guess of the actual value.
//
// The `big2k` and `big4k` cases are too big for `f64`, and use a simpler guess.
fn check(x: &BigUint, n: u32) {
let root = x.nth_root(n);
if n == 2 {
assert_eq!(root, x.sqrt())
} else if n == 3 {
assert_eq!(root, x.cbrt())
}
let lo = root.pow(n);
assert!(lo <= *x);
assert_eq!(lo.nth_root(n), root);
assert_eq!((&lo - 1u32).nth_root(n), &root - 1u32);
let hi = (&root + 1u32).pow(n);
assert!(hi > *x);
assert_eq!(hi.nth_root(n), &root + 1u32);
assert_eq!((&hi - 1u32).nth_root(n), root);
}
fn bench_sqrt(b: &mut Bencher, bits: u64) {
let x = get_rng().gen_biguint(bits);
eprintln!("bench_sqrt({})", x);
check(&x, 2);
b.iter(|| x.sqrt());
}
#[bench]
fn big64_sqrt(b: &mut Bencher) {
bench_sqrt(b, 64);
}
#[bench]
fn big1k_sqrt(b: &mut Bencher) {
bench_sqrt(b, 1024);
}
#[bench]
fn big2k_sqrt(b: &mut Bencher) {
bench_sqrt(b, 2048);
}
#[bench]
fn big4k_sqrt(b: &mut Bencher) {
bench_sqrt(b, 4096);
}
fn bench_cbrt(b: &mut Bencher, bits: u64) {
let x = get_rng().gen_biguint(bits);
eprintln!("bench_cbrt({})", x);
check(&x, 3);
b.iter(|| x.cbrt());
}
#[bench]
fn big64_cbrt(b: &mut Bencher) {
bench_cbrt(b, 64);
}
#[bench]
fn big1k_cbrt(b: &mut Bencher) {
bench_cbrt(b, 1024);
}
#[bench]
fn big2k_cbrt(b: &mut Bencher) {
bench_cbrt(b, 2048);
}
#[bench]
fn big4k_cbrt(b: &mut Bencher) {
bench_cbrt(b, 4096);
}
fn bench_nth_root(b: &mut Bencher, bits: u64, n: u32) {
let x = get_rng().gen_biguint(bits);
eprintln!("bench_{}th_root({})", n, x);
check(&x, n);
b.iter(|| x.nth_root(n));
}
#[bench]
fn big64_nth_10(b: &mut Bencher) {
bench_nth_root(b, 64, 10);
}
#[bench]
fn big1k_nth_10(b: &mut Bencher) {
bench_nth_root(b, 1024, 10);
}
#[bench]
fn big1k_nth_100(b: &mut Bencher) {
bench_nth_root(b, 1024, 100);
}
#[bench]
fn big1k_nth_1000(b: &mut Bencher) {
bench_nth_root(b, 1024, 1000);
}
#[bench]
fn big1k_nth_10000(b: &mut Bencher) {
bench_nth_root(b, 1024, 10000);
}
#[bench]
fn big2k_nth_10(b: &mut Bencher) {
bench_nth_root(b, 2048, 10);
}
#[bench]
fn big2k_nth_100(b: &mut Bencher) {
bench_nth_root(b, 2048, 100);
}
#[bench]
fn big2k_nth_1000(b: &mut Bencher) {
bench_nth_root(b, 2048, 1000);
}
#[bench]
fn big2k_nth_10000(b: &mut Bencher) {
bench_nth_root(b, 2048, 10000);
}
#[bench]
fn big4k_nth_10(b: &mut Bencher) {
bench_nth_root(b, 4096, 10);
}
#[bench]
fn big4k_nth_100(b: &mut Bencher) {
bench_nth_root(b, 4096, 100);
}
#[bench]
fn big4k_nth_1000(b: &mut Bencher) {
bench_nth_root(b, 4096, 1000);
}
#[bench]
fn big4k_nth_10000(b: &mut Bencher) {
bench_nth_root(b, 4096, 10000);
}
|
