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
|
use rand::Rng;
use test::{Bencher, black_box};
macro_rules! int_log10_bench {
($t:ty, $predictable:ident, $random:ident, $random_small:ident) => {
#[bench]
fn $predictable(bench: &mut Bencher) {
bench.iter(|| {
for n in 0..(<$t>::BITS / 8) {
for i in 1..=(100 as $t) {
let x = black_box(i << (n * 8));
black_box(x.ilog10());
}
}
});
}
#[bench]
fn $random(bench: &mut Bencher) {
let mut rng = crate::bench_rng();
/* Exponentially distributed random numbers from the whole range of the type. */
let numbers: Vec<$t> = (0..256)
.map(|_| {
let x = rng.gen::<$t>() >> rng.gen_range(0..<$t>::BITS);
if x != 0 { x } else { 1 }
})
.collect();
bench.iter(|| {
for x in &numbers {
black_box(black_box(x).ilog10());
}
});
}
#[bench]
fn $random_small(bench: &mut Bencher) {
let mut rng = crate::bench_rng();
/* Exponentially distributed random numbers from the range 0..256. */
let numbers: Vec<$t> = (0..256)
.map(|_| {
let x = (rng.gen::<u8>() >> rng.gen_range(0..u8::BITS)) as $t;
if x != 0 { x } else { 1 }
})
.collect();
bench.iter(|| {
for x in &numbers {
black_box(black_box(x).ilog10());
}
});
}
};
}
int_log10_bench! {u8, u8_log10_predictable, u8_log10_random, u8_log10_random_small}
int_log10_bench! {u16, u16_log10_predictable, u16_log10_random, u16_log10_random_small}
int_log10_bench! {u32, u32_log10_predictable, u32_log10_random, u32_log10_random_small}
int_log10_bench! {u64, u64_log10_predictable, u64_log10_random, u64_log10_random_small}
int_log10_bench! {u128, u128_log10_predictable, u128_log10_random, u128_log10_random_small}
macro_rules! int_log_bench {
($t:ty, $random:ident, $random_small:ident, $geometric:ident) => {
#[bench]
fn $random(bench: &mut Bencher) {
let mut rng = crate::bench_rng();
/* Exponentially distributed random numbers from the whole range of the type. */
let numbers: Vec<$t> = (0..256)
.map(|_| {
let x = rng.gen::<$t>() >> rng.gen_range(0..<$t>::BITS);
if x >= 2 { x } else { 2 }
})
.collect();
bench.iter(|| {
for &b in &numbers {
for &x in &numbers {
black_box(black_box(x).ilog(b));
}
}
});
}
#[bench]
fn $random_small(bench: &mut Bencher) {
let mut rng = crate::bench_rng();
/* Exponentially distributed random numbers from the range 0..256. */
let numbers: Vec<$t> = (0..256)
.map(|_| {
let x = (rng.gen::<u8>() >> rng.gen_range(0..u8::BITS)) as $t;
if x >= 2 { x } else { 2 }
})
.collect();
bench.iter(|| {
for &b in &numbers {
for &x in &numbers {
black_box(black_box(x).ilog(b));
}
}
});
}
#[bench]
fn $geometric(bench: &mut Bencher) {
let bases: [$t; 16] = [2, 3, 4, 5, 7, 8, 9, 15, 16, 17, 31, 32, 33, 63, 64, 65];
let base_and_numbers: Vec<($t, Vec<$t>)> = bases
.iter()
.map(|&b| {
let numbers = (0..=<$t>::MAX.ilog(b)).map(|exp| b.pow(exp)).collect();
(b, numbers)
})
.collect();
bench.iter(|| {
for (b, numbers) in &base_and_numbers {
for &x in numbers {
black_box(black_box(x).ilog(black_box(*b)));
}
}
});
}
};
}
int_log_bench! {u8, u8_log_random, u8_log_random_small, u8_log_geometric}
int_log_bench! {u16, u16_log_random, u16_log_random_small, u16_log_geometric}
int_log_bench! {u32, u32_log_random, u32_log_random_small, u32_log_geometric}
int_log_bench! {u64, u64_log_random, u64_log_random_small, u64_log_geometric}
int_log_bench! {u128, u128_log_random, u128_log_random_small, u128_log_geometric}
|
