aboutsummaryrefslogtreecommitdiff
path: root/tests/f2s_test.rs
blob: d6249a3a89041fe0b15c867651be94b4c7682e76 (plain)
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
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
// Translated from C to Rust. The original C code can be found at
// https://github.com/ulfjack/ryu and carries the following license:
//
// Copyright 2018 Ulf Adams
//
// The contents of this file may be used under the terms of the Apache License,
// Version 2.0.
//
//    (See accompanying file LICENSE-Apache or copy at
//     http://www.apache.org/licenses/LICENSE-2.0)
//
// Alternatively, the contents of this file may be used under the terms of
// the Boost Software License, Version 1.0.
//    (See accompanying file LICENSE-Boost or copy at
//     https://www.boost.org/LICENSE_1_0.txt)
//
// Unless required by applicable law or agreed to in writing, this software
// is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.

#![allow(
    clippy::approx_constant,
    clippy::float_cmp,
    clippy::non_ascii_literal,
    clippy::unreadable_literal,
    clippy::unseparated_literal_suffix
)]

#[macro_use]
mod macros;

use std::f32;

fn pretty(f: f32) -> String {
    ryu::Buffer::new().format(f).to_owned()
}

#[test]
fn test_ryu() {
    check!(0.3);
    check!(1234000000000.0);
    check!(1.234e13);
    check!(2.71828);
    check!(1.1e32);
    check!(1.1e-32);
    check!(2.7182817);
    check!(1e-45);
    check!(3.4028235e38);
    check!(-0.001234);
}

#[test]
fn test_random() {
    let n = if cfg!(miri) { 100 } else { 1000000 };
    let mut buffer = ryu::Buffer::new();
    for _ in 0..n {
        let f: f32 = rand::random();
        assert_eq!(f, buffer.format_finite(f).parse().unwrap());
    }
}

#[test]
#[cfg_attr(miri, ignore)]
fn test_non_finite() {
    for i in 0u32..1 << 23 {
        let f = f32::from_bits((((1 << 8) - 1) << 23) + i);
        assert!(!f.is_finite(), "f={}", f);
        ryu::Buffer::new().format_finite(f);
    }
}

#[test]
fn test_basic() {
    check!(0.0);
    check!(-0.0);
    check!(1.0);
    check!(-1.0);
    assert_eq!(pretty(f32::NAN.copysign(1.0)), "NaN");
    assert_eq!(pretty(f32::NAN.copysign(-1.0)), "NaN");
    assert_eq!(pretty(f32::INFINITY), "inf");
    assert_eq!(pretty(f32::NEG_INFINITY), "-inf");
}

#[test]
fn test_switch_to_subnormal() {
    check!(1.1754944e-38);
}

#[test]
fn test_min_and_max() {
    assert_eq!(f32::from_bits(0x7f7fffff), 3.4028235e38);
    check!(3.4028235e38);
    assert_eq!(f32::from_bits(1), 1e-45);
    check!(1e-45);
}

// Check that we return the exact boundary if it is the shortest
// representation, but only if the original floating point number is even.
#[test]
fn test_boundary_round_even() {
    check!(33554450.0);
    check!(9000000000.0);
    check!(34366720000.0);
}

// If the exact value is exactly halfway between two shortest representations,
// then we round to even. It seems like this only makes a difference if the
// last two digits are ...2|5 or ...7|5, and we cut off the 5.
#[test]
fn test_exact_value_round_even() {
    check!(305404.12);
    check!(8099.0312);
}

#[test]
fn test_lots_of_trailing_zeros() {
    // Pattern for the first test: 00111001100000000000000000000000
    check!(0.00024414062);
    check!(0.0024414062);
    check!(0.0043945312);
    check!(0.0063476562);
}

#[test]
fn test_regression() {
    check!(4.7223665e21);
    check!(8388608.0);
    check!(16777216.0);
    check!(33554436.0);
    check!(67131496.0);
    check!(1.9310392e-38);
    check!(-2.47e-43);
    check!(1.993244e-38);
    check!(4103.9004);
    check!(5339999700.0);
    check!(6.0898e-39);
    check!(0.0010310042);
    check!(2.882326e17);
    check!(7.038531e-26);
    check!(9.223404e17);
    check!(67108870.0);
    check!(1e-44);
    check!(2.816025e14);
    check!(9.223372e18);
    check!(1.5846086e29);
    check!(1.1811161e19);
    check!(5.368709e18);
    check!(4.6143166e18);
    check!(0.007812537);
    check!(1e-45);
    check!(1.18697725e20);
    check!(1.00014165e-36);
    check!(200.0);
    check!(33554432.0);
}

#[test]
fn test_looks_like_pow5() {
    // These numbers have a mantissa that is the largest power of 5 that fits,
    // and an exponent that causes the computation for q to result in 10, which
    // is a corner case for Ryū.
    assert_eq!(f32::from_bits(0x5D1502F9), 6.7108864e17);
    check!(6.7108864e17);
    assert_eq!(f32::from_bits(0x5D9502F9), 1.3421773e18);
    check!(1.3421773e18);
    assert_eq!(f32::from_bits(0x5E1502F9), 2.6843546e18);
    check!(2.6843546e18);
}

#[test]
fn test_output_length() {
    check!(1.0); // already tested in Basic
    check!(1.2);
    check!(1.23);
    check!(1.234);
    check!(1.2345);
    check!(1.23456);
    check!(1.234567);
    check!(1.2345678);
    check!(1.23456735e-36);
}