1#![cfg(all(not(feature = "std"), feature = "compact"))]
2
3// These are adapted from libm, a port of musl libc's libm to Rust.
4// libm can be found online [here](https://github.com/rust-lang/libm),
5// and is similarly licensed under an Apache2.0/MIT license
6
7use core::f64;
8use minimal_lexical::libm;
9
10#[test]
11fn fabsf_sanity_test() {
12    assert_eq!(libm::fabsf(-1.0), 1.0);
13    assert_eq!(libm::fabsf(2.8), 2.8);
14}
15
16/// The spec: https://en.cppreference.com/w/cpp/numeric/math/fabs
17#[test]
18fn fabsf_spec_test() {
19    assert!(libm::fabsf(f32::NAN).is_nan());
20    for f in [0.0, -0.0].iter().copied() {
21        assert_eq!(libm::fabsf(f), 0.0);
22    }
23    for f in [f32::INFINITY, f32::NEG_INFINITY].iter().copied() {
24        assert_eq!(libm::fabsf(f), f32::INFINITY);
25    }
26}
27
28#[test]
29fn sqrtf_sanity_test() {
30    assert_eq!(libm::sqrtf(100.0), 10.0);
31    assert_eq!(libm::sqrtf(4.0), 2.0);
32}
33
34/// The spec: https://en.cppreference.com/w/cpp/numeric/math/sqrt
35#[test]
36fn sqrtf_spec_test() {
37    // Not Asserted: FE_INVALID exception is raised if argument is negative.
38    assert!(libm::sqrtf(-1.0).is_nan());
39    assert!(libm::sqrtf(f32::NAN).is_nan());
40    for f in [0.0, -0.0, f32::INFINITY].iter().copied() {
41        assert_eq!(libm::sqrtf(f), f);
42    }
43}
44
45const POS_ZERO: &[f64] = &[0.0];
46const NEG_ZERO: &[f64] = &[-0.0];
47const POS_ONE: &[f64] = &[1.0];
48const NEG_ONE: &[f64] = &[-1.0];
49const POS_FLOATS: &[f64] = &[99.0 / 70.0, f64::consts::E, f64::consts::PI];
50const NEG_FLOATS: &[f64] = &[-99.0 / 70.0, -f64::consts::E, -f64::consts::PI];
51const POS_SMALL_FLOATS: &[f64] = &[(1.0 / 2.0), f64::MIN_POSITIVE, f64::EPSILON];
52const NEG_SMALL_FLOATS: &[f64] = &[-(1.0 / 2.0), -f64::MIN_POSITIVE, -f64::EPSILON];
53const POS_EVENS: &[f64] = &[2.0, 6.0, 8.0, 10.0, 22.0, 100.0, f64::MAX];
54const NEG_EVENS: &[f64] = &[f64::MIN, -100.0, -22.0, -10.0, -8.0, -6.0, -2.0];
55const POS_ODDS: &[f64] = &[3.0, 7.0];
56const NEG_ODDS: &[f64] = &[-7.0, -3.0];
57const NANS: &[f64] = &[f64::NAN];
58const POS_INF: &[f64] = &[f64::INFINITY];
59const NEG_INF: &[f64] = &[f64::NEG_INFINITY];
60
61const ALL: &[&[f64]] = &[
62    POS_ZERO,
63    NEG_ZERO,
64    NANS,
65    NEG_SMALL_FLOATS,
66    POS_SMALL_FLOATS,
67    NEG_FLOATS,
68    POS_FLOATS,
69    NEG_EVENS,
70    POS_EVENS,
71    NEG_ODDS,
72    POS_ODDS,
73    NEG_INF,
74    POS_INF,
75    NEG_ONE,
76    POS_ONE,
77];
78const POS: &[&[f64]] = &[POS_ZERO, POS_ODDS, POS_ONE, POS_FLOATS, POS_EVENS, POS_INF];
79const NEG: &[&[f64]] = &[NEG_ZERO, NEG_ODDS, NEG_ONE, NEG_FLOATS, NEG_EVENS, NEG_INF];
80
81fn powd(base: f64, exponent: f64, expected: f64) {
82    let res = libm::powd(base, exponent);
83    assert!(
84        if expected.is_nan() {
85            res.is_nan()
86        } else {
87            libm::powd(base, exponent) == expected
88        },
89        "{} ** {} was {} instead of {}",
90        base,
91        exponent,
92        res,
93        expected
94    );
95}
96
97fn powd_test_sets_as_base(sets: &[&[f64]], exponent: f64, expected: f64) {
98    sets.iter().for_each(|s| s.iter().for_each(|val| powd(*val, exponent, expected)));
99}
100
101fn powd_test_sets_as_exponent(base: f64, sets: &[&[f64]], expected: f64) {
102    sets.iter().for_each(|s| s.iter().for_each(|val| powd(base, *val, expected)));
103}
104
105fn powd_test_sets(sets: &[&[f64]], computed: &dyn Fn(f64) -> f64, expected: &dyn Fn(f64) -> f64) {
106    sets.iter().for_each(|s| {
107        s.iter().for_each(|val| {
108            let exp = expected(*val);
109            let res = computed(*val);
110
111            assert!(
112                if exp.is_nan() {
113                    res.is_nan()
114                } else {
115                    exp == res
116                },
117                "test for {} was {} instead of {}",
118                val,
119                res,
120                exp
121            );
122        })
123    });
124}
125
126#[test]
127fn powd_zero_as_exponent() {
128    powd_test_sets_as_base(ALL, 0.0, 1.0);
129    powd_test_sets_as_base(ALL, -0.0, 1.0);
130}
131
132#[test]
133fn powd_one_as_base() {
134    powd_test_sets_as_exponent(1.0, ALL, 1.0);
135}
136
137#[test]
138fn powd_nan_inputs() {
139    // NAN as the base:
140    // (NAN ^ anything *but 0* should be NAN)
141    powd_test_sets_as_exponent(f64::NAN, &ALL[2..], f64::NAN);
142
143    // NAN as the exponent:
144    // (anything *but 1* ^ NAN should be NAN)
145    powd_test_sets_as_base(&ALL[..(ALL.len() - 2)], f64::NAN, f64::NAN);
146}
147
148#[test]
149fn powd_infinity_as_base() {
150    // Positive Infinity as the base:
151    // (+Infinity ^ positive anything but 0 and NAN should be +Infinity)
152    powd_test_sets_as_exponent(f64::INFINITY, &POS[1..], f64::INFINITY);
153
154    // (+Infinity ^ negative anything except 0 and NAN should be 0.0)
155    powd_test_sets_as_exponent(f64::INFINITY, &NEG[1..], 0.0);
156
157    // Negative Infinity as the base:
158    // (-Infinity ^ positive odd ints should be -Infinity)
159    powd_test_sets_as_exponent(f64::NEG_INFINITY, &[POS_ODDS], f64::NEG_INFINITY);
160
161    // (-Infinity ^ anything but odd ints should be == -0 ^ (-anything))
162    // We can lump in pos/neg odd ints here because they don't seem to
163    // cause panics (div by zero) in release mode (I think).
164    powd_test_sets(ALL, &|v: f64| libm::powd(f64::NEG_INFINITY, v), &|v: f64| libm::powd(-0.0, -v));
165}
166
167#[test]
168fn infinity_as_exponent() {
169    // Positive/Negative base greater than 1:
170    // (pos/neg > 1 ^ Infinity should be Infinity - note this excludes NAN as the base)
171    powd_test_sets_as_base(&ALL[5..(ALL.len() - 2)], f64::INFINITY, f64::INFINITY);
172
173    // (pos/neg > 1 ^ -Infinity should be 0.0)
174    powd_test_sets_as_base(&ALL[5..ALL.len() - 2], f64::NEG_INFINITY, 0.0);
175
176    // Positive/Negative base less than 1:
177    let base_below_one = &[POS_ZERO, NEG_ZERO, NEG_SMALL_FLOATS, POS_SMALL_FLOATS];
178
179    // (pos/neg < 1 ^ Infinity should be 0.0 - this also excludes NAN as the base)
180    powd_test_sets_as_base(base_below_one, f64::INFINITY, 0.0);
181
182    // (pos/neg < 1 ^ -Infinity should be Infinity)
183    powd_test_sets_as_base(base_below_one, f64::NEG_INFINITY, f64::INFINITY);
184
185    // Positive/Negative 1 as the base:
186    // (pos/neg 1 ^ Infinity should be 1)
187    powd_test_sets_as_base(&[NEG_ONE, POS_ONE], f64::INFINITY, 1.0);
188
189    // (pos/neg 1 ^ -Infinity should be 1)
190    powd_test_sets_as_base(&[NEG_ONE, POS_ONE], f64::NEG_INFINITY, 1.0);
191}
192
193#[test]
194fn powd_zero_as_base() {
195    // Positive Zero as the base:
196    // (+0 ^ anything positive but 0 and NAN should be +0)
197    powd_test_sets_as_exponent(0.0, &POS[1..], 0.0);
198
199    // (+0 ^ anything negative but 0 and NAN should be Infinity)
200    // (this should panic because we're dividing by zero)
201    powd_test_sets_as_exponent(0.0, &NEG[1..], f64::INFINITY);
202
203    // Negative Zero as the base:
204    // (-0 ^ anything positive but 0, NAN, and odd ints should be +0)
205    powd_test_sets_as_exponent(-0.0, &POS[3..], 0.0);
206
207    // (-0 ^ anything negative but 0, NAN, and odd ints should be Infinity)
208    // (should panic because of divide by zero)
209    powd_test_sets_as_exponent(-0.0, &NEG[3..], f64::INFINITY);
210
211    // (-0 ^ positive odd ints should be -0)
212    powd_test_sets_as_exponent(-0.0, &[POS_ODDS], -0.0);
213
214    // (-0 ^ negative odd ints should be -Infinity)
215    // (should panic because of divide by zero)
216    powd_test_sets_as_exponent(-0.0, &[NEG_ODDS], f64::NEG_INFINITY);
217}
218
219#[test]
220fn special_cases() {
221    // One as the exponent:
222    // (anything ^ 1 should be anything - i.e. the base)
223    powd_test_sets(ALL, &|v: f64| libm::powd(v, 1.0), &|v: f64| v);
224
225    // Negative One as the exponent:
226    // (anything ^ -1 should be 1/anything)
227    powd_test_sets(ALL, &|v: f64| libm::powd(v, -1.0), &|v: f64| 1.0 / v);
228
229    // Factoring -1 out:
230    // (negative anything ^ integer should be (-1 ^ integer) * (positive anything ^ integer))
231    [POS_ZERO, NEG_ZERO, POS_ONE, NEG_ONE, POS_EVENS, NEG_EVENS].iter().for_each(|int_set| {
232        int_set.iter().for_each(|int| {
233            powd_test_sets(ALL, &|v: f64| libm::powd(-v, *int), &|v: f64| {
234                libm::powd(-1.0, *int) * libm::powd(v, *int)
235            });
236        })
237    });
238
239    // Negative base (imaginary results):
240    // (-anything except 0 and Infinity ^ non-integer should be NAN)
241    NEG[1..(NEG.len() - 1)].iter().for_each(|set| {
242        set.iter().for_each(|val| {
243            powd_test_sets(&ALL[3..7], &|v: f64| libm::powd(*val, v), &|_| f64::NAN);
244        })
245    });
246}
247
248#[test]
249fn normal_cases() {
250    assert_eq!(libm::powd(2.0, 20.0), (1 << 20) as f64);
251    assert_eq!(libm::powd(-1.0, 9.0), -1.0);
252    assert!(libm::powd(-1.0, 2.2).is_nan());
253    assert!(libm::powd(-1.0, -1.14).is_nan());
254}
255
256#[test]
257fn fabsd_sanity_test() {
258    assert_eq!(libm::fabsd(-1.0), 1.0);
259    assert_eq!(libm::fabsd(2.8), 2.8);
260}
261
262/// The spec: https://en.cppreference.com/w/cpp/numeric/math/fabs
263#[test]
264fn fabsd_spec_test() {
265    assert!(libm::fabsd(f64::NAN).is_nan());
266    for f in [0.0, -0.0].iter().copied() {
267        assert_eq!(libm::fabsd(f), 0.0);
268    }
269    for f in [f64::INFINITY, f64::NEG_INFINITY].iter().copied() {
270        assert_eq!(libm::fabsd(f), f64::INFINITY);
271    }
272}
273
274#[test]
275fn sqrtd_sanity_test() {
276    assert_eq!(libm::sqrtd(100.0), 10.0);
277    assert_eq!(libm::sqrtd(4.0), 2.0);
278}
279
280/// The spec: https://en.cppreference.com/w/cpp/numeric/math/sqrt
281#[test]
282fn sqrtd_spec_test() {
283    // Not Asserted: FE_INVALID exception is raised if argument is negative.
284    assert!(libm::sqrtd(-1.0).is_nan());
285    assert!(libm::sqrtd(f64::NAN).is_nan());
286    for f in [0.0, -0.0, f64::INFINITY].iter().copied() {
287        assert_eq!(libm::sqrtd(f), f);
288    }
289}
290