1#[cfg(f16_enabled)]
2#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
3pub fn scalbnf16(x: f16, n: i32) -> f16 {
4 super::generic::scalbn(x, n)
5}
6
7#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
8pub fn scalbnf(x: f32, n: i32) -> f32 {
9 super::generic::scalbn(x, n)
10}
11
12#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
13pub fn scalbn(x: f64, n: i32) -> f64 {
14 super::generic::scalbn(x, n)
15}
16
17#[cfg(f128_enabled)]
18#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
19pub fn scalbnf128(x: f128, n: i32) -> f128 {
20 super::generic::scalbn(x, n)
21}
22
23#[cfg(test)]
24mod tests {
25 use super::*;
26 use crate::support::{CastFrom, CastInto, Float};
27
28 // Tests against N3220
29 fn spec_test<F: Float>(f: impl Fn(F, i32) -> F)
30 where
31 u32: CastInto<F::Int>,
32 F::Int: CastFrom<i32>,
33 F::Int: CastFrom<u32>,
34 {
35 // `scalbn(±0, n)` returns `±0`.
36 assert_biteq!(f(F::NEG_ZERO, 10), F::NEG_ZERO);
37 assert_biteq!(f(F::NEG_ZERO, 0), F::NEG_ZERO);
38 assert_biteq!(f(F::NEG_ZERO, -10), F::NEG_ZERO);
39 assert_biteq!(f(F::ZERO, 10), F::ZERO);
40 assert_biteq!(f(F::ZERO, 0), F::ZERO);
41 assert_biteq!(f(F::ZERO, -10), F::ZERO);
42
43 // `scalbn(x, 0)` returns `x`.
44 assert_biteq!(f(F::MIN, 0), F::MIN);
45 assert_biteq!(f(F::MAX, 0), F::MAX);
46 assert_biteq!(f(F::INFINITY, 0), F::INFINITY);
47 assert_biteq!(f(F::NEG_INFINITY, 0), F::NEG_INFINITY);
48 assert_biteq!(f(F::ZERO, 0), F::ZERO);
49 assert_biteq!(f(F::NEG_ZERO, 0), F::NEG_ZERO);
50
51 // `scalbn(±∞, n)` returns `±∞`.
52 assert_biteq!(f(F::INFINITY, 10), F::INFINITY);
53 assert_biteq!(f(F::INFINITY, -10), F::INFINITY);
54 assert_biteq!(f(F::NEG_INFINITY, 10), F::NEG_INFINITY);
55 assert_biteq!(f(F::NEG_INFINITY, -10), F::NEG_INFINITY);
56
57 // NaN should remain NaNs.
58 assert!(f(F::NAN, 10).is_nan());
59 assert!(f(F::NAN, 0).is_nan());
60 assert!(f(F::NAN, -10).is_nan());
61 assert!(f(-F::NAN, 10).is_nan());
62 assert!(f(-F::NAN, 0).is_nan());
63 assert!(f(-F::NAN, -10).is_nan());
64 }
65
66 #[test]
67 #[cfg(f16_enabled)]
68 fn spec_test_f16() {
69 spec_test::<f16>(scalbnf16);
70 }
71
72 #[test]
73 fn spec_test_f32() {
74 spec_test::<f32>(scalbnf);
75 }
76
77 #[test]
78 fn spec_test_f64() {
79 spec_test::<f64>(scalbn);
80 }
81
82 #[test]
83 #[cfg(f128_enabled)]
84 fn spec_test_f128() {
85 spec_test::<f128>(scalbnf128);
86 }
87}
88