compiler_builtins/math/libm_math/
fabs.rs

1/// Absolute value (magnitude) (f16)
2///
3/// Calculates the absolute value (magnitude) of the argument `x`,
4/// by direct manipulation of the bit representation of `x`.
5#[cfg(f16_enabled)]
6#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
7pub fn fabsf16(x: f16) -> f16 {
8    super::generic::fabs(x)
9}
10
11/// Absolute value (magnitude) (f32)
12///
13/// Calculates the absolute value (magnitude) of the argument `x`,
14/// by direct manipulation of the bit representation of `x`.
15#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
16pub fn fabsf(x: f32) -> f32 {
17    select_implementation! {
18        name: fabsf,
19        use_arch: all(target_arch = "wasm32", intrinsics_enabled),
20        args: x,
21    }
22
23    super::generic::fabs(x)
24}
25
26/// Absolute value (magnitude) (f64)
27///
28/// Calculates the absolute value (magnitude) of the argument `x`,
29/// by direct manipulation of the bit representation of `x`.
30#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
31pub fn fabs(x: f64) -> f64 {
32    select_implementation! {
33        name: fabs,
34        use_arch: all(target_arch = "wasm32", intrinsics_enabled),
35        args: x,
36    }
37
38    super::generic::fabs(x)
39}
40
41/// Absolute value (magnitude) (f128)
42///
43/// Calculates the absolute value (magnitude) of the argument `x`,
44/// by direct manipulation of the bit representation of `x`.
45#[cfg(f128_enabled)]
46#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
47pub fn fabsf128(x: f128) -> f128 {
48    super::generic::fabs(x)
49}
50
51#[cfg(test)]
52mod tests {
53    use super::*;
54    use crate::support::Float;
55
56    /// Based on https://en.cppreference.com/w/cpp/numeric/math/fabs
57    fn spec_test<F: Float>(f: impl Fn(F) -> F) {
58        assert_biteq!(f(F::ZERO), F::ZERO);
59        assert_biteq!(f(F::NEG_ZERO), F::ZERO);
60        assert_biteq!(f(F::INFINITY), F::INFINITY);
61        assert_biteq!(f(F::NEG_INFINITY), F::INFINITY);
62        assert!(f(F::NAN).is_nan());
63
64        // Not spec rewquired but we expect it
65        assert!(f(F::NAN).is_sign_positive());
66        assert!(f(F::from_bits(F::NAN.to_bits() | F::SIGN_MASK)).is_sign_positive());
67    }
68
69    #[test]
70    #[cfg(f16_enabled)]
71    fn sanity_check_f16() {
72        assert_eq!(fabsf16(-1.0f16), 1.0);
73        assert_eq!(fabsf16(2.8f16), 2.8);
74    }
75
76    #[test]
77    #[cfg(f16_enabled)]
78    fn spec_tests_f16() {
79        spec_test::<f16>(fabsf16);
80    }
81
82    #[test]
83    fn sanity_check_f32() {
84        assert_eq!(fabsf(-1.0f32), 1.0);
85        assert_eq!(fabsf(2.8f32), 2.8);
86    }
87
88    #[test]
89    fn spec_tests_f32() {
90        spec_test::<f32>(fabsf);
91    }
92
93    #[test]
94    fn sanity_check_f64() {
95        assert_eq!(fabs(-1.0f64), 1.0);
96        assert_eq!(fabs(2.8f64), 2.8);
97    }
98
99    #[test]
100    fn spec_tests_f64() {
101        spec_test::<f64>(fabs);
102    }
103
104    #[test]
105    #[cfg(f128_enabled)]
106    fn sanity_check_f128() {
107        assert_eq!(fabsf128(-1.0f128), 1.0);
108        assert_eq!(fabsf128(2.8f128), 2.8);
109    }
110
111    #[test]
112    #[cfg(f128_enabled)]
113    fn spec_tests_f128() {
114        spec_test::<f128>(fabsf128);
115    }
116}
compiler_builtins/math/libm_math/fabs.rs

compiler_builtins/math/libm_math/
fabs.rs
