core/num/imp/
libm.rs

1//! Bindings to math functions provided by the system `libm` or by the `libm` crate, exposed
2//! via `compiler-builtins`.
3//!
4//! The functions in the root of this module are "guaranteed" to be available; see the
5//! `full_availability` module in compiler-builtins for details.
6
7// SAFETY: These symbols have standard interfaces in C and are defined by `libm`, or are
8// provided by `compiler-builtins` on unsupported platforms.
9#[allow(dead_code)] // This list reflects what is available rather than what is consumed.
10unsafe extern "C" {
11    pub(crate) safe fn cbrt(x: f64) -> f64;
12    pub(crate) safe fn cbrtf(n: f32) -> f32;
13    pub(crate) safe fn ceil(x: f64) -> f64;
14    pub(crate) safe fn ceilf(x: f32) -> f32;
15    pub(crate) safe fn ceilf128(x: f128) -> f128;
16    pub(crate) safe fn ceilf16(x: f16) -> f16;
17    pub(crate) safe fn copysign(x: f64, y: f64) -> f64;
18    pub(crate) safe fn copysignf(x: f32, y: f32) -> f32;
19    pub(crate) safe fn copysignf128(x: f128, y: f128) -> f128;
20    pub(crate) safe fn copysignf16(x: f16, y: f16) -> f16;
21    pub(crate) safe fn fabs(x: f64) -> f64;
22    pub(crate) safe fn fabsf(x: f32) -> f32;
23    pub(crate) safe fn fabsf128(x: f128) -> f128;
24    pub(crate) safe fn fabsf16(x: f16) -> f16;
25    pub(crate) safe fn fdim(a: f64, b: f64) -> f64;
26    pub(crate) safe fn fdimf(a: f32, b: f32) -> f32;
27    pub(crate) safe fn fdimf128(x: f128, y: f128) -> f128;
28    pub(crate) safe fn fdimf16(x: f16, y: f16) -> f16;
29    pub(crate) safe fn floor(x: f64) -> f64;
30    pub(crate) safe fn floorf(x: f32) -> f32;
31    pub(crate) safe fn floorf128(x: f128) -> f128;
32    pub(crate) safe fn floorf16(x: f16) -> f16;
33    pub(crate) safe fn fma(x: f64, y: f64, z: f64) -> f64;
34    pub(crate) safe fn fmaf(x: f32, y: f32, z: f32) -> f32;
35    pub(crate) safe fn fmaf128(x: f128, y: f128, z: f128) -> f128;
36    pub(crate) safe fn fmax(x: f64, y: f64) -> f64;
37    pub(crate) safe fn fmaxf(x: f32, y: f32) -> f32;
38    pub(crate) safe fn fmaxf128(x: f128, y: f128) -> f128;
39    pub(crate) safe fn fmaxf16(x: f16, y: f16) -> f16;
40    pub(crate) safe fn fmaximum(x: f64, y: f64) -> f64;
41    pub(crate) safe fn fmaximumf(x: f32, y: f32) -> f32;
42    pub(crate) safe fn fmaximumf128(x: f128, y: f128) -> f128;
43    pub(crate) safe fn fmaximumf16(x: f16, y: f16) -> f16;
44    pub(crate) safe fn fmin(x: f64, y: f64) -> f64;
45    pub(crate) safe fn fminf(x: f32, y: f32) -> f32;
46    pub(crate) safe fn fminf128(x: f128, y: f128) -> f128;
47    pub(crate) safe fn fminf16(x: f16, y: f16) -> f16;
48    pub(crate) safe fn fminimum(x: f64, y: f64) -> f64;
49    pub(crate) safe fn fminimumf(x: f32, y: f32) -> f32;
50    pub(crate) safe fn fminimumf128(x: f128, y: f128) -> f128;
51    pub(crate) safe fn fminimumf16(x: f16, y: f16) -> f16;
52    pub(crate) safe fn fmod(x: f64, y: f64) -> f64;
53    pub(crate) safe fn fmodf(x: f32, y: f32) -> f32;
54    pub(crate) safe fn fmodf128(x: f128, y: f128) -> f128;
55    pub(crate) safe fn fmodf16(x: f16, y: f16) -> f16;
56    pub(crate) safe fn rint(x: f64) -> f64;
57    pub(crate) safe fn rintf(x: f32) -> f32;
58    pub(crate) safe fn rintf128(x: f128) -> f128;
59    pub(crate) safe fn rintf16(x: f16) -> f16;
60    pub(crate) safe fn round(x: f64) -> f64;
61    pub(crate) safe fn roundeven(x: f64) -> f64;
62    pub(crate) safe fn roundevenf(x: f32) -> f32;
63    pub(crate) safe fn roundevenf128(x: f128) -> f128;
64    pub(crate) safe fn roundevenf16(x: f16) -> f16;
65    pub(crate) safe fn roundf(x: f32) -> f32;
66    pub(crate) safe fn roundf128(x: f128) -> f128;
67    pub(crate) safe fn roundf16(x: f16) -> f16;
68    pub(crate) safe fn sqrt(x: f64) -> f64;
69    pub(crate) safe fn sqrtf(x: f32) -> f32;
70    pub(crate) safe fn sqrtf128(x: f128) -> f128;
71    pub(crate) safe fn sqrtf16(x: f16) -> f16;
72    pub(crate) safe fn trunc(x: f64) -> f64;
73    pub(crate) safe fn truncf(x: f32) -> f32;
74    pub(crate) safe fn truncf128(x: f128) -> f128;
75    pub(crate) safe fn truncf16(x: f16) -> f16;
76}
77
78/// These symbols will be available when `std` is available, and on many no-std platforms. However,
79/// since this isn't a guarantee, we cannot rely on them for stable implementations.
80pub(crate) mod likely_available {
81    cfg_select! {
82        all(target_env = "msvc", target_arch = "x86") => {
83            /* these symbols are not available on x86 msvc */
84        }
85        _ => {
86            #[allow(dead_code)]
87            unsafe extern "C" {
88                pub(crate) safe fn acosf(n: f32) -> f32;
89                pub(crate) safe fn asinf(n: f32) -> f32;
90                pub(crate) safe fn atan2f(a: f32, b: f32) -> f32;
91                pub(crate) safe fn atanf(n: f32) -> f32;
92                pub(crate) safe fn cosf(x: f32) -> f32;
93                pub(crate) safe fn coshf(n: f32) -> f32;
94                pub(crate) safe fn erfcf(x: f32) -> f32;
95                pub(crate) safe fn erff(x: f32) -> f32;
96                pub(crate) safe fn exp2f(x: f32) -> f32;
97                pub(crate) safe fn expf(x: f32) -> f32;
98                pub(crate) safe fn expm1f(n: f32) -> f32;
99                pub(crate) safe fn hypotf(x: f32, y: f32) -> f32;
100                pub(crate) safe fn ldexpf(f: f32, n: i32) -> f32;
101                pub(crate) safe fn log10f(x: f32) -> f32;
102                pub(crate) safe fn log1pf(n: f32) -> f32;
103                pub(crate) safe fn log2f(x: f32) -> f32;
104                pub(crate) safe fn logf(x: f32) -> f32;
105                pub(crate) safe fn powf(x: f32, y: f32) -> f32;
106                pub(crate) safe fn sinf(x: f32) -> f32;
107                pub(crate) safe fn sinhf(n: f32) -> f32;
108                pub(crate) safe fn tanf(n: f32) -> f32;
109                pub(crate) safe fn tanhf(n: f32) -> f32;
110                pub(crate) safe fn tgammaf(x: f32) -> f32;
111            }
112        }
113    }
114
115    #[allow(dead_code)]
116    unsafe extern "C" {
117        pub(crate) safe fn acos(x: f64) -> f64;
118        pub(crate) safe fn asin(x: f64) -> f64;
119        pub(crate) safe fn atan(x: f64) -> f64;
120        pub(crate) safe fn atan2(x: f64, y: f64) -> f64;
121        pub(crate) safe fn cos(x: f64) -> f64;
122        pub(crate) safe fn cosh(x: f64) -> f64;
123        pub(crate) safe fn erf(x: f64) -> f64;
124        pub(crate) safe fn erfc(x: f64) -> f64;
125        pub(crate) safe fn exp(x: f64) -> f64;
126        pub(crate) safe fn exp2(x: f64) -> f64;
127        pub(crate) safe fn expm1(x: f64) -> f64;
128        pub(crate) safe fn hypot(x: f64, y: f64) -> f64;
129        pub(crate) safe fn ldexp(f: f64, n: i32) -> f64;
130        pub(crate) safe fn log(x: f64) -> f64;
131        pub(crate) safe fn log10(x: f64) -> f64;
132        pub(crate) safe fn log1p(x: f64) -> f64;
133        pub(crate) safe fn log2(x: f64) -> f64;
134        pub(crate) safe fn pow(x: f64, y: f64) -> f64;
135        pub(crate) safe fn sin(x: f64) -> f64;
136        pub(crate) safe fn sinh(x: f64) -> f64;
137        pub(crate) safe fn tan(x: f64) -> f64;
138        pub(crate) safe fn tanh(x: f64) -> f64;
139        pub(crate) safe fn tgamma(x: f64) -> f64;
140    }
141}
142
143/// These symbols exist on some platforms but do not have a compiler-builtins fallback.
144pub(crate) mod maybe_available {
145    #[allow(dead_code)]
146    unsafe extern "C" {
147        pub(crate) safe fn acosf128(x: f128) -> f128;
148        pub(crate) safe fn asinf128(x: f128) -> f128;
149        pub(crate) safe fn atanf128(x: f128) -> f128;
150        pub(crate) safe fn cbrtf128(x: f128) -> f128;
151        pub(crate) safe fn cosf128(x: f128) -> f128;
152        pub(crate) safe fn erff128(x: f128) -> f128;
153        pub(crate) safe fn expf128(x: f128) -> f128;
154        pub(crate) safe fn exp2f128(x: f128) -> f128;
155        pub(crate) safe fn expm1f128(x: f128) -> f128;
156        pub(crate) safe fn hypotf128(x: f128, y: f128) -> f128;
157        pub(crate) safe fn ldexpf128(f: f128, n: i32) -> f128;
158        pub(crate) safe fn log10f128(x: f128) -> f128;
159        pub(crate) safe fn log1pf128(x: f128) -> f128;
160        pub(crate) safe fn log2f128(x: f128) -> f128;
161        pub(crate) safe fn logf128(x: f128) -> f128;
162        pub(crate) safe fn powf128(x: f128, y: f128) -> f128;
163        pub(crate) safe fn sinf128(x: f128) -> f128;
164        pub(crate) safe fn tanf128(x: f128) -> f128;
165        pub(crate) safe fn tanhf128(x: f128) -> f128;
166        pub(crate) safe fn tgammaf128(x: f128) -> f128;
167    }
168}
core/num/imp/libm.rs

core/num/imp/
libm.rs
