use crate::float::Float; | |
use crate::int::Int; | |
/// Returns `a` raised to the power `b` | |
fn pow<F: Float>(a: F, b: i32) -> F { | |
let mut a = a; | |
let recip = b < 0; | |
let mut pow = Int::abs_diff(b, 0); | |
let mut mul = F::ONE; | |
loop { | |
if (pow & 1) != 0 { | |
mul *= a; | |
} | |
pow >>= 1; | |
if pow == 0 { | |
break; | |
} | |
a *= a; | |
} | |
if recip { | |
F::ONE / mul | |
} else { | |
mul | |
} | |
} | |
intrinsics! { | |
pub extern "C" fn __powisf2(a: f32, b: i32) -> f32 { | |
pow(a, b) | |
} | |
pub extern "C" fn __powidf2(a: f64, b: i32) -> f64 { | |
pow(a, b) | |
} | |
} |