Trait num_traits::ops::mul_add::MulAdd

source · [−]
pub trait MulAdd<A = Self, B = Self> {
    type Output;

    fn mul_add(self, a: A, b: B) -> Self::Output;
}
Expand description

Fused multiply-add. Computes (self * a) + b with only one rounding error, yielding a more accurate result than an unfused multiply-add.

Using mul_add can be more performant than an unfused multiply-add if the target architecture has a dedicated fma CPU instruction.

Note that A and B are Self by default, but this is not mandatory.

Example

use std::f32;

let m = 10.0_f32;
let x = 4.0_f32;
let b = 60.0_f32;

// 100.0
let abs_difference = (m.mul_add(x, b) - (m*x + b)).abs();

assert!(abs_difference <= 100.0 * f32::EPSILON);

Required Associated Types

The resulting type after applying the fused multiply-add.

Required Methods

Performs the fused multiply-add operation (self * a) + b

Implementations on Foreign Types

Implementors