Function mul_add

pub fn mul_add(x: f32, y: f32, z: f32) -> f32

🔬This is a nightly-only experimental API. (core_float_math)

Experimental version of mul_add in core. See f32::mul_add for details.

Examples

#![feature(core_float_math)]

use core::f32;

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

assert_eq!(f32::mul_add(m, x, b), 100.0);
assert_eq!(m * x + b, 100.0);

let one_plus_eps = 1.0_f32 + f32::EPSILON;
let one_minus_eps = 1.0_f32 - f32::EPSILON;
let minus_one = -1.0_f32;

// The exact result (1 + eps) * (1 - eps) = 1 - eps * eps.
assert_eq!(f32::mul_add(one_plus_eps, one_minus_eps, minus_one), -f32::EPSILON * f32::EPSILON);
// Different rounding with the non-fused multiply and add.
assert_eq!(one_plus_eps * one_minus_eps + minus_one, 0.0);

This standalone function is for testing only. It will be stabilized as an inherent method.