pub fn sqrtf(mut d: f32) -> f32 {
    let mut q = 0.5;

    d = if d < 0. { f32::NAN } else { d };

    if d < 5.293_955_920_339_377_e-23 {
        d *= 1.888_946_593_147_858_e+22;
        q = 7.275_957_614_183_426_e-12 * 0.5;
    }

    if d > 1.844_674_407_370_955_2_e+19 {
        d *= 5.421_010_862_427_522_e-20;
        q = 4_294_967_296. * 0.5;
    }

    // http://en.wikipedia.org/wiki/Fast_inverse_square_root
    let mut x = f32::from_bits(0x_5f37_5a86 - ((d + 1e-45).to_bits() >> 1));

    x *= 1.5 - 0.5 * d * x * x;
    x *= 1.5 - 0.5 * d * x * x;
    x *= (1.5 - 0.5 * d * x * x) * d;

    let d2 = (d + x.mul_as_doubled(x)) * x.recpre();

    if (d == 0.) || (d == f32::INFINITY) {
        d
    } else {
        (d2.0 + d2.1) * q
    }
}
/// Square root function
///
/// The error bound of the returned value is 0.5001 ULP.
Square root function
The error bound of the returned value is 0.5001 ULP.
Square root function The error bound of the returned value is 0 . 5001 ULP .
pub fn sqrtf(mut d: f32) -> f32 {
    let mut q = 0.5;
    d = if d < 0. { f32::NAN } else { d };
    if d < 5.293_955_920_339_377_e-23 {
        d *= 1.888_946_593_147_858_e+22;
        q = 7.275_957_614_183_426_e-12 * 0.5;
    }
    if d > 1.844_674_407_370_955_2_e+19 {
        d *= 5.421_010_862_427_522_e-20;
        q = 4_294_967_296. * 0.5;
    }
    // http://en.wikipedia.org/wiki/Fast_inverse_square_root
    let mut x = f32::from_bits(0x_5f37_5a86 - ((d + 1e-45).to_bits() >> 1));
    x *= 1.5 - 0.5 * d * x * x;
    x *= 1.5 - 0.5 * d * x * x;
    x *= (1.5 - 0.5 * d * x * x) * d;
    let d2 = (d + x.mul_as_doubled(x)) * x.recpre();
    if (d == 0.) || (d == f32::INFINITY) {
        d
    } else {
        (d2.0 + d2.1) * q
    }
}
pub fn sqrtf ( mut d : f32 ) -> f32 { let mut q = 0.5 ; d = if d < 0. { f32 :: NAN } else { d } ; if d < 5.293_955_920_339_377_e-23 { d *= 1.888_946_593_147_858_e+22 ; q = 7.275_957_614_183_426_e-12 * 0.5 ; } if d > 1.844_674_407_370_955_2_e+19 { d *= 5.421_010_862_427_522_e-20 ; q = 4_294_967_296. * 0.5 ; } // http://en.wikipedia.org/wiki/Fast_inverse_square_root let mut x = f32 :: from_bits ( 0x_5f37_5a86 - ( ( d + 1e-45 ) . to_bits ( ) >> 1 ) ) ; x *= 1.5 - 0.5 * d * x * x ; x *= 1.5 - 0.5 * d * x * x ; x *= ( 1.5 - 0.5 * d * x * x ) * d ; let d2 = ( d + x . mul_as_doubled ( x ) ) * x . recpre ( ) ; if ( d == 0. ) || ( d == f32 :: INFINITY ) { d } else { ( d2 . 0 + d2 . 1 ) * q } }
Square root function
The error bound of the returned value is 0.5001 ULP.
Square root function The error bound of the returned value is 0 . 5001 ULP .
d
f32
d
f32