[AlotOfReading]

I'm pretty sure it's not faster, but it was fun to write:

    float asin(float x) {
      float x2 = 1.0f-fabs(x);
      u32 i = bitcast(x2);
      i = 0x5f3759df - (i>>1);
      float inv = bitcast(i);
      return copysign(pi/2-pi/2*(x2*inv),x);
    }

Courtesy of evil floating point bithacks.

[teo_zero]

The bad thing about this method is that it's slower than native CPU instructions. The good thing is that the result is very precise for at least 2 values of x, namely 1.0 and -1.0

JK

[AlotOfReading]

Yeah, it's an interesting approximation. It follows the shape of the curve pretty well except around 0, much better than low degree polynomials. Polynomial approximations have much better relative error bounds though.

[jacquesm]

That could do with some subtitles.

[irishcoffee]

https://en.wikipedia.org/wiki/Fast_inverse_square_root

[def-pri-pub]

> floating point bithacks

The forbidden magic

[adampunk]

// what the fuck

[chuckadams]

You brought Zalgo. I blame this decade on you.

[moffkalast]

> float asinine(float x) {

FTFY :P