ArcCos Challenge

The objective is to build the fastest replacement for RTL ArcCos.

ArcCos returns the inverse cosine of X. X must be between -1 and 1. The return value will be in the range [-Pi/2..Pi/2], in radians.

There are three overloaded functions differing in the input and output datatype.

function ArcCos(const X: Extended): Extended; overload;
function ArcCos(const X: Double): Double; overload;
function ArcCos(const X: Single): Single; overload;

Validation and Benchmark Tool: