The return type of Math.Abs is float, so explicit cast to float in the return statement of Mathf.Abs is unnecessary and leads to increase execution time

Mathf.Abs:
public static float Abs(float f) { return (float)Math.Abs(f); }
Custom Abs method:
float Abs (float input) { return Math.Abs(input); }
Math.Abs:
public static float Abs (float value);

Steps to reproduce:
1. Open the attached "1372997-sample" project
2. Enter Play mode
3. Observe the Console

Expected result: executing time of Mathf.Abs is taking the approximately same amount of time as the custom Abs method
Actual result: executing Mathf.Abs takes noticeably more time