math.Abs vs if value < 0

[Diego Augusto Molina]

Hi! I wanted to ask what is the difference between the current implementation of math.Abs and the following:

```go

func Abs(x float64) float64 {

    if x < 0 {

       return -x

    }

   return x

}

```

math.Abs would appear to return a copy of the input with the sign bit set to zero. I tried the special conditions of NaN (the one returned by math.NaN()), +Inf, and -Inf and the above would appear to work the same.

I guess my main question is: would "-x" behave differently under any condition? Was there a particular motivation for the current implementation? Not judging nor asking for any change, just trying to learn.

Thank you!

[Axel Wagner]

It gives a different result for -0: https://go.dev/play/p/LAVIaAZsVNi

Also, the math.Abs implementation is branch-less. Depending on what the compiler makes of either, that might perform better.

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