This is a simple example/tutorial on how to intermix assembly (x86_64) code with go.

Readme.md

The source files below should be arranged as:

./main.go
./sqrt/sqrt.s
./sqrt/sqrt.go

To run:

>> go build main.go
>> ./main
sqrt(2) = 1.4142135623730951

main.go

package main

import ("fmt"
        "./sqrt")

func main() {
    x := 2.0
    fmt.Printf("sqrt(%v) = %v\n", x, sqrt.Sqrt(x));
}

sqrt.go

package sqrt

/*
extern double as_sqrt(double);
*/
import "C"

func Sqrt(x float64) float64 {
    return float64(C.as_sqrt(C.double(x)))
}

sqrt.S

	.text
	.globl as_sqrt
	.balign 16
	.type as_sqrt, @function

as_sqrt:

	sqrtsd %xmm0, %xmm0
	retq
	
	.size as_sqrt, .-as_sqrt