gistfile1.txt

$ cat test.go 
package main

import "fmt"

var x int64 = +1

func main() {
	m := signum(x)
	fmt.Println(m)
}

//go:noinline
func signum(x int64) int {
	return int((x >> 63) | int64(uint64(-x)>>63))
}
vagrant@vagrant-ubuntu-trusty-32:~/gopath/src/github.com/EricLagergren/decimal$ go run test.go 
0