<a href="/pkg/math/big/"><code>math/big</code></a>.
You can also examine what the compiler emits as assembly code
(the actual output may differ from what you see here):
</p>

<pre>
$ cat x.go
package main

func main() {
	println(3)
}
$ GOOS=linux GOARCH=amd64 go tool compile -S x.go        # or: go build -gcflags -S x.go
"".main STEXT size=74 args=0x0 locals=0x10

		log.Fatal(err)
	}
	s := string(bs)

	// Diagnose common mistakes people make,
	// since there is no apifmt to format these files.
	// The missing final newline is important for the
	// final release step of cat next/*.txt >go1.X.txt.
	// If the files don't end in full lines, the concatenation goes awry.
	if strings.Contains(s, "\r") {
		log.Printf("%s: contains CRLFs", filename)
		exitCode = 1
	}