Performance comparison between switch statement and jump table

switch.go

package main

import "fmt"
import "time"
import "math/rand"

var jumpTable = [32]func(){
	noop, noop, noop, noop,
	noop, noop, noop, noop,
	noop, noop, noop, noop,
	noop, noop, noop, noop,
	noop, noop, noop, noop,
	noop, noop, noop, noop,
	noop, noop, noop, noop,
	noop, noop, noop, noop,
}

func noop() {
}

func runJumpTable(code []uint32) {
	for _, c := range code {
		jumpTable[c]()
	}
}

func runSwitch(code []uint32) {
	for _, c := range code {
		switch c {
		case 0:
		case 1:
		case 2:
		case 3:
		case 4:
		case 5:
		case 6:
		case 7:
		case 8:
		case 9:
		case 10:
		case 11:
		case 12:
		case 13:
		case 14:
		case 15:
		case 16:
		case 17:
		case 18:
		case 19:
		case 20:
		case 21:
		case 22:
		case 23:
		case 24:
		case 25:
		case 26:
		case 27:
		case 28:
		case 29:
		case 30:
		case 31:
		}
	}
}

func main() {
	var code [5000]uint32
	for i := 0; i < 5000; i++ {
		code[i] = rand.Uint32() % 32
	}

	t := time.Now()
	runSwitch(code[:])
	fmt.Println("switch cost:", time.Since(t))

	t = time.Now()
	runJumpTable(code[:])
	fmt.Println("jumt table cost:", time.Since(t))
}