index-tag-bit-manipulation.go

package main

import (
	"fmt"
	"math"
)

func main() {
	memAddress := uint(26)

	// memAddressSize := uint(32)
	entriesNum := uint(8)
	indexSize := uint(math.Log2(float64(entriesNum)))
	// tagSize := memAddressSize - indexSize

	tag := memAddress >> indexSize

	ones := ^uint(0)
	indexMask := ones^(ones << indexSize)
	index := memAddress & indexMask

	fmt.Printf("reference %d (%05b)\n", memAddress, memAddress)
	fmt.Printf("index: %03b\ntag: %02b\n", index, tag)
}