package arm

import "encoding/binary"

// Call branches to a PC-relative offset, setting the register X30 to PC+4.
// The offset starts from the address of this instruction and is encoded as "imm26" times 4.
// This instruction is also known as BL (branch with link).
func Call(code []byte, offset uint32) []byte {
	return binary.LittleEndian.AppendUint32(code, EncodeCall(offset))
}

// EncodeCall returns the raw encoding of a call with the given offset.
func EncodeCall(offset uint32) uint32 {
	return uint32(0b100101<<26) | offset
}