Auto-increment addressing can be used with linked lists to efficiently traverse the list and perform operations on each node. In a singly linked list, each node contains a value and a pointer to the next node. Auto-increment addressing simplifies the process of moving from one node to the next without the need for explicit pointer manipulation. Here’s how you can use auto-increment with linked lists:
Assuming a singly linked list node structure like this:
struct Node {
int value;
struct Node* next;
};
And let’s assume we have a linked list with three nodes: A -> B -> C, where A is the head node.
; Assume R1 contains the memory address of the head node (A)
TRAVERSE:
LOAD R2, [R1] ; Load the value at the current node (node A: R2 = A.value)
; Here, you can perform operations with the value in R2 (e.g., print, compare, etc.)
; Example: Print the value in R2 (assuming an output routine to display R2 value)
OUT R2
LOAD R1, [R1+4] ; Load the address of the next node (node B) and increment R1
CMP R1, #0 ; Compare R1 with 0 to check if we reached the end of the list (null pointer)
JNZ TRAVERSE ; Jump back to TRAVERSE if R1 is not equal to 0 (i.e., list traversal is not completed)
The [R1+4] auto-increment addressing mode is used to access the next node in the linked list. The pointer to the next node is located at an offset of 4 bytes from the current node’s memory address. After loading the next node’s address into R1, the loop continues to traverse the list until it reaches the end (i.e., R1 becomes 0, indicating a null pointer).
