If-else implementation in assembly in ARM Architecture - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the basic purpose of an if-else statement in programming?

An if-else statement lets the program choose between two paths based on a condition: one path if the condition is true, and another if it is false.

beginner

How is a condition typically checked in ARM assembly for an if-else structure?

A condition is checked by comparing values using instructions like CMP, which sets flags in the processor. Then conditional branch instructions decide the flow based on those flags.

beginner

What ARM instruction is used to compare two registers?

The CMP instruction compares two registers by subtracting one from the other and setting condition flags without storing the result.

intermediate

Name two ARM conditional branch instructions used in if-else implementations.

BNE (Branch if Not Equal) and BEQ (Branch if Equal) are commonly used to control flow after a comparison.

beginner

Why is it important to use labels in ARM assembly when implementing if-else?

Labels mark positions in code to jump to, allowing the program to skip or execute blocks of instructions based on conditions, mimicking if-else logic.

Which ARM instruction sets the condition flags for branching decisions?

A CMP

B MOV

C ADD

D STR

CMP compares two values and sets condition flags used by branch instructions.

What does the BNE instruction do in ARM assembly?

A Branches if values are not equal

B Branches if values are equal

C Branches always

D Branches if greater

BNE means Branch if Not Equal, used after a CMP instruction.

In an if-else structure, what is the role of labels in ARM assembly?

A Store data

B Mark jump points for branching

C Perform arithmetic

D Load values

Labels mark where the program should jump to based on conditions.

Which instruction would you use to jump unconditionally in ARM assembly?

A BEQ

B BNE

C B

D CMP

The B instruction causes an unconditional branch to a label.

What is the first step in implementing an if-else in ARM assembly?

A Use a branch instruction

B Define labels

C Load values

D Compare values with CMP

You first compare values to set condition flags for branching.

Explain how an if-else statement is implemented in ARM assembly language.

Think about how the program decides which code to run based on a condition.

Describe the role of the CMP and branch instructions in controlling program flow for if-else in ARM assembly.

Focus on how comparison and branching work together.