Arithmetic Operations

7 min read | Beginner Level

Basic Arithmetic Instructions

Assembly language provides fundamental arithmetic operations that mirror basic math. Our compiler supports ADD, SUB, and MUL instructions.

ADD Instruction

ADD performs addition of two operands:

ADD Rd, Rn, operand

Examples:

MOV R0, #10
MOV R1, #20
ADD R2, R0, R1   // R2 = R0 + R1 = 30

MOV R3, #15
ADD R4, R3, #5   // R4 = R3 + 5 = 20

SUB Instruction

SUB performs subtraction:

SUB Rd, Rn, operand

Examples:

MOV R0, #50
MOV R1, #20
SUB R2, R0, R1   // R2 = R0 - R1 = 30

MOV R3, #100
SUB R4, R3, #25  // R4 = R3 - 25 = 75

MUL Instruction

MUL performs multiplication:

MUL Rd, Rn, Rm

Examples:

MOV R0, #6
MOV R1, #7
MUL R2, R0, R1   // R2 = R0 * R1 = 42

MOV R3, #12
MOV R4, #5
MUL R5, R3, R4   // R5 = 60

Practical Example: Computing Average

// Calculate average of three numbers
MOV R0, #10      // First number
MOV R1, #20      // Second number
MOV R2, #30      // Third number

ADD R3, R0, R1   // R3 = 10 + 20 = 30
ADD R3, R3, R2   // R3 = 30 + 30 = 60 (sum)

MOV R4, #3       // Divisor
// Note: Division not directly supported in basic version
// Result R3 contains sum (60)
HALT

Complex Calculations

Example: Calculate (5 + 3) * (7 - 2)

MOV R0, #5
MOV R1, #3
ADD R2, R0, R1   // R2 = 8

MOV R3, #7
MOV R4, #2
SUB R5, R3, R4   // R5 = 5

MUL R6, R2, R5   // R6 = 8 * 5 = 40
HALT