Syntax & Conventions

Instructions

Each line contains one instruction:

INSTRUCTION operand1, operand2

Example:

LOAD R0, 10
ADD R0, R1
PRINT R0

Comments

Comments start with ; and continue to the end of the line:

; This is a comment
LOAD R0, 10    ; Load 10 into R0 (inline comment)

Labels

Labels mark locations in code and end with ::

my_label:
    LOAD R0, 10
    JMP my_label    ; Jump to my_label

Labels are used for:

• Jump targets (JMP label)
• Function entry points (CALL function_name)
• Loop start/end points

Case Sensitivity

Romasm is case-insensitive for instructions and registers:

LOAD R0, 10    ; Valid
load r0, 10    ; Also valid
Load R0, 10    ; Also valid

However, labels are case-sensitive, so be consistent!

Registers

Registers are specified as R0 through R8:

LOAD R0, 10      ; R0 is a register
ADD R0, R1       ; Both R0 and R1 are registers

Immediate Values

Literal numbers can be used directly:

LOAD R0, 42      ; 42 is an immediate value
CMP R0, 10       ; 10 is an immediate value

Memory Addresses

Memory is accessed using square brackets:

LOAD R0, [100]   ; Load from memory address 100
STORE R0, [200]  ; Store to memory address 200

Labels as Operands

Labels can be used as jump targets:

JMP my_label     ; Jump to label
CALL my_function ; Call function at label

Loading Constants

; Load common constants into registers
LOAD R1, 1       ; Constant 1
LOAD R2, 2       ; Constant 2
LOAD R3, 100     ; Scaling factor
LOAD R4, 1000    ; Another scaling factor

Loops

; Count from 1 to 10
LOAD R0, 1       ; Counter
LOAD R1, 10      ; Max value

loop:
    PRINT R0
    INC R0
    CMP R0, R1
    JLE loop     ; Jump if R0 <= R1

Conditionals

; If-else pattern
LOAD R0, 10
LOAD R1, 5
CMP R0, R1
JGT greater     ; Jump if R0 > R1
; R0 <= R1
LOAD R2, 0
JMP done

greater:
LOAD R2, 1

done:

Function Calls

; Call a function
LOAD R0, 3000    ; Argument (30 degrees scaled)
CALL sin         ; Call sin function
; Result in R0
PRINT R0

Naming

• Use descriptive labels: loop, is_even, calculate_sum
• Avoid single-letter labels except for very short functions
• Use underscores for multi-word labels: my_function, not myfunction

Comments

• Comment complex logic and algorithms
• Document function inputs/outputs
• Explain scaling factors for fixed-point arithmetic
• Note register usage conventions

Formatting

• Use consistent indentation (spaces or tabs)
• Align labels at the start of lines
• Add blank lines between logical sections
• Group related instructions together

Missing Operands

; ❌ Wrong
ADD R0

; ✅ Correct
ADD R0, R1

Wrong Operand Order

; ADD: reg1 = reg1 + reg2
; ❌ Wrong (if you want R0 = R0 + R1)
ADD R1, R0

; ✅ Correct
ADD R0, R1

Undefined Labels

; ❌ Wrong - label doesn't exist
JMP non_existent_label

; ✅ Correct - define label first
my_label:
    LOAD R0, 10
JMP my_label