Instruction Set

Instruction Set

This page provides a detailed reference for the MVM (Micro Virtual Machine) byte-code instruction set. The VM directly executes the instructions listed here.

Overview

MVM employs a simple, human-readable assembly language. Each instruction is represented by a mnemonic (a short, descriptive word), followed by zero or more arguments. Instructions are generally executed sequentially, unless a control flow instruction alters the execution order.

Instruction Format:

<instruction_name> <argument_1> <argument_2> ...

Example:

MOV G1 R4      // Move the value in register G1 to register R4
ADD G1 G2      // Add the values in G1 and G2, store the result in R4
               // (Most results are automaticly stored in R4)
JMP 10         // Jump to line 10 in the code

Instruction Categories:

To make it easier to understand and navigate, group the instructions into categories based on their functionality:

Data Transfer Instructions:

Instruction	Description	Argument 1	Argument 2
MOV	Moves a value from one register(argument 1) to another (argument 2)	source: Register	destnination: Register
LIT	Loads a Literal(A normal 32 BIT integer) into a register(argument 1)	register: Register	literal: Int

Arithmetic Instructions:

Instruction	Description	Arguments
ADD	Add the values in the two Argument registers and store the result in the destination register.	Argument 1 Register, Argument 2 Register
SUB	Subtract the value in the second Argument register from the first and store the result.	Argument 1 Register, Argument 2 Register
MUL	Multiply the values in the two Argument registers and store the result.	Argument 1 Register, Argument 2 Register
DIV	Divide the value in the first Argument register by the second and store the result (quotient).	Argument 1 Register, Argument 2 Register
MOD	Calculate the remainder (modulus) of the division and store the result.	Argument 1 Register, Argument 2 Register
EQ	Check if the values in two registers are equal. Set R4 to 0 if equal, 1 if not.	Argument 1 Register, Argument 2 Register

Stack Operations:

Instruction	Description	Arguments
PUSH	Push a value from a register onto the stack.	Source Register
POP	Pop a value from the stack and store it in the destination register.	Destination Register
PEEK	Copy the value at the top of the stack to the destination register.	Destination Register

Control Flow Instructions:

Instruction	Description	Arguments
JMP	Unconditionally jump to the specified line number in the program.	Target Instruction Line Number , N/A
JZ	Jump to the specified line number if the value in the test register is zero.	Target Instruction Line Number, Test Register
JNZ	Jump to the specified line number if the value in the test register is not zero.	Target Instruction Line Number, Test Register

Memory Access Instructions:

Instruction	Description	Arguments
LOAD	Load a value from the specified memory address into the destination register.	Memory Address, Destination Register
STORE	Store the value from the source register into the specified memory address.	Source Register, Memory Address

Bitwise Instructions:

Instruction	Description	Arguments
AND	Perform a bitwise AND operation on the values in two registers and store the result in R4.	Argument 1 Register, Argument 2 Register
OR	Perform a bitwise OR operation on the values in two registers and store the result in R4.	Argument 1 Register, Argument 2 Register
XOR	Perform a bitwise XOR operation on the values in two registers and store the result in R4.	Argument 1 Register, Argument 2 Register
NOT	Perform a bitwise NOT operation on the value in the Argument register and store the result in R4.	Argument Register, N/A
SHL	Shift the bits in the Argument register to the left by the specified amount and store the result in R4.	Argument Register, Shift Amount
SHR	Shift the bits in the Argument register to the right by the specified amount and store the result in R4.	Argument Register, Shift Amount

System Calls:

Instruction	Description	Arguments
SYSCALL	Execute the system call specified by the system call number in S1, using the arguments in S2, S3, and S4.	System Call Number (S1), Argument 1 (S2), Argument 2 (S3), Argument 3 (S4)

I/O Instructions:

Instruction	Description	Arguments
PRINTS	Print the value at the top of the stack to the console.	N/A

Argument Types:

• Registers: The MVM uses the following register types:
  • G1-G4: General-purpose registers (used for data manipulation).
  • S1-S4: System call registers (used for system call arguments).
  • R1-R4: Return registers (used for storing results of operations and system calls).
• Memory Addresses: Memory addresses are represented as decimal integers.
• Literal Values: Literal values are also represented as decimal integers.

Additional Notes:

• Line Numbering: Line numbers are implicit and start at 1.
• Case Sensitivity: Instructions and register names are not case-sensitive (e.g., MOV, mov, and Mov are not equivalent).
• Comments: Are not yet implemented

Examples: TODO. Later!!!!! Im you can see how it works!