Machines - Educational Virtual Machine Project ============================================== Playground for the development of simple compilers, an educational exploration of virtual machine architectures and language implementation. This project demonstrates two distinct VM paradigms with complete compilation toolchains from high-level languages down to bytecode execution. NOTE - it's a work in progress, still squashing bugs here and there * Overview This repository contains two fully functional virtual machines built from scratch in C, along with compilers that target them from higher-level languages. The project showcases the entire compilation pipeline: lexing, parsing, AST generation, code generation, bytecode serialization, and execution. * Virtual Machines アトム (Atom) - Stack-Based VM A minimalist stack-based virtual machine inspired by stack machine architectures and functional programming principles. Architecture: - Word Size: 64-bit unsigned integers - Stack: 256 words - Memory: 65,535 words - Execution Model: Push/pop operations on implicit stack - Instruction Set: 22 operations Key Features: - Stack-based arithmetic and control flow - Function calls with return stack - Tuple data structures - Memory-mapped data segment Instruction Categories: - Memory Operations: LOAD, STORE, PUSH - Arithmetic: ADD, SUB, MUL, DIV, INC - Control Flow: JMP, JEQ, JNE, CALL, RET - Data Structures: MAKE_TUPLE - I/O: PRINT プルート (Pluto) - Register-Based VM A register-based virtual machine modeled after x86-64 architecture with simplified instruction encoding and 4 general-purpose registers. Architecture: - Word Size: 64-bit signed integers - Registers: 4 GP registers (AX, BX, CX, DX) + PC, SP, Flags - Stack: 2,048 words - Memory: 32KB addressable - Execution Model: Explicit register manipulation - Instruction Set: 29 operations Key Features: - Multiple addressing modes (register, immediate, memory, indirect) - Flag register (Zero, Negative, Positive) - System call interface (read, write, atoi, exit) - Rich conditional branching Instruction Categories: - Data Movement: MOV, PSH, POP - Arithmetic: ADD, SUB, MUL, DIV, MOD, INC, DEC - Bitwise: AND, BOR, XOR, NOT, SHL, SHR - Comparison: CMP - Control Flow: JMP, JEQ, JNE, JLE, JLT, JGE, JGT, CALL, RET - System: SYSCALL * Compilation Pipeline High-Level Language (LISP/StackLang) ↓ [Ruby Lexer] Tokens ↓ [Ruby Parser] Abstract Syntax Tree ↓ [Ruby Compiler] Assembly (.atom/.pluto) ↓ [C Assembler] Bytecode (binary format) ↓ [C VM Interpreter] Execution & Output * Building Each VM can be built independently: make -C atom-vm make -C pluto-vm * Running Examples Pluto VM ./pluto-vm/pluto-vm examples/fact.pluto # Factorial calculation ./pluto-vm/pluto-vm examples/mul.pluto # Interactive multiplication Key Implementation Details ========================== Atom VM: - Bytecode serialization with 8-byte instruction encoding - PC-addressed assembly with label resolution - Call stack for function returns - Separate data and code segments Pluto VM: - Flexible operand encoding (register/immediate/address/indirect) - Flag register for conditional execution - System call interface for I/O operations - Data directives: db, dw, dd, dq Educational Goals ================= This project demonstrates: 1. Two VM Paradigms: Stack vs. register-based architectures 2. Toolchain: From source code to execution 3. Language Implementation: Lexing, parsing, compilation, and code generation 4. Low-Level Programming: Memory management, bytecode design, instruction encoding