diff options
Diffstat (limited to 'crates/sloth_vm/src/lib.rs')
| -rw-r--r-- | crates/sloth_vm/src/lib.rs | 261 |
1 files changed, 255 insertions, 6 deletions
diff --git a/crates/sloth_vm/src/lib.rs b/crates/sloth_vm/src/lib.rs index 1dfb191..9240577 100644 --- a/crates/sloth_vm/src/lib.rs +++ b/crates/sloth_vm/src/lib.rs @@ -7,24 +7,273 @@ unused_lifetimes )] -const STACK_SIZE: usize = 1024; +use sloth_bytecode::Instruction; pub struct Chunk { code: Vec<u8>, - constants: Vec<u64>, + constants: Vec<Data>, } pub struct VM { - stack: [u8; STACK_SIZE], - constants: Vec<u8>, + vm_return: Option<Data>, + stack: Stack, } impl VM { - // + fn new() -> Self { + Self { + vm_return: None, + stack: Stack::default(), + } + } + + fn run(&mut self, chunk: &Chunk) { + let mut pointer = 0; + + loop { + let instruction = Instruction::disassemble(&chunk.code, &mut pointer); + + match instruction { + Instruction::Constant(idx) => { + let value = chunk.constants[idx as usize]; + self.stack.push(value); + } + Instruction::Load(_) => todo!(), + Instruction::Push(_) => todo!(), + Instruction::Dup => { + let value = self.stack.pop(); + self.stack.push(value); + self.stack.push(value); + } + Instruction::Pop => { + self.stack.pop(); + } + Instruction::Add => { + let value = match self.stack.pop2() { + (Data::Integer(lhs), Data::Integer(rhs)) => Data::Integer(lhs + rhs), + (Data::Float(lhs), Data::Float(rhs)) => Data::Float(lhs + rhs), + _ => panic!(), + }; + + self.stack.push(value); + } + Instruction::Sub => { + let value = match self.stack.pop2() { + (Data::Integer(lhs), Data::Integer(rhs)) => Data::Integer(lhs - rhs), + (Data::Float(lhs), Data::Float(rhs)) => Data::Float(lhs - rhs), + _ => panic!(), + }; + + self.stack.push(value); + } + Instruction::Mul => { + let value = match self.stack.pop2() { + (Data::Integer(lhs), Data::Integer(rhs)) => Data::Integer(lhs * rhs), + (Data::Float(lhs), Data::Float(rhs)) => Data::Float(lhs * rhs), + _ => panic!(), + }; + + self.stack.push(value); + } + Instruction::Div => { + let value = match self.stack.pop2() { + (Data::Integer(lhs), Data::Integer(rhs)) => Data::Integer(lhs / rhs), + (Data::Float(lhs), Data::Float(rhs)) => Data::Float(lhs / rhs), + _ => panic!(), + }; + + self.stack.push(value); + } + Instruction::Mod => { + let value = match self.stack.pop2() { + (Data::Integer(lhs), Data::Integer(rhs)) => Data::Integer(lhs % rhs), + (Data::Float(lhs), Data::Float(rhs)) => Data::Float(lhs % rhs), + _ => panic!(), + }; + + self.stack.push(value); + } + Instruction::VMReturn => { + let value = self.stack.pop(); + self.vm_return = Some(value); + break; + } + Instruction::VMExit => break, + } + } + } +} + +#[derive(Debug, Clone, Copy, PartialEq)] +pub enum Data { + Integer(i128), + Float(f64), + Bool(bool), + Empty, +} + +const STACK_SIZE: usize = 1024; + +#[derive(Debug)] +pub struct Stack { + pointer: usize, + stack: [Data; STACK_SIZE], +} + +impl Default for Stack { + fn default() -> Self { + Self { + pointer: Default::default(), + stack: [Data::Empty; STACK_SIZE], + } + } +} + +impl Stack { + #[inline(always)] + pub fn push(&mut self, value: Data) { + if self.pointer >= STACK_SIZE { + panic!("Stack overflow"); + } + + self.stack[self.pointer] = value; + self.pointer += 1; + } + + #[inline(always)] + pub fn pop(&mut self) -> Data { + if self.pointer == 0 { + panic!("Stack underflow"); + } + + self.pointer -= 1; + self.stack[self.pointer] + } + + #[inline(always)] + pub fn pop2(&mut self) -> (Data, Data) { + (self.pop(), self.pop()) + } } #[cfg(test)] mod tests { + use crate::{Chunk, Data, VM}; + #[test] - fn add_program() {} + fn arithmetic_ops() { + let mut vm = VM::new(); + + // Addition + vm.run(&Chunk { + code: vec![ + 0x00, 0, 0, 0, 0, 0, 0, 0, 0, // Load constant from 0 + 0x10, // Duplicate + 0x20, // Add + 0xF0, // Return VM + ], + constants: vec![Data::Integer(7)], + }); + + let add1 = vm.vm_return; + + vm.run(&Chunk { + code: vec![ + 0x00, 0, 0, 0, 0, 0, 0, 0, 0, // Load constant from 0 + 0x00, 0, 0, 0, 0, 0, 0, 0, 1, // Load constant from 1 + 0x20, // Add + 0xF0, // Return VM + ], + constants: vec![Data::Integer(2), Data::Integer(11)], + }); + + let add2 = vm.vm_return; + + // Subtraction + vm.run(&Chunk { + code: vec![ + 0x00, 0, 0, 0, 0, 0, 0, 0, 0, // Load constant from 0 + 0x10, // Duplicate + 0x21, // Subtraction + 0xF0, // Return VM + ], + constants: vec![Data::Integer(7)], + }); + + let sub1 = vm.vm_return; + + vm.run(&Chunk { + code: vec![ + 0x00, 0, 0, 0, 0, 0, 0, 0, 0, // Load constant from 0 + 0x00, 0, 0, 0, 0, 0, 0, 0, 1, // Load constant from 1 + 0x21, // Subtraction + 0xF0, // Return VM + ], + constants: vec![Data::Integer(2), Data::Integer(11)], + }); + + let sub2 = vm.vm_return; + + // Multiplication + vm.run(&Chunk { + code: vec![ + 0x00, 0, 0, 0, 0, 0, 0, 0, 0, // Load constant from 0 + 0x10, // Duplicate + 0x22, // Multiplication + 0xF0, // Return VM + ], + constants: vec![Data::Integer(7)], + }); + + let mul1 = vm.vm_return; + + vm.run(&Chunk { + code: vec![ + 0x00, 0, 0, 0, 0, 0, 0, 0, 0, // Load constant from 0 + 0x00, 0, 0, 0, 0, 0, 0, 0, 1, // Load constant from 1 + 0x22, // Multiplication + 0xF0, // Return VM + ], + constants: vec![Data::Integer(2), Data::Integer(11)], + }); + + let mul2 = vm.vm_return; + + // Division + vm.run(&Chunk { + code: vec![ + 0x00, 0, 0, 0, 0, 0, 0, 0, 0, // Load constant from 0 + 0x10, // Duplicate + 0x23, // Division + 0xF0, // Return VM + ], + constants: vec![Data::Integer(7)], + }); + + let div1 = vm.vm_return; + + vm.run(&Chunk { + code: vec![ + 0x00, 0, 0, 0, 0, 0, 0, 0, 0, // Load constant from 0 + 0x00, 0, 0, 0, 0, 0, 0, 0, 1, // Load constant from 1 + 0x23, // Division + 0xF0, // Return VM + ], + constants: vec![Data::Integer(2), Data::Integer(11)], + }); + + let div2 = vm.vm_return; + + assert_eq!(add1, Some(Data::Integer(14))); + assert_eq!(add2, Some(Data::Integer(13))); + + assert_eq!(sub1, Some(Data::Integer(0))); + assert_eq!(sub2, Some(Data::Integer(9))); + + assert_eq!(mul1, Some(Data::Integer(49))); + assert_eq!(mul2, Some(Data::Integer(22))); + + assert_eq!(div1, Some(Data::Integer(1))); + assert_eq!(div2, Some(Data::Integer(5))); + } } |