Implement register allocation algorithm, with a few bugs.

This commit is contained in:
Jesse Brault 2026-03-05 23:19:00 -06:00
parent 272d288213
commit 8e9ae9ed98
16 changed files with 447 additions and 145 deletions

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@ -57,7 +57,8 @@ fn main() {
if args.show_ir {
for declaration in compilation_unit.declarations() {
if let ModuleLevelDeclaration::Function(function) = declaration {
let ir_function = function.to_ir(&symbol_table);
let mut ir_function = function.to_ir(&symbol_table);
ir_function.assign_registers();
println!("{}", ir_function)
}
}

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@ -4,9 +4,10 @@ use crate::ir::ir_assign::IrAssign;
use crate::ir::ir_expression::IrExpression;
use crate::ir::ir_operation::IrOperation;
use crate::ir::ir_statement::IrStatement;
use crate::ir::ir_variable::IrVariable;
use crate::ir::ir_variable::{IrVariable, IrVirtualRegisterVariable};
use crate::symbol_table::SymbolTable;
use crate::type_info::TypeInfo;
use std::rc::Rc;
pub fn expression_to_ir_expression(
expression: &Expression,
@ -22,13 +23,13 @@ pub fn expression_to_ir_expression(
.add_statement(IrStatement::Call(ir_call));
None
} else {
let t_var = IrVariable::new(&builder.new_t_var(), call.type_info());
let assign = IrAssign::new(t_var, IrOperation::Call(ir_call));
let destination = assign.destination().clone();
let t_var = IrVirtualRegisterVariable::new(&builder.new_t_var(), call.type_info());
let as_rc = Rc::new(t_var);
let assign = IrAssign::new(as_rc.clone(), IrOperation::Call(ir_call));
builder
.current_block_mut()
.add_statement(IrStatement::Assign(assign));
Some(IrExpression::Variable(destination))
Some(IrExpression::Variable(IrVariable::VirtualRegister(as_rc)))
}
}
Expression::IntegerLiteral(integer_literal) => {
@ -43,13 +44,16 @@ pub fn expression_to_ir_expression(
}
Expression::Additive(additive_expression) => {
let ir_add = additive_expression.to_ir(builder, symbol_table);
let t_var = IrVariable::new(&builder.new_t_var(), additive_expression.type_info());
let assign = IrAssign::new(t_var, IrOperation::Add(ir_add));
let destination = assign.destination().clone();
let t_var = IrVirtualRegisterVariable::new(
&builder.new_t_var(),
additive_expression.type_info(),
);
let as_rc = Rc::new(t_var);
let assign = IrAssign::new(as_rc.clone(), IrOperation::Add(ir_add));
builder
.current_block_mut()
.add_statement(IrStatement::Assign(assign));
Some(IrExpression::Variable(destination))
Some(IrExpression::Variable(IrVariable::VirtualRegister(as_rc)))
}
}
}

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@ -8,7 +8,6 @@ use crate::constants_table::ConstantsTable;
use crate::diagnostic::Diagnostic;
use crate::ir::ir_function::IrFunction;
use crate::ir::ir_parameter::IrParameter;
use crate::ir::ir_variable::IrVariable;
use crate::source_range::SourceRange;
use crate::symbol::FunctionSymbol;
use crate::symbol_table::{SymbolInsertError, SymbolTable};

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@ -8,10 +8,11 @@ use crate::ir::ir_assign::IrAssign;
use crate::ir::ir_expression::IrExpression;
use crate::ir::ir_operation::IrOperation;
use crate::ir::ir_statement::IrStatement;
use crate::ir::ir_variable::IrVariable;
use crate::ir::ir_variable::{IrVariable, IrVirtualRegisterVariable};
use crate::source_range::SourceRange;
use crate::symbol::{ExpressibleSymbol, VariableSymbol};
use crate::symbol_table::{SymbolInsertError, SymbolTable};
use std::rc::Rc;
pub struct LetStatement {
declared_name: String,
@ -106,14 +107,11 @@ impl LetStatement {
let destination_symbol =
symbol_table.get_variable_symbol(self.scope_id.unwrap(), &self.declared_name);
let ir_assign = IrAssign::new(
IrVariable::new(self.declared_name(), self.initializer().type_info()),
init_operation,
);
let destination_ir_variable = ir_assign.destination();
destination_symbol
.borrow_mut()
.set_ir_variable(destination_ir_variable.clone());
let destination_vr_variable =
IrVirtualRegisterVariable::new(self.declared_name(), self.initializer().type_info());
let as_rc = Rc::new(destination_vr_variable);
let ir_assign = IrAssign::new(as_rc.clone(), init_operation);
destination_symbol.borrow_mut().set_vr_variable(as_rc);
builder
.current_block_mut()

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@ -1,5 +1,5 @@
use crate::ir::ir_expression::IrExpression;
use crate::ir::ir_variable::IrVariable;
use crate::ir::ir_variable::IrVirtualRegisterVariable;
use std::collections::HashSet;
use std::fmt::{Display, Formatter};
use std::rc::Rc;
@ -16,6 +16,13 @@ impl IrAdd {
right: right.into(),
}
}
pub fn vr_uses(&self) -> HashSet<Rc<IrVirtualRegisterVariable>> {
let mut set = HashSet::new();
set.extend(self.left.vr_uses());
set.extend(self.right.vr_uses());
set
}
}
impl Display for IrAdd {
@ -23,12 +30,3 @@ impl Display for IrAdd {
write!(f, "{} + {}", self.left, self.right)
}
}
impl IrAdd {
pub fn uses(&self) -> HashSet<Rc<IrVariable>> {
let mut set = HashSet::new();
set.extend(self.left.uses());
set.extend(self.right.uses());
set
}
}

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@ -1,32 +1,47 @@
use crate::ir::ir_operation::IrOperation;
use crate::ir::ir_variable::IrVariable;
use crate::ir::ir_variable::{IrStackVariable, IrVariable, IrVirtualRegisterVariable};
use std::collections::HashSet;
use std::fmt::{Display, Formatter};
use std::ops::Deref;
use std::rc::Rc;
pub struct IrAssign {
destination: Rc<IrVariable>,
destination: Box<IrVariable>,
initializer: Box<IrOperation>,
}
impl IrAssign {
pub fn new(destination: IrVariable, initializer: IrOperation) -> Self {
pub fn new(destination: Rc<IrVirtualRegisterVariable>, initializer: IrOperation) -> Self {
Self {
destination: Rc::new(destination),
destination: Box::new(IrVariable::VirtualRegister(destination)),
initializer: initializer.into(),
}
}
pub fn destination(&self) -> &Rc<IrVariable> {
&self.destination
pub fn vr_definitions(&self) -> HashSet<Rc<IrVirtualRegisterVariable>> {
match self.destination.deref() {
IrVariable::VirtualRegister(vr_variable) => {
let mut set = HashSet::new();
set.insert(vr_variable.clone());
set
}
IrVariable::Stack(_) => HashSet::new(),
}
}
pub fn initializer(&self) -> &IrOperation {
&self.initializer
pub fn vr_uses(&self) -> HashSet<Rc<IrVirtualRegisterVariable>> {
self.initializer.vr_uses()
}
pub fn uses(&self) -> HashSet<Rc<IrVariable>> {
self.initializer.uses()
pub fn propagate_spills(&mut self, spills: &HashSet<Rc<IrVirtualRegisterVariable>>) {
if let IrVariable::VirtualRegister(vr_variable) = self.destination.deref() {
if spills.contains(vr_variable) {
self.destination = Box::new(IrVariable::Stack(IrStackVariable::new(
vr_variable.name(),
vr_variable.type_info().clone(),
)));
}
}
}
}

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@ -1,5 +1,5 @@
use crate::ir::ir_statement::IrStatement;
use crate::ir::ir_variable::IrVariable;
use crate::ir::ir_variable::IrVirtualRegisterVariable;
use std::cell::RefCell;
use std::collections::{HashMap, HashSet};
use std::fmt::{Display, Formatter};
@ -13,6 +13,8 @@ pub struct IrBlock {
statements: Vec<IrStatement>,
}
type LivenessMapByStatement = HashMap<usize, HashSet<Rc<IrVirtualRegisterVariable>>>;
impl IrBlock {
pub fn new(id: usize, debug_label: &str, statements: Vec<IrStatement>) -> Self {
Self {
@ -32,30 +34,25 @@ impl IrBlock {
&self.statements
}
fn definitions(&self) -> HashSet<Rc<IrVariable>> {
fn vr_definitions(&self) -> HashSet<Rc<IrVirtualRegisterVariable>> {
let mut set = HashSet::new();
for statement in &self.statements {
set.extend(statement.definitions())
set.extend(statement.vr_definitions());
}
set
}
fn uses(&self) -> HashSet<Rc<IrVariable>> {
fn vr_uses(&self) -> HashSet<Rc<IrVirtualRegisterVariable>> {
let mut set = HashSet::new();
for statement in &self.statements {
set.extend(statement.uses());
set.extend(statement.vr_uses());
}
set
}
fn live_in_live_out(
&self,
) -> (
HashMap<usize, HashSet<Rc<IrVariable>>>,
HashMap<usize, HashSet<Rc<IrVariable>>>,
) {
let mut live_in: HashMap<usize, HashSet<Rc<IrVariable>>> = HashMap::new();
let mut live_out: HashMap<usize, HashSet<Rc<IrVariable>>> = HashMap::new();
fn live_in_live_out(&self) -> (LivenessMapByStatement, LivenessMapByStatement) {
let mut live_in: LivenessMapByStatement = HashMap::new();
let mut live_out: LivenessMapByStatement = HashMap::new();
loop {
let mut did_work = false;
@ -73,17 +70,17 @@ impl IrBlock {
// this will need to be updated when we add jumps
if let Some(successor_live_in) = live_in.get(&(statement_index + 1)) {
let statement_live_out = live_out.get_mut(&statement_index).unwrap();
for ir_variable in successor_live_in {
if statement_live_out.insert(ir_variable.clone()) {
for vr_variable in successor_live_in {
if statement_live_out.insert(vr_variable.clone()) {
did_work = true;
}
}
}
// in: use(s) U ( out(s) - def(s) )
let mut new_ins = statement.uses();
let mut new_ins = statement.vr_uses();
let statement_live_out = live_out.get(&statement_index).unwrap();
let defs = statement.definitions();
let defs = statement.vr_definitions();
let rhs = statement_live_out - &defs;
new_ins.extend(rhs);
@ -101,15 +98,20 @@ impl IrBlock {
(live_in, live_out)
}
fn interference_graph(&self) -> HashMap<Rc<IrVariable>, HashSet<Rc<IrVariable>>> {
let mut all_variables: HashSet<Rc<IrVariable>> = HashSet::new();
fn interference_graph(
&self,
) -> HashMap<Rc<IrVirtualRegisterVariable>, HashSet<Rc<IrVirtualRegisterVariable>>> {
let mut all_vr_variables: HashSet<Rc<IrVirtualRegisterVariable>> = HashSet::new();
for statement in &self.statements {
all_variables.extend(statement.definitions());
all_variables.extend(statement.uses());
all_vr_variables.extend(statement.vr_definitions());
all_vr_variables.extend(statement.vr_uses());
}
let mut graph: HashMap<Rc<IrVariable>, HashSet<Rc<IrVariable>>> = HashMap::new();
for variable in all_variables {
let mut graph: HashMap<
Rc<IrVirtualRegisterVariable>,
HashSet<Rc<IrVirtualRegisterVariable>>,
> = HashMap::new();
for variable in all_vr_variables {
graph.insert(variable, HashSet::new());
}
@ -117,17 +119,18 @@ impl IrBlock {
for (statement_index, statement) in self.statements.iter().enumerate() {
let statement_live_out = live_out.get(&statement_index).unwrap();
for definition_variable in statement.definitions() {
for definition_vr_variable in statement.vr_definitions() {
for live_out_variable in statement_live_out {
if definition_variable != *live_out_variable {
// we do the following check to avoid adding an edge to itself
if definition_vr_variable != *live_out_variable {
graph
.get_mut(&definition_variable)
.get_mut(&definition_vr_variable)
.unwrap()
.insert(live_out_variable.clone());
graph
.get_mut(live_out_variable)
.unwrap()
.insert(definition_variable.clone());
.insert(definition_vr_variable.clone());
}
}
}
@ -135,6 +138,23 @@ impl IrBlock {
graph
}
pub fn assign_registers(&mut self) {
let mut spills: HashSet<Rc<IrVirtualRegisterVariable>> = HashSet::new();
loop {
let (registers, new_spills) = register_assignment::assign_registers(self);
if spills != new_spills {
spills = new_spills;
// mutate all IrVirtualRegisters to constituent statements
for statement in &mut self.statements {
statement.propagate_spills(&spills);
}
} else {
println!("{:?}", registers);
break;
}
}
}
}
impl Display for IrBlock {
@ -154,8 +174,8 @@ impl Display for IrBlock {
)?;
}
writeln!(f, " // ---- {} meta ----", self.debug_label)?;
writeln!(f, " // definitions: {:?}", self.definitions())?;
writeln!(f, " // uses: {:?}", self.uses())?;
writeln!(f, " // definitions: {:?}", self.vr_definitions())?;
writeln!(f, " // uses: {:?}", self.vr_uses())?;
writeln!(
f,
" // interference graph: {:?}",
@ -164,3 +184,168 @@ impl Display for IrBlock {
Ok(())
}
}
mod register_assignment {
use super::*;
#[derive(Debug)]
struct WorkItem {
vr: Rc<IrVirtualRegisterVariable>,
edges: HashSet<Rc<IrVirtualRegisterVariable>>,
color: bool,
}
pub fn assign_registers(
block: &IrBlock,
) -> (
HashMap<Rc<IrVirtualRegisterVariable>, usize>,
HashSet<Rc<IrVirtualRegisterVariable>>,
) {
let k = 8;
let mut spills: HashSet<Rc<IrVirtualRegisterVariable>> = HashSet::new();
loop {
// 1. get interference graph
let mut interference_graph = block.interference_graph();
let mut work_stack: Vec<WorkItem> = vec![];
loop {
// 2. coloring by simplification
// try to find a node (virtual register) with less than k outgoing edges,
// and mark as color
// if not, pick any, and mark as spill for step 3
let register_lt_k = interference_graph.iter().find_map(|(vr, neighbors)| {
if neighbors.len() < k { Some(vr) } else { None }
});
if let Some(vr) = register_lt_k {
let vr = vr.clone();
// remove both outgoing and incoming edges; save either set for WorkItem
// first, outgoing:
let outgoing_edges = interference_graph.remove(&vr).unwrap();
// second, incoming
interference_graph.iter_mut().for_each(|(_, neighbors)| {
neighbors.remove(&vr);
});
// push to work stack
work_stack.push(WorkItem {
vr,
edges: outgoing_edges,
color: true,
})
} else {
// pick any
let vr = interference_graph.iter().last().unwrap().0.clone();
// first, outgoing
let outgoing_edges = interference_graph.remove(&vr).unwrap();
// second, incoming
interference_graph.iter_mut().for_each(|(_, neighbors)| {
neighbors.remove(&vr);
});
work_stack.push(WorkItem {
vr,
edges: outgoing_edges,
color: false, // spill
});
}
if interference_graph.is_empty() {
break;
}
}
// 3. assign colors to registers
let mut rebuilt_graph: HashMap<
Rc<IrVirtualRegisterVariable>,
HashSet<Rc<IrVirtualRegisterVariable>>,
> = HashMap::new();
let mut register_assignments: HashMap<Rc<IrVirtualRegisterVariable>, usize> =
HashMap::new();
let mut new_spills: HashSet<Rc<IrVirtualRegisterVariable>> = HashSet::new();
while let Some(work_item) = work_stack.pop() {
if work_item.color {
assign_register(&work_item, &mut rebuilt_graph, k, &mut register_assignments);
} else {
// first, see if we can optimistically color
// find how many assignments have been made for the outgoing edges
// if it's less than k, we can do it
let mut number_of_assigned_edges = 0;
for edge in &work_item.edges {
if register_assignments.contains_key(edge) {
number_of_assigned_edges += 1;
}
}
if number_of_assigned_edges < k {
// optimistically color
assign_register(
&work_item,
&mut rebuilt_graph,
k,
&mut register_assignments,
);
} else {
// spill
new_spills.insert(work_item.vr.clone());
}
}
}
if spills.eq(&new_spills) {
return (register_assignments, spills);
} else {
spills = new_spills;
}
}
}
fn assign_register(
work_item: &WorkItem,
rebuilt_graph: &mut HashMap<
Rc<IrVirtualRegisterVariable>,
HashSet<Rc<IrVirtualRegisterVariable>>,
>,
k: usize,
register_assignments: &mut HashMap<Rc<IrVirtualRegisterVariable>, usize>,
) {
let this_vertex_vr = &work_item.vr;
// init the vertex
rebuilt_graph.insert(this_vertex_vr.clone(), HashSet::new());
// add edges, both outgoing and incoming
let neighbors = rebuilt_graph.get_mut(this_vertex_vr).unwrap();
// outgoing
for edge in &work_item.edges {
neighbors.insert(edge.clone());
}
// incoming
for neighbor in neighbors.clone() {
if rebuilt_graph.contains_key(&neighbor) {
rebuilt_graph
.get_mut(&neighbor)
.unwrap()
.insert(this_vertex_vr.clone());
}
}
// find a register which is not yet shared by all outgoing edges' vertices
// I think the bug is somewhere here
'outer: for i in 0..k {
for edge in rebuilt_graph.get_mut(this_vertex_vr).unwrap().iter() {
if register_assignments.contains_key(edge) {
let assignment = register_assignments.get(edge).unwrap();
if *assignment == i {
continue 'outer;
}
}
}
register_assignments.insert(this_vertex_vr.clone(), i);
break;
}
}
}

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@ -1,5 +1,6 @@
use crate::ir::ir_expression::IrExpression;
use crate::ir::ir_variable::IrVariable;
use crate::ir::ir_variable::{IrStackVariable, IrVariable, IrVirtualRegisterVariable};
use crate::type_info::TypeInfo;
use std::collections::HashSet;
use std::fmt::{Display, Formatter};
use std::rc::Rc;
@ -17,13 +18,19 @@ impl IrCall {
}
}
pub fn uses(&self) -> HashSet<Rc<IrVariable>> {
pub fn vr_uses(&self) -> HashSet<Rc<IrVirtualRegisterVariable>> {
let mut set = HashSet::new();
for argument in &self.arguments {
set.extend(argument.uses());
set.extend(argument.vr_uses())
}
set
}
pub fn propagate_spills(&mut self, spills: &HashSet<Rc<IrVirtualRegisterVariable>>) {
for argument in &mut self.arguments {
argument.propagate_spills(spills);
}
}
}
impl Display for IrCall {

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@ -1,16 +1,59 @@
use crate::ir::ir_parameter::IrParameter;
use crate::ir::ir_variable::IrVariable;
use crate::ir::ir_variable::{IrStackVariable, IrVariable, IrVirtualRegisterVariable};
use std::collections::HashSet;
use std::fmt::{Display, Formatter};
use std::rc::Rc;
pub enum IrExpression {
Parameter(Rc<IrParameter>),
Variable(Rc<IrVariable>),
Variable(IrVariable),
Int(i32),
String(Rc<str>),
}
impl IrExpression {
pub fn vr_uses(&self) -> HashSet<Rc<IrVirtualRegisterVariable>> {
match self {
IrExpression::Parameter(_) => HashSet::new(),
IrExpression::Variable(ir_variable) => {
let mut set = HashSet::new();
if let IrVariable::VirtualRegister(vr_variable) = ir_variable {
set.insert(vr_variable.clone());
}
set
}
IrExpression::Int(_) => HashSet::new(),
IrExpression::String(_) => HashSet::new(),
}
}
pub fn propagate_spills(&mut self, spills: &HashSet<Rc<IrVirtualRegisterVariable>>) {
match self {
IrExpression::Parameter(_) => {
// no-op
}
IrExpression::Variable(ir_variable) => {
if let IrVariable::VirtualRegister(vr_variable) = ir_variable {
if spills.contains(vr_variable) {
let name = vr_variable.name().to_string();
let type_info = vr_variable.type_info().clone();
let _ = std::mem::replace(
ir_variable,
IrVariable::Stack(IrStackVariable::new(&name, type_info)),
);
}
}
}
IrExpression::Int(_) => {
// no-op
}
IrExpression::String(_) => {
// no-op
}
}
}
}
impl Display for IrExpression {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
match self {
@ -29,24 +72,3 @@ impl Display for IrExpression {
}
}
}
impl IrExpression {
pub fn uses(&self) -> HashSet<Rc<IrVariable>> {
let mut set = HashSet::new();
match self {
IrExpression::Parameter(_) => {
// no-op
}
IrExpression::Variable(ir_variable) => {
set.insert(ir_variable.clone());
}
IrExpression::Int(_) => {
// no-op
}
IrExpression::String(_) => {
// no-op
}
}
set
}
}

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@ -1,6 +1,5 @@
use crate::ir::ir_block::IrBlock;
use crate::ir::ir_parameter::IrParameter;
use crate::ir::ir_variable::IrVariable;
use crate::type_info::TypeInfo;
use std::cell::RefCell;
use std::fmt::Display;
@ -27,6 +26,10 @@ impl IrFunction {
entry,
}
}
pub fn assign_registers(&mut self) {
self.entry.borrow_mut().assign_registers();
}
}
impl Display for IrFunction {

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@ -1,7 +1,7 @@
use crate::ir::ir_add::IrAdd;
use crate::ir::ir_call::IrCall;
use crate::ir::ir_expression::IrExpression;
use crate::ir::ir_variable::IrVariable;
use crate::ir::ir_variable::{IrVariable, IrVirtualRegisterVariable};
use std::collections::HashSet;
use std::fmt::{Display, Formatter};
use std::rc::Rc;
@ -29,11 +29,11 @@ impl Display for IrOperation {
}
impl IrOperation {
pub fn uses(&self) -> HashSet<Rc<IrVariable>> {
pub fn vr_uses(&self) -> HashSet<Rc<IrVirtualRegisterVariable>> {
match self {
IrOperation::Load(ir_expression) => ir_expression.uses(),
IrOperation::Add(ir_add) => ir_add.uses(),
IrOperation::Call(ir_call) => ir_call.uses(),
IrOperation::Load(ir_expression) => ir_expression.vr_uses(),
IrOperation::Add(ir_add) => ir_add.vr_uses(),
IrOperation::Call(ir_call) => ir_call.vr_uses(),
}
}
}

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@ -1,5 +1,5 @@
use crate::ir::ir_expression::IrExpression;
use crate::ir::ir_variable::IrVariable;
use crate::ir::ir_variable::IrVirtualRegisterVariable;
use std::collections::HashSet;
use std::fmt::{Display, Formatter};
use std::rc::Rc;
@ -13,8 +13,14 @@ impl IrReturn {
Self { value }
}
pub fn uses(&self) -> HashSet<Rc<IrVariable>> {
self.value.as_ref().map_or(HashSet::new(), |v| v.uses())
pub fn vr_uses(&self) -> HashSet<Rc<IrVirtualRegisterVariable>> {
self.value.as_ref().map_or(HashSet::new(), |v| v.vr_uses())
}
pub fn propagate_spills(&mut self, spills: &HashSet<Rc<IrVirtualRegisterVariable>>) {
if let Some(ir_expression) = self.value.as_mut() {
ir_expression.propagate_spills(spills);
}
}
}

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@ -1,7 +1,7 @@
use crate::ir::ir_assign::IrAssign;
use crate::ir::ir_call::IrCall;
use crate::ir::ir_return::IrReturn;
use crate::ir::ir_variable::IrVariable;
use crate::ir::ir_variable::IrVirtualRegisterVariable;
use std::collections::HashSet;
use std::fmt::{Display, Formatter};
use std::rc::Rc;
@ -13,34 +13,34 @@ pub enum IrStatement {
}
impl IrStatement {
pub fn definitions(&self) -> HashSet<Rc<IrVariable>> {
let mut set = HashSet::new();
pub fn vr_definitions(&self) -> HashSet<Rc<IrVirtualRegisterVariable>> {
match self {
IrStatement::Assign(ir_assign) => {
set.insert(ir_assign.destination().clone());
IrStatement::Assign(ir_assign) => ir_assign.vr_definitions(),
IrStatement::Call(_) => HashSet::new(),
IrStatement::Return(_) => HashSet::new(),
}
IrStatement::Call(_) => {
// no-op
}
IrStatement::Return(_) => {
// no-op
}
}
set
}
pub fn uses(&self) -> HashSet<Rc<IrVariable>> {
let mut set = HashSet::new();
pub fn vr_uses(&self) -> HashSet<Rc<IrVirtualRegisterVariable>> {
match self {
IrStatement::Assign(ir_assign) => ir_assign.vr_uses(),
IrStatement::Call(ir_call) => ir_call.vr_uses(),
IrStatement::Return(ir_return) => ir_return.vr_uses(),
}
}
pub fn propagate_spills(&mut self, spills: &HashSet<Rc<IrVirtualRegisterVariable>>) {
match self {
IrStatement::Assign(ir_assign) => {
set.extend(ir_assign.uses());
ir_assign.propagate_spills(spills);
}
IrStatement::Call(ir_call) => {
set.extend(ir_call.uses());
ir_call.propagate_spills(spills);
}
IrStatement::Return(ir_return) => {
ir_return.propagate_spills(spills);
}
IrStatement::Return(ir_return) => set.extend(ir_return.uses()),
}
set
}
}

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@ -3,13 +3,43 @@ use std::fmt::{Debug, Display, Formatter};
use std::hash::{Hash, Hasher};
use std::rc::Rc;
/// Represents a virtual register
pub struct IrVariable {
pub enum IrVariable {
VirtualRegister(Rc<IrVirtualRegisterVariable>),
Stack(IrStackVariable),
}
impl IrVariable {
pub fn new(name: &str, type_info: TypeInfo) -> IrVariable {
IrVariable::VirtualRegister(Rc::new(IrVirtualRegisterVariable::new(name, type_info)))
}
pub fn type_info(&self) -> &TypeInfo {
match self {
IrVariable::VirtualRegister(vr_variable) => vr_variable.type_info(),
IrVariable::Stack(stack_variable) => stack_variable.type_info(),
}
}
}
impl Display for IrVariable {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
match self {
IrVariable::VirtualRegister(vr_variable) => {
write!(f, "{}", vr_variable)
}
IrVariable::Stack(stack_variable) => {
write!(f, "{}", stack_variable)
}
}
}
}
pub struct IrVirtualRegisterVariable {
name: Rc<str>,
type_info: TypeInfo,
}
impl IrVariable {
impl IrVirtualRegisterVariable {
pub fn new(name: &str, type_info: TypeInfo) -> Self {
Self {
name: name.into(),
@ -26,28 +56,54 @@ impl IrVariable {
}
}
impl Display for IrVariable {
impl Display for IrVirtualRegisterVariable {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
write!(f, "{}", self.name)
}
}
impl Debug for IrVariable {
impl Debug for IrVirtualRegisterVariable {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
write!(f, "{}", self.name)
}
}
impl Hash for IrVariable {
fn hash<H: Hasher>(&self, state: &mut H) {
self.name.hash(state);
}
}
impl Eq for IrVirtualRegisterVariable {}
impl PartialEq for IrVariable {
impl PartialEq for IrVirtualRegisterVariable {
fn eq(&self, other: &Self) -> bool {
self.name == other.name
}
}
impl Eq for IrVariable {}
impl Hash for IrVirtualRegisterVariable {
fn hash<H: Hasher>(&self, state: &mut H) {
self.name.hash(state);
}
}
pub struct IrStackVariable {
name: Rc<str>,
type_info: TypeInfo,
offset: Option<isize>,
}
impl IrStackVariable {
pub fn new(name: &str, type_info: TypeInfo) -> Self {
Self {
name: name.into(),
type_info,
offset: None,
}
}
pub fn type_info(&self) -> &TypeInfo {
&self.type_info
}
}
impl Display for IrStackVariable {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
write!(f, "{}", self.name)
}
}

View File

@ -1,6 +1,6 @@
use crate::ir::ir_expression::IrExpression;
use crate::ir::ir_parameter::IrParameter;
use crate::ir::ir_variable::IrVariable;
use crate::ir::ir_variable::{IrVariable, IrVirtualRegisterVariable};
use crate::type_info::TypeInfo;
use std::cell::RefCell;
use std::rc::Rc;
@ -100,7 +100,7 @@ impl ParameterSymbol {
pub struct VariableSymbol {
name: Rc<str>,
type_info: Option<TypeInfo>,
ir_variable: Option<Rc<IrVariable>>,
vr_variable: Option<Rc<IrVirtualRegisterVariable>>,
#[deprecated]
register: Option<usize>,
@ -111,7 +111,7 @@ impl VariableSymbol {
Self {
name: name.into(),
type_info: None,
ir_variable: None,
vr_variable: None,
register: None,
}
}
@ -134,12 +134,12 @@ impl VariableSymbol {
.expect("TypeInfo not initialized. Did you type check?")
}
pub fn set_ir_variable(&mut self, ir_variable: Rc<IrVariable>) {
self.ir_variable = Some(ir_variable);
pub fn set_vr_variable(&mut self, ir_variable: Rc<IrVirtualRegisterVariable>) {
self.vr_variable = Some(ir_variable);
}
pub fn ir_variable(&self) -> &Rc<IrVariable> {
self.ir_variable
pub fn vr_variable(&self) -> &Rc<IrVirtualRegisterVariable> {
self.vr_variable
.as_ref()
.expect("ir_variable not yet initialized")
}
@ -168,9 +168,9 @@ impl ExpressibleSymbol {
ExpressibleSymbol::Parameter(parameter_symbol) => {
IrExpression::Parameter(parameter_symbol.borrow().ir_parameter().clone())
}
ExpressibleSymbol::Variable(variable_symbol) => {
IrExpression::Variable(variable_symbol.borrow().ir_variable().clone())
}
ExpressibleSymbol::Variable(variable_symbol) => IrExpression::Variable(
IrVariable::VirtualRegister(variable_symbol.borrow().vr_variable().clone()),
),
}
}
}

View File

@ -0,0 +1,8 @@
extern fn println(message: Any) -> Void
fn main()
let a = 1
let b = 2
let c = 3
let x = a + b + c
end