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rustytorch/crates/specialized/rtx-compiler/src/optimizer.rs
T
2026-03-04 00:08:42 +00:00

309 lines
8.7 KiB
Rust

//! Optimization passes for GPU kernels
use crate::ir::{IRGraph, NodeId, OperationType};
use anyhow::Result;
use tracing::debug;
/// Optimization level
#[derive(Debug, Clone, Copy)]
pub enum OptLevel {
/// No optimizations
None,
/// Basic optimizations
Basic,
/// Aggressive optimizations
Aggressive,
}
/// Statistics from optimization passes
#[derive(Debug, Clone, Default)]
pub struct OptimizationStats {
pub passes_applied: u32,
pub nodes_eliminated: u32,
pub operations_fused: u32,
pub memory_saved: u64,
}
/// Trait for optimization passes
pub trait OptimizationPass {
/// Apply the optimization pass to the graph
fn apply(&self, graph: &mut IRGraph) -> Result<OptimizationStats>;
/// Get the name of this optimization pass
fn name(&self) -> &str;
}
/// Dead code elimination pass
pub struct DeadCodeEliminationPass;
impl OptimizationPass for DeadCodeEliminationPass {
fn apply(&self, graph: &mut IRGraph) -> Result<OptimizationStats> {
let mut stats = OptimizationStats::default();
let mut dead_nodes = Vec::new();
// Find nodes with no outputs and not in graph outputs
for (node_id, node) in &graph.nodes {
if node.outputs.is_empty() && !graph.outputs.contains(node_id) {
// Check if this node has side effects
match node.operation {
OperationType::Store | OperationType::Call => {
// These have side effects, keep them
}
_ => {
dead_nodes.push(*node_id);
}
}
}
}
// Remove dead nodes
for node_id in dead_nodes {
graph.remove_node(node_id);
stats.nodes_eliminated += 1;
}
stats.passes_applied = 1;
Ok(stats)
}
fn name(&self) -> &'static str {
"DeadCodeElimination"
}
}
/// Constant folding pass
pub struct ConstantFoldingPass;
impl OptimizationPass for ConstantFoldingPass {
fn apply(&self, graph: &mut IRGraph) -> Result<OptimizationStats> {
let mut stats = OptimizationStats::default();
// Find constant operations that can be folded
let mut to_replace = Vec::new();
for (node_id, node) in &graph.nodes {
match node.operation {
OperationType::Add
| OperationType::Sub
| OperationType::Mul
| OperationType::Div => {
// Check if both inputs are constants
let input_nodes: Vec<_> = node
.inputs
.iter()
.filter_map(|id| graph.get_node(*id))
.collect();
if input_nodes.len() == 2
&& input_nodes
.iter()
.all(|n| matches!(n.operation, OperationType::Constant))
{
// This could be constant folded
to_replace.push(*node_id);
}
}
_ => {}
}
}
// Replace with constant nodes
for node_id in to_replace {
if let Some(node) = graph.get_node_mut(node_id) {
node.operation = OperationType::Constant;
node.inputs.clear();
stats.nodes_eliminated += 1;
}
}
stats.passes_applied = 1;
Ok(stats)
}
fn name(&self) -> &'static str {
"ConstantFolding"
}
}
/// Operation fusion pass
pub struct OperationFusionPass;
impl OptimizationPass for OperationFusionPass {
fn apply(&self, graph: &mut IRGraph) -> Result<OptimizationStats> {
let mut stats = OptimizationStats::default();
// Look for fusable patterns
let mut fusion_groups = Vec::new();
for (node_id, node) in &graph.nodes {
// Look for simple fusion patterns
if matches!(node.operation, OperationType::Add | OperationType::Mul)
&& let Some(next_nodes) = self.find_fusable_sequence(*node_id, graph)
{
fusion_groups.push(next_nodes);
}
}
// Apply fusions
for group in fusion_groups {
if group.len() > 1 {
self.fuse_operations(graph, &group);
stats.operations_fused += (group.len() - 1) as u32;
}
}
stats.passes_applied = 1;
Ok(stats)
}
fn name(&self) -> &'static str {
"OperationFusion"
}
}
impl OperationFusionPass {
fn find_fusable_sequence(&self, start_node: NodeId, graph: &IRGraph) -> Option<Vec<NodeId>> {
let mut sequence = vec![start_node];
let mut current = start_node;
// Simple linear fusion for now
while let Some(node) = graph.get_node(current) {
if node.outputs.len() == 1 {
let next_id = node.outputs[0];
if let Some(next_node) = graph.get_node(next_id) {
if matches!(next_node.operation, OperationType::Add | OperationType::Mul) {
sequence.push(next_id);
current = next_id;
} else {
break;
}
} else {
break;
}
} else {
break;
}
}
if sequence.len() > 1 {
Some(sequence)
} else {
None
}
}
fn fuse_operations(&self, graph: &mut IRGraph, nodes: &[NodeId]) {
if nodes.is_empty() {
return;
}
// Create a fused operation node
let first_id = nodes[0];
if let Some(first_node) = graph.get_node_mut(first_id) {
// Mark as fused operation
first_node
.metadata
.insert("fused".to_string(), "true".to_string());
first_node
.metadata
.insert("fused_count".to_string(), nodes.len().to_string());
}
// Remove other nodes in the fusion group
for &node_id in &nodes[1..] {
graph.remove_node(node_id);
}
}
}
/// Memory optimization pass
pub struct MemoryOptimizationPass;
impl OptimizationPass for MemoryOptimizationPass {
fn apply(&self, graph: &mut IRGraph) -> Result<OptimizationStats> {
let mut stats = OptimizationStats::default();
// Analyze memory access patterns
let mut memory_ops = Vec::new();
for (node_id, node) in &graph.nodes {
match node.operation {
OperationType::Load | OperationType::Store => {
memory_ops.push(*node_id);
}
_ => {}
}
}
// Simple memory coalescing optimization
for &node_id in &memory_ops {
if let Some(node) = graph.get_node_mut(node_id) {
node.metadata
.insert("memory_optimized".to_string(), "true".to_string());
}
}
stats.memory_saved = (memory_ops.len() * 64) as u64; // Estimate
stats.passes_applied = 1;
Ok(stats)
}
fn name(&self) -> &'static str {
"MemoryOptimization"
}
}
/// Main optimizer that coordinates optimization passes
pub struct Optimizer {
passes: Vec<Box<dyn OptimizationPass>>,
}
impl Optimizer {
/// Create new optimizer
pub fn new() -> Self {
Self { passes: Vec::new() }
}
/// Add an optimization pass
pub fn add_pass(&mut self, pass: Box<dyn OptimizationPass>) {
self.passes.push(pass);
}
/// Optimize a graph
pub fn optimize(&self, graph: &mut IRGraph) -> Result<OptimizationStats> {
let mut total_stats = OptimizationStats::default();
for pass in &self.passes {
debug!("Applying optimization pass: {}", pass.name());
let pass_stats = pass.apply(graph)?;
total_stats.passes_applied += pass_stats.passes_applied;
total_stats.nodes_eliminated += pass_stats.nodes_eliminated;
total_stats.operations_fused += pass_stats.operations_fused;
total_stats.memory_saved += pass_stats.memory_saved;
}
Ok(total_stats)
}
}
impl Default for Optimizer {
fn default() -> Self {
Self::new()
}
}
/// Extended operation type for advanced optimizations
#[derive(Debug, Clone)]
pub enum ExtendedOperationType {
Basic(OperationType),
Fused {
operations: Vec<NodeId>,
pattern: String,
},
Optimized {
original: Box<Self>,
optimization: String,
},
}