1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-07-25 21:27:35 +00:00

JSSpecCompiler: Add bare-bones DCE pass

Right now the only dead code it eliminates is the unused phi nodes.
This commit is contained in:
Dan Klishch 2023-08-29 15:47:39 -04:00 committed by Andrew Kaster
parent 162c334508
commit 5338cdd153
6 changed files with 286 additions and 0 deletions

View file

@ -0,0 +1,86 @@
/*
* Copyright (c) 2023, Dan Klishch <danilklishch@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Vector.h>
#include "Compiler/EnableGraphPointers.h"
namespace JSSpecCompiler {
namespace Detail {
template<typename GraphVertex, typename GraphNode>
class StronglyConnectedComponents
: private EnableGraphPointers<StronglyConnectedComponents<GraphVertex, GraphNode>> {
using Self = StronglyConnectedComponents<GraphVertex, GraphNode>;
using Vertex = typename EnableGraphPointers<Self>::Vertex;
public:
StronglyConnectedComponents(Vector<GraphNode> const& graph)
: m_graph(graph)
{
}
Vector<Vector<GraphVertex>> find()
{
Vector<Vector<GraphVertex>> result;
size_t n = m_graph.size();
Self::with_graph(n, [&] {
for (size_t i = 0; i < m_graph.size(); ++i)
find_order(i);
for (size_t i = n; i--;) {
if (!m_order[i]->is_processed) {
result.empend();
find_component(GraphVertex(m_order[i]), result.last());
}
}
});
return result;
}
private:
friend EnableGraphPointers<Self>;
void find_order(Vertex u)
{
if (u->is_visited)
return;
u->is_visited = true;
for (auto v : GraphVertex(u)->incoming_edges)
find_order(Vertex(v));
m_order.append(u);
}
void find_component(GraphVertex u, Vector<GraphVertex>& current_scc)
{
current_scc.empend(u);
Vertex(u)->is_processed = true;
for (auto v : u->outgoing_edges)
if (!Vertex(v)->is_processed)
find_component(v, current_scc);
}
struct NodeData {
bool is_visited = false;
bool is_processed = false;
};
Vector<GraphNode> const& m_graph;
Vector<NodeData> m_nodes;
Vector<Vertex> m_order;
};
}
template<typename NodeData>
auto find_strongly_connected_components(Vector<NodeData> const& graph)
{
using Vertex = RemoveCVReference<decltype(graph[0].outgoing_edges[0])>;
return Detail::StronglyConnectedComponents<Vertex, NodeData>(graph).find();
}
}