verilator/src/V3Graph.cpp
2024-03-25 23:06:25 +00:00

391 lines
14 KiB
C++

// -*- mode: C++; c-file-style: "cc-mode" -*-
//*************************************************************************
// DESCRIPTION: Verilator: Graph optimizations
//
// Code available from: https://verilator.org
//
//*************************************************************************
//
// Copyright 2003-2024 by Wilson Snyder. This program is free software; you
// can redistribute it and/or modify it under the terms of either the GNU
// Lesser General Public License Version 3 or the Perl Artistic License
// Version 2.0.
// SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
//
//*************************************************************************
#define VL_MT_DISABLED_CODE_UNIT 1
#include "config_build.h"
#include "verilatedos.h"
#include "V3Graph.h"
#include "V3File.h"
#include "V3Global.h"
#include <map>
#include <memory>
#include <unordered_map>
#include <unordered_set>
#include <vector>
VL_DEFINE_DEBUG_FUNCTIONS;
//######################################################################
//######################################################################
// Vertices
V3GraphVertex::V3GraphVertex(V3Graph* graphp, const V3GraphVertex& old)
: m_fanout{old.m_fanout}
, m_color{old.m_color}
, m_rank{old.m_rank} {
m_userp = nullptr;
graphp->vertices().linkBack(this);
}
V3GraphVertex::V3GraphVertex(V3Graph* graphp)
: m_fanout{0}
, m_color{0}
, m_rank{0} {
m_userp = nullptr;
graphp->vertices().linkBack(this);
}
void V3GraphVertex::unlinkEdges(V3Graph*) {
while (V3GraphEdge* const ep = m_outs.frontp()) VL_DO_DANGLING(ep->unlinkDelete(), ep);
while (V3GraphEdge* const ep = m_ins.frontp()) VL_DO_DANGLING(ep->unlinkDelete(), ep);
}
void V3GraphVertex::unlinkDelete(V3Graph* graphp) {
// Delete edges
unlinkEdges(graphp);
// Unlink from vertex list
graphp->m_vertices.unlink(this);
// Delete
delete this; // this=nullptr;
}
void V3GraphVertex::rerouteEdges(V3Graph* graphp) {
// Make new edges for each from/to pair
for (V3GraphEdge& iedge : inEdges()) {
for (V3GraphEdge& oedge : outEdges()) {
new V3GraphEdge{graphp, iedge.fromp(), oedge.top(),
std::min(iedge.weight(), oedge.weight()),
iedge.cutable() && oedge.cutable()};
}
}
// Remove old edges
unlinkEdges(graphp);
}
template <GraphWay::en T_Way>
V3GraphEdge* V3GraphVertex::findConnectingEdgep(V3GraphVertex* waywardp) {
// O(edges) linear search. Searches search both nodes' edge lists in
// parallel. The lists probably aren't _both_ huge, so this is
// unlikely to blow up even on fairly nasty graphs.
constexpr GraphWay way{T_Way};
constexpr GraphWay inv = way.invert();
auto& aEdges = this->edges<way>();
auto aIt = aEdges.begin();
auto aEnd = aEdges.end();
auto& bEdges = waywardp->edges<inv>();
auto bIt = bEdges.begin();
auto bEnd = bEdges.end();
while (aIt != aEnd && bIt != bEnd) {
V3GraphEdge& aedge = *aIt++;
if (aedge.furtherp<way>() == waywardp) return &aedge;
V3GraphEdge& bedge = *bIt++;
if (bedge.furtherp<inv>() == this) return &bedge;
}
return nullptr;
}
template V3GraphEdge* V3GraphVertex::findConnectingEdgep<GraphWay::FORWARD>(V3GraphVertex*);
template V3GraphEdge* V3GraphVertex::findConnectingEdgep<GraphWay::REVERSE>(V3GraphVertex*);
// cppcheck-has-bug-suppress constParameter
void V3GraphVertex::v3errorEnd(std::ostringstream& str) const VL_RELEASE(V3Error::s().m_mutex) {
std::ostringstream nsstr;
nsstr << str.str();
if (debug()) {
nsstr << endl;
nsstr << "-vertex: " << this << endl;
}
if (FileLine* const flp = fileline()) {
flp->v3errorEnd(nsstr);
} else {
V3Error::v3errorEnd(nsstr);
}
}
void V3GraphVertex::v3errorEndFatal(std::ostringstream& str) const
VL_RELEASE(V3Error::s().m_mutex) {
v3errorEnd(str);
assert(0); // LCOV_EXCL_LINE
VL_UNREACHABLE;
}
std::ostream& operator<<(std::ostream& os, V3GraphVertex* vertexp) {
os << " VERTEX=" << vertexp->name();
if (vertexp->rank()) os << " r" << vertexp->rank();
if (vertexp->fanout() != 0.0) os << " f" << vertexp->fanout();
if (vertexp->color()) os << " c" << vertexp->color();
return os;
}
//######################################################################
//######################################################################
// Edges
void V3GraphEdge::init(V3Graph* /*graphp*/, V3GraphVertex* fromp, V3GraphVertex* top, int weight,
bool cutable) {
UASSERT(fromp, "Null from pointer");
UASSERT(top, "Null to pointer");
m_fromp = fromp;
m_top = top;
m_weight = weight;
m_cutable = cutable;
m_userp = nullptr;
// Link vertices to this edge
m_fromp->outEdges().linkBack(this);
m_top->inEdges().linkBack(this);
}
void V3GraphEdge::relinkFromp(V3GraphVertex* newFromp) {
m_fromp->outEdges().unlink(this);
m_fromp = newFromp;
m_fromp->outEdges().linkBack(this);
}
void V3GraphEdge::relinkTop(V3GraphVertex* newTop) {
m_top->inEdges().unlink(this);
m_top = newTop;
m_top->inEdges().linkBack(this);
}
void V3GraphEdge::unlinkDelete() {
// Unlink from side
m_fromp->outEdges().unlink(this);
// Unlink to side
m_top->inEdges().unlink(this);
// Delete
delete this;
}
std::string V3GraphEdge::name() const { return m_fromp->name() + "->" + m_top->name(); }
int V3GraphEdge::sortCmp(const V3GraphEdge* rhsp) const {
if (!m_weight || !rhsp->m_weight) return 0;
return top()->sortCmp(rhsp->top());
}
//######################################################################
//######################################################################
// Graph top level
// Constructors
V3Graph::V3Graph() {}
V3Graph::~V3Graph() { clear(); }
void V3Graph::clear() {
// Empty it of all points, as if making a new object
// Delete the old edges
for (V3GraphVertex& vertex : vertices()) {
while (V3GraphEdge* const edgep = vertex.outEdges().unlinkFront()) {
VL_DO_DANGLING(delete edgep, edgep);
}
}
// Delete the old vertices
while (V3GraphVertex* const vertexp = vertices().unlinkFront()) {
VL_DO_DANGLING(delete vertexp, vertexp);
}
}
void V3Graph::userClearVertices() {
// Clear user() in all of tree
// We may use the userCnt trick in V3Ast later... (but gblCnt would be
// in V3Graph instead of static - which has the complication of finding
// the graph pointer given a vertex.) For now, we don't call this often, and
// the extra code on each read of user() would probably slow things
// down more than help.
for (V3GraphVertex& vertex : vertices()) {
vertex.user(0);
vertex.userp(nullptr); // It's a union, but might be different size than user()
}
}
void V3Graph::userClearEdges() {
// Clear user() in all of tree
for (V3GraphVertex& vertex : vertices()) {
for (V3GraphEdge& edge : vertex.outEdges()) {
edge.user(0);
edge.userp(nullptr); // It's a union, but might be different size than user()
}
}
}
void V3Graph::clearColors() {
// Reset colors
for (V3GraphVertex& vertex : vertices()) vertex.color(0);
}
//======================================================================
// Dumping
void V3Graph::loopsMessageCb(V3GraphVertex* vertexp) {
vertexp->v3fatalSrc("Loops detected in graph: " << vertexp);
}
void V3Graph::loopsVertexCb(V3GraphVertex* vertexp) {
// Needed here as V3GraphVertex<< isn't defined until later in header
if (debug()) std::cerr << "-Info-Loop: " << cvtToHex(vertexp) << " " << vertexp << endl;
}
void V3Graph::dump(std::ostream& os) const {
// This generates a file used by graphviz, https://www.graphviz.org
os << " Graph:\n";
// Print vertices
for (const V3GraphVertex& vertex : vertices()) {
os << "\tNode: " << vertex.name();
if (vertex.color()) os << " color=" << vertex.color();
os << '\n';
// Print edges
for (const V3GraphEdge& edge : vertex.inEdges()) dumpEdge(os, vertex, edge);
for (const V3GraphEdge& edge : vertex.outEdges()) dumpEdge(os, vertex, edge);
}
}
void V3Graph::dumpEdge(std::ostream& os, const V3GraphVertex& vertex,
const V3GraphEdge& edge) const {
if (edge.weight() && (edge.fromp() == &vertex || edge.top() == &vertex)) {
os << "\t\t";
if (edge.fromp() == &vertex) os << "-> " << edge.top()->name();
if (edge.top() == &vertex) os << "<- " << edge.fromp()->name();
if (edge.cutable()) os << " [CUTABLE]";
os << '\n';
}
}
void V3Graph::dumpEdges(std::ostream& os, const V3GraphVertex& vertex) const {
for (const V3GraphEdge& edge : vertex.inEdges()) dumpEdge(os, vertex, edge);
for (const V3GraphEdge& edge : vertex.outEdges()) dumpEdge(os, vertex, edge);
}
void V3Graph::dumpDotFilePrefixed(const string& nameComment, bool colorAsSubgraph) const {
dumpDotFile(v3Global.debugFilename(nameComment) + ".dot", colorAsSubgraph);
}
//! Variant of dumpDotFilePrefixed without --dump option check
void V3Graph::dumpDotFilePrefixedAlways(const string& nameComment, bool colorAsSubgraph) const {
dumpDotFile(v3Global.debugFilename(nameComment) + ".dot", colorAsSubgraph);
}
void V3Graph::dumpDotFile(const string& filename, bool colorAsSubgraph) const {
// This generates a file used by graphviz, https://www.graphviz.org
// "hardcoded" parameters:
const std::unique_ptr<std::ofstream> logp{V3File::new_ofstream(filename)};
if (logp->fail()) v3fatal("Can't write " << filename);
// Header
*logp << "digraph v3graph {\n";
*logp << "\tgraph\t[label=\"" << filename << "\",\n";
*logp << "\t\t labelloc=t, labeljust=l,\n";
*logp << "\t\t //size=\"7.5,10\",\n";
*logp << "\t\t rankdir=" << dotRankDir() << "];\n";
// List of all possible subgraphs
// Collections of explicit ranks
std::unordered_set<std::string> ranks;
std::unordered_multimap<std::string, const V3GraphVertex*> rankSets;
std::multimap<std::string, const V3GraphVertex*> subgraphs;
for (const V3GraphVertex& vertex : vertices()) {
const string vertexSubgraph
= (colorAsSubgraph && vertex.color()) ? cvtToStr(vertex.color()) : "";
subgraphs.emplace(vertexSubgraph, &vertex);
const string& dotRank = vertex.dotRank();
if (!dotRank.empty()) {
ranks.emplace(dotRank);
rankSets.emplace(dotRank, &vertex);
}
}
// We use a map here, as we don't want to corrupt anything (userp) in the graph,
// and we don't care if this is slow.
std::unordered_map<const V3GraphVertex*, int> numMap;
// Print vertices
int n = 0;
string subgr;
for (auto it = subgraphs.cbegin(); it != subgraphs.cend(); ++it) {
const string vertexSubgraph = it->first;
const V3GraphVertex* vertexp = it->second;
numMap[vertexp] = n;
if (subgr != vertexSubgraph) {
if (subgr != "") *logp << "\t};\n";
subgr = vertexSubgraph;
if (subgr != "") {
*logp << "\tsubgraph cluster_" << subgr << " {\n";
*logp << "\tlabel=\"" << subgr << "\"\n";
}
}
if (subgr != "") *logp << "\t";
*logp << "\tn" << vertexp->dotName() << (n++) << "\t[fontsize=8 "
<< "label=\"" << (vertexp->name() != "" ? vertexp->name() : "\\N");
if (vertexp->rank()) *logp << " r" << vertexp->rank();
if (vertexp->fanout() != 0.0) *logp << " f" << vertexp->fanout();
if (vertexp->color()) *logp << "\\n c" << vertexp->color();
*logp << "\"";
*logp << ", color=" << vertexp->dotColor();
if (vertexp->dotStyle() != "") *logp << ", style=" << vertexp->dotStyle();
if (vertexp->dotShape() != "") *logp << ", shape=" << vertexp->dotShape();
*logp << "];\n";
}
if (subgr != "") *logp << "\t};\n";
// Print edges
for (const V3GraphVertex& vertex : vertices()) {
for (const V3GraphEdge& edge : vertex.outEdges()) {
if (edge.weight()) {
const int fromVnum = numMap[edge.fromp()];
const int toVnum = numMap[edge.top()];
*logp << "\tn" << edge.fromp()->dotName() << fromVnum << " -> n"
<< edge.top()->dotName() << toVnum
<< " ["
// <<"fontsize=8 label=\""<<(edge.name()!="" ? edge.name() : "\\E")<<"\""
<< "fontsize=8 label=\"" << (edge.dotLabel() != "" ? edge.dotLabel() : "")
<< "\""
<< " weight=" << edge.weight() << " color=" << edge.dotColor();
if (edge.dotStyle() != "") *logp << " style=" << edge.dotStyle();
// if (edge.cutable()) *logp << ",constraint=false"; // to rank without
// following edges
*logp << "];\n";
}
}
}
// Print ranks
for (const auto& dotRank : ranks) {
*logp << "\t{ rank=";
if (dotRank != "sink" && dotRank != "source" && dotRank != "min" && dotRank != "max") {
*logp << "same";
} else {
*logp << dotRank;
}
*logp << "; ";
auto bounds = rankSets.equal_range(dotRank);
for (auto it{bounds.first}; it != bounds.second; ++it) {
if (it != bounds.first) *logp << ", ";
*logp << 'n' << numMap[it->second] << "";
}
*logp << " }\n";
}
// Vertex::m_user end, now unused
// Trailer
*logp << "}\n";
logp->close();
cout << "dot -Tpdf -o ~/a.pdf " << filename << "\n";
}