verilator/src/V3Graph.cpp
2021-01-01 10:29:54 -05:00

394 lines
14 KiB
C++

// -*- mode: C++; c-file-style: "cc-mode" -*-
//*************************************************************************
// DESCRIPTION: Verilator: Graph optimizations
//
// Code available from: https://verilator.org
//
//*************************************************************************
//
// Copyright 2003-2021 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
//
//*************************************************************************
#include "config_build.h"
#include "verilatedos.h"
#include "V3Global.h"
#include "V3File.h"
#include "V3Graph.h"
#include <map>
#include <memory>
#include <vector>
int V3Graph::s_debug = 0;
int V3Graph::debug() { return std::max(V3Error::debugDefault(), s_debug); }
//######################################################################
//######################################################################
// 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;
verticesPushBack(graphp);
}
V3GraphVertex::V3GraphVertex(V3Graph* graphp)
: m_fanout{0}
, m_color{0}
, m_rank{0} {
m_userp = nullptr;
verticesPushBack(graphp);
}
void V3GraphVertex::verticesPushBack(V3Graph* graphp) {
m_vertices.pushBack(graphp->m_vertices, this);
}
void V3GraphVertex::unlinkEdges(V3Graph*) {
for (V3GraphEdge* edgep = outBeginp(); edgep; /*BELOW*/) {
V3GraphEdge* nextp = edgep->outNextp();
edgep->unlinkDelete();
edgep = nextp;
}
for (V3GraphEdge* edgep = inBeginp(); edgep; /*BELOW*/) {
V3GraphEdge* nextp = edgep->inNextp();
edgep->unlinkDelete();
edgep = nextp;
}
}
void V3GraphVertex::unlinkDelete(V3Graph* graphp) {
// Delete edges
unlinkEdges(graphp);
// Unlink from vertex list
m_vertices.unlink(graphp->m_vertices, this);
// Delete
delete this; // this=nullptr;
}
void V3GraphVertex::rerouteEdges(V3Graph* graphp) {
// Make new edges for each from/to pair
for (V3GraphEdge* iedgep = inBeginp(); iedgep; iedgep = iedgep->inNextp()) {
for (V3GraphEdge* oedgep = outBeginp(); oedgep; oedgep = oedgep->outNextp()) {
new V3GraphEdge(graphp, iedgep->fromp(), oedgep->top(),
std::min(iedgep->weight(), oedgep->weight()),
iedgep->cutable() && oedgep->cutable());
}
}
// Remove old edges
unlinkEdges(graphp);
}
bool V3GraphVertex::inSize1() const { return !inEmpty() && !inBeginp()->inNextp(); }
bool V3GraphVertex::outSize1() const { return !outEmpty() && !outBeginp()->outNextp(); }
uint32_t V3GraphVertex::inHash() const {
// We want the same hash ignoring the order of edges.
// So we need an associative operator, like XOR.
// However with XOR multiple edges to the same source will cancel out,
// so we use ADD. (Generally call this only after removing duplicates though)
uint32_t hash = 0;
for (V3GraphEdge* edgep = this->inBeginp(); edgep; edgep = edgep->inNextp()) {
hash += cvtToHash(edgep->fromp());
}
return hash;
}
uint32_t V3GraphVertex::outHash() const {
uint32_t hash = 0;
for (V3GraphEdge* edgep = this->outBeginp(); edgep; edgep = edgep->outNextp()) {
hash += cvtToHash(edgep->top());
}
return hash;
}
V3GraphEdge* V3GraphVertex::findConnectingEdgep(GraphWay way, const 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.
GraphWay inv = way.invert();
V3GraphEdge* aedgep = this->beginp(way);
V3GraphEdge* bedgep = waywardp->beginp(inv);
while (aedgep && bedgep) {
if (aedgep->furtherp(way) == waywardp) return aedgep;
if (bedgep->furtherp(inv) == this) return bedgep;
aedgep = aedgep->nextp(way);
bedgep = bedgep->nextp(inv);
}
return nullptr;
}
void V3GraphVertex::v3errorEnd(std::ostringstream& str) const {
std::ostringstream nsstr;
nsstr << str.str();
if (debug()) {
nsstr << endl;
nsstr << "-vertex: " << this << endl;
}
if (!fileline()) {
V3Error::v3errorEnd(nsstr);
} else {
fileline()->v3errorEnd(nsstr);
}
}
void V3GraphVertex::v3errorEndFatal(std::ostringstream& str) const {
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
outPushBack();
inPushBack();
}
V3GraphEdge* V3GraphEdge::relinkFromp(V3GraphVertex* newFromp) {
V3GraphEdge* oldNxt = outNextp();
m_outs.unlink(m_fromp->m_outs, this);
m_fromp = newFromp;
outPushBack();
return oldNxt;
}
void V3GraphEdge::unlinkDelete() {
// Unlink from side
m_outs.unlink(m_fromp->m_outs, this);
// Unlink to side
m_ins.unlink(m_top->m_ins, this);
// Delete
delete this; // this=nullptr;
}
void V3GraphEdge::outPushBack() {
// m_fromp->m_outsp.push_back(this);
m_outs.pushBack(m_fromp->m_outs, this);
}
void V3GraphEdge::inPushBack() {
// m_top->m_insp.push_back(this);
m_ins.pushBack(m_top->m_ins, this);
}
//######################################################################
//######################################################################
// Graph top level
// Constructors
V3Graph::V3Graph() {
// Anything here is probably needed in clear() also
verticesUnlink();
}
V3Graph::~V3Graph() { clear(); }
void V3Graph::clear() {
// Empty it of all points, as if making a new object
// Delete the old edges
for (V3GraphVertex* vertexp = verticesBeginp(); vertexp; vertexp = vertexp->verticesNextp()) {
for (V3GraphEdge* edgep = vertexp->outBeginp(); edgep; /*BELOW*/) {
V3GraphEdge* nextp = edgep->outNextp();
VL_DO_DANGLING(delete edgep, edgep);
edgep = nextp;
}
vertexp->outUnlink();
}
// Delete the old vertices
for (V3GraphVertex* vertexp = verticesBeginp(); vertexp; /*BELOW*/) {
V3GraphVertex* nextp = vertexp->verticesNextp();
VL_DO_DANGLING(delete vertexp, vertexp);
vertexp = nextp;
}
verticesUnlink();
}
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* vertexp = verticesBeginp(); vertexp; vertexp = vertexp->verticesNextp()) {
vertexp->user(0);
vertexp->userp(nullptr); // Its a union, but might be different size than user()
}
}
void V3Graph::userClearEdges() {
// Clear user() in all of tree
for (V3GraphVertex* vertexp = verticesBeginp(); vertexp; vertexp = vertexp->verticesNextp()) {
for (V3GraphEdge* edgep = vertexp->outBeginp(); edgep; edgep = edgep->outNextp()) {
edgep->user(0);
edgep->userp(nullptr); // Its a union, but might be different size than user()
}
}
}
void V3Graph::clearColors() {
// Reset colors
for (V3GraphVertex* vertexp = verticesBeginp(); vertexp; vertexp = vertexp->verticesNextp()) {
vertexp->m_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) {
// This generates a file used by graphviz, https://www.graphviz.org
os << " Graph:\n";
// Print vertices
for (V3GraphVertex* vertexp = verticesBeginp(); vertexp; vertexp = vertexp->verticesNextp()) {
os << "\tNode: " << vertexp->name();
if (vertexp->color()) os << " color=" << vertexp->color();
os << '\n';
// Print edges
for (V3GraphEdge* edgep = vertexp->inBeginp(); edgep; edgep = edgep->inNextp()) {
dumpEdge(os, vertexp, edgep);
}
for (V3GraphEdge* edgep = vertexp->outBeginp(); edgep; edgep = edgep->outNextp()) {
dumpEdge(os, vertexp, edgep);
}
}
}
void V3Graph::dumpEdge(std::ostream& os, V3GraphVertex* vertexp, V3GraphEdge* edgep) {
if (edgep->weight() && (edgep->fromp() == vertexp || edgep->top() == vertexp)) {
os << "\t\t";
if (edgep->fromp() == vertexp) os << "-> " << edgep->top()->name();
if (edgep->top() == vertexp) os << "<- " << edgep->fromp()->name();
if (edgep->cutable()) os << " [CUTABLE]";
os << '\n';
}
}
void V3Graph::dumpDotFilePrefixed(const string& nameComment, bool colorAsSubgraph) const {
if (v3Global.opt.dumpTree()) {
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
typedef std::multimap<string, V3GraphVertex*> SubgraphMmap;
SubgraphMmap subgraphs;
for (V3GraphVertex* vertexp = verticesBeginp(); vertexp; vertexp = vertexp->verticesNextp()) {
string vertexSubgraph
= (colorAsSubgraph && vertexp->color()) ? cvtToStr(vertexp->color()) : "";
subgraphs.emplace(vertexSubgraph, vertexp);
}
// 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 (SubgraphMmap::const_iterator it = subgraphs.begin(); it != subgraphs.end(); ++it) {
string vertexSubgraph = it->first;
V3GraphVertex* vertexp = it->second;
numMap[vertexp] = n;
if (subgr != vertexSubgraph) {
if (subgr != "") *logp << "\t};\n";
subgr = vertexSubgraph;
if (subgr != "") *logp << "\tsubgraph cluster_" << 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 (V3GraphVertex* vertexp = verticesBeginp(); vertexp; vertexp = vertexp->verticesNextp()) {
for (V3GraphEdge* edgep = vertexp->outBeginp(); edgep; edgep = edgep->outNextp()) {
if (edgep->weight()) {
int fromVnum = numMap[edgep->fromp()];
int toVnum = numMap[edgep->top()];
*logp << "\tn" << edgep->fromp()->dotName() << fromVnum << " -> n"
<< edgep->top()->dotName() << toVnum
<< " ["
//<<"fontsize=8 label=\""<<(edgep->name()!="" ? edgep->name() : "\\E")<<"\""
<< "fontsize=8 label=\""
<< (edgep->dotLabel() != "" ? edgep->dotLabel() : "") << "\""
<< " weight=" << edgep->weight() << " color=" << edgep->dotColor();
if (edgep->dotStyle() != "") *logp << " style=" << edgep->dotStyle();
// if (edgep->cutable()) { *logp<<",constraint=false"; } // to rank without
// following edges
*logp << "];\n";
}
}
}
// Vertex::m_user end, now unused
// Trailer
*logp << "}\n";
logp->close();
cout << "dot -Tpdf -o ~/a.pdf " << filename << endl;
}