verilator/src/V3SenTree.h
2018-01-02 18:05:06 -05:00

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// -*- mode: C++; c-file-style: "cc-mode" -*-
//*************************************************************************
// DESCRIPTION: Verilator: Break always into sensitivity block domains
//
// Code available from: http://www.veripool.org/verilator
//
//*************************************************************************
//
// Copyright 2003-2018 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.
//
// Verilator is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
//*************************************************************************
// V3Block's Transformations:
//
// Note this can be called multiple times.
// Create a IBLOCK(initial), SBLOCK(combo)
// ALWAYS: Remove any-edges from sense list
// If no POS/NEG in senselist, Fold into SBLOCK(combo)
// Else fold into SBLOCK(sequent).
// OPTIMIZE: When support async clocks, fold into that block if possible
// INITIAL: Move into IBLOCK
// WIRE: Move into SBLOCK(combo)
//
//*************************************************************************
#ifndef _V3SENTREE_H_
#define _V3SENTREE_H_
#include "config_build.h"
#include "verilatedos.h"
#include <cstdio>
#include <cstdarg>
#include <unistd.h>
#include <map>
#include <algorithm>
#include <vector>
#include "V3Global.h"
#include "V3Ast.h"
//######################################################################
// Collect SenTrees under the entire scope
// And provide functions to find/add a new one
class SenTreeFinder : public AstNVisitor {
private:
// STATE
AstTopScope* m_topscopep; // Top scope to add statement to
vector<AstSenTree*> m_treesp; // List of sensitive blocks, for folding
// VISITORS
static int debug() {
static int level = -1;
if (VL_UNLIKELY(level < 0)) level = v3Global.opt.debugSrcLevel(__FILE__);
return level;
}
virtual void visit(AstNodeModule* nodep) {
// Only do the top
if (nodep->isTop()) {
nodep->iterateChildren(*this);
}
}
virtual void visit(AstTopScope* nodep) {
m_topscopep = nodep;
nodep->iterateChildren(*this);
// Don't clear topscopep, the namer persists beyond this visit
}
virtual void visit(AstScope* nodep) {
// But no SenTrees under TopScope's scope
}
// Memorize existing block names
virtual void visit(AstActive* nodep) {
// Don't grab SenTrees under Actives, only those that are global (under Scope directly)
nodep->iterateChildren(*this);
}
virtual void visit(AstSenTree* nodep) {
m_treesp.push_back(nodep);
}
// Empty visitors, speed things up
virtual void visit(AstNodeStmt* nodep) { }
virtual void visit(AstNode* nodep) {
nodep->iterateChildren(*this);
}
// METHODS
public:
void clear() {
m_topscopep = NULL;
m_treesp.clear();
}
AstSenTree* getSenTree(FileLine* fl, AstSenTree* sensesp) {
// Return a global sentree that matches given sense list.
// Not the fastest, but there tend to be few clocks
AstSenTree* treep = NULL;
//sensesp->dumpTree(cout," Lookingfor: ");
for (vector<AstSenTree*>::iterator it = m_treesp.begin(); it!=m_treesp.end(); ++it) {
treep = *it;
if (treep) { // Not deleted
if (treep->sameTree(sensesp)) {
UINFO(8," Found SBLOCK "<<treep<<endl);
goto found;
}
}
treep = NULL;
}
found:
// Not found, form a new one
if (!treep) {
UASSERT(m_topscopep,"Never called main()");
treep = sensesp->cloneTree(false);
m_topscopep->addStmtsp(treep);
UINFO(8," New SENTREE "<<treep<<endl);
m_treesp.push_back(treep);
// Note blocks may have also been added above in the Active visitor
}
return treep;
}
public:
// CONSTUCTORS
SenTreeFinder() {
clear();
}
virtual ~SenTreeFinder() {}
void main(AstTopScope* nodep) {
nodep->accept(*this);
}
};
#endif // Guard