forked from github/verilator
248 lines
7.8 KiB
C++
248 lines
7.8 KiB
C++
// -*- mode: C++; c-file-style: "cc-mode" -*-
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//*************************************************************************
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// DESCRIPTION: Verilator: Generated Clock repairs
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//
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// Code available from: http://www.veripool.org/verilator
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//
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//*************************************************************************
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//
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// Copyright 2003-2018 by Wilson Snyder. This program is free software; you can
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// redistribute it and/or modify it under the terms of either the GNU
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// Lesser General Public License Version 3 or the Perl Artistic License
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// Version 2.0.
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//
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// Verilator is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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//*************************************************************************
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// GENCLK TRANSFORMATIONS:
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// Follow control-flow graph with assignments and var usages
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// ASSIGNDLY to variable later used as clock requires change detect
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//
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//*************************************************************************
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#include "config_build.h"
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#include "verilatedos.h"
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#include <cstdio>
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#include <cstdarg>
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#include <unistd.h>
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#include "V3Global.h"
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#include "V3GenClk.h"
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#include "V3Ast.h"
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//######################################################################
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// GenClk state, as a visitor of each AstNode
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class GenClkBaseVisitor : public AstNVisitor {
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protected:
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VL_DEBUG_FUNC; // Declare debug()
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};
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//######################################################################
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// GenClk Read
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class GenClkRenameVisitor : public GenClkBaseVisitor {
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private:
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// NODE STATE
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// Cleared on top scope
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// AstVarScope::user2() -> AstVarScope*. Signal replacing activation with
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// AstVarRef::user3() -> bool. Signal is replaced activation (already done)
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AstUser2InUse m_inuser2;
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AstUser3InUse m_inuser3;
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// STATE
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AstActive* m_activep; // Inside activate statement
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AstNodeModule* m_topModp; // Top module
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AstScope* m_scopetopp; // Scope under TOPSCOPE
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// METHODS
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AstVarScope* genInpClk(AstVarScope* vscp) {
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if (vscp->user2p()) {
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return VN_CAST(vscp->user2p(), VarScope);
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} else {
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AstVar* varp = vscp->varp();
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string newvarname = "__VinpClk__"+vscp->scopep()->nameDotless()+"__"+varp->name();
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// Create: VARREF(inpclk)
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// ...
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// ASSIGN(VARREF(inpclk), VARREF(var))
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AstVar* newvarp = new AstVar (varp->fileline(), AstVarType::MODULETEMP, newvarname, varp);
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m_topModp->addStmtp(newvarp);
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AstVarScope* newvscp = new AstVarScope(vscp->fileline(), m_scopetopp, newvarp);
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m_scopetopp->addVarp(newvscp);
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AstAssign* asninitp = new AstAssign (vscp->fileline(),
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new AstVarRef(vscp->fileline(), newvscp, true),
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new AstVarRef(vscp->fileline(), vscp, false));
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m_scopetopp->addFinalClkp(asninitp);
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//
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vscp->user2p(newvscp);
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return newvscp;
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}
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}
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// VISITORS
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virtual void visit(AstTopScope* nodep) {
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AstNode::user2ClearTree(); // user2p() used on entire tree
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AstScope* scopep = nodep->scopep();
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if (!scopep) nodep->v3fatalSrc("No scope found on top level");
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m_scopetopp = scopep;
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iterateChildren(nodep);
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}
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//----
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virtual void visit(AstVarRef* nodep) {
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// Consumption/generation of a variable,
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AstVarScope* vscp = nodep->varScopep();
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if (!vscp) nodep->v3fatalSrc("Scope not assigned");
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if (m_activep && !nodep->user3()) {
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nodep->user3(true);
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if (vscp->isCircular()) {
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UINFO(8," VarActReplace "<<nodep<<endl);
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// Replace with the new variable
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AstVarScope* newvscp = genInpClk(vscp);
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AstVarRef* newrefp = new AstVarRef(nodep->fileline(), newvscp, nodep->lvalue());
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nodep->replaceWith(newrefp);
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pushDeletep(nodep); VL_DANGLING(nodep);
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}
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}
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}
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virtual void visit(AstActive* nodep) {
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m_activep = nodep;
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if (!nodep->sensesp()) nodep->v3fatalSrc("Unlinked");
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iterateChildren(nodep->sensesp()); // iterateAndNext?
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m_activep = NULL;
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iterateChildren(nodep);
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}
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virtual void visit(AstCFunc* nodep) {
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iterateChildren(nodep);
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}
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//-----
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virtual void visit(AstNode* nodep) {
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iterateChildren(nodep);
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}
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public:
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// CONSTRUCTORS
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GenClkRenameVisitor(AstTopScope* nodep, AstNodeModule* topModp) {
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m_topModp = topModp;
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m_scopetopp = NULL;
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m_activep = NULL;
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iterate(nodep);
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}
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virtual ~GenClkRenameVisitor() {}
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};
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//######################################################################
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// GenClk Read
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class GenClkReadVisitor : public GenClkBaseVisitor {
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private:
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// NODE STATE
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// Cleared on top scope
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// AstVarScope::user() -> bool. Set when the var has been used as clock
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AstUser1InUse m_inuser1;
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// STATE
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AstActive* m_activep; // Inside activate statement
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bool m_tracingCall; // Iterating into a call to a cfunc
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AstNodeAssign* m_assignp; // Inside assigndly statement
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AstNodeModule* m_topModp; // Top module
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// VISITORS
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virtual void visit(AstTopScope* nodep) {
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AstNode::user1ClearTree(); // user1p() used on entire tree
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iterateChildren(nodep);
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{
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// Make the new clock signals and replace any activate references
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// See rename, it does some AstNode::userClearTree()'s
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GenClkRenameVisitor visitor (nodep, m_topModp);
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}
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}
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virtual void visit(AstNodeModule* nodep) {
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// Only track the top scopes, not lower level functions
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if (nodep->isTop()) {
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m_topModp = nodep;
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iterateChildren(nodep);
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}
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}
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virtual void visit(AstCCall* nodep) {
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iterateChildren(nodep);
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if (!nodep->funcp()->entryPoint()) {
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// Enter the function and trace it
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m_tracingCall = true;
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iterate(nodep->funcp());
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}
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}
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virtual void visit(AstCFunc* nodep) {
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if (!m_tracingCall && !nodep->entryPoint()) {
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// Only consider logic within a CFunc when looking
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// at the call to it, and not when scanning whatever
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// scope it happens to live beneath.
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return;
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}
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m_tracingCall = false;
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iterateChildren(nodep);
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}
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//----
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virtual void visit(AstVarRef* nodep) {
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// Consumption/generation of a variable,
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AstVarScope* vscp = nodep->varScopep();
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if (!vscp) nodep->v3fatalSrc("Scope not assigned");
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if (m_activep) {
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UINFO(8," VarAct "<<nodep<<endl);
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vscp->user1(true);
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}
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if (m_assignp && nodep->lvalue() && vscp->user1()) {
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// Variable was previously used as a clock, and is now being set
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// Thus a unordered generated clock...
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UINFO(8," VarSetAct "<<nodep<<endl);
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vscp->circular(true);
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}
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}
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virtual void visit(AstNodeAssign* nodep) {
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//UINFO(8,"ASS "<<nodep<<endl);
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m_assignp = nodep;
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iterateChildren(nodep);
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m_assignp = NULL;
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}
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virtual void visit(AstActive* nodep) {
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UINFO(8,"ACTIVE "<<nodep<<endl);
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m_activep = nodep;
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if (!nodep->sensesp()) nodep->v3fatalSrc("Unlinked");
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iterateChildren(nodep->sensesp()); // iterateAndNext?
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m_activep = NULL;
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iterateChildren(nodep);
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}
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//-----
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virtual void visit(AstVar*) {} // Don't want varrefs under it
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virtual void visit(AstNode* nodep) {
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iterateChildren(nodep);
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}
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public:
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// CONSTRUCTORS
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explicit GenClkReadVisitor(AstNetlist* nodep)
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: m_activep(NULL)
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, m_tracingCall(false)
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, m_assignp(NULL)
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, m_topModp(NULL) {
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iterate(nodep);
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}
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virtual ~GenClkReadVisitor() {}
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};
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//######################################################################
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// GenClk class functions
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void V3GenClk::genClkAll(AstNetlist* nodep) {
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UINFO(2,__FUNCTION__<<": "<<endl);
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{
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GenClkReadVisitor visitor (nodep);
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} // Destruct before checking
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V3Global::dumpCheckGlobalTree("genclk", 0, v3Global.opt.dumpTreeLevel(__FILE__) >= 3);
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}
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