// VISITORS
virtual void visit(AstNodeVarRef* nodep, AstNUser*) {
nodep->iterateChildren(*this);
// We only allow a LHS ref for the var being set, and a RHS ref for something else being read.
if (nodep->varScopep()->varp()->isSc()) {
clearSimple("SystemC sig"); // Don't want to eliminate the VL_ASSIGN_SI's
}
if (nodep->lvalue()) {
if (m_lhsVarRef) clearSimple(">1 lhs varRefs");
m_lhsVarRef = nodep;
} else {
if (m_rhsVarRefs.size()>1) {
AstNodeVarRef* lastRefp = m_rhsVarRefs.back();
if (0) { // Diable the multiple-input optimization
clearSimple(">1 rhs varRefs");
} else {
if (m_buffersOnly) clearSimple(">1 rhs varRefs");
if (!nodep->varScopep()->varp()->gateMultiInputOptimizable()
// We didn't check multiInput on the first varref, so check it here
|| !lastRefp->varScopep()->varp()->gateMultiInputOptimizable()) {
clearSimple("!gateMultiInputOptimizable");
}
}
}
m_rhsVarRefs.push_back(nodep);
}
}
virtual AstNUser* visit(GateVarVertex *vvertexp, AstNUser*) {
// Check that we haven't been here before
if (vvertexp->varScp()->user2()) return NULL;
vvertexp->varScp()->user2(true);
AstNodeVarRef* dupVarRefp = (AstNodeVarRef*) vvertexp->iterateInEdges(*this, (AstNUser*) vvertexp);
if (dupVarRefp && vvertexp->inSize1()) {
V3GraphEdge* edgep = vvertexp->inBeginp();
GateLogicVertex* lvertexp = (GateLogicVertex*)edgep->fromp();
if (!vvertexp->dedupable()) vvertexp->varScp()->v3fatalSrc("GateLogicVertex* visit should have returned NULL if consumer var vertex is not dedupable.");
GateOkVisitor okVisitor(lvertexp->nodep(), false, true);
if (okVisitor.isSimple()) {
AstVarScope* dupVarScopep = dupVarRefp->varScopep();
GateVarVertex* dupVvertexp = (GateVarVertex*) (dupVarScopep->user1p());
UINFO(4,"replacing " << vvertexp << " with " << dupVvertexp << endl);
++m_numDeduped;
// Replace all of this varvertex's consumers with dupVarRefp
for (V3GraphEdge* outedgep = vvertexp->outBeginp();outedgep;) {
GateLogicVertex* consumeVertexp = dynamic_cast<GateLogicVertex*>(outedgep->top());
AstNode* consumerp = consumeVertexp->nodep();
GateElimVisitor elimVisitor(consumerp,vvertexp->varScp(),dupVarRefp);
outedgep = outedgep->relinkFromp(dupVvertexp);
}
// Propogate attributes
dupVvertexp->propagateAttrClocksFrom(vvertexp);
// Remove inputs links
while (V3GraphEdge* inedgep = vvertexp->inBeginp()) {
inedgep->unlinkDelete(); VL_DANGLING(inedgep);
}
// replaceAssigns() does the deleteTree on lvertexNodep in a later step
AstNode* lvertexNodep = lvertexp->nodep();
lvertexNodep->unlinkFrBack();
vvertexp->varScp()->valuep(lvertexNodep);
lvertexNodep = NULL;
vvertexp->user(true);
lvertexp->user(true);
}
}
return NULL;
}
// CONSTUCTORS
GateOkVisitor(AstNode* nodep, bool buffersOnly) {
m_isSimple = true;
m_substTreep = NULL;
m_buffersOnly = buffersOnly;
m_lhsVarRef = NULL;
// Iterate
nodep->accept(*this);
// Check results
if (!m_substTreep) {
clearSimple("No assignment found\n");
}
for (GateVarRefList::const_iterator it = rhsVarRefs().begin();
it != rhsVarRefs().end(); ++it) {
if (m_lhsVarRef && m_lhsVarRef->varScopep() == (*it)->varScopep()) {
clearSimple("Circular logic\n"); // Oh my, we'll get a UNOPTFLAT much later.
}
}
if (debug()>=9 && !m_isSimple) {
nodep->dumpTree(cout,"\tgate!Ok: ");
}
}
