void SSABuilder::deconvertSSA(ControlFlowGraph* fg,OpndManager& opndManager) {
const Nodes& nodes = fg->getNodes();
Nodes::const_iterator niter;
for(niter = nodes.begin(); niter != nodes.end(); ++niter) {
Node* node = *niter;
Inst *headInst = (Inst*)node->getFirstInst();
for (Inst *inst = headInst->getNextInst(); inst != NULL; ) {
Inst *nextInst = inst->getNextInst();
if (inst->isPhi()) {
inst->unlink();
} else {
for (U_32 i = 0; i < inst->getNumSrcOperands(); i++) {
Opnd *opnd = inst->getSrc(i);
if (opnd->isSsaVarOpnd()) {
SsaVarOpnd *ssa = (SsaVarOpnd *)opnd;
VarOpnd *var = ssa->getVar();
inst->setSrc(i,var);
} else if (opnd->isVarOpnd()) {
}
}
Opnd *dst = inst->getDst();
if (dst->isSsaVarOpnd()) {
SsaVarOpnd *ssa = (SsaVarOpnd *)dst;
inst->setDst(ssa->getVar());
}
}
inst = nextInst;
}
}
}
//
// traverse dominator tree and rename variables
//
void SSABuilder::renameNode(RenameStack *renameStack, DominatorNode* dt,
const StlVectorSet<VarOpnd *> *whatVars)
{
if (dt == NULL) return;
Node* node = dt->getNode();
Inst* head = (Inst*)node->getFirstInst();
#ifdef DEBUG_SSA
std::ostream &cout = Log::out();
if (Log::isEnabled()) {
cout << "renameNode "; FlowGraph::printLabel(cout, node); cout << std::endl;
}
#endif
for (Inst* i = head->getNextInst(); i != NULL; i = i->getNextInst()) {
if (!i->isPhi()) {
// replace src with ssa opnd
U_32 nSrcs = i->getNumSrcOperands();
for (U_32 j = 0; j < nSrcs; j++) {
Opnd *srcj = i->getSrc(j);
VarOpnd *srcjVar = (srcj->isSsaVarOpnd()
? srcj->asSsaVarOpnd()->getVar()
: srcj->asVarOpnd());
if (!(srcjVar && !srcjVar->isAddrTaken()))
continue;
if (whatVars && !whatVars->has(srcjVar)) continue;
SsaVarOpnd* ssa = renameStack->lookup(srcjVar);
assert(ssa);
i->setSrc(j,ssa);
}
}
// for both Phi and non-Phi
// we replace any non-ssa dst with a new ssa opnd
// and record it in the RenameStack map
Opnd* dst = i->getDst();
VarOpnd *theVar = dst->asVarOpnd();
if (theVar && (!theVar->isAddrTaken())
&& !(whatVars && !whatVars->has(theVar))) {
SsaVarOpnd* ssaDst = opndManager.createSsaVarOpnd((VarOpnd*)dst);
#ifdef DEBUG_SSA
if (Log::isEnabled()) {
cout << "SSA "; ssaDst->print(cout); cout << ::std::endl;
}
#endif
renameStack->insert((VarOpnd*)dst, ssaDst);
i->setDst(ssaDst);
#ifdef DEBUG_SSA
if (Log::isEnabled()) {
i->print(cout); cout << ::std::endl;
}
#endif
// record stVar inst
} else if (dst->isSsaVarOpnd()) {
SsaVarOpnd* ssaDst = dst->asSsaVarOpnd();
theVar = ssaDst->getVar();
if (whatVars && !whatVars->has(theVar))
continue;
#ifdef DEBUG_SSA
if (Log::isEnabled()) {
cout << "SSA "; ssaDst->print(cout); cout << ::std::endl;
}
#endif
renameStack->insert(ssaDst->getVar(), ssaDst);
#ifdef DEBUG_SSA
if (Log::isEnabled()) {
i->print(cout); cout << ::std::endl;
}
#endif
}
}
// add var sources to following phi instructions
const Edges& edges = node->getOutEdges();
Edges::const_iterator
eiter = edges.begin(),
eend = edges.end();
for(eiter = edges.begin(); eiter != eend; ++eiter) {
Edge* e = *eiter;
Node* succ = e->getTargetNode();
// Phi insts are inserted to the beginning of the block
// if succ does not have phi insts, then we can skip it
Inst *phi = (Inst*)succ->getSecondInst();
if (phi==NULL || !phi->isPhi()) continue;
// node is jth predecessor for succ
// replace jth var of phi insts
Inst* nextphi = phi->getNextInst();
for (;phi!=NULL && phi->isPhi(); phi = nextphi) {
nextphi = phi->getNextInst();
// get var
Opnd *theopnd = phi->getDst();
VarOpnd *thevar = theopnd->asVarOpnd();
if (!thevar) {
SsaVarOpnd *theSsaVar = theopnd->asSsaVarOpnd();
assert(theSsaVar);
#ifdef DEBUG_SSA
if (Log::isEnabled()) {
Log::out() << "case 2" << ::std::endl;
}
#endif
thevar = theSsaVar->getVar();
}
if (whatVars && !whatVars->has(thevar)) continue;
SsaVarOpnd* ssa = renameStack->lookup((VarOpnd*)thevar);
if (ssa != NULL) {
#ifdef DEBUG_SSA
if (Log::isEnabled()) {
cout << "redge";
// cout << (I_32)j;
cout << " with ssa "; ssa->print(cout); cout << ::std::endl;
}
#endif
addPhiSrc((PhiInst*)phi,ssa);
} else {
#ifdef DEBUG_SSA
if (Log::isEnabled()) {
cout << "no source for phi of var ";
thevar->print(cout);
cout << ::std::endl;
}
#endif
// if ssa is NULL, then the phi must be a dead phi inst
// (no more use of var afterwards). it will be removed.
}
}
}
}
