Ejemplo n.º 1
0
// Collects nodes that involved in PRE that are not stores or checks.
// These nodes require temps.
//
bool TR_LocalAnalysisInfo::collectSupportedNodes(TR::Node *node, TR::Node *parent)
   {
   if (node->getVisitCount() == _visitCount)
      return false;

   node->setVisitCount(_visitCount);

   bool flag = false;
   bool childRelevant = false;
   TR::ILOpCode &opCode = node->getOpCode();

   int32_t i;
   for (i = 0; i < node->getNumChildren(); i++)
      {
      TR::Node *child = node->getChild(i);
      if (collectSupportedNodes(child, node))
         flag = true;

      if (_checkExpressions->get(child->getLocalIndex()))
         childRelevant = true;
      }

   if (TR_LocalAnalysis::isSupportedNode(node, _compilation, parent))
      {
      _supportedNodesAsArray[node->getLocalIndex()] = node;

      bool indirectionSafe = true;
      if (opCode.isIndirect() && (opCode.isLoadVar() || opCode.isStore()))
         {
         indirectionSafe = false;
         if (node->getFirstChild()->isThisPointer() &&
             node->getFirstChild()->isNonNull())
            {
            indirectionSafe = true;
            TR::Node *firstChild = node->getFirstChild();
            TR::SymbolReference *symRef = firstChild->getSymbolReference();
            int32_t len;
            const char *sig = symRef->getTypeSignature(len);

            TR::SymbolReference *otherSymRef = node->getSymbolReference();

            TR_OpaqueClassBlock *cl = NULL;
            if (sig && (len > 0))
               cl = _compilation->fe()->getClassFromSignature(sig, len, symRef->getOwningMethod(_compilation));

            TR_OpaqueClassBlock *otherClassObject = NULL;
            int32_t otherLen;
            const char *otherSig = otherSymRef->getOwningMethod(_compilation)->classNameOfFieldOrStatic(otherSymRef->getCPIndex(), otherLen);
            if (otherSig)
               {
               otherSig = classNameToSignature(otherSig, otherLen, _compilation);
               otherClassObject = _compilation->fe()->getClassFromSignature(otherSig, otherLen, otherSymRef->getOwningMethod(_compilation));
               }

            if (!cl ||
                !otherClassObject ||
                (cl != otherClassObject))
               indirectionSafe = false;
            }
         }

      if (childRelevant ||
         (!indirectionSafe || (opCode.isArrayLength())) ||
         (node->getOpCode().isArrayRef()) ||
         (opCode.hasSymbolReference() && (node->getSymbolReference()->isUnresolved() || node->getSymbol()->isArrayShadowSymbol())) ||
         (opCode.isDiv() || opCode.isRem()))
         _checkExpressions->set(node->getLocalIndex());
      }

   return flag;
   }