C++ Node::isNonNegative方法代码示例

//.........这里部分代码省略.........
   // Don't move object header store past a GC point
   //
   if ((currentNode->getOpCode().isWrtBar() || currentNode->canCauseGC()) && mayBeObjectHeaderStore(movingNode, fe()))
      {
      if (trace())
    	   traceMsg(comp(),"cannot move possible object header store %s past GC point %s\n", getDebug()->getName(movingNode), getDebug()->getName(currentNode));
      return true;
      }

   if (TR::Compiler->target.cpu.isPower() && opCode.getOpCodeValue() == TR::allocationFence)
      {
      // Can't move allocations past flushes
      if (movingNode->getOpCodeValue() == TR::treetop &&
          movingNode->getFirstChild()->getOpCode().isNew() &&
          (currentNode->getAllocation() == NULL ||
           currentNode->getAllocation() == movingNode->getFirstChild()))
         {
         if (trace())
            {
            traceMsg(comp(),"cannot move %p beyond flush %p - ", movingNode, currentNode);
            if (currentNode->getAllocation() == NULL)
               traceMsg(comp(),"(flush with null allocation)\n");
            else
               traceMsg(comp(),"(flush for allocation %p)\n", currentNode->getAllocation());
            }
         return true;
         }

      // Can't move certain stores past flushes
      // Exclude all indirect stores, they may be for stack allocs, in which case the flush is needed at least as a scheduling barrier
      // Direct stores to autos and parms are the only safe candidates
      if (movingNode->getOpCode().isStoreIndirect() ||
          (movingNode->getOpCode().isStoreDirect() && !movingNode->getSymbol()->isParm() && !movingNode->getSymbol()->isAuto()))
         {
         if (trace())
            traceMsg(comp(),"cannot move %p beyond flush %p - (flush for possible stack alloc)", movingNode, currentNode);
         return true;
         }
      }

   for (int32_t i = 0; i < currentNode->getNumChildren(); i++)
      {
      TR::Node *child = currentNode->getChild(i);

      //Any node that has side effects (like call and newarrya) cannot be evaluated in the middle of the tree.
      if (movingTreeRefInfo->getFirstRefNodesList()->find(child))
         {
         //for calls and unresolve symbol that are not under check

         if (child->exceptionsRaised() ||
             (child->getOpCode().hasSymbolReference() && child->getSymbolReference()->isUnresolved()))
    	    {
    	    if (trace())
    	       traceMsg(comp(),"cannot move %p beyond %p - cannot change evaluation point of %p\n ",movingNode,currentTreeRefInfo->getTreeTop()->getNode(),child);
            return true;
    	    }

         else if(movingNode->getOpCode().isStore())
            {
            TR::SymbolReference *stSymRef = movingNode->getSymbolReference();
            int32_t stSymRefNum = stSymRef->getReferenceNumber();
            //TR::SymbolReference *stSymRef = movingNode->getSymbolReference();
            int32_t numHelperSymbols = comp()->getSymRefTab()->getNumHelperSymbols();
            if ((comp()->getSymRefTab()->isNonHelper(stSymRefNum, TR::SymbolReferenceTable::vftSymbol))||
                (comp()->getSymRefTab()->isNonHelper(stSymRefNum, TR::SymbolReferenceTable::contiguousArraySizeSymbol))||
                (comp()->getSymRefTab()->isNonHelper(stSymRefNum, TR::SymbolReferenceTable::discontiguousArraySizeSymbol))||
                (stSymRef == comp()->getSymRefTab()->findHeaderFlagsSymbolRef())||
                (stSymRef->getSymbol() == comp()->getSymRefTab()->findGenericIntShadowSymbol()))

               return true;
            }

         else if (movingNode->getOpCode().isResolveOrNullCheck())
            {
    	    if (trace())
    	       traceMsg(comp(),"cannot move %p beyond %p - node %p under ResolveOrNullCheck",movingNode,currentTreeRefInfo->getTreeTop()->getNode(),currentNode);
            return true;
            }

    	 else if (TR::Compiler->target.is64Bit() &&
    		  movingNode->getOpCode().isBndCheck() &&
    		  ((opCode.getOpCodeValue() == TR::i2l) || (opCode.getOpCodeValue() == TR::iu2l)) &&
    		  !child->isNonNegative())
    	    {
    	    if (trace())
    	       traceMsg(comp(),"cannot move %p beyond %p - changing the eval point of %p will casue extra cg instruction ",movingNode,currentTreeRefInfo->getTreeTop()->getNode(),currentNode);
    	    return true;
    	    }
         }

      //don't recurse over nodes each are not the first reference
      if (child->getReferenceCount()==1 || currentTreeRefInfo->getFirstRefNodesList()->find(child))
         {
         if (isAnySymInDefinedOrUsedBy(currentTreeRefInfo, child, movingTreeRefInfo ))
            return true;
         }
      }

   return false;
   }