C++ Node::getBlock方法代码示例

void TR_ReachingDefinitions::initializeGenAndKillSetInfo()
   {
   // For each block in the CFG build the gen and kill set for this analysis.
   // Go in treetop order, which guarantees that we see the correct (i.e. first)
   // evaluation point for each node.
   //
   TR::Block *block;
   int32_t   blockNum = 0;
   bool      seenException = false;
   TR_BitVector defsKilled(getNumberOfBits(), trMemory()->currentStackRegion());

   comp()->incVisitCount();
   for (TR::TreeTop *treeTop = comp()->getStartTree(); treeTop; treeTop = treeTop->getNextTreeTop())
      {
      TR::Node *node = treeTop->getNode();

      if (node->getOpCodeValue() == TR::BBStart)
         {
         block = node->getBlock();
         blockNum = block->getNumber();
         seenException  = false;
         if (traceRD())
            traceMsg(comp(), "\nNow generating gen and kill information for block_%d\n", blockNum);
         continue;
         }

#if DEBUG
      if (node->getOpCodeValue() == TR::BBEnd && traceRD())
         {
         traceMsg(comp(), "  Block %d:\n", blockNum);
         traceMsg(comp(), "     Gen set ");
         if (_regularGenSetInfo[blockNum])
            _regularGenSetInfo[blockNum]->print(comp());
         else
            traceMsg(comp(), "{}");
         traceMsg(comp(), "\n     Kill set ");
         if (_regularKillSetInfo[blockNum])
            _regularKillSetInfo[blockNum]->print(comp());
         else
            traceMsg(comp(), "{}");
         traceMsg(comp(), "\n     Exception Gen set ");
         if (_exceptionGenSetInfo[blockNum])
            _exceptionGenSetInfo[blockNum]->print(comp());
         else
            traceMsg(comp(), "{}");
         traceMsg(comp(), "\n     Exception Kill set ");
         if (_exceptionKillSetInfo[blockNum])
            _exceptionKillSetInfo[blockNum]->print(comp());
         else
            traceMsg(comp(), "{}");
         continue;
         }
#endif

      initializeGenAndKillSetInfoForNode(node, defsKilled, seenException, blockNum, NULL);

      if (!seenException && treeHasChecks(treeTop))
         seenException = true;
      }
   }

void
TR::RegDepCopyRemoval::makeFreshCopy(TR_GlobalRegisterNumber reg)
   {
   RegDepInfo &dep = getRegDepInfo(reg);
   if (!performTransformation(comp(),
         "%schange %s in GlRegDeps n%un to an explicit copy of n%un\n",
         optDetailString(),
         registerName(reg),
         _regDeps->getGlobalIndex(),
         dep.value->getGlobalIndex()))
      return;

   // Split the block at fallthrough if necessary to avoid putting copies
   // between branches and BBEnd.
   TR::Node *curNode = _treetop->getNode();
   if (curNode->getOpCodeValue() == TR::BBEnd)
      {
      TR::Block *curBlock = curNode->getBlock();
      if (curBlock->getLastRealTreeTop() != curBlock->getLastNonControlFlowTreeTop())
         {
         TR::Block *fallthrough = curBlock->getNextBlock();
         fallthrough = curBlock->splitEdge(curBlock, fallthrough, comp());
         TR_ASSERT(curBlock->getNextBlock() == fallthrough, "bad block placement from splitEdge\n");
         fallthrough->setIsExtensionOfPreviousBlock();
         _treetop = fallthrough->getExit();
         TR::Node *newNode = _treetop->getNode();
         newNode->setChild(0, _regDeps);
         newNode->setNumChildren(1);
         curNode->setNumChildren(0);
         if (trace())
            traceMsg(comp(), "\tsplit fallthrough edge to insert copy, created block_%d\n", fallthrough->getNumber());
         }
      }

   // Make and insert the copy
   TR::Node *copyNode = NULL;
   if (dep.value->getOpCode().isLoadConst())
      {
      // No need to depend on the other register.
      // TODO heuristic for whether this is really better than a reg-reg move?
      generateRegcopyDebugCounter("const-remat");
      copyNode = TR::Node::create(dep.value->getOpCodeValue(), 0);
      copyNode->setConstValue(dep.value->getConstValue());
      }
   else
      {
      generateRegcopyDebugCounter("fresh-copy");
      copyNode = TR::Node::create(TR::PassThrough, 1, dep.value);
      copyNode->setCopyToNewVirtualRegister();
      }

   TR::Node *copyTreetopNode = TR::Node::create(TR::treetop, 1, copyNode);
   _treetop->insertBefore(TR::TreeTop::create(comp(), copyTreetopNode));
   if (trace())
      traceMsg(comp(), "\tcopy is n%un\n", copyNode->getGlobalIndex());

   updateSingleRegDep(reg, copyNode);
   }

int32_t
TR::RegDepCopyRemoval::perform()
   {
   if (!cg()->supportsPassThroughCopyToNewVirtualRegister())
      return 0;

   discardAllNodeChoices();
   TR::TreeTop *tt;
   for (tt = comp()->getStartTree(); tt != NULL; tt = tt->getNextTreeTop())
      {
      TR::Node *node = tt->getNode();
      switch (node->getOpCodeValue())
         {
         case TR::BBStart:
            if (!node->getBlock()->isExtensionOfPreviousBlock())
               {
               if (trace())
                  traceMsg(comp(), "clearing remembered node choices at start of extended block at block_%d\n", node->getBlock()->getNumber());
               discardAllNodeChoices();
               }
            if (node->getNumChildren() > 0)
               processRegDeps(node->getFirstChild(), tt);
            break;
         case TR::BBEnd:
            if (node->getNumChildren() > 0)
               processRegDeps(node->getFirstChild(), tt);
            break;
         default:
            if (node->getOpCode().isSwitch())
               {
               TR::Node *defaultDest = node->getSecondChild();
               if (defaultDest->getNumChildren() > 0)
                  processRegDeps(defaultDest->getFirstChild(), tt);
               }
            else if (node->getOpCode().isBranch())
               {
               int nChildren = node->getNumChildren();
               // only the last child may be GlRegDeps
               for (int i = 0; i < nChildren - 1; i++)
                  TR_ASSERT(node->getChild(i)->getOpCodeValue() != TR::GlRegDeps, "GlRegDeps for branch is not the last child\n");
               if (nChildren > 0)
                  {
                  TR::Node *lastChild = node->getChild(nChildren - 1);
                  if (lastChild->getOpCodeValue() == TR::GlRegDeps)
                     processRegDeps(lastChild, tt);
                  }
               }
            break;
         }
      }
   return 1; // a bit arbitrary...
   }

int32_t TR_LocalLiveRangeReduction::perform()
   {
   if (TR::Compiler->target.cpu.isZ())
      return false;

   TR::TreeTop * exitTT, * nextTT;
   TR::Block *b;
   TR::TreeTop * tt;

   //calculate number of TreeTops in each bb (or extended bb)
   for (tt = comp()->getStartTree(); tt; tt = nextTT)
      {
      TR::StackMemoryRegion stackMemoryRegion(*trMemory());

      TR::Node *node = tt->getNode();
      b = node->getBlock();
      exitTT = b->getExit();
      _numTreeTops = b->getNumberOfRealTreeTops()+2; //include both BBStart/BBend

      //support for extended blocks
      while ((nextTT = exitTT->getNextTreeTop()) && (b = nextTT->getNode()->getBlock(), b->isExtensionOfPreviousBlock()))
         {

         _numTreeTops += b->getNumberOfRealTreeTops()+2;
         exitTT = b->getExit();
         }

      _treesRefInfoArray = (TR_TreeRefInfo**)trMemory()->allocateStackMemory(_numTreeTops*sizeof(TR_TreeRefInfo*));
      memset(_treesRefInfoArray, 0, _numTreeTops*sizeof(TR_TreeRefInfo*));
      _movedTreesList.deleteAll();
      _depPairList.deleteAll();
      transformExtendedBlock(tt,exitTT->getNextTreeTop());
      }

   if (trace())
      traceMsg(comp(), "\nEnding LocalLiveRangeReducer\n");

   return 2;
   }

TR::TreeTop *
OMR::Simplifier::simplifyExtendedBlock(TR::TreeTop * treeTop)
   {
   TR::Block * block = 0;

   _containingStructure = NULL;
   _blockRemoved = false;

   for (; treeTop; treeTop = treeTop->getNextTreeTop())
      {
      TR::Node * node = treeTop->getNode();
      TR_ASSERT(node->getOpCodeValue() == TR::BBStart, "Simplification, expected BBStart treetop");

      TR::Block * b = node->getBlock();
      if (block && !b->isExtensionOfPreviousBlock())
         break;

      if (b->isOSRCodeBlock() || b->isOSRCatchBlock())
         {
         b->setHasBeenVisited();
         treeTop = b->getExit();
         continue;
         }

#ifdef DEBUG
      if (block != b)
         b->setHasBeenVisited();
#endif

      if (!block && _reassociate &&
          comp()->getFlowGraph()->getStructure() != NULL         // [99391] getStructureOf() only valid if structure isn't invalidated
         )
         { // b is first block in the extended block
         TR_BlockStructure *blockStructure = b->getStructureOf();

         if(blockStructure)
            {
            TR_Structure *parent = blockStructure->getParent();
            while (parent)
               {
               TR_RegionStructure *region = parent->asRegion();
               if (region->isNaturalLoop() /* || region->containsInternalCycles() */)
                  {
                  _containingStructure = region;
                  break;
                  }
               parent = parent->getParent();
               }
            }
         }

      block = b;

      if (trace())
         traceMsg(comp(), "simplifying block_%d\n", block->getNumber());

      _performLowerTreeSimplifier=NULL;
      _performLowerTreeNode=NULL;
      simplify(block);

      if(_performLowerTreeSimplifier)
         {
         _performLowerTreeNode = postWalkLowerTreeSimplifier(_performLowerTreeSimplifier, _performLowerTreeNode, block, (TR::Simplifier *) this);
         _performLowerTreeSimplifier->setNode(_performLowerTreeNode);
         }

      // If the block itself was removed from the CFG during simplification, find
      // the next 'legitimate' block to be simplified
      //
      //if (comp()->getFlowGraph()->getRemovedNodes().find(block))
        if(block->nodeIsRemoved())
         {
         TR::TreeTop * tt = findNextLegalTreeTop(comp(), block);
         // in certain cases the removed block might be the last one we haven't
         // visited and therefore we won't be able to find a treetop to continue
         // in such cases we exit the loop
         //
         treeTop = tt ? tt->getPrevTreeTop() : 0;
         if (!treeTop)
            break;
         }
      else
         {
         treeTop = block->getExit();
         }
      }

   // now remove any unreachable blocks
   //
   if (_blockRemoved)
      {
      // if the next block to be processed has been removed,
      // find the next valid block to process
      //
      if (treeTop)
         {
         TR::Block *b = treeTop->getNode()->getBlock();
         //if (comp()->getFlowGraph()->getRemovedNodes().find(b))
           if(b->nodeIsRemoved())
            treeTop = findNextLegalTreeTop(comp(), b);
//.........这里部分代码省略.........

int32_t TR::DeadTreesElimination::process(TR::TreeTop *startTree, TR::TreeTop *endTree)
   {
   TR::StackMemoryRegion stackRegion(*comp()->trMemory());
   LongestPathMap longestPaths(std::less<TR::Node*>(), stackRegion);

   typedef TR::typed_allocator<CRAnchor, TR::Region&> CRAnchorAlloc;
   typedef TR::forward_list<CRAnchor, CRAnchorAlloc> CRAnchorList;
   CRAnchorList anchors(stackRegion);

   vcount_t visitCount = comp()->incOrResetVisitCount();
   TR::TreeTop *treeTop;
   for (treeTop = startTree; (treeTop != endTree); treeTop = treeTop->getNextTreeTop())
      treeTop->getNode()->initializeFutureUseCounts(visitCount);

   TR::Block *block = NULL;
   bool delayedRegStoresBeforeThisPass = _delayedRegStores;

   // Update visitCount as they are used in this optimization and need to be
   visitCount = comp()->incOrResetVisitCount();
   for (TR::TreeTopIterator iter(startTree, comp()); iter != endTree; ++iter)
      {
      TR::Node *node = iter.currentTree()->getNode();

      if (node->getOpCodeValue() == TR::BBStart)
         {
         block = node->getBlock();
         if (!block->isExtensionOfPreviousBlock())
            longestPaths.clear();
         }

      int vcountLimit = MAX_VCOUNT - 3;
      if (comp()->getVisitCount() > vcountLimit)
         {
         dumpOptDetails(comp(),
            "%sVisit count %d exceeds limit %d; stopping\n",
            optDetailString(), comp()->getVisitCount(), vcountLimit);
         return 0;
         }

      // correct at all intermediate stages
      //
      if ((node->getOpCodeValue() != TR::treetop) &&
          (!node->getOpCode().isAnchor() || (node->getFirstChild()->getReferenceCount() != 1)) &&
          (!node->getOpCode().isStoreReg() || (node->getFirstChild()->getReferenceCount() != 1)) &&
          (delayedRegStoresBeforeThisPass ||
           (iter.currentTree() == block->getLastRealTreeTop()) ||
           !node->getOpCode().isStoreReg() ||
           (node->getVisitCount() == visitCount)))
         {
         if (node->getOpCode().isAnchor() && node->getFirstChild()->getOpCode().isLoadIndirect())
            anchors.push_front(CRAnchor(iter.currentTree(), block));

         TR::TransformUtil::recursivelySetNodeVisitCount(node, visitCount);
         continue;
         }

      if (node->getOpCode().isStoreReg())
         _delayedRegStores = true;

      TR::Node *child = node->getFirstChild();
      if (child->getOpCodeValue() == TR::PassThrough)
         {
         TR::Node *newChild = child->getFirstChild();
         node->setAndIncChild(0, newChild);
         newChild->incFutureUseCount();
         if (child->getReferenceCount() <= 1)
            optimizer()->prepareForNodeRemoval(child);
         child->recursivelyDecReferenceCount();
         recursivelyDecFutureUseCount(child);
         child = newChild;
         }

      bool treeTopCanBeEliminated = false;

      // If the treetop child has been seen before then it must be anchored
      // somewhere above already; so we don't need the treetop to be anchoring
      // this node (as the computation is already done at the first reference to
      // the node).
      //

      if (visitCount == child->getVisitCount())
         {
         treeTopCanBeEliminated = true;
         }
      else
         {
         TR::ILOpCode &childOpCode = child->getOpCode();
         TR::ILOpCodes opCodeValue = childOpCode.getOpCodeValue();
         bool seenConditionalBranch = false;

         bool callWithNoSideEffects = child->getOpCode().isCall() &&
              child->getSymbolReference()->getSymbol()->isResolvedMethod() &&
              child->getSymbolReference()->getSymbol()->castToResolvedMethodSymbol()->isSideEffectFree();

         if (callWithNoSideEffects)
            {
            treeTopCanBeEliminated = true;
            }
         else if (!((childOpCode.isCall() && !callWithNoSideEffects) ||
               childOpCode.isStore() ||
//.........这里部分代码省略.........

static bool isSafeToReplaceNode(TR::Node *currentNode, TR::TreeTop *curTreeTop, bool *seenConditionalBranch,
      vcount_t visitCount, TR::Compilation *comp, List<OMR::TreeInfo> *targetTrees, bool &cannotBeEliminated,
      LongestPathMap &longestPaths)
   {
   LexicalTimer tx("safeToReplace", comp->phaseTimer());

   TR::SparseBitVector symbolReferencesInNode(comp->allocator());

   // Collect all symbols that could be killed between here and the next reference
   //
   comp->incVisitCount();
   //////vcount_t visitCount = comp->getVisitCount();
   int32_t numDeadSubNodes = 0;
   bool cantMoveUnderBranch = false;
   bool seenInternalPointer = false;
   bool seenArraylet = false;
   int32_t curMaxHeight = getLongestPathOfDAG(currentNode, longestPaths);
   collectSymbolReferencesInNode(currentNode, symbolReferencesInNode, &numDeadSubNodes, visitCount, comp,
         &seenInternalPointer, &seenArraylet, &cantMoveUnderBranch);

   bool registersScarce = comp->cg()->areAssignableGPRsScarce();
#ifdef J9_PROJECT_SPECIFIC
   bool isBCD = currentNode->getType().isBCD();
#endif

   if (numDeadSubNodes > 1 &&
#ifdef J9_PROJECT_SPECIFIC
       !isBCD &&
#endif
       registersScarce)
      {
      return false;
      }

   OMR::TreeInfo *curTreeInfo = findOrCreateTreeInfo(curTreeTop, targetTrees, comp);
   int32_t curHeight = curTreeInfo->getHeight()+curMaxHeight;
   if (curHeight > MAX_ALLOWED_HEIGHT)
      {
      cannotBeEliminated = true;
      return false;
      }

   // TEMPORARY
   // Don't allow removal of a node containing an unresolved reference if
   // the gcOnResolve option is set
   //
   bool isUnresolvedReference = currentNode->hasUnresolvedSymbolReference();
   if (isUnresolvedReference)
      return false;

   bool mayBeVolatileReference = currentNode->mightHaveVolatileSymbolReference();
   //if (mayBeVolatileReference)
   //   return false;

   // Now scan forwards through the trees looking for the next use and checking
   // to see if any symbols in the subtree are getting modified; if so it is not
   // safe to replace the node at its next use.
   //

   comp->incVisitCount();
   for (TR::TreeTop *treeTop = curTreeTop->getNextTreeTop(); treeTop; treeTop = treeTop->getNextTreeTop())

      {
      TR::Node *node = treeTop->getNode();
      if(node->getOpCodeValue() == TR::treetop)
          node = node->getFirstChild();

      if (node->getOpCodeValue() == TR::BBStart &&
          !node->getBlock()->isExtensionOfPreviousBlock())
         return true;

      if (cantMoveUnderBranch && (node->getOpCode().isBranch()
         || node->getOpCode().isJumpWithMultipleTargets()))
         return false;

      if (node->canGCandReturn() &&
          seenInternalPointer)
         return false;

      int32_t tempHeight = 0;
      int32_t maxHeight = 0;
      bool canMoveIfVolatile = true;
      if (containsNode(node, currentNode, visitCount, comp, &tempHeight, &maxHeight, canMoveIfVolatile))
         {
         // TEMPORARY
         // Disable moving an unresolved reference down to the middle of a
         // JNI call, until the resolve helper is fixed properly
         //
         if (isUnresolvedReference && node->getFirstChild()->getOpCode().isCall() &&
             node->getFirstChild()->getSymbol()->castToMethodSymbol()->isJNI())
            return false;

         if (curTreeInfo)
            {
            OMR::TreeInfo *treeInfo = findOrCreateTreeInfo(treeTop, targetTrees, comp);
            int32_t height = treeInfo->getHeight();
            int32_t maxHeightUsed = maxHeight;
            if (maxHeightUsed < curMaxHeight)
               maxHeightUsed = curMaxHeight;

//.........这里部分代码省略.........