void TR::ValidateNodeRefCountWithinBlock::validate(TR::TreeTop *firstTreeTop,
TR::TreeTop *exitTreeTop)
{
_nodeChecklist.empty();
for (TR::TreeTop *tt = firstTreeTop; tt != exitTreeTop->getNextTreeTop();
tt = tt->getNextTreeTop())
{
TR::Node *node = tt->getNode();
node->setLocalIndex(node->getReferenceCount());
validateRefCountPass1(node);
}
/**
* We start again from the start of the block, and check the localIndex to
* make sure it is 0.
*
* NOTE: Walking the tree backwards causes huge stack usage in validateRefCountPass2.
*/
_nodeChecklist.empty();
for (TR::TreeTop *tt = firstTreeTop; tt != exitTreeTop->getNextTreeTop();
tt = tt->getNextTreeTop())
{
validateRefCountPass2(tt->getNode());
}
}
int32_t
OMR::Simplifier::perform()
{
vcount_t visitCount = comp()->incOrResetVisitCount();
TR::TreeTop * tt;
for (tt = comp()->getStartTree(); tt; tt = tt->getNextTreeTop())
tt->getNode()->initializeFutureUseCounts(visitCount);
comp()->incVisitCount();
for (tt = comp()->getStartTree(); tt; tt = tt->getNextTreeTop())
cleanupFlags(tt->getNode());
visitCount = comp()->incVisitCount();
tt = comp()->getStartTree();
while (tt)
tt = simplifyExtendedBlock(tt);
comp()->getFlowGraph()->removeUnreachableBlocks();
if (manager()->numPassesCompleted() == 0)
manager()->incNumPassesCompleted();
return 1;
}
void TR::ILValidator::checkSoundness(TR::TreeTop *start, TR::TreeTop *stop)
{
soundnessRule(start, start != NULL, "Start tree must exist");
soundnessRule(stop, !stop || stop->getNode() != NULL, "Stop tree must have a node");
TR::NodeChecklist treetopNodes(comp()), ancestorNodes(comp()), visitedNodes(comp());
// Can't use iterators here, because those presuppose the IL is sound. Walk trees the old-fashioned way.
//
for (TR::TreeTop *currentTree = start; currentTree != stop; currentTree = currentTree->getNextTreeTop())
{
soundnessRule(currentTree, currentTree->getNode() != NULL, "Tree must have a node");
soundnessRule(currentTree, !treetopNodes.contains(currentTree->getNode()), "Treetop node n%dn encountered twice", currentTree->getNode()->getGlobalIndex());
treetopNodes.add(currentTree->getNode());
TR::TreeTop *next = currentTree->getNextTreeTop();
if (next)
{
soundnessRule(currentTree, next->getNode() != NULL, "Tree after n%dn must have a node", currentTree->getNode()->getGlobalIndex());
soundnessRule(currentTree, next->getPrevTreeTop() == currentTree, "Doubly-linked treetop list must be consistent: n%dn->n%dn<-n%dn", currentTree->getNode()->getGlobalIndex(), next->getNode()->getGlobalIndex(), next->getPrevTreeTop()->getNode()->getGlobalIndex());
}
else
{
soundnessRule(currentTree, stop == NULL, "Reached the end of the trees after n%dn without encountering the stop tree n%dn", currentTree->getNode()->getGlobalIndex(), stop? stop->getNode()->getGlobalIndex() : 0);
checkNodeSoundness(currentTree, currentTree->getNode(), ancestorNodes, visitedNodes);
}
}
}
static bool safeToMoveGuard(TR::Block *destination, TR::TreeTop *guardCandidate,
TR::TreeTop *branchDest, TR_BitVector &privArgSymRefs)
{
static char *disablePrivArgMovement = feGetEnv("TR_DisableRuntimeGuardPrivArgMovement");
TR::TreeTop *start = destination ? destination->getExit() : TR::comp()->getStartTree();
if (guardCandidate->getNode()->isHCRGuard())
{
for (TR::TreeTop *tt = start; tt && tt != guardCandidate; tt = tt->getNextTreeTop())
{
if (tt->getNode()->canGCandReturn())
return false;
}
}
else if (guardCandidate->getNode()->isOSRGuard())
{
for (TR::TreeTop *tt = start; tt && tt != guardCandidate; tt = tt->getNextTreeTop())
{
if (TR::comp()->isPotentialOSRPoint(tt->getNode(), NULL, true))
return false;
}
}
else
{
privArgSymRefs.empty();
for (TR::TreeTop *tt = start; tt && tt != guardCandidate; tt = tt->getNextTreeTop())
{
// It's safe to move the guard if there are only priv arg stores and live monitor stores
// ahead of the guard
if (tt->getNode()->getOpCodeValue() != TR::BBStart
&& tt->getNode()->getOpCodeValue() != TR::BBEnd
&& !tt->getNode()->chkIsPrivatizedInlinerArg()
&& !(tt->getNode()->getOpCode().hasSymbolReference() && tt->getNode()->getSymbol()->holdsMonitoredObject())
&& !tt->getNode()->isNopableInlineGuard())
return false;
if (tt->getNode()->chkIsPrivatizedInlinerArg() && (disablePrivArgMovement ||
// If the priv arg is not for this guard
(guardCandidate->getNode()->getInlinedSiteIndex() > -1 &&
// if priv arg store does not have the same inlined site index as the guard's caller, that means it is not a priv arg for this guard,
// then we cannot move the guard and its priv args up across other calls' priv args
tt->getNode()->getInlinedSiteIndex() != TR::comp()->getInlinedCallSite(guardCandidate->getNode()->getInlinedSiteIndex())._byteCodeInfo.getCallerIndex())))
return false;
if (tt->getNode()->chkIsPrivatizedInlinerArg())
privArgSymRefs.set(tt->getNode()->getSymbolReference()->getReferenceNumber());
if (tt->getNode()->isNopableInlineGuard()
&& tt->getNode()->getBranchDestination() != branchDest)
return false;
}
}
return true;
}
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;
}
}
// Add an async check into a block - MUST be at block entry
//
void TR_AsyncCheckInsertion::insertAsyncCheck(TR::Block *block, TR::Compilation *comp, const char *counterPrefix)
{
TR::TreeTop *lastTree = block->getLastRealTreeTop();
TR::TreeTop *asyncTree =
TR::TreeTop::create(comp,
TR::Node::createWithSymRef(lastTree->getNode(), TR::asynccheck, 0,
comp->getSymRefTab()->findOrCreateAsyncCheckSymbolRef(comp->getMethodSymbol())));
if (lastTree->getNode()->getOpCode().isReturn())
{
TR::TreeTop *prevTree = lastTree->getPrevTreeTop();
prevTree->join(asyncTree);
asyncTree->join(lastTree);
}
else
{
TR::TreeTop *nextTree = block->getEntry()->getNextTreeTop();
block->getEntry()->join(asyncTree);
asyncTree->join(nextTree);
}
const char * const name = TR::DebugCounter::debugCounterName(comp,
"asynccheck.insert/%s/(%s)/%s/block_%d",
counterPrefix,
comp->signature(),
comp->getHotnessName(),
block->getNumber());
TR::DebugCounter::prependDebugCounter(comp, name, asyncTree->getNextTreeTop());
}
TR_DominatorVerifier::TR_DominatorVerifier(TR_Dominators &findDominators)
: _compilation(findDominators.comp())
{
TR::StackMemoryRegion stackMemoryRegion(*trMemory());
_dominators = &findDominators;
TR::CFG *cfg = comp()->getFlowGraph();
_visitCount = comp()->incVisitCount();
_numBlocks = cfg->getNumberOfNodes()+1;
if (debug("traceVER"))
{
dumpOptDetails(comp(), "Printing out the TreeTops from DominatorVerifier\n");
TR::TreeTop *currentTree = comp()->getStartTree();
while (!(currentTree == NULL))
{
comp()->getDebug()->print(comp()->getOutFile(), currentTree);
currentTree = currentTree->getNextTreeTop();
}
dumpOptDetails(comp(), "Printing out the CFG from DominatorVerifier\n");
if (cfg != NULL)
comp()->getDebug()->print(comp()->getOutFile(), cfg);
}
TR_DominatorsChk expensiveAlgorithm(comp());
expensiveAlgorithmCorrect = isExpensiveAlgorithmCorrect(expensiveAlgorithm);
if (expensiveAlgorithmCorrect)
{
if (debug("traceVER"))
dumpOptDetails(comp(), "Dominators computed by the expensive algorithm are correct\n");
}
else
{
if (debug("traceVER"))
dumpOptDetails(comp(), "Dominators computed by the expensive algorithm are NOT correct\n");
TR_ASSERT(0, "Dominators computed by the expensive algorithm are NOT correct\n");
}
bothImplementationsConsistent = areBothImplementationsConsistent(expensiveAlgorithm, findDominators);
if (bothImplementationsConsistent)
{
if (debug("traceVER"))
dumpOptDetails(comp(), "Dominators computed by the two implementations are consistent\n");
}
else
{
if (debug("traceVER"))
dumpOptDetails(comp(), "Dominators computed by the two implementations are NOT consistent\n");
TR_ASSERT(0, "Dominators computed by the two implementations are NOT consistent\n");
}
}
void TR::SoundnessRule::validate(TR::ResolvedMethodSymbol *methodSymbol)
{
TR::TreeTop *start = methodSymbol->getFirstTreeTop();
TR::TreeTop *stop = methodSymbol->getLastTreeTop();
checkSoundnessCondition(start, start != NULL, "Start tree must exist");
checkSoundnessCondition(stop, !stop || stop->getNode() != NULL,
"Stop tree must have a node");
TR::NodeChecklist treetopNodes(comp()), ancestorNodes(comp()), visitedNodes(comp());
/* NOTE: Can't use iterators here, because iterators presuppose that the IL is sound. */
for (TR::TreeTop *currentTree = start; currentTree != stop;
currentTree = currentTree->getNextTreeTop())
{
checkSoundnessCondition(currentTree, currentTree->getNode() != NULL,
"Tree must have a node");
checkSoundnessCondition(currentTree, !treetopNodes.contains(currentTree->getNode()),
"Treetop node n%dn encountered twice",
currentTree->getNode()->getGlobalIndex());
treetopNodes.add(currentTree->getNode());
TR::TreeTop *next = currentTree->getNextTreeTop();
if (next)
{
checkSoundnessCondition(currentTree, next->getNode() != NULL,
"Tree after n%dn must have a node",
currentTree->getNode()->getGlobalIndex());
checkSoundnessCondition(currentTree, next->getPrevTreeTop() == currentTree,
"Doubly-linked treetop list must be consistent: n%dn->n%dn<-n%dn",
currentTree->getNode()->getGlobalIndex(),
next->getNode()->getGlobalIndex(),
next->getPrevTreeTop()->getNode()->getGlobalIndex());
}
else
{
checkSoundnessCondition(currentTree, stop == NULL,
"Reached the end of the trees after n%dn without encountering the stop tree n%dn",
currentTree->getNode()->getGlobalIndex(),
stop? stop->getNode()->getGlobalIndex() : 0);
checkNodeSoundness(currentTree, currentTree->getNode(),
ancestorNodes, visitedNodes);
}
}
}
TR::TreeTop *
OMR::TreeTop::getExtendedBlockExitTreeTop()
{
TR_ASSERT(self()->getNode()->getOpCodeValue() == TR::BBStart, "getExitTreeTop, is only valid for a bbStart");
TR::Block * b;
TR::TreeTop * exitTT = self()->getNode()->getBlock()->getExit(), * nextTT;
while ((nextTT = exitTT->getNextTreeTop()) && (b = nextTT->getNode()->getBlock(), b->isExtensionOfPreviousBlock()))
exitTT = b->getExit();
return exitTT;
}
inline TR::TreeTop *
OMR::TreeTop::getNextRealTreeTop()
{
TR::TreeTop *treeTop;
for (treeTop = self()->getNextTreeTop();
treeTop && treeTop->getNode() && treeTop->getNode()->getOpCode().isExceptionRangeFence();
treeTop = treeTop->getNextTreeTop())
{}
return treeTop;
}
void
OMR::CodeGenPhase::performCleanUpFlagsPhase(TR::CodeGenerator * cg, TR::CodeGenPhase * phase)
{
TR::TreeTop * tt;
vcount_t visitCount = cg->comp()->incVisitCount();
for (tt = cg->comp()->getStartTree(); tt; tt = tt->getNextTreeTop())
{
cg->cleanupFlags(tt->getNode());
}
}
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...
}
static TR::TreeTop *findNextLegalTreeTop(TR::Compilation *comp, TR::Block *block)
{
vcount_t startVisitCount = comp->getStartTree()->getNode()->getVisitCount();
TR::TreeTop * tt = NULL;
for (tt = comp->getStartTree(); tt; tt = tt->getNextTreeTop())
{
if (tt->getNode()->getVisitCount() < startVisitCount)
break;
if (tt->getNode()->getOpCodeValue() == TR::BBStart)
tt = tt->getNode()->getBlock()->getExit();
}
return tt;
}
static bool blockHasCalls(TR::Block *block, TR::Compilation *comp)
{
intptrj_t visitCount = comp->incVisitCount();
TR::TreeTop *currentTree = block->getEntry();
TR::TreeTop *exitTree = block->getExit();
bool hasCalls = false;
while (!hasCalls && currentTree != exitTree)
{
hasCalls = examineNode(currentTree->getNode(), visitCount);
currentTree = currentTree->getNextTreeTop();
}
return hasCalls;
}
inline TR::Block *
OMR::TreeTop::getEnclosingBlock( bool forward)
{
TR::TreeTop * tt = self();
if (forward)
while (tt->getNode()->getOpCodeValue() != TR::BBEnd)
{
tt = tt->getNextTreeTop();
//TR_ASSERT(tt && tt->getNode(), "either tt or node on a tt null here, we will segfault");
}
else
while (tt->getNode()->getOpCodeValue() != TR::BBStart)
{
tt = tt->getPrevTreeTop();
//TR_ASSERT(tt && tt->getNode(), "either tt or node on a tt null here, we will segfault");
}
return tt->getNode()->getBlock();
}
int32_t
OMR::Simplifier::performOnBlock(TR::Block * block)
{
if (block->getEntry())
{
TR::TreeTop *extendedExitTree = block->getEntry()->getExtendedBlockExitTreeTop();
vcount_t visitCount = comp()->incOrResetVisitCount();
for (TR::TreeTop * tt = block->getEntry(); tt; tt = tt->getNextTreeTop())
{
tt->getNode()->initializeFutureUseCounts(visitCount);
if (tt == extendedExitTree)
break;
}
comp()->incVisitCount();
simplifyExtendedBlock(block->getEntry());
}
return 0;
}
void
OMR::TreeTop::removeDeadTrees(TR::Compilation * comp, TR::TreeTop* first, TR::TreeTop* last)
{
for (TR::TreeTop* cur = first; cur != last; cur = cur->getNextTreeTop())
{
int numChildren = cur->getNode()->getNumChildren();
for (int child = numChildren-1; child>0; --child)
{
TR::Node * node = cur->getNode()->getChild(child);
cur->insertAfter(TR::TreeTop::create(comp, TR::Node::create(TR::treetop, 1, node)));
node->decReferenceCount();
}
if (numChildren != 0)
{
TR::Node * node = cur->getNode()->getChild(0);
cur->setNode(TR::Node::create(TR::treetop, 1, node));
node->decReferenceCount();
}
}
}
void
TR_ExpressionsSimplification::invalidateCandidates()
{
_visitCount = comp()->incVisitCount();
if (trace())
{
traceMsg(comp(), "Checking which candidates may be invalidated\n");
ListIterator<TR::TreeTop> treeTops(_candidateTTs);
for (TR::TreeTop *treeTop = treeTops.getFirst(); treeTop; treeTop = treeTops.getNext())
{
traceMsg(comp(), " Candidate treetop: %p node: %p\n", treeTop, treeTop->getNode());
}
}
TR_ScratchList<TR::Block> blocksInLoop(trMemory());
_currentRegion->getBlocks(&blocksInLoop);
ListIterator<TR::Block> blocks(&blocksInLoop);
for (TR::Block *currentBlock = blocks.getFirst(); currentBlock; currentBlock = blocks.getNext())
{
TR::TreeTop *tt = currentBlock->getEntry();
TR::TreeTop *exitTreeTop = currentBlock->getExit();
while (tt != exitTreeTop)
{
TR::Node *currentNode = tt->getNode();
if (trace())
traceMsg(comp(), "Looking at treeTop [%p]\n", currentNode);
removeCandidate(currentNode, tt);
tt = tt->getNextTreeTop();
}
}
removeUnsupportedCandidates();
}
//---------------------------- collecting ref info at the beginning -----------------------------------------
void TR_LocalLiveRangeReduction::collectInfo(TR::TreeTop *entryTree,TR::TreeTop *exitTree)
{
TR::TreeTop *currentTree = entryTree;
TR_TreeRefInfo *treeRefInfo;
int32_t i = 0;
int32_t maxRefCount = 0;
vcount_t visitCount = comp()->getVisitCount();
while (!(currentTree == exitTree))
{
treeRefInfo = new (trStackMemory()) TR_TreeRefInfo(currentTree, trMemory());
collectRefInfo(treeRefInfo, currentTree->getNode(),visitCount,&maxRefCount);
_treesRefInfoArray[i++] = treeRefInfo;
initPotentialDeps(treeRefInfo);
treeRefInfo->resetSyms();
populatePotentialDeps(treeRefInfo,treeRefInfo->getTreeTop()->getNode());
currentTree = currentTree->getNextTreeTop();
}
comp()->setVisitCount(visitCount+maxRefCount);
}
bool TR_LocalLiveRangeReduction::moveTreeBefore(TR_TreeRefInfo *treeToMove,TR_TreeRefInfo *anchor,int32_t passNumber)
{
TR::TreeTop *treeToMoveTT = treeToMove->getTreeTop();
TR::TreeTop *anchorTT = anchor->getTreeTop();
if (treeToMoveTT->getNextRealTreeTop() == anchorTT)
{
addDepPair(treeToMove, anchor);
return false;
}
if (!performTransformation(comp(), "%sPass %d: moving tree [%p] before Tree %p\n", OPT_DETAILS, passNumber, treeToMoveTT->getNode(),anchorTT->getNode()))
return false;
// printf("Moving [%p] before Tree %p\n", treeToMoveTT->getNode(),anchorTT->getNode());
//changing location in block
TR::TreeTop *origPrevTree = treeToMoveTT->getPrevTreeTop();
TR::TreeTop *origNextTree = treeToMoveTT->getNextTreeTop();
origPrevTree->setNextTreeTop(origNextTree);
origNextTree->setPrevTreeTop(origPrevTree);
TR::TreeTop *prevTree = anchorTT->getPrevTreeTop();
anchorTT->setPrevTreeTop(treeToMoveTT);
treeToMoveTT->setNextTreeTop(anchorTT);
treeToMoveTT->setPrevTreeTop(prevTree);
prevTree->setNextTreeTop(treeToMoveTT);
//UPDATE REFINFO
//find locations of treeTops in TreeTopsRefInfo array
//startIndex points to the currentTree that has moved
//endIndex points to the treeTop after which we moved the tree (nextTree)
int32_t startIndex = getIndexInArray(treeToMove);
int32_t endIndex = getIndexInArray(anchor)-1;
int32_t i=0;
for ( i = startIndex+1; i<= endIndex ; i++)
{
TR_TreeRefInfo *currentTreeRefInfo = _treesRefInfoArray[i];
List<TR::Node> *firstList = currentTreeRefInfo->getFirstRefNodesList();
List<TR::Node> *midList = currentTreeRefInfo->getMidRefNodesList();
List<TR::Node> *lastList = currentTreeRefInfo->getLastRefNodesList();
List<TR::Node> *M_firstList = treeToMove->getFirstRefNodesList();
List<TR::Node> *M_midList = treeToMove->getMidRefNodesList();
List<TR::Node> *M_lastList = treeToMove->getLastRefNodesList();
if (trace())
{
traceMsg(comp(),"Before move:\n");
printRefInfo(treeToMove);
printRefInfo(currentTreeRefInfo);
}
updateRefInfo(treeToMove->getTreeTop()->getNode(), currentTreeRefInfo, treeToMove , false);
treeToMove->resetSyms();
currentTreeRefInfo->resetSyms();
populatePotentialDeps(currentTreeRefInfo,currentTreeRefInfo->getTreeTop()->getNode());
populatePotentialDeps(treeToMove,treeToMove->getTreeTop()->getNode());
if (trace())
{
traceMsg(comp(),"After move:\n");
printRefInfo(treeToMove);
printRefInfo(currentTreeRefInfo);
traceMsg(comp(),"------------------------\n");
}
}
TR_TreeRefInfo *temp = _treesRefInfoArray[startIndex];
for (i = startIndex; i< endIndex ; i++)
{
_treesRefInfoArray[i] = _treesRefInfoArray[i+1];
}
_treesRefInfoArray[endIndex]=temp;
#if defined(DEBUG) || defined(PROD_WITH_ASSUMES)
if (!(comp()->getOption(TR_EnableParanoidOptCheck) || debug("paranoidOptCheck")))
return true;
//verifier
{
TR::StackMemoryRegion stackMemoryRegion(*trMemory());
vcount_t visitCount = comp()->getVisitCount();
int32_t maxRefCount = 0;
TR::TreeTop *tt;
TR_TreeRefInfo **treesRefInfoArrayTemp = (TR_TreeRefInfo**)trMemory()->allocateStackMemory(_numTreeTops*sizeof(TR_TreeRefInfo*));
memset(treesRefInfoArrayTemp, 0, _numTreeTops*sizeof(TR_TreeRefInfo*));
TR_TreeRefInfo *treeRefInfoTemp;
//collect info
for ( int32_t i = 0; i<_numTreeTops-1; i++)
{
tt =_treesRefInfoArray[i]->getTreeTop();
treeRefInfoTemp = new (trStackMemory()) TR_TreeRefInfo(tt, trMemory());
collectRefInfo(treeRefInfoTemp, tt->getNode(),visitCount,&maxRefCount);
treesRefInfoArrayTemp[i] = treeRefInfoTemp;
}
comp()->setVisitCount(visitCount+maxRefCount);
for ( int32_t i = 0; i<_numTreeTops-1; i++)
{
if (!verifyRefInfo(treesRefInfoArrayTemp[i]->getFirstRefNodesList(),_treesRefInfoArray[i]->getFirstRefNodesList()))
{
printOnVerifyError(_treesRefInfoArray[i],treesRefInfoArrayTemp[i]);
TR_ASSERT(0,"fail to verify firstRefNodesList for %p\n",_treesRefInfoArray[i]->getTreeTop()->getNode());
}
if (!verifyRefInfo(treesRefInfoArrayTemp[i]->getMidRefNodesList(),_treesRefInfoArray[i]->getMidRefNodesList()))
{
printOnVerifyError(_treesRefInfoArray[i],treesRefInfoArrayTemp[i]);
TR_ASSERT(0,"fail to verify midRefNodesList for %p\n",_treesRefInfoArray[i]->getTreeTop()->getNode());
}
if (!verifyRefInfo(treesRefInfoArrayTemp[i]->getLastRefNodesList(),_treesRefInfoArray[i]->getLastRefNodesList()))
{
printOnVerifyError(_treesRefInfoArray[i],treesRefInfoArrayTemp[i]);
TR_ASSERT(0,"fail to verify lastRefNodesList for %p\n",_treesRefInfoArray[i]->getTreeTop()->getNode());
}
}
} // scope of the stack memory region
#endif
return true;
}
TR_BitVector *
addVeryRefinedCallAliasSets(TR::ResolvedMethodSymbol * methodSymbol, TR_BitVector * aliases, List<void> * methodsPeeked)
{
TR::Compilation *comp = TR::comp();
void * methodId = methodSymbol->getResolvedMethod()->getPersistentIdentifier();
if (methodsPeeked->find(methodId))
{
// This can't be allocated into the alias region as it must be accessed across optimizations
TR_BitVector *heapAliases = new (comp->trHeapMemory()) TR_BitVector(comp->getSymRefCount(), comp->trMemory(), heapAlloc, growable);
*heapAliases |= *aliases;
return heapAliases;
}
// stop if the peek is getting very deep
//
if (methodsPeeked->getSize() >= PEEK_THRESHOLD)
return 0;
methodsPeeked->add(methodId);
dumpOptDetails(comp, "O^O REFINING ALIASES: Peeking into the IL to refine aliases \n");
if (!methodSymbol->getResolvedMethod()->genMethodILForPeeking(methodSymbol, comp, true))
return 0;
TR::SymbolReferenceTable * symRefTab = comp->getSymRefTab();
for (TR::TreeTop * tt = methodSymbol->getFirstTreeTop(); tt; tt = tt->getNextTreeTop())
{
TR::Node *node = tt->getNode();
if (node->getOpCode().isResolveCheck())
return 0;
if ((node->getOpCodeValue() == TR::treetop) ||
(node->getOpCodeValue() == TR::compressedRefs) ||
node->getOpCode().isCheck())
node = node->getFirstChild();
if (node->getOpCode().isStore())
{
TR::SymbolReference * symRefInCallee = node->getSymbolReference(), * symRefInCaller;
TR::Symbol * symInCallee = symRefInCallee->getSymbol();
TR::DataType type = symInCallee->getDataType();
if (symInCallee->isShadow())
{
if (symInCallee->isArrayShadowSymbol())
symRefInCaller = symRefTab->getSymRef(symRefTab->getArrayShadowIndex(type));
else if (symInCallee->isArrayletShadowSymbol())
symRefInCaller = symRefTab->getSymRef(symRefTab->getArrayletShadowIndex(type));
else
symRefInCaller = symRefTab->findShadowSymbol(symRefInCallee->getOwningMethod(comp), symRefInCallee->getCPIndex(), type);
if (symRefInCaller)
{
if (symRefInCaller->reallySharesSymbol(comp))
symRefInCaller->setSharedShadowAliases(aliases, symRefTab);
aliases->set(symRefInCaller->getReferenceNumber());
}
}
else if (symInCallee->isStatic())
{
symRefInCaller = symRefTab->findStaticSymbol(symRefInCallee->getOwningMethod(comp), symRefInCallee->getCPIndex(), type);
if (symRefInCaller)
{
if (symRefInCaller->reallySharesSymbol(comp))
symRefInCaller->setSharedStaticAliases(aliases, symRefTab);
else
aliases->set(symRefInCaller->getReferenceNumber());
}
}
}
else if (node->getOpCode().isCall())
{
if (node->getOpCode().isCallIndirect())
return 0;
TR::ResolvedMethodSymbol * calleeSymbol = node->getSymbol()->getResolvedMethodSymbol();
if (!calleeSymbol)
return 0;
TR_ResolvedMethod * calleeMethod = calleeSymbol->getResolvedMethod();
if (!calleeMethod->isCompilable(comp->trMemory()) || calleeMethod->isJNINative())
return 0;
if (!addVeryRefinedCallAliasSets(calleeSymbol, aliases, methodsPeeked))
return 0;
}
else if (node->getOpCodeValue() == TR::monent)
return 0;
}
// This can't be allocated into the alias region as it must be accessed across optimizations
TR_BitVector *heapAliases = new (comp->trHeapMemory()) TR_BitVector(comp->getSymRefCount(), comp->trMemory(), heapAlloc, growable);
*heapAliases |= *aliases;
return heapAliases;
}
int32_t TR_CatchBlockRemover::perform()
{
TR::CFG *cfg = comp()->getFlowGraph();
if (cfg == NULL)
{
if (trace())
traceMsg(comp(), "Can't do Catch Block Removal, no CFG\n");
return 0;
}
if (trace())
traceMsg(comp(), "Starting Catch Block Removal\n");
bool thereMayBeRemovableCatchBlocks = false;
{
TR::StackMemoryRegion stackMemoryRegion(*trMemory());
TR::Block *block;
ListIterator<TR::CFGEdge> edgeIterator;
// Go through all blocks that have exception successors and see if any of them
// are not reached. Mark each of these edges with a visit count so they can
// be identified later.
//
vcount_t visitCount = comp()->incOrResetVisitCount();
TR::CFGNode *cfgNode;
for (cfgNode = cfg->getFirstNode(); cfgNode; cfgNode = cfgNode->getNext())
{
if (cfgNode->getExceptionSuccessors().empty())
continue;
block = toBlock(cfgNode);
uint32_t reachedExceptions = 0;
TR::TreeTop *treeTop;
for (treeTop = block->getEntry(); treeTop != block->getExit(); treeTop = treeTop->getNextTreeTop())
{
reachedExceptions |= treeTop->getNode()->exceptionsRaised();
if (treeTop->getNode()->getOpCodeValue() == TR::monexitfence) // for live monitor metadata
reachedExceptions |= TR::Block::CanCatchMonitorExit;
}
if (reachedExceptions & TR::Block::CanCatchUserThrows)
continue;
for (auto edge = block->getExceptionSuccessors().begin(); edge != block->getExceptionSuccessors().end();)
{
TR::CFGEdge * current = *(edge++);
TR::Block *catchBlock = toBlock(current->getTo());
if (catchBlock->isOSRCodeBlock() || catchBlock->isOSRCatchBlock()) continue;
if (!reachedExceptions &&
performTransformation(comp(), "%sRemove redundant exception edge from block_%d at [%p] to catch block_%d at [%p]\n", optDetailString(), block->getNumber(), block, catchBlock->getNumber(), catchBlock))
{
cfg->removeEdge(block, catchBlock);
thereMayBeRemovableCatchBlocks = true;
}
else
{
if (!catchBlock->canCatchExceptions(reachedExceptions))
{
current->setVisitCount(visitCount);
thereMayBeRemovableCatchBlocks = true;
}
}
}
}
bool edgesRemoved = false;
// Now look to see if there are any catch blocks for which all exception
// predecessors have the visit count set. If so, the block is unreachable and
// can be removed.
// If only some of the exception predecessors are marked, these edges are
// left in place to identify the try/catch structure properly.
//
while (thereMayBeRemovableCatchBlocks)
{
thereMayBeRemovableCatchBlocks = false;
for (cfgNode = cfg->getFirstNode(); cfgNode; cfgNode = cfgNode->getNext())
{
if (cfgNode->getExceptionPredecessors().empty())
continue;
auto edgeIt = cfgNode->getExceptionPredecessors().begin();
for (; edgeIt != cfgNode->getExceptionPredecessors().end(); ++edgeIt)
{
if ((*edgeIt)->getVisitCount() != visitCount)
break;
}
if (edgeIt == cfgNode->getExceptionPredecessors().end() && performTransformation(comp(), "%sRemove redundant catch block_%d at [%p]\n", optDetailString(), cfgNode->getNumber(), cfgNode))
{
while (!cfgNode->getExceptionPredecessors().empty())
{
cfg->removeEdge(cfgNode->getExceptionPredecessors().front());
}
edgesRemoved = true;
thereMayBeRemovableCatchBlocks = true;
}
}
}
// Any transformations invalidate use/def and value number information
//
if (edgesRemoved)
{
optimizer()->setUseDefInfo(NULL);
optimizer()->setValueNumberInfo(NULL);
requestOpt(OMR::treeSimplification, true);
}
} // scope of the stack memory region
if (trace())
traceMsg(comp(), "\nEnding Catch Block Removal\n");
return 1; // actual cost
}
void TR::DeadTreesElimination::prePerformOnBlocks()
{
_cannotBeEliminated = false;
_delayedRegStores = false;
_targetTrees.deleteAll();
// Walk through all the blocks to remove trivial dead trees of the form
// treetop
// => node
// The problem with these trees is in the scenario where the earlier use
// of 'node' is also dead. However, our analysis won't find that because
// the reference count is > 1.
vcount_t visitCount = comp()->incOrResetVisitCount();
for (TR::TreeTop *tt = comp()->getStartTree();
tt != 0;
tt = tt->getNextTreeTop())
{
bool removed = false;
TR::Node *node = tt->getNode();
if (node->getOpCodeValue() == TR::treetop &&
node->getFirstChild()->getVisitCount() == visitCount &&
performTransformation(comp(), "%sRemove trivial dead tree: %p\n", optDetailString(), node))
{
TR::TransformUtil::removeTree(comp(), tt);
removed = true;
}
else
{
if (node->getOpCode().isCheck() &&
node->getFirstChild()->getOpCode().isCall() &&
node->getFirstChild()->getReferenceCount() == 1 &&
node->getFirstChild()->getSymbolReference()->getSymbol()->isResolvedMethod() &&
node->getFirstChild()->getSymbolReference()->getSymbol()->castToResolvedMethodSymbol()->isSideEffectFree() &&
performTransformation(comp(), "%sRemove dead check of side-effect free call: %p\n", optDetailString(), node))
{
TR::TransformUtil::removeTree(comp(), tt);
removed = true;
}
}
if (removed
&& tt->getNextTreeTop()->getNode()->getOpCodeValue() == TR::Goto
&& tt->getPrevTreeTop()->getNode()->getOpCodeValue() == TR::BBStart
&& !tt->getPrevTreeTop()->getNode()->getBlock()->isExtensionOfPreviousBlock())
{
requestOpt(OMR::redundantGotoElimination, tt->getEnclosingBlock());
}
if (node->getVisitCount() >= visitCount)
continue;
TR::TransformUtil::recursivelySetNodeVisitCount(tt->getNode(), visitCount);
}
// If the last use of an iRegLoad has been removed, then remove the node from
// the BBStart and remove the corresponding dependency node from each of the block's
// predecessors.
//
while (1)
{
bool glRegDepRemoved = false;
for (TR::Block * b = comp()->getStartBlock(); b; b = b->getNextBlock())
{
TR::TreeTop * startTT = b->getEntry();
TR::Node * startNode = startTT->getNode();
if (startNode->getNumChildren() > 0 && !debug("disableEliminationOfGlRegDeps"))
{
TR::Node * glRegDeps = startNode->getFirstChild();
TR_ASSERT(glRegDeps->getOpCodeValue() == TR::GlRegDeps, "expected TR::GlRegDeps");
for (int32_t i = glRegDeps->getNumChildren() - 1; i >= 0; --i)
{
TR::Node * dep = glRegDeps->getChild(i);
if (dep->getReferenceCount() == 1 &&
(!dep->getOpCode().isFloatingPoint() ||
cg()->getSupportsJavaFloatSemantics()) &&
performTransformation(comp(), "%sRemove GlRegDep : %p\n", optDetailString(), glRegDeps->getChild(i)))
{
glRegDeps->removeChild(i);
glRegDepRemoved = true;
TR_GlobalRegisterNumber registerNum = dep->getGlobalRegisterNumber();
for (auto e = b->getPredecessors().begin(); e != b->getPredecessors().end(); ++e)
{
TR::Block * pred = toBlock((*e)->getFrom());
if (pred == comp()->getFlowGraph()->getStart())
continue;
TR::Node * parent = pred->getLastRealTreeTop()->getNode();
if ( parent->getOpCode().isJumpWithMultipleTargets() && parent->getOpCode().hasBranchChildren())
{
for (int32_t j = parent->getCaseIndexUpperBound() - 1; j > 0; --j)
{
TR::Node * caseNode = parent->getChild(j);
TR_ASSERT(caseNode->getOpCode().isCase() || caseNode->getOpCodeValue() == TR::branch,
"having problems navigating a switch");
if (caseNode->getBranchDestination() == startTT &&
caseNode->getNumChildren() > 0 &&
0) // can't do this now that all glRegDeps are hung off the default branch
removeGlRegDep(caseNode, registerNum, pred, this);
}
}
else if (!parent->getOpCode().isReturn() &&
parent->getOpCodeValue() != TR::igoto &&
!( parent->getOpCode().isJumpWithMultipleTargets() && parent->getOpCode().hasBranchChildren()) &&
!(parent->getOpCodeValue()==TR::treetop &&
parent->getFirstChild()->getOpCode().isCall() &&
parent->getFirstChild()->getOpCode().isIndirect()))
{
if (pred->getNextBlock() == b)
parent = pred->getExit()->getNode();
removeGlRegDep(parent, registerNum, pred, this);
}
}
}
}
if (glRegDeps->getNumChildren() == 0)
startNode->removeChild(0);
}
}
if (!glRegDepRemoved)
break;
}
}
/**
* A runtime guard block may have monitor stores and privarg stores along with the guard
* it self. This method will rearrange these stores and split the block, managing any
* uncommoning necessary for eventual block order.
*
* The provided block will become the privarg block, containing any privarg stores and additonal
* temps for uncommoning. It must be evaluated first. The returned block will contain monitor
* stores and the guard. If no split is required, the provided block will be returned.
*
* @param comp Compilation object
* @param block Block to manipulate
* @param cfg Current CFG
* @return The block containing the guard.
*/
static TR::Block* splitRuntimeGuardBlock(TR::Compilation *comp, TR::Block* block, TR::CFG *cfg)
{
TR::NodeChecklist checklist(comp);
TR::TreeTop *start = block->getFirstRealTreeTop();
TR::TreeTop *guard = block->getLastRealTreeTop();
TR::TreeTop *firstPrivArg = NULL;
TR::TreeTop *firstMonitor = NULL;
// Manage the unexpected case that monitors and priv args are reversed
bool privThenMonitor = false;
TR_ASSERT(isMergeableGuard(guard->getNode()), "last node must be guard %p", guard->getNode());
// Search for privarg and monitor stores
// Only commoned nodes under the guard are required to be anchored, due to the guard being
// evaluted before the monitor stores later on
bool anchoredTemps = false;
for (TR::TreeTop *tt = start; tt && tt->getNode()->getOpCodeValue() != TR::BBEnd; tt = tt->getNextTreeTop())
{
TR::Node * node = tt->getNode();
if (node->getOpCode().hasSymbolReference() && node->getSymbol()->holdsMonitoredObject())
firstMonitor = firstMonitor == NULL ? tt : firstMonitor;
else if (node->chkIsPrivatizedInlinerArg())
{
if (firstPrivArg == NULL)
{
firstPrivArg = tt;
privThenMonitor = (firstMonitor == NULL);
}
}
else if (isMergeableGuard(node))
anchoredTemps |= anchorCommonNodes(comp, node, start, checklist);
else
TR_ASSERT(0, "Node other than monitor or privarg store %p before runtime guard", node);
}
// If there are monitors then privargs, they must be swapped around, such that all privargs are
// evaluated first
if (firstPrivArg && firstMonitor && !privThenMonitor)
{
TR::TreeTop *monitorEnd = firstPrivArg->getPrevTreeTop();
firstMonitor->getPrevTreeTop()->join(firstPrivArg);
guard->getPrevTreeTop()->join(firstMonitor);
monitorEnd->join(guard);
}
// If there were temps created or privargs in the block, perform a split
TR::TreeTop *split = NULL;
if (firstPrivArg)
split = firstMonitor ? firstMonitor : guard;
else if (anchoredTemps)
split = start;
if (split)
return block->split(split, cfg, true /* fixupCommoning */, false /* copyExceptionSuccessors */);
return block;
}
TR_LocalAnalysisInfo::TR_LocalAnalysisInfo(TR::Compilation *c, bool t)
: _compilation(c), _trace(t), _trMemory(c->trMemory())
{
_numNodes = -1;
#if 0 // somehow stops PRE from happening
// We are going to increment visit count for every tree so can reach max
// for big methods quickly. Perhaps can improve containsCall() in the future.
comp()->resetVisitCounts(0);
#endif
if (comp()->getVisitCount() > HIGH_VISIT_COUNT)
{
_compilation->resetVisitCounts(1);
dumpOptDetails(comp(), "\nResetting visit counts for this method before LocalAnalysisInfo\n");
}
TR::CFG *cfg = comp()->getFlowGraph();
_numBlocks = cfg->getNextNodeNumber();
TR_ASSERT(_numBlocks > 0, "Local analysis, node numbers not assigned");
// Allocate information on the stack. It is the responsibility of the user
// of this class to determine the life of the information by using jitStackMark
// and jitStackRelease.
//
//_blocksInfo = (TR::Block **) trMemory()->allocateStackMemory(_numBlocks*sizeof(TR::Block *));
//memset(_blocksInfo, 0, _numBlocks*sizeof(TR::Block *));
TR::TreeTop *currentTree = comp()->getStartTree();
// Only do this if not done before; typically this would be done in the
// first call to this method through LocalTransparency and would NOT
// need to be re-done by LocalAnticipatability.
//
if (_numNodes < 0)
{
_optimizer = comp()->getOptimizer();
int32_t numBuckets;
int32_t numNodes = comp()->getNodeCount();
if (numNodes < 10)
numBuckets = 1;
else if (numNodes < 100)
numBuckets = 7;
else if (numNodes < 500)
numBuckets = 31;
else if (numNodes < 3000)
numBuckets = 127;
else if (numNodes < 6000)
numBuckets = 511;
else
numBuckets = 1023;
// Allocate hash table for matching expressions
//
HashTable hashTable(numBuckets, comp());
_hashTable = &hashTable;
// Null checks are handled differently as the criterion for
// commoning a null check is different than that used for
// other nodes; for a null check, the null check reference is
// important (and not the actual indirect access itself)
//
_numNullChecks = 0;
while (currentTree)
{
if (currentTree->getNode()->getOpCodeValue() == TR::NULLCHK)
//////if (currentTree->getNode()->getOpCode().isNullCheck())
_numNullChecks++;
currentTree = currentTree->getNextTreeTop();
}
if (_numNullChecks == 0)
_nullCheckNodesAsArray = NULL;
else
{
_nullCheckNodesAsArray = (TR::Node**)trMemory()->allocateStackMemory(_numNullChecks*sizeof(TR::Node*));
memset(_nullCheckNodesAsArray, 0, _numNullChecks*sizeof(TR::Node*));
}
currentTree = comp()->getStartTree();
int32_t symRefCount = comp()->getSymRefCount();
_checkSymbolReferences = new (trStackMemory()) TR_BitVector(symRefCount, trMemory(), stackAlloc);
_numNodes = 1;
_numNullChecks = 0;
// This loop counts all the nodes that are going to take part in PRE.
// This is a computation intensive loop as we check if the node that
// is syntactically equivalent to a given node has been seen before
// and if so we use the local index of the original node (that
// is syntactically equivalent to the given node). Could be improved
// in complexity with value numbering at some stage.
//
_visitCount = comp()->incVisitCount();
while (currentTree)
{
TR::Node *firstNodeInTree = currentTree->getNode();
TR::ILOpCode *opCode = &firstNodeInTree->getOpCode();
if (((firstNodeInTree->getOpCodeValue() == TR::treetop) ||
(comp()->useAnchors() && firstNodeInTree->getOpCode().isAnchor())) &&
(firstNodeInTree->getFirstChild()->getOpCode().isStore()))
{
firstNodeInTree->setLocalIndex(-1);
if (comp()->useAnchors() && firstNodeInTree->getOpCode().isAnchor())
firstNodeInTree->getSecondChild()->setLocalIndex(-1);
firstNodeInTree = firstNodeInTree->getFirstChild();
opCode = &firstNodeInTree->getOpCode();
}
// This call finds nodes with opcodes that are supported by PRE
// in this subtree; this accounts for all opcodes other than stores/checks
// which are handled later on below
//
bool firstNodeInTreeHasCallsInStoreLhs = false;
countSupportedNodes(firstNodeInTree, NULL, firstNodeInTreeHasCallsInStoreLhs);
if ((opCode->isStore() && !firstNodeInTree->getSymbolReference()->getSymbol()->isAutoOrParm()) ||
opCode->isCheck())
{
int32_t oldExpressionOnRhs = hasOldExpressionOnRhs(firstNodeInTree);
//
// Return value 0 denotes that the node contains some sub-expression
// that cannot participate in PRE; e.g. a call or a new
//
// Return value -1 denotes that the node can participate in PRE
// but did not match with any existing expression seen so far
//
// Any other return value (should be positive always) denotes that
// the node can participate in PRE and has been matched with a seen
// expression having local index == return value
//
if (oldExpressionOnRhs == -1)
{
if (trace())
{
traceMsg(comp(), "\nExpression #%d is : \n", _numNodes);
comp()->getDebug()->print(comp()->getOutFile(), firstNodeInTree, 6, true);
}
firstNodeInTree->setLocalIndex(_numNodes++);
}
else
firstNodeInTree->setLocalIndex(oldExpressionOnRhs);
if (opCode->isCheck() &&
(firstNodeInTree->getFirstChild()->getOpCode().isStore() &&
!firstNodeInTree->getFirstChild()->getSymbolReference()->getSymbol()->isAutoOrParm()))
{
int oldExpressionOnRhs = hasOldExpressionOnRhs(firstNodeInTree->getFirstChild());
if (oldExpressionOnRhs == -1)
{
if (trace())
{
traceMsg(comp(), "\nExpression #%d is : \n", _numNodes);
comp()->getDebug()->print(comp()->getOutFile(), firstNodeInTree->getFirstChild(), 6, true);
}
firstNodeInTree->getFirstChild()->setLocalIndex(_numNodes++);
}
else
firstNodeInTree->getFirstChild()->setLocalIndex(oldExpressionOnRhs);
}
}
else
firstNodeInTree->setLocalIndex(-1);
currentTree = currentTree->getNextTreeTop();
}
}
_supportedNodesAsArray = (TR::Node**)trMemory()->allocateStackMemory(_numNodes*sizeof(TR::Node*));
memset(_supportedNodesAsArray, 0, _numNodes*sizeof(TR::Node*));
_checkExpressions = new (trStackMemory()) TR_BitVector(_numNodes, trMemory(), stackAlloc);
//_checkExpressions.init(_numNodes, trMemory(), stackAlloc);
// This loop goes through the trees and collects the nodes
// that would take part in PRE. Each node has its local index set to
// the bit position that it occupies in the bit vector analyses.
//
currentTree = comp()->getStartTree();
_visitCount = comp()->incVisitCount();
while (currentTree)
{
TR::Node *firstNodeInTree = currentTree->getNode();
TR::ILOpCode *opCode = &firstNodeInTree->getOpCode();
if (((firstNodeInTree->getOpCodeValue() == TR::treetop) ||
(comp()->useAnchors() && firstNodeInTree->getOpCode().isAnchor())) &&
(firstNodeInTree->getFirstChild()->getOpCode().isStore()))
{
firstNodeInTree = firstNodeInTree->getFirstChild();
opCode = &firstNodeInTree->getOpCode();
}
collectSupportedNodes(firstNodeInTree, NULL);
if ((opCode->isStore() && !firstNodeInTree->getSymbolReference()->getSymbol()->isAutoOrParm()) ||
opCode->isCheck())
{
if (opCode->isCheck())
{
_checkSymbolReferences->set(firstNodeInTree->getSymbolReference()->getReferenceNumber());
_checkExpressions->set(firstNodeInTree->getLocalIndex());
}
if (!_supportedNodesAsArray[firstNodeInTree->getLocalIndex()])
_supportedNodesAsArray[firstNodeInTree->getLocalIndex()] = firstNodeInTree;
if (opCode->isCheck() &&
firstNodeInTree->getFirstChild()->getOpCode().isStore() &&
!firstNodeInTree->getFirstChild()->getSymbolReference()->getSymbol()->isAutoOrParm() &&
!_supportedNodesAsArray[firstNodeInTree->getFirstChild()->getLocalIndex()])
_supportedNodesAsArray[firstNodeInTree->getFirstChild()->getLocalIndex()] = firstNodeInTree->getFirstChild();
}
currentTree = currentTree->getNextTreeTop();
}
//initialize(toBlock(cfg->getStart()));
}
void TR_ExpressionsSimplification::simplifyInvariantLoopExpressions(ListIterator<TR::Block> &blocks)
{
// Need to locate the induction variable of the loop
//
LoopInfo *loopInfo = findLoopInfo(_currentRegion);
if (trace())
{
if (!loopInfo)
{
traceMsg(comp(), "Accurate loop info is not found, cannot carry out summation reduction\n");
}
else
{
traceMsg(comp(), "Accurate loop info has been found, will try to carry out summation reduction\n");
if (loopInfo->getBoundaryNode())
{
traceMsg(comp(), "Variable iterations from node %p has not been handled\n",loopInfo->getBoundaryNode());
}
else
{
traceMsg(comp(), "Natural Loop %p will run %d times\n", _currentRegion, loopInfo->getNumIterations());
}
}
}
// Initialize the list of candidates
//
_candidateTTs = new (trStackMemory()) TR_ScratchList<TR::TreeTop>(trMemory());
for (TR::Block *currentBlock = blocks.getFirst(); currentBlock; currentBlock = blocks.getNext())
{
if (trace())
traceMsg(comp(), "Analyzing block #%d, which must be executed once per iteration\n", currentBlock->getNumber());
// Scan through each node in the block
//
TR::TreeTop *tt = currentBlock->getEntry();
TR::TreeTop *exitTreeTop = currentBlock->getExit();
while (tt != exitTreeTop)
{
TR::Node *currentNode = tt->getNode();
if (trace())
traceMsg(comp(), "Analyzing tree top node %p\n", currentNode);
if (loopInfo)
{
// requires loop info for the number of iterations
setSummationReductionCandidates(currentNode, tt);
}
setStoreMotionCandidates(currentNode, tt);
tt = tt->getNextTreeTop();
}
}
// New code: without using any UDI
// walk through the trees in the loop
// to invalidate the candidates
//
if (!_supportedExpressions)
{
_supportedExpressions = new (trStackMemory()) TR_BitVector(comp()->getNodeCount(), trMemory(), stackAlloc, growable);
}
invalidateCandidates();
ListIterator<TR::TreeTop> treeTops(_candidateTTs);
for (TR::TreeTop *treeTop = treeTops.getFirst(); treeTop; treeTop = treeTops.getNext())
{
if (trace())
traceMsg(comp(), "Candidate TreeTop: %p, Node:%p\n", treeTop, treeTop->getNode());
bool usedCandidate = false;
bool isPreheaderBlockInvalid = false;
if (loopInfo)
{
usedCandidate = tranformSummationReductionCandidate(treeTop, loopInfo, &isPreheaderBlockInvalid);
}
if (isPreheaderBlockInvalid)
{
break;
}
if (!usedCandidate)
{
tranformStoreMotionCandidate(treeTop, &isPreheaderBlockInvalid);
}
if (isPreheaderBlockInvalid)
{
break;
}
}
}
TR_ExpressionsSimplification::LoopInfo*
TR_ExpressionsSimplification::findLoopInfo(TR_RegionStructure* region)
{
ListIterator<TR::CFGEdge> exitEdges(®ion->getExitEdges());
if (region->getExitEdges().getSize() != 1)
{
if (trace())
traceMsg(comp(), "Region with more than 1 exit edges can't be handled\n");
return 0;
}
TR_StructureSubGraphNode* exitNode = toStructureSubGraphNode(exitEdges.getFirst()->getFrom());
if (!exitNode->getStructure()->asBlock())
{
if (trace())
traceMsg(comp(), "The exit block can't be found\n");
return 0;
}
TR::Block *exitBlock = exitNode->getStructure()->asBlock()->getBlock();
TR::Node *lastTreeInExitBlock = exitBlock->getLastRealTreeTop()->getNode();
if (trace())
{
traceMsg(comp(), "The exit block is %d\n", exitBlock->getNumber());
traceMsg(comp(), "The branch node is %p\n", lastTreeInExitBlock);
}
if (!lastTreeInExitBlock->getOpCode().isBranch())
{
if (trace())
traceMsg(comp(), "The branch node couldn't be found\n");
return 0;
}
if (lastTreeInExitBlock->getNumChildren() < 2)
{
if (trace())
traceMsg(comp(), "The branch node has less than 2 children\n");
return 0;
}
TR::Node *firstChildOfLastTree = lastTreeInExitBlock->getFirstChild();
TR::Node *secondChildOfLastTree = lastTreeInExitBlock->getSecondChild();
if (!firstChildOfLastTree->getOpCode().hasSymbolReference())
{
if (trace())
traceMsg(comp(), "The branch node's first child node %p - its opcode does not have a symbol reference\n", firstChildOfLastTree);
return 0;
}
TR::SymbolReference *firstChildSymRef = firstChildOfLastTree->getSymbolReference();
if (trace())
traceMsg(comp(), "Symbol Reference: %p Symbol: %p\n", firstChildSymRef, firstChildSymRef->getSymbol());
// Locate the induction variable that matches with the exit node symbol
//
TR_InductionVariable *indVar = region->findMatchingIV(firstChildSymRef);
if (!indVar) return 0;
if (!indVar->getIncr()->asIntConst())
{
if (trace())
traceMsg(comp(), "Increment is not a constant\n");
return 0;
}
int32_t increment = indVar->getIncr()->getLowInt();
_visitCount = comp()->incVisitCount();
bool indVarWrittenAndUsedUnexpectedly = false;
if (firstChildOfLastTree->getReferenceCount() > 1)
{
TR::TreeTop *cursorTreeTopInExitBlock = exitBlock->getEntry();
TR::TreeTop *exitTreeTopInExitBlock = exitBlock->getExit();
bool loadSeen = false;
while (cursorTreeTopInExitBlock != exitTreeTopInExitBlock)
{
TR::Node *cursorNode = cursorTreeTopInExitBlock->getNode();
if (checkForLoad(cursorNode, firstChildOfLastTree))
loadSeen = true;
if (!cursorNode->getOpCode().isStore() &&
(cursorNode->getNumChildren() > 0))
cursorNode = cursorNode->getFirstChild();
if (cursorNode->getOpCode().isStore() &&
(cursorNode->getSymbolReference() == firstChildSymRef))
{
indVarWrittenAndUsedUnexpectedly = true;
if ((cursorNode->getFirstChild() == firstChildOfLastTree) ||
!loadSeen)
indVarWrittenAndUsedUnexpectedly = false;
else
break;
}
cursorTreeTopInExitBlock = cursorTreeTopInExitBlock->getNextTreeTop();
}
}
if (indVarWrittenAndUsedUnexpectedly)
{
return 0;
}
int32_t lowerBound;
int32_t upperBound = 0;
TR::Node *bound = 0;
bool equals = false;
switch(lastTreeInExitBlock->getOpCodeValue())
{
case TR::ificmplt:
case TR::ificmpgt:
equals = true;
case TR::ificmple:
case TR::ificmpge:
if (!(indVar->getEntry() && indVar->getEntry()->asIntConst()))
{
if (trace())
traceMsg(comp(), "Entry value is not a constant\n");
return 0;
}
lowerBound = indVar->getEntry()->getLowInt();
if (secondChildOfLastTree->getOpCode().isLoadConst())
{
upperBound = secondChildOfLastTree->getInt();
}
else if (secondChildOfLastTree->getOpCode().isLoadVar())
{
bound = secondChildOfLastTree;
}
else
{
if (trace())
traceMsg(comp(), "Second child is not a const or a load\n");
return 0;
}
return new (trStackMemory()) LoopInfo(bound, lowerBound, upperBound, increment, equals);
default:
if (trace())
traceMsg(comp(), "The condition has not been implemeted\n");
return 0;
}
return 0;
}
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;
if (height < curTreeInfo->getHeight())
height = curTreeInfo->getHeight();
height++;
if ((height+maxHeightUsed) > MAX_ALLOWED_HEIGHT)
{
cannotBeEliminated = true;
return false;
}
treeInfo->setHeight(height);
}
return true;
}
if (mayBeVolatileReference && !canMoveIfVolatile)
return false;
if ((node->getOpCode().isBranch() &&
(node->getOpCodeValue() != TR::Goto)) ||
(node->getOpCode().isJumpWithMultipleTargets() && node->getOpCode().hasBranchChildren()))
*seenConditionalBranch = true;
if (node->getOpCodeValue() == TR::treetop ||
node->getOpCode().isNullCheck() ||
node->getOpCode().isResolveCheck() ||
node->getOpCodeValue() == TR::ArrayStoreCHK ||
node->getOpCode().isSpineCheck())
{
node = node->getFirstChild();
}
if (node->getOpCode().isStore())
{
// For a store, just the single symbol reference is killed.
// Resolution of the store symbol is handled by TR::ResolveCHK
//
if (symbolReferencesInNode.ValueAt(node->getSymbolReference()->getReferenceNumber()))
return false;
}
// Node Aliasing Changes
// Check if the definition modifies any symbol in the subtree
//
if (node->mayKill(true).containsAny(symbolReferencesInNode, comp))
return false;
}
return true;
}
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() ||
((opCodeValue == TR::New ||
opCodeValue == TR::anewarray ||
opCodeValue == TR::newarray) &&
child->getReferenceCount() > 1) ||
opCodeValue == TR::multianewarray ||
opCodeValue == TR::MergeNew ||
opCodeValue == TR::checkcast ||
opCodeValue == TR::Prefetch ||
opCodeValue == TR::iu2l ||
((childOpCode.isDiv() ||
childOpCode.isRem()) &&
child->getNumChildren() == 3)))
{
// Perform the rather complex check to see whether its safe
// to disconnect the child node from the treetop
//
bool safeToReplaceNode = false;
if (child->getReferenceCount() == 1)
{
safeToReplaceNode = true;
#ifdef J9_PROJECT_SPECIFIC
if (child->getOpCode().isPackedExponentiation())
{
// pdexp has a possible message side effect in truncating or no significant digits left cases
safeToReplaceNode = false;
}
#endif
if (opCodeValue == TR::loadaddr)
treeTopCanBeEliminated = true;
}
else if (!_cannotBeEliminated)
{
safeToReplaceNode = isSafeToReplaceNode(
child,
iter.currentTree(),
&seenConditionalBranch,
visitCount,
comp(),
&_targetTrees,
_cannotBeEliminated,
longestPaths);
}
if (safeToReplaceNode)
{
if (childOpCode.hasSymbolReference())
{
TR::SymbolReference *symRef = child->getSymbolReference();
if (symRef->getSymbol()->isAuto() || symRef->getSymbol()->isParm())
treeTopCanBeEliminated = true;
else
{
if (childOpCode.isLoad() ||
(opCodeValue == TR::loadaddr) ||
(opCodeValue == TR::instanceof) ||
(((opCodeValue == TR::New) ||
(opCodeValue == TR::anewarray ||
opCodeValue == TR::newarray)) &&
///child->getFirstChild()->isNonNegative()))
child->markedAllocationCanBeRemoved()))
// opCodeValue == TR::multianewarray ||
// opCodeValue == TR::MergeNew)
treeTopCanBeEliminated = true;
}
}
else
treeTopCanBeEliminated = true;
}
}
// Fix for the case when a float to non-float conversion node swings
// down past a branch on IA32; this would cause a FP value to be commoned
// across a branch where there was none originally; this causes pblms
// as a value is left on the stack.
//
if (treeTopCanBeEliminated &&
seenConditionalBranch)
{
if (!cg()->getSupportsJavaFloatSemantics())
{
if (child->getOpCode().isConversion() ||
child->getOpCode().isBooleanCompare())
{
if (child->getFirstChild()->getOpCode().isFloatingPoint() &&
!child->getOpCode().isFloatingPoint())
treeTopCanBeEliminated = false;
}
}
}
if (treeTopCanBeEliminated)
{
TR::NodeChecklist visited(comp());
bool containsFloatingPoint = false;
for (int32_t i = 0; i < child->getNumChildren(); ++i)
{
// Anchor nodes with reference count > 1
//
bool highGlobalIndex = false;
if (fixUpTree(child->getChild(i), iter.currentTree(), visited, highGlobalIndex, self(), visitCount))
containsFloatingPoint = true;
if (highGlobalIndex)
{
dumpOptDetails(comp(),
"%sGlobal index limit exceeded; stopping\n",
optDetailString());
return 0;
}
}
if (seenConditionalBranch &&
containsFloatingPoint)
{
if (!cg()->getSupportsJavaFloatSemantics())
treeTopCanBeEliminated = false;
}
}
}
// Update visitCount as they are used in this optimization and need to be
// correct at all intermediate stages
//
if (!treeTopCanBeEliminated)
TR::TransformUtil::recursivelySetNodeVisitCount(node, visitCount);
if (treeTopCanBeEliminated)
{
TR::TreeTop *prevTree = iter.currentTree()->getPrevTreeTop();
TR::TreeTop *nextTree = iter.currentTree()->getNextTreeTop();
if (!node->getOpCode().isStoreReg() || (node->getFirstChild()->getReferenceCount() == 1))
{
// Actually going to remove the treetop now
//
if (performTransformation(comp(), "%sRemove tree : [" POINTER_PRINTF_FORMAT "] ([" POINTER_PRINTF_FORMAT "] = %s)\n", optDetailString(), node, node->getFirstChild(), node->getFirstChild()->getOpCode().getName()))
{
prevTree->join(nextTree);
optimizer()->prepareForNodeRemoval(node);
///child->recursivelyDecReferenceCount();
node->recursivelyDecReferenceCount();
recursivelyDecFutureUseCount(child);
iter.jumpTo(prevTree);
if (child->getReferenceCount() == 1)
requestOpt(OMR::treeSimplification, true, block);
if (nextTree->getNode()->getOpCodeValue() == TR::Goto
&& prevTree->getNode()->getOpCodeValue() == TR::BBStart
&& !prevTree->getNode()->getBlock()->isExtensionOfPreviousBlock())
{
requestOpt(
OMR::redundantGotoElimination,
prevTree->getNode()->getBlock());
}
}
}
else
{
if (performTransformation(comp(), "%sMove tree : [" POINTER_PRINTF_FORMAT "]([" POINTER_PRINTF_FORMAT "] = %s) to end of block\n", optDetailString(), node, node->getFirstChild(), node->getFirstChild()->getOpCode().getName()))
{
prevTree->join(nextTree);
node->setVisitCount(visitCount);
TR::TreeTop *lastTree = findLastTreetop(block, prevTree);
TR::TreeTop *prevLastTree = lastTree->getPrevTreeTop();
TR::TreeTop *cursorTreeTop = nextTree;
while (cursorTreeTop != lastTree)
{
if (cursorTreeTop->getNode()->getOpCode().isStoreReg() &&
(cursorTreeTop->getNode()->getGlobalRegisterNumber() == iter.currentTree()->getNode()->getGlobalRegisterNumber()))
{
lastTree = cursorTreeTop;
prevLastTree = lastTree->getPrevTreeTop();
break;
}
cursorTreeTop = cursorTreeTop->getNextTreeTop();
}
if (lastTree->getNode()->getOpCodeValue() == TR::BBStart)
{
prevLastTree = lastTree;
lastTree = block->getExit();
}
TR::Node *lastNode = lastTree->getNode();
TR::Node *prevLastNode = prevLastTree->getNode();
if (lastNode->getOpCode().isIf() && !lastNode->getOpCode().isCompBranchOnly() &&
prevLastNode->getOpCode().isStoreReg() &&
((prevLastNode->getFirstChild() == lastNode->getFirstChild()) ||
(prevLastNode->getFirstChild() == lastNode->getSecondChild())))
{
lastTree = prevLastTree;
prevLastTree = lastTree->getPrevTreeTop();
}
prevLastTree->join(iter.currentTree());
iter.currentTree()->join(lastTree);
iter.jumpTo(prevTree);
requestOpt(OMR::treeSimplification, true, block);
}
}
}
}
for (auto it = anchors.begin(); it != anchors.end(); ++it)
{
TR::Node *anchor = it->tree->getNode();
TR::Node *load = anchor->getChild(0);
if (load->getReferenceCount() > 1)
continue;
// We can eliminate the indirect load immediately, but for the moment the
// subtree providing the base object has to be anchored.
TR::Node *heapBase = anchor->getChild(1);
TR::Node::recreate(anchor, TR::treetop);
anchor->setAndIncChild(0, load->getChild(0));
anchor->setChild(1, NULL);
anchor->setNumChildren(1);
if (!heapBase->getOpCode().isLoadConst())
{
it->tree->insertAfter(
TR::TreeTop::create(
comp(),
TR::Node::create(heapBase, TR::treetop, 1, heapBase)));
}
load->recursivelyDecReferenceCount();
heapBase->recursivelyDecReferenceCount();
// A later pass of dead trees can likely move (or even remove) the base
// object expression.
requestOpt(OMR::deadTreesElimination, true, it->block);
}
return 1; // actual cost
}
/**
* Search for direct loads in the taken side of a guard
*
* @param firstBlock The guard's branch destination
* @param coldPathLoads BitVector of symbol reference numbers for any direct loads seen until the merge back to mainline
*/
static void collectColdPathLoads(TR::Block* firstBlock, TR_BitVector &coldPathLoads)
{
TR_Stack<TR::Block*> blocksToCheck(TR::comp()->trMemory(), 8, false, stackAlloc);
blocksToCheck.push(firstBlock);
TR::NodeChecklist checklist(TR::comp());
coldPathLoads.empty();
while (!blocksToCheck.isEmpty())
{
TR::Block *block = blocksToCheck.pop();
for (TR::TreeTop *tt = block->getFirstRealTreeTop(); tt->getNode()->getOpCodeValue() != TR::BBEnd; tt = tt->getNextTreeTop())
collectDirectLoads(tt->getNode(), coldPathLoads, checklist);
// Search for any successors that have not merged with the mainline
for (auto itr = block->getSuccessors().begin(), end = block->getSuccessors().end(); itr != end; ++itr)
{
TR::Block *dest = (*itr)->getTo()->asBlock();
if (dest != TR::comp()->getFlowGraph()->getEnd() && dest->getPredecessors().size() == 1)
blocksToCheck.push(dest);
}
}
}
