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EscapeAnalysis.cpp
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/*******************************************************************************
* Copyright (c) 2000, 2020 IBM Corp. and others
*
* This program and the accompanying materials are made available under
* the terms of the Eclipse Public License 2.0 which accompanies this
* distribution and is available at https://www.eclipse.org/legal/epl-2.0/
* or the Apache License, Version 2.0 which accompanies this distribution and
* is available at https://www.apache.org/licenses/LICENSE-2.0.
*
* This Source Code may also be made available under the following
* Secondary Licenses when the conditions for such availability set
* forth in the Eclipse Public License, v. 2.0 are satisfied: GNU
* General Public License, version 2 with the GNU Classpath
* Exception [1] and GNU General Public License, version 2 with the
* OpenJDK Assembly Exception [2].
*
* [1] https://www.gnu.org/software/classpath/license.html
* [2] http://openjdk.java.net/legal/assembly-exception.html
*
* SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
*******************************************************************************/
#ifdef J9ZTPF
#define __TPF_DO_NOT_MAP_ATOE_REMOVE
#endif
#include "optimizer/EscapeAnalysis.hpp"
#include "optimizer/EscapeAnalysisTools.hpp"
#include <algorithm>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include "codegen/CodeGenerator.hpp"
#include "env/FrontEnd.hpp"
#include "codegen/RecognizedMethods.hpp"
#include "compile/Compilation.hpp"
#include "compile/CompilationTypes.hpp"
#include "compile/Method.hpp"
#include "compile/ResolvedMethod.hpp"
#include "compile/SymbolReferenceTable.hpp"
#include "compile/VirtualGuard.hpp"
#include "control/Options.hpp"
#include "control/Options_inlines.hpp"
#include "control/Recompilation.hpp"
#include "control/RecompilationInfo.hpp"
#include "cs2/bitvectr.h"
#include "env/CompilerEnv.hpp"
#include "env/ObjectModel.hpp"
#include "env/TRMemory.hpp"
#include "env/jittypes.h"
#include "env/VMAccessCriticalSection.hpp"
#include "env/VMJ9.h"
#include "il/AliasSetInterface.hpp"
#include "il/AutomaticSymbol.hpp"
#include "il/Block.hpp"
#include "il/DataTypes.hpp"
#include "il/ILOpCodes.hpp"
#include "il/ILOps.hpp"
#include "il/MethodSymbol.hpp"
#include "il/Node.hpp"
#include "il/Node_inlines.hpp"
#include "il/ParameterSymbol.hpp"
#include "il/ResolvedMethodSymbol.hpp"
#include "il/StaticSymbol.hpp"
#include "il/Symbol.hpp"
#include "il/SymbolReference.hpp"
#include "il/TreeTop.hpp"
#include "il/TreeTop_inlines.hpp"
#include "infra/Array.hpp"
#include "infra/Assert.hpp"
#include "infra/BitVector.hpp"
#include "infra/Cfg.hpp"
#include "infra/Checklist.hpp"
#include "infra/Link.hpp"
#include "infra/List.hpp"
#include "infra/SimpleRegex.hpp"
#include "infra/TRCfgEdge.hpp"
#include "infra/TRCfgNode.hpp"
#include "optimizer/Inliner.hpp"
#include "optimizer/Optimization.hpp"
#include "optimizer/OptimizationManager.hpp"
#include "optimizer/Optimizations.hpp"
#include "optimizer/Optimizer.hpp"
#include "optimizer/Structure.hpp"
#include "optimizer/TransformUtil.hpp"
#include "optimizer/DataFlowAnalysis.hpp"
#include "optimizer/UseDefInfo.hpp"
#include "optimizer/ValueNumberInfo.hpp"
#include "optimizer/LocalOpts.hpp"
#include "optimizer/MonitorElimination.hpp"
#include "ras/Debug.hpp"
#include "runtime/J9Profiler.hpp"
#include "runtime/J9Runtime.hpp"
#define OPT_DETAILS "O^O ESCAPE ANALYSIS: "
#define MAX_SIZE_FOR_ONE_CONTIGUOUS_OBJECT 2416 // Increased from 72
#define MAX_SIZE_FOR_ALL_OBJECTS 3000 // Increased from 500
#define MAX_SNIFF_BYTECODE_SIZE 1600
#define LOCAL_OBJECTS_COLLECTABLE 1
extern void createGuardSiteForRemovedGuard(TR::Compilation *comp, TR::Node* ifNode);
static bool blockIsInLoop(TR::Block *block)
{
for (TR_Structure *s = block->getStructureOf()->getParent(); s; s = s->getParent())
{
TR_RegionStructure *region = s->asRegion();
if (region->isNaturalLoop() || region->containsInternalCycles())
return true;
}
return false;
}
TR_EscapeAnalysis::TR_EscapeAnalysis(TR::OptimizationManager *manager)
: TR::Optimization(manager),
_newObjectNoZeroInitSymRef(NULL),
_newArrayNoZeroInitSymRef(NULL),
_dependentAllocations(manager->comp()->trMemory()),
_inlineCallSites(manager->comp()->trMemory()),
_dememoizedAllocs(manager->comp()->trMemory()),
_devirtualizedCallSites(manager->comp()->trMemory()),
_aNewArrayNoZeroInitSymRef(NULL)
{
_newObjectNoZeroInitSymRef = comp()->getSymRefTab()->findOrCreateNewObjectNoZeroInitSymbolRef(0);
_newArrayNoZeroInitSymRef = comp()->getSymRefTab()->findOrCreateNewArrayNoZeroInitSymbolRef(0);
_aNewArrayNoZeroInitSymRef = comp()->getSymRefTab()->findOrCreateANewArrayNoZeroInitSymbolRef(0);
_maxPassNumber = 0;
_dememoizationSymRef = NULL;
_createStackAllocations = true;
_createLocalObjects = comp()->target().cpu.isX86() || comp()->target().cpu.isPower() || comp()->target().cpu.isZ();
_desynchronizeCalls = true;
#if CHECK_MONITORS
/* monitors */
_removeMonitors = true;
#endif
static char *disableLoopAliasAllocationChecking = feGetEnv("TR_disableEALoopAliasAllocationChecking");
_doLoopAllocationAliasChecking = (disableLoopAliasAllocationChecking == NULL);
}
char *TR_EscapeAnalysis::getClassName(TR::Node *classNode)
{
char *className = NULL;
if (classNode->getOpCodeValue() == TR::loadaddr)
{
TR::SymbolReference *symRef = classNode->getSymbolReference();
if (symRef->getSymbol()->isClassObject())
{
int32_t classNameLength;
char *classNameChars = TR::Compiler->cls.classNameChars(comp(), symRef, classNameLength);
if (NULL != classNameChars)
{
className = (char *)trMemory()->allocateStackMemory(classNameLength+1, TR_Memory::EscapeAnalysis);
memcpy(className, classNameChars, classNameLength);
className[classNameLength] = 0;
}
}
}
return className;
}
bool TR_EscapeAnalysis::isImmutableObject(TR::Node *node)
{
// For debugging issues with the special handling of immutable objects
// that allows them to be discontiguously allocated even if they escape
static char *disableImmutableObjectHandling = feGetEnv("TR_disableEAImmutableObjectHandling");
if (disableImmutableObjectHandling)
{
return false;
}
if (node->getOpCodeValue() != TR::New)
{
return false;
}
char *className = getClassName(node->getFirstChild());
if (NULL != className &&
!strncmp("java/lang/", className, 10) &&
(!strcmp("Integer", &className[10]) ||
!strcmp("Long", &className[10]) ||
!strcmp("Short", &className[10]) ||
!strcmp("Byte", &className[10]) ||
!strcmp("Boolean", &className[10]) ||
!strcmp("Character", &className[10]) ||
!strcmp("Double", &className[10]) ||
!strcmp("Float", &className[10])))
{
return true;
}
return false;
}
bool TR_EscapeAnalysis::isImmutableObject(Candidate *candidate)
{
if (candidate->_isImmutable)
return true;
bool b = isImmutableObject(candidate->_node);
candidate->_isImmutable = b;
return b;
}
int32_t TR_EscapeAnalysis::perform()
{
if (comp()->isOptServer() && (comp()->getMethodHotness() <= warm))
return 0;
// EA generates direct stores/loads to instance field which is different
// from a normal instance field read/write. Field watch would need special handling
// for stores/loads generated by EA.
if (comp()->incompleteOptimizerSupportForReadWriteBarriers())
return 0;
static char *doESCNonQuiet = feGetEnv("TR_ESCAPENONQUIET");
if (doESCNonQuiet && comp()->getOutFile() == NULL)
return 0;
int32_t nodeCount = 0;
vcount_t visitCount = comp()->incVisitCount(); //@TODO: needs a change to TR_Node's
//countNumberOfNodesInSubtree
//we should probably leave it as is
//for the next iteration
TR::TreeTop *tt = comp()->getStartTree();
for (; tt; tt = tt->getNextTreeTop())
nodeCount += tt->getNode()->countNumberOfNodesInSubtree(visitCount);
// Set thresholds depending on the method's hotness
//
TR_Hotness methodHotness = comp()->getMethodHotness();
if (methodHotness > hot)
{
_maxPassNumber = 6;
_maxSniffDepth = 8;
_maxInlinedBytecodeSize = 5000 - nodeCount;
}
else
{
_maxPassNumber = 3;
//_maxPassNumber = (methodHotness < hot) ? 2 : 3;
_maxSniffDepth = 4;
_maxInlinedBytecodeSize = 4000 - nodeCount;
}
// under HCR we can protect the top level sniff with an HCR guard
// nested sniffs are not currently supported
if (comp()->getHCRMode() != TR::none)
_maxSniffDepth = 1;
TR_ASSERT_FATAL(_maxSniffDepth < 16, "The argToCall and nonThisArgToCall flags are 16 bits - a depth limit greater than 16 will not fit in these flags");
if (getLastRun())
_maxPassNumber = 0; // Notwithstanding our heuristics, if this is the last run, our max "pass number" is zero (which is the first pass)
_maxPeekedBytecodeSize = comp()->getMaxPeekedBytecodeSize();
// Escape analysis is organized so that it may decide another pass of
// the analysis is required immediately after the current one. It leaves
// it up to the optimization strategy to re-invoke the analysis, but we
// keep track here of the number of passes through the analysis so we
// can restrict the number of passes. Each time we end the local loop of
// passes the current pass number is reset to zero in case escape analysis
// is called again later in the optimization strategy.
//
if (manager()->numPassesCompleted() == 0)
{
//
void *data = manager()->getOptData();
TR_BitVector *peekableCalls = NULL;
if (data != NULL)
{
peekableCalls = ((TR_EscapeAnalysis::PersistentData *)data)->_peekableCalls;
delete ((TR_EscapeAnalysis::PersistentData *) data) ;
manager()->setOptData(NULL);
}
manager()->setOptData(new (comp()->allocator()) TR_EscapeAnalysis::PersistentData(comp()));
if (peekableCalls != NULL)
((TR_EscapeAnalysis::PersistentData *)manager()->getOptData())->_peekableCalls = peekableCalls;
}
else
{
if (trace())
{
/////printf("secs Performing pass %d of Escape Analysis for %s\n", _currentPass, comp()->signature());
}
}
int32_t cost = 0;
{
TR::StackMemoryRegion stackMemoryRegion(*trMemory());
_callsToProtect = new (trStackMemory()) CallLoadMap(CallLoadMapComparator(), comp()->trMemory()->currentStackRegion());
#if CHECK_MONITORS
/* monitors */
TR_MonitorStructureChecker inspector;
if (inspector.checkMonitorStructure(comp()->getFlowGraph()))
{
_removeMonitors = false;
if (trace())
traceMsg(comp(), "Disallowing monitor-removal because of strange monitor structure\n");
}
#endif
cost = performAnalysisOnce();
if (!_callsToProtect->empty() && manager()->numPassesCompleted() < _maxPassNumber)
{
TR::CFG *cfg = comp()->getFlowGraph();
TR::Block *block = NULL;
TR::TreeTop *lastTree = comp()->findLastTree();
TR_EscapeAnalysisTools tools(comp());
RemainingUseCountMap *remainingUseCount = new (comp()->trStackMemory()) RemainingUseCountMap(RemainingUseCountMapComparator(), comp()->trMemory()->currentStackRegion());
for (TR::TreeTop *tt = comp()->findLastTree(); tt != NULL; tt = tt->getPrevTreeTop())
{
TR::Node *node = tt->getNode();
if (node->getOpCodeValue() == TR::BBEnd)
block = node->getBlock();
else if (node->getStoreNode() && node->getStoreNode()->getOpCode().isStoreDirect())
node = node->getStoreNode()->getFirstChild();
else if (node->getOpCode().isCheck() || node->getOpCode().isAnchor() || node->getOpCodeValue() == TR::treetop)
node = node->getFirstChild();
auto nodeLookup = _callsToProtect->find(node);
if (nodeLookup == _callsToProtect->end()
|| TR_EscapeAnalysisTools::isFakeEscape(node)
|| node->getSymbol() == NULL
|| node->getSymbol()->getResolvedMethodSymbol() == NULL
|| node->getSymbol()->getResolvedMethodSymbol()->getResolvedMethod() == NULL)
continue;
if (node->getReferenceCount() > 1)
{
auto useCount = remainingUseCount->find(node);
if (useCount == remainingUseCount->end())
{
(*remainingUseCount)[node] = node->getReferenceCount() - 1;
continue;
}
if (useCount->second > 1)
{
useCount->second -= 1;
continue;
}
}
if (!performTransformation(comp(), "%sHCR CALL PEEKING: Protecting call [%p] n%dn with an HCR guard and escape helper\n", OPT_DETAILS, node, node->getGlobalIndex()))
continue;
((TR_EscapeAnalysis::PersistentData*)manager()->getOptData())->_processedCalls->set(node->getGlobalIndex());
_repeatAnalysis = true;
optimizer()->setValueNumberInfo(NULL);
cfg->invalidateStructure();
TR::TreeTop *prevTT = tt->getPrevTreeTop();
TR::Block *callBlock = block->split(tt, comp()->getFlowGraph(), true, true);
// check uncommoned nodes for stores of the candidate - if so we need to add the new temp to the
// list of loads
for (TR::TreeTop *itr = block->getExit(); itr != prevTT; itr = itr->getPrevTreeTop())
{
TR::Node *storeNode = itr->getNode()->getStoreNode();
if (storeNode
&& storeNode->getOpCodeValue() == TR::astore
&& nodeLookup->second.first->get(storeNode->getFirstChild()->getGlobalIndex()))
nodeLookup->second.second->push_back(TR::Node::createWithSymRef(TR::aload, 0, storeNode->getSymbolReference()));
}
TR::Node *guard = TR_VirtualGuard::createHCRGuard(comp(),
node->getByteCodeInfo().getCallerIndex(),
node,
NULL,
node->getSymbol()->getResolvedMethodSymbol(),
node->getSymbol()->getResolvedMethodSymbol()->getResolvedMethod()->classOfMethod());
block->getExit()->insertBefore(TR::TreeTop::create(comp(), guard));
TR::Block *heapificationBlock = TR::Block::createEmptyBlock(node, comp(), MAX_COLD_BLOCK_COUNT);
heapificationBlock->getExit()->join(lastTree->getNextTreeTop());
lastTree->join(heapificationBlock->getEntry());
lastTree = heapificationBlock->getExit();
heapificationBlock->setIsCold();
guard->setBranchDestination(heapificationBlock->getEntry());
cfg->addNode(heapificationBlock);
cfg->addEdge(block, heapificationBlock);
cfg->addEdge(heapificationBlock, callBlock);
heapificationBlock->getExit()->insertBefore(TR::TreeTop::create(comp(), TR::Node::create(node, TR::Goto, 0, callBlock->getEntry())));
tools.insertFakeEscapeForLoads(heapificationBlock, node, nodeLookup->second.second);
traceMsg(comp(), "Created heapification block_%d\n", heapificationBlock->getNumber());
((TR_EscapeAnalysis::PersistentData*)manager()->getOptData())->_peekableCalls->set(node->getGlobalIndex());
_callsToProtect->erase(nodeLookup);
tt = prevTT->getNextTreeTop();
}
}
} // scope of the stack memory region
if (_repeatAnalysis && manager()->numPassesCompleted() < _maxPassNumber)
{
// Ask the optimizer to repeat this analysis
//
requestOpt(OMR::eachEscapeAnalysisPassGroup);
manager()->incNumPassesCompleted();
}
else
{
// Don't repeat this analysis, reset the pass count for next time
//
manager()->setNumPassesCompleted(0);
}
return cost;
}
const char *
TR_EscapeAnalysis::optDetailString() const throw()
{
return "O^O ESCAPE ANALYSIS: ";
}
void TR_EscapeAnalysis::rememoize(Candidate *candidate, bool mayDememoizeNextTime)
{
if (!candidate->_dememoizedConstructorCall)
return;
TR_ASSERT(candidate->_treeTop->getEnclosingBlock() == candidate->_dememoizedConstructorCall->getEnclosingBlock(),
"Dememoized constructor call %p must be in the same block as allocation %p", candidate->_treeTop->getNode(), candidate->_dememoizedConstructorCall->getNode());
if (trace())
traceMsg(comp(), " Rememoizing%s [%p] using constructor call [%p]\n", mayDememoizeNextTime?"":" and inlining", candidate->_node, candidate->_dememoizedConstructorCall->getNode()->getFirstChild());
// Change trees back
//
candidate->_node->getFirstChild()->recursivelyDecReferenceCount(); // remove loadaddr of class
candidate->_node->setAndIncChild(0, candidate->_dememoizedConstructorCall->getNode()->getFirstChild()->getSecondChild()); // original call argument
TR::Node::recreate(candidate->_node, TR::acall);
candidate->_node->setSymbolReference(candidate->_dememoizedMethodSymRef);
candidate->_dememoizedConstructorCall->unlink(true);
// Only rememoize once
//
_inlineCallSites.remove(candidate->_dememoizedConstructorCall);
candidate->_dememoizedConstructorCall = NULL;
candidate->_dememoizedMethodSymRef = NULL;
if (!mayDememoizeNextTime)
{
// Inline the memoization method so we can apply EA to it even though dememoization failed.
// This also prevents us from re-trying dememoization when it's hopeless.
//
_inlineCallSites.add(candidate->_treeTop);
}
}
static const char *ynmString(TR_YesNoMaybe arg)
{
switch (arg)
{
case TR_yes:
return "yes";
case TR_no:
return "no";
case TR_maybe:
return "maybe";
}
return "";
}
static TR_YesNoMaybe ynmOr(TR_YesNoMaybe left, TR_YesNoMaybe right)
{
switch (left)
{
case TR_yes:
return TR_yes;
case TR_no:
return right;
case TR_maybe:
return (right == TR_yes)? TR_yes : TR_maybe;
}
return TR_maybe;
}
static TR_YesNoMaybe candidateHasField(Candidate *candidate, TR::Node *fieldNode, int32_t fieldOffset, TR_EscapeAnalysis *ea)
{
TR::Compilation *comp = ea->comp();
TR::SymbolReference *fieldSymRef = fieldNode->getSymbolReference();
int32_t fieldSize = fieldNode->getSize();
int32_t minHeaderSize, maxHeaderSize;
if (candidate->_origKind == TR::New)
{
minHeaderSize = maxHeaderSize = comp->fej9()->getObjectHeaderSizeInBytes();
}
else
{
minHeaderSize = std::min(TR::Compiler->om.contiguousArrayHeaderSizeInBytes(), TR::Compiler->om.discontiguousArrayHeaderSizeInBytes());
maxHeaderSize = std::max(TR::Compiler->om.contiguousArrayHeaderSizeInBytes(), TR::Compiler->om.discontiguousArrayHeaderSizeInBytes());
}
TR_YesNoMaybe withinObjectBound = TR_maybe;
TR_YesNoMaybe withinObjectHeader = TR_maybe;
TR_YesNoMaybe belongsToAllocatedClass = TR_maybe;
TR_YesNoMaybe result = TR_maybe;
if (fieldOffset + fieldSize <= candidate->_size)
withinObjectBound = TR_yes;
else
withinObjectBound = TR_no;
if (fieldOffset + fieldSize <= minHeaderSize)
withinObjectHeader = TR_yes;
else if (fieldOffset > maxHeaderSize)
withinObjectHeader = TR_no;
else
withinObjectHeader = TR_maybe;
// Test a few conditions to try to avoid calling getDeclaringClassFromFieldOrStatic
// because that requires VM access.
//
static char *debugEAFieldValidityCheck = feGetEnv("TR_debugEAFieldValidityCheck");
if (withinObjectHeader == TR_yes)
{
result = TR_yes;
}
else
{
TR_OpaqueClassBlock *fieldClassInCP = fieldSymRef->getOwningMethod(comp)->getClassFromFieldOrStatic(comp, fieldSymRef->getCPIndex());
if ( fieldClassInCP
&& TR_yes == comp->fej9()->isInstanceOf((TR_OpaqueClassBlock*)candidate->_class, fieldClassInCP, true))
{
// Short cut: There's no need to look up the declaring class of the
// field because we already know the candidate's class contains the
// field since it inherits the class we're using to access the field
// in the constant pool.
//
if (!debugEAFieldValidityCheck
|| performTransformation(comp, "%sQuick Using candidateHasField=yes (withinObjectBound=%s) for candidate [%p] field access [%p]\n",
OPT_DETAILS, ynmString(withinObjectBound), candidate->_node, fieldNode))
{
belongsToAllocatedClass = TR_yes;
result = TR_yes;
}
}
}
// If we're still not sure, go ahead and try getDeclaringClassFromFieldOrStatic
//
if (result == TR_maybe)
{
TR::VMAccessCriticalSection candidateHasFieldCriticalSection(comp->fej9(),
TR::VMAccessCriticalSection::tryToAcquireVMAccess,
comp);
if (candidateHasFieldCriticalSection.hasVMAccess())
{
TR_OpaqueClassBlock *fieldDeclaringClass = fieldSymRef->getOwningMethod(comp)->getDeclaringClassFromFieldOrStatic(comp, fieldSymRef->getCPIndex());
if (fieldDeclaringClass)
belongsToAllocatedClass = comp->fej9()->isInstanceOf((TR_OpaqueClassBlock*)candidate->_class, fieldDeclaringClass, true);
result = ynmOr(withinObjectHeader, belongsToAllocatedClass);
if (debugEAFieldValidityCheck)
{
if (!performTransformation(comp, "%sUsing candidateHasField=%s (withinObjectBound=%s) for candidate [%p] field access [%p]\n",
OPT_DETAILS, ynmString(result), ynmString(withinObjectBound), candidate->_node, fieldNode))
{
// Conservatively return TR_no.
// We do the performTransformation even if result is already TR_no
// just to support countOptTransformations.
//
result = TR_no;
}
}
}
else if (ea->trace())
{
traceMsg(comp, " Unable to acquire vm access; conservatively assume field [%p] does not belong to candidate [%p]\n", fieldNode, candidate->_node);
}
}
if (debugEAFieldValidityCheck)
{
if ( (withinObjectBound != result)
&& !performTransformation(comp, "%sSubstituting candidateHasField=%s (withinObjectBound=%s) for candidate [%p] field access [%p]\n",
OPT_DETAILS, ynmString(result), ynmString(withinObjectBound), candidate->_node, fieldNode))
{
// Use old logic for debugging purposes
// Note: This is not necessarily correct, hence the env var guard.
// Once we have confidence in the newer logic, this withinObjectBound
// logic can eventually be deleted.
//
result = withinObjectBound;
}
}
if (ea->trace())
traceMsg(comp, " Candidate [%p] field access [%p] candidateHasField=%s (withinObjectBound=%s withinObjectHeader=%s belongsToAllocatedClass=%s)\n",
candidate->_node, fieldNode,
ynmString(result),
ynmString(withinObjectBound),
ynmString(withinObjectHeader),
ynmString(belongsToAllocatedClass));
return result;
}
//
// Hack markers
//
// PR 78801: Currently, BCD shadows don't have reliable size information, and
// BCD temps require size information. This makes it hard to create BCD temps
// from shadows.
//
#define CANT_CREATE_BCD_TEMPS (1)
int32_t TR_EscapeAnalysis::performAnalysisOnce()
{
int32_t cost = 0;
Candidate *candidate, *next;
if (trace())
{
traceMsg(comp(), "Starting Escape Analysis pass %d\n", manager()->numPassesCompleted());
comp()->dumpMethodTrees("Trees before Escape Analysis");
}
_useDefInfo = NULL; // Build these only if required
_invalidateUseDefInfo = false;
_valueNumberInfo = NULL;
_otherDefsForLoopAllocation = NULL;
_methodSymbol = NULL;
_nodeUsesThroughAternary = NULL;
_repeatAnalysis = false;
_somethingChanged = false;
_inBigDecimalAdd = false;
_candidates.setFirst(NULL);
_inlineCallSites.deleteAll();
_dependentAllocations.deleteAll();
_fixedVirtualCallSites.setFirst(NULL);
_parms = NULL;
_ignoreableUses = NULL;
_nonColdLocalObjectsValueNumbers = NULL;
_allLocalObjectsValueNumbers = NULL;
_visitedNodes = NULL;
_aliasesOfAllocNode = NULL;
_aliasesOfOtherAllocNode = NULL;
_notOptimizableLocalObjectsValueNumbers = NULL;
_notOptimizableLocalStringObjectsValueNumbers = NULL;
// Walk the trees and find the "new" nodes.
// Any that are candidates for local allocation or desynchronization are
// added to the list of candidates.
//
findCandidates();
cost++;
if (!_candidates.isEmpty())
{
_useDefInfo = optimizer()->getUseDefInfo();
_blocksWithFlushOnEntry = new (trStackMemory()) TR_BitVector(comp()->getFlowGraph()->getNextNodeNumber(), trMemory(), stackAlloc);
_visitedNodes = new (trStackMemory()) TR_BitVector(comp()->getNodeCount(), trMemory(), stackAlloc, growable);
_aliasesOfAllocNode =
_doLoopAllocationAliasChecking
? new (trStackMemory()) TR_BitVector(0, trMemory(), stackAlloc, growable) : NULL;
_aliasesOfOtherAllocNode =
_doLoopAllocationAliasChecking
? new (trStackMemory()) TR_BitVector(0, trMemory(), stackAlloc, growable) : NULL;
if (!_useDefInfo)
{
if (trace())
traceMsg(comp(), "Can't do Escape Analysis, no use/def information\n");
_candidates.setFirst(NULL);
}
_valueNumberInfo = optimizer()->getValueNumberInfo();
if (!_valueNumberInfo)
{
if (trace())
traceMsg(comp(), "Can't do Escape Analysis, no value number information\n");
_candidates.setFirst(NULL);
}
else
{
_ignoreableUses = new (trStackMemory()) TR_BitVector(0, trMemory(), stackAlloc);
_nonColdLocalObjectsValueNumbers = new (trStackMemory()) TR_BitVector(_valueNumberInfo->getNumberOfValues(), trMemory(), stackAlloc);
_allLocalObjectsValueNumbers = new (trStackMemory()) TR_BitVector(_valueNumberInfo->getNumberOfValues(), trMemory(), stackAlloc);
_notOptimizableLocalObjectsValueNumbers = new (trStackMemory()) TR_BitVector(_valueNumberInfo->getNumberOfValues(), trMemory(), stackAlloc);
_notOptimizableLocalStringObjectsValueNumbers = new (trStackMemory()) TR_BitVector(_valueNumberInfo->getNumberOfValues(), trMemory(), stackAlloc);
}
}
if ( !_candidates.isEmpty())
{
findLocalObjectsValueNumbers();
findIgnoreableUses();
}
// Complete the candidate info by finding all uses and defs that are reached
// from each candidate.
//
if (!_candidates.isEmpty())
{
checkDefsAndUses();
cost++;
}
if (trace())
printCandidates("Initial candidates");
// Look through the trees to see which candidates escape the method. This
// may involve sniffing into called methods.
//
_sniffDepth = 0;
_parms = NULL;
if (!_candidates.isEmpty())
{
//if (comp()->getMethodSymbol()->mayContainMonitors())
if (cg()->getEnforceStoreOrder())
{
TR_FlowSensitiveEscapeAnalysis flowSensitiveAnalysis(comp(), optimizer(), comp()->getFlowGraph()->getStructure(), this);
}
bool ignoreRecursion = false;
checkEscape(comp()->getStartTree(), false, ignoreRecursion);
cost++;
}
//fixup those who have virtual calls
for (candidate = _candidates.getFirst(); candidate; candidate = next)
{
next = candidate->getNext();
if (!candidate->isLocalAllocation())
continue;
if (!candidate->hasVirtualCallsToBeFixed())
continue;
dumpOptDetails(comp(), "Fixup indirect calls sniffed for candidate =%p\n",candidate->_node);
TR::TreeTop *callSite, *callSiteNext = NULL;
ListIterator<TR::TreeTop> it(candidate->getVirtualCallSitesToBeFixed());
for (callSite = it.getFirst(); callSite; callSite = callSiteNext)
{
//TR::TreeTop *directCallTree = findCallSiteFixed(callSite);
bool found = findCallSiteFixed(callSite);
callSiteNext = it.getNext();
if (!found)
{
if (!_devirtualizedCallSites.find(callSite))
_devirtualizedCallSites.add(callSite);
_fixedVirtualCallSites.add(new (trStackMemory()) TR_EscapeAnalysis::TR_CallSitesFixedMapper(callSite, NULL));
dumpOptDetails(comp(), "adding Map:vCall = %p direct = %p\n",callSite, NULL);
_repeatAnalysis = true;
_somethingChanged = true;
candidate->getCallSites()->remove(callSite);
//candidate->getCallSites()->add(directCallTree);
}
else
{
dumpOptDetails(comp(), "found MAp for %p\n",callSite);
//fixup the callSite list
candidate->getCallSites()->remove(callSite);
//candidate->getCallSites()->add(directCallTree);
}
}
candidate->setLocalAllocation(false);
if (trace())
traceMsg(comp(), " Make [%p] non-local because we'll try it again in another pass\n", candidate->_node);
}
//fixup those callSite which were devirtualize
//fixup the coldBlockInfo too
for (candidate = _candidates.getFirst(); candidate; candidate = next)
{
next = candidate->getNext();
if (!candidate->isLocalAllocation())
continue;
TR::TreeTop *callSite, *callSiteNext = NULL;
ListIterator<TR::TreeTop> it(candidate->getCallSites());
for (callSite = it.getFirst(); callSite; callSite = callSiteNext)
{
callSiteNext = it.getNext();
//TR::TreeTop *directCallTree = findCallSiteFixed(callSite);
bool found = findCallSiteFixed(callSite);
if (found)
{
if (trace())
traceMsg(comp(), "replacing callsite %p for candidate %p with it's direct call\n",callSite,candidate->_node);
candidate->getCallSites()->remove(callSite);
candidate->setLocalAllocation(false);
//candidate->getCallSites()->add(directCallTree);
}
}
ListIterator<TR_ColdBlockEscapeInfo> coldBlockInfoIt(candidate->getColdBlockEscapeInfo());
for (TR_ColdBlockEscapeInfo *info = coldBlockInfoIt.getFirst(); info != NULL; info = coldBlockInfoIt.getNext())
{
ListIterator<TR::TreeTop> treesIt(info->getTrees());
for (TR::TreeTop *escapeTree = treesIt.getFirst(); escapeTree != NULL; escapeTree = treesIt.getNext())
{
if (findCallSiteFixed(escapeTree))
{
candidate->setLocalAllocation(false);
break;
}
}
if (!candidate->isLocalAllocation())
break;
}
}
// Check whether tentative dememoization can proceed
//
bool shouldRepeatDueToDememoization = false;
for (candidate = _candidates.getFirst(); candidate; candidate = next)
{
next = candidate->getNext();
if (candidate->_dememoizedConstructorCall)
{
if ( candidate->isLocalAllocation()
&& !candidate->mustBeContiguousAllocation()
&& candidate->getCallSites()->isSingleton()
&& candidate->getCallSites()->find(candidate->_dememoizedConstructorCall)
&& performTransformation(comp(), "%sDememoizing [%p]\n", OPT_DETAILS, candidate->_node))
{
// Dememoization worked!
// Inline the constructor and catch this candidate on the next pass
candidate->setLocalAllocation(false);
if (trace())
traceMsg(comp(), "2 setting local alloc %p to false\n", candidate->_node);
_inlineCallSites.add(candidate->_dememoizedConstructorCall);
_repeatAnalysis = true;
}
else
{
// Dememoization failed on this pass; must re-memoize instead
bool mayDememoizeNextTime = true;
// allow the call to be inlined at least in the last pass
// and prevent from dememoizing the call again
//
if (candidate->isLocalAllocation())
_repeatAnalysis = true;
if (_repeatAnalysis)
{
if (manager()->numPassesCompleted() == _maxPassNumber-1)
mayDememoizeNextTime = false;
else
shouldRepeatDueToDememoization = true;
}
else
mayDememoizeNextTime = false;
if (trace())
{
traceMsg(comp(), " Fail [%p] because dememoization failed; will%s attempt again on next EA pass\n", candidate->_node, mayDememoizeNextTime? "":" NOT");
traceMsg(comp(), " Fail [%p] because dememoization failed; will%s attempt dememoization again on next EA pass\n", candidate->_node, mayDememoizeNextTime? "":" NOT");
traceMsg(comp(), " 4 booleans are %d %d %d %d\n", candidate->isLocalAllocation(), candidate->mustBeContiguousAllocation(), candidate->getCallSites()->isSingleton(), candidate->getCallSites()->find(candidate->_dememoizedConstructorCall));
}
// if mayDememoizeNextTime is false, then the following call to
// rememoize will add valueOf to the list of calls to be inlined
//
rememoize(candidate, mayDememoizeNextTime);
if (trace())
traceMsg(comp(), "8 removing cand %p to false\n", candidate->_node);
}
_candidates.remove(candidate);
}
}
// Decide whether or not another pass of escape analysis is appropriate.
// If we are allowed to do another pass and there are candidates which are
// contiguous only because they are arguments to calls and those calls can
// be inlined, then inline the calls and mark the candidates so that they
// are not replaced in this pass.
// This should result in the candidates being found to be non-contiguous
// candidates in a later pass.
//
if (manager()->numPassesCompleted() < _maxPassNumber)
{
for (candidate = _candidates.getFirst(); candidate; candidate = next)
{
next = candidate->getNext();
if (!candidate->isLocalAllocation())
continue;
if (trace())
traceMsg(comp(), " 0 Look at [%p] must be %d\n", candidate->_node, candidate->mustBeContiguousAllocation());
if (candidate->mustBeContiguousAllocation() || !candidate->hasCallSites() ||
(candidate->_stringCopyNode && (candidate->_stringCopyNode != candidate->_node) &&
!candidate->escapesInColdBlocks() &&
!candidate->isLockedObject() &&
!candidate->_seenSelfStore &&
!candidate->_seenStoreToLocalObject))
continue;
if (trace())
traceMsg(comp(), " 0.5 Look at [%p]\n", candidate->_node);
// If any of the call sites for this parm is a guarded virtual call - there would be nothing
// gained by inlining any of them - we will still end up with a call and will have to make
// it contiguous
//
TR::TreeTop *callSite;
bool seenGuardedCall = false;
ListIterator<TR::TreeTop> it(candidate->getCallSites());
for (callSite = it.getFirst(); callSite; callSite = it.getNext())
{
TR::Node *callNode = callSite->getNode();
if (callNode->isTheVirtualCallNodeForAGuardedInlinedCall())
{
seenGuardedCall = true;
break;
}
}
if (trace())
traceMsg(comp(), " 1 Look at [%p]\n", candidate->_node);
// If any of the calls is a guarded virtual call or
// If the depth of inlining required is greater than the number of
// passes left, or if the number of bytecodes needed to be inlined
// will exceed the maximum, enough inlining can't be done.
// In this case force the candidate to be contiguous.
//
if (seenGuardedCall ||
candidate->_maxInlineDepth >= (_maxPassNumber-manager()->numPassesCompleted()) ||
candidate->_inlineBytecodeSize > (_maxInlinedBytecodeSize-getOptData()->_totalInlinedBytecodeSize))
{
candidate->setMustBeContiguousAllocation();
if (trace())
traceMsg(comp(), " Make [%p] contiguous because we can't inline enough\n", candidate->_node);
continue;
}
// Take each call site that needs to be inlined and add it to the
// list of inlined call sites
//
while ((callSite = candidate->getCallSites()->popHead()))
{
TR::Node *node = callSite->getNode();
if (node->getOpCode().isTreeTop())
node = node->getFirstChild();
//traceMsg(comp(), "For alloc node %p call site %p\n", candidate->_node, node);
//if (node->isTheVirtualCallNodeForAGuardedInlinedCall())
if (!_inlineCallSites.find(callSite))
{
if (comp()->getMethodHotness() <= warm)
{
// Up to warm, inlining at this point can interfere with existing
// profiling and compilation heuristics, causing us to miss even
// better inlining opportunities in subsequent hot and scorching
// compiles. Only inline selected methods where the benefit of
// profiling heuristics is outweighed by the cost of not inlining
// at warm.
//
// TODO: There must be a similar heuristic in the inliner for this
// sort of thing? They ought to share code.
//
switch (node->getSymbol()->castToMethodSymbol()->getRecognizedMethod())
{
case TR::java_lang_Object_init:
break;
default: