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LocalAnalysis.cpp
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LocalAnalysis.cpp
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/*******************************************************************************
* Copyright (c) 2000, 2021 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 http://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
*******************************************************************************/
#include "optimizer/LocalAnalysis.hpp"
#include <stdint.h>
#include <string.h>
#include "codegen/CodeGenerator.hpp"
#include "env/FrontEnd.hpp"
#include "compile/Compilation.hpp"
#include "compile/Method.hpp"
#include "compile/ResolvedMethod.hpp"
#include "compile/SymbolReferenceTable.hpp"
#include "cs2/bitvectr.h"
#include "env/TRMemory.hpp"
#include "env/jittypes.h"
#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/ResolvedMethodSymbol.hpp"
#include "il/Symbol.hpp"
#include "il/SymbolReference.hpp"
#include "il/TreeTop.hpp"
#include "il/TreeTop_inlines.hpp"
#include "infra/Assert.hpp"
#include "infra/BitVector.hpp"
#include "infra/Cfg.hpp"
#include "infra/List.hpp"
#include "infra/CfgEdge.hpp"
#include "optimizer/Optimizer.hpp"
#include "ras/Debug.hpp"
class TR_OpaqueClassBlock;
bool TR_LocalAnalysis::isSupportedNodeForFieldPrivatization(TR::Node *node, TR::Compilation *comp, TR::Node *parent)
{
// types of stores that may be supported by field privatization
bool isSupportedStoreNode =
node->getOpCode().isStore() && node->getOpCodeValue() != TR::astorei;
return isSupportedNode(node, comp, parent, isSupportedStoreNode);
}
bool TR_LocalAnalysis::isSupportedNode(TR::Node *node, TR::Compilation *comp, TR::Node *parent, bool isSupportedStoreNode)
{
return isSupportedNodeForFunctionality(node, comp, parent, isSupportedStoreNode) &&
isSupportedNodeForPREPerformance(node, comp, parent);
}
bool TR_LocalAnalysis::isSupportedNodeForPREPerformance(TR::Node *node, TR::Compilation *comp, TR::Node *parent)
{
TR::SymbolReference *symRef = node->getOpCode().hasSymbolReference()?node->getSymbolReference():NULL;
if (node->getOpCode().isStore() && symRef &&
symRef->getSymbol()->isAutoOrParm())
{
//dumpOptDetails("Returning false for store %p\n", node);
return false;
}
if (node->getOpCode().isLoadConst() && !comp->cg()->isMaterialized(node))
{
return false;
}
if (node->getOpCode().hasSymbolReference() &&
(node->getSymbolReference() == comp->getSymRefTab()->findJavaLangClassFromClassSymbolRef()))
{
return false;
}
return true;
}
bool TR_LocalAnalysis::isSupportedNodeForFunctionality(TR::Node *node, TR::Compilation *comp, TR::Node *parent, bool isSupportedStoreNode)
{
#if 0
// This needs to be tested more. The idea is to check parent when making PRE decision
if (node->getOpCode().isLoadConst() &&
(parent->getOpCode().isStore()))
return true;
#endif
if (parent &&
(parent->getOpCodeValue() == TR::Prefetch) &&
(node->getOpCodeValue() == TR::aloadi))
return false;
if (node->isThisPointer() && !node->isNonNull())
return false;
if ((node->getOpCodeValue() == TR::a2l) || (node->getOpCodeValue() == TR::a2i))
return false;
if (node->getOpCode().isSpineCheck() /* &&
node->getFirstChild()->getOpCode().isStore() */ )
return false;
if (comp->requiresSpineChecks() &&
node->getOpCode().hasSymbolReference() &&
node->getSymbol()->isArrayShadowSymbol())
return false;
if (node->getOpCode().isCall() &&
!node->getSymbolReference()->isUnresolved() &&
node->getSymbol()->castToMethodSymbol()->isPureFunction() &&
(node->getDataType() != TR::NoType))
return true;
if (node->getOpCode().hasSymbolReference() &&
(node->getSymbolReference()->isSideEffectInfo() ||
node->getSymbolReference()->isOverriddenBitAddress() ||
node->getSymbolReference()->isUnresolved()))
return false;
if (isSupportedOpCode(node->getOpCode(), comp) || isSupportedStoreNode || node->getOpCode().isLoadConst())
{
if (node->getDataType() == TR::Address)
{
if (!node->addressPointsAtObject())
return false;
}
return true;
}
return false;
}
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()));
}
TR_LocalAnalysis::TR_LocalAnalysis(TR_LocalAnalysisInfo &info, bool trace)
: _lainfo(info), _trace(trace)
{
_registersScarce = false; //comp()->cg()->areAssignableGPRsScarce();
}
void TR_LocalAnalysis::initializeLocalAnalysis(bool isSparse, bool lock)
{
_info = (TR_LocalAnalysisInfo::LAInfo*) trMemory()->allocateStackMemory(_lainfo._numBlocks*sizeof(TR_LocalAnalysisInfo::LAInfo));
memset(_info, 0, _lainfo._numBlocks*sizeof(TR_LocalAnalysisInfo::LAInfo));
TR::BitVector blocksSeen(comp()->allocator());
initializeBlocks(toBlock(comp()->getFlowGraph()->getStart()), blocksSeen);
int32_t i;
for (i = 0; i < _lainfo._numBlocks; i++)
{
_info[i]._analysisInfo = allocateContainer(getNumNodes());
_info[i]._downwardExposedAnalysisInfo = allocateContainer(getNumNodes());
_info[i]._downwardExposedStoreAnalysisInfo = allocateContainer(getNumNodes());
}
}
void TR_LocalAnalysis::initializeBlocks(TR::Block *block, TR::BitVector &blocksSeen)
{
_info[block->getNumber()]._block = block;
blocksSeen[block->getNumber()] = true;
TR::Block *next;
for (auto nextEdge = block->getSuccessors().begin(); nextEdge != block->getSuccessors().end(); ++nextEdge)
{
next = toBlock((*nextEdge)->getTo());
if (!blocksSeen.ValueAt(next->getNumber()))
initializeBlocks(next, blocksSeen);
}
for (auto nextEdge = block->getExceptionSuccessors().begin(); nextEdge != block->getExceptionSuccessors().end(); ++nextEdge)
{
next = toBlock((*nextEdge)->getTo());
if (!blocksSeen.ValueAt(next->getNumber()))
initializeBlocks(next, blocksSeen);
}
}
// Checks for syntactic equivalence and returns the side-table index
// of the syntactically equivalent node if it found one; else it returns
// -1 signifying that this is the first time any node similar syntactically
// to this node has been seen. Adds the node to the hash table if seen for the
// first time.
//
//
int TR_LocalAnalysisInfo::hasOldExpressionOnRhs(TR::Node *node, bool recalcContainsCall, bool storeLhsContainsCall)
{
//
// Get the relevant portion of the subtree
// for this node; this is different for a null check
// as its null check reference is the only
// sub-expression that matters
//
TR::Node *relevantSubtree = NULL;
if (node->getOpCodeValue() == TR::NULLCHK)
relevantSubtree = node->getNullCheckReference();
else
relevantSubtree = node;
// containsCall checks whether the relevant node has some
// sub-expression that cannot be commoned, e.g. call or a new
//
bool nodeContainsCall;
if (!recalcContainsCall && (relevantSubtree == node))
{
// can use pre-calculated value of containsCall and storeLhsContainsCall, to avoid visitCount overflow
nodeContainsCall = node->containsCall();
}
else
{
storeLhsContainsCall = false;
nodeContainsCall = containsCall(relevantSubtree, storeLhsContainsCall);
}
if (nodeContainsCall)
{
//
// If the node is not a store, a call-like sub-expression is inadmissable;
// if the node is a store, a call-like sub-expression is allowed on the RHS
// of the store as this does not inhibit privatization in any way as
// the private temp store's RHS simply points at original RHS. But if a call-like
// sub-expression is present in the LHS of the store, that is inadmissable
//
if (!node->getOpCode().isStore() ||
storeLhsContainsCall)
return 0;
}
bool seenIndirectStore = false;
#ifdef J9_PROJECT_SPECIFIC
bool seenIndirectBCDStore = false;
#endif
bool seenWriteBarrier = false;
int32_t storeNumChildren = node->getNumChildren();
// Need to save the node's isStoreIndirect flag before the node
// is recreated below. The recreation is done for convenience
// of syntactic comparison between loads and stores of the same field.
// Since a store node is transformed to a load, isStoreIndirect
// of the original store node will become false after the recreation.
bool isStoreIndirect = node->getOpCode().isStoreIndirect();
// If node is a null check, compare the
// null check reference only to establish syntactic equivalence
//
if (node->getOpCodeValue() == TR::NULLCHK)
/////if (node->getOpCode().isNullCheck())
{
int32_t k;
for (k=0;k<_numNullChecks;k++)
{
if (!(_nullCheckNodesAsArray[k] == NULL))
{
if (areSyntacticallyEquivalent(_nullCheckNodesAsArray[k]->getNullCheckReference(), node->getNullCheckReference()))
return _nullCheckNodesAsArray[k]->getLocalIndex();
}
}
_nullCheckNodesAsArray[_numNullChecks++] = node;
}
else
{
//
// If this node is a global store, then equivalence check is different.
// We try to give a store to field (or static) o.f the same index as
// a load of o.f. This is so that privatization happens for fields/statics.
// So the store's opcode value is changed temporarily to be a load before
// syntactic equivalence is checked; this enables matching stores/loads to
// same global symbol.
//
if (node->getOpCode().isStore() &&
!node->getSymbolReference()->getSymbol()->isAutoOrParm())
{
if (node->getOpCode().isWrtBar())
seenWriteBarrier = true;
#ifdef J9_PROJECT_SPECIFIC
seenIndirectBCDStore = node->getType().isBCD();
#endif
TR::Node::recreate(node, _compilation->il.opCodeForCorrespondingLoadOrStore(node->getOpCodeValue()));
if (isStoreIndirect)
{
node->setNumChildren(1);
}
else
{
node->setNumChildren(0);
}
#ifdef J9_PROJECT_SPECIFIC
if (seenIndirectBCDStore)
node->setBCDStoreIsTemporarilyALoad(true);
#endif
seenIndirectStore = true;
}
int32_t hashValue = _hashTable->hash(node);
HashTable::Cursor cursor(_hashTable, hashValue);
TR::Node *other;
bool isOtherStoreIndirect = false;
for (other = cursor.firstNode(); other; other = cursor.nextNode())
{
// Convert other node's opcode to be a load temporarily
// (only for syntactic equivalence check; see explanation above)
// to enable matching global stores/loads.
//
bool seenOtherIndirectStore = false;
#ifdef J9_PROJECT_SPECIFIC
bool seenOtherIndirectBCDStore = false;
#endif
bool seenOtherWriteBarrier = false;
int32_t otherStoreNumChildren = other->getNumChildren();
if (other->getOpCode().isStore() &&
!other->getSymbolReference()->getSymbol()->isAutoOrParm())
{
if (other->getOpCode().isWrtBar())
seenOtherWriteBarrier = true;
// Need to save the node's isStoreIndirect flag before the node
// is recreated below. The recreation is done for convenience
// of syntactic comparison between loads and stores of the same field.
// Since a store node is transformed to a load, isStoreIndirect
// of the original store node will become false after the recreation.
isOtherStoreIndirect = other->getOpCode().isStoreIndirect();
#ifdef J9_PROJECT_SPECIFIC
seenOtherIndirectBCDStore = other->getType().isBCD();
#endif
TR::Node::recreate(other, _compilation->il.opCodeForCorrespondingLoadOrStore(other->getOpCodeValue()));
if (isOtherStoreIndirect)
{
other->setNumChildren(1);
}
else
{
other->setNumChildren(0);
}
#ifdef J9_PROJECT_SPECIFIC
if (seenOtherIndirectBCDStore)
other->setBCDStoreIsTemporarilyALoad(true);
#endif
seenOtherIndirectStore = true;
}
bool areSame = areSyntacticallyEquivalent(node, other);
// Restore the other node's state to what it was originally
// (if it was a global store)
//
if (seenOtherWriteBarrier)
{
other->setNumChildren(otherStoreNumChildren);
if (otherStoreNumChildren == 3)
TR::Node::recreate(other, TR::awrtbari);
else
TR::Node::recreate(other, TR::awrtbar);
}
else if (seenOtherIndirectStore)
{
other->setNumChildren(otherStoreNumChildren);
#ifdef J9_PROJECT_SPECIFIC
if (seenOtherIndirectBCDStore)
other->setBCDStoreIsTemporarilyALoad(false);
#endif
TR::Node::recreate(other, _compilation->il.opCodeForCorrespondingLoadOrStore(other->getOpCodeValue()));
}
if (areSame)
{
if (seenWriteBarrier)
{
node->setNumChildren(storeNumChildren);
if (storeNumChildren == 3)
TR::Node::recreate(node, TR::awrtbari);
else
TR::Node::recreate(node, TR::awrtbar);
}
else if (seenIndirectStore)
{
node->setNumChildren(storeNumChildren);
#ifdef J9_PROJECT_SPECIFIC
if (seenIndirectBCDStore)
node->setBCDStoreIsTemporarilyALoad(false);
#endif
TR::Node::recreate(node, _compilation->il.opCodeForCorrespondingLoadOrStore(node->getOpCodeValue()));
}
return other->getLocalIndex();
}
}
// No match from existing nodes in the hash table;
// add this node to the hash table.
//
_hashTable->add(node, hashValue);
}
// Restore this node's state to what it was before
// (if it was a global store)
//
if (seenWriteBarrier)
{
node->setNumChildren(storeNumChildren);
if (storeNumChildren == 3)
TR::Node::recreate(node, TR::awrtbari);
else
TR::Node::recreate(node, TR::awrtbar);
}
else if (seenIndirectStore)
{
node->setNumChildren(storeNumChildren);
#ifdef J9_PROJECT_SPECIFIC
if (seenIndirectBCDStore)
node->setBCDStoreIsTemporarilyALoad(false);
#endif
TR::Node::recreate(node, _compilation->il.opCodeForCorrespondingLoadOrStore(node->getOpCodeValue()));
}
return -1;
}
bool TR_LocalAnalysisInfo::isCallLike(TR::Node *node) {
TR::ILOpCode &opCode = node->getOpCode();
TR::ILOpCodes opCodeValue = opCode.getOpCodeValue();
if ((opCode.isCall() && !node->isPureCall()) ||
opCodeValue == TR::New ||
opCodeValue == TR::newarray ||
opCodeValue == TR::anewarray ||
opCodeValue == TR::multianewarray)
return true;
//if (debug("preventUnresolvedPRE"))
{
if (node->hasUnresolvedSymbolReference())
return true;
}
if (node->getOpCode().hasSymbolReference())
{
if (node->getSymbolReference()->getSymbol()->isVolatile() ||
(node->getSymbolReference()->getSymbol()->isMethodMetaData() &&
!node->getSymbolReference()->getSymbol()->isImmutableField()))
return true;
if (node->getSymbolReference()->isSideEffectInfo() ||
node->getSymbolReference()->isOverriddenBitAddress())
return true;
if (node->isThisPointer() && !node->isNonNull())
return true;
if (comp()->requiresSpineChecks() &&
//node->getOpCode().hasSymbolReference() &&
node->getSymbol()->isArrayShadowSymbol())
{
//containsCallInStoreLhs = true;
return true;
}
// Note that this change is only needed because javaLangClassFromClass loads are being skipped for performance (see earlier code in this file) and
// we want to avoid strange side effects of a parent being commoned but a child is not a candidate for commoning.
//
if (node->getOpCode().hasSymbolReference() &&
(node->getSymbolReference() == comp()->getSymRefTab()->findJavaLangClassFromClassSymbolRef()))
{
return true;
}
}
return false;
}
// Check if this node contains a call or call-like opcode that
// cannot be moved (duplicated) by PRE
//
// This method iterates over the children of the call, so it needs a visit count mechanism
// to avoid processing nodes twice. However, the trees are already in a similar situation so
// the node visit counts must not be corrupted for those iterations.
// Simply incrementing for each use of containsCall will not work, for large programs the visit
// count will overflow.
// To get around this, we use two visit counts:
// if the old visit count is the current one, the new visit count is old visit count + 2
// otherwise, the new visit count is old visit count + 1
// At the end of processing the node tree is revisited and the visit counts reset to the old
// visit count or to zero.
// It is guaranteed that there is room for old visit count + 2, that is checked before all
// this starts.
//
bool TR_LocalAnalysisInfo::containsCall(TR::Node *node, bool &containsCallInStoreLhs)
{
bool result = containsCallInTree(node, containsCallInStoreLhs);
containsCallResetVisitCounts(node);
return result;
}
bool TR_LocalAnalysisInfo::containsCallInTree(TR::Node *node, bool &containsCallInStoreLhs)
{
vcount_t visitCount = node->getVisitCount();
if (visitCount == _visitCount+1 || visitCount == _visitCount+2)
return false;
if (visitCount == _visitCount)
visitCount = 2;
else
visitCount = 1;
node->setVisitCount(_visitCount + visitCount);
if (isCallLike(node))
return true;
int32_t i;
for (i = 0;i < node->getNumChildren();i++)
{
bool childHasCalls = containsCallInTree(node->getChild(i), containsCallInStoreLhs);
if (childHasCalls)
{
if (node->getOpCode().isStoreIndirect() &&
(i == 0))
containsCallInStoreLhs = true;
return true;
}
}
return false;
}
void TR_LocalAnalysisInfo::containsCallResetVisitCounts(TR::Node *node)
{
int32_t i;
i = node->getVisitCount();
if (i == _visitCount+2)
i = _visitCount;
else if (i == _visitCount+1)
i = 0;
else
return;
node->setVisitCount(i);
for (i = 0; i < node->getNumChildren(); i++)
containsCallResetVisitCounts(node->getChild(i));
}
//
// Returns true if the two subtrees are identical syntactically; only special case
// is TR::aiadd (or TR::aladd) which may not participate in PRE; expressions containing
// the TR::aiadd (or TR::aladd) are matched correctly though by the special case code.
//
bool TR_LocalAnalysisInfo::areSyntacticallyEquivalent(TR::Node *node1, TR::Node *node2)
{
if (!_optimizer->areNodesEquivalent(node1,node2))
return false;
if (!(node1->getNumChildren() == node2->getNumChildren()))
return false;
if (node1 == node2)
return true;
int32_t i;
for (i = 0;i < node1->getNumChildren();i++)
{
if (node1->getChild(i)->getLocalIndex() != node2->getChild(i)->getLocalIndex())
return false;
else
{
if (node1->getChild(i)->getLocalIndex() == MAX_SCOUNT)
{
if ((node1->getChild(i)->getOpCode().isLoadConst() || node1->getChild(i)->getOpCode().isLoadVarDirect()) && (node2->getChild(i)->getOpCode().isLoadConst() || node2->getChild(i)->getOpCode().isLoadVarDirect()))
{
if (!_optimizer->areNodesEquivalent(node1->getChild(i), node2->getChild(i)))
return false;
}
else if ((node1->getChild(i)->getOpCode().isArrayRef()) && (node2->getChild(i)->getOpCode().isArrayRef()))
{
for (int32_t j = 0;j < node1->getChild(i)->getNumChildren();j++)
{
TR::Node *grandChild1 = node1->getChild(i)->getChild(j);
TR::Node *grandChild2 = node2->getChild(i)->getChild(j);
if (grandChild1->getLocalIndex() != grandChild2->getLocalIndex())
return false;
else
{
if (grandChild1->getLocalIndex() == MAX_SCOUNT)
{
if ((grandChild1->getOpCode().isLoadConst() || grandChild1->getOpCode().isLoadVarDirect()) && (grandChild2->getOpCode().isLoadConst() || grandChild2->getOpCode().isLoadVarDirect()))
{
if (!_optimizer->areNodesEquivalent(grandChild1, grandChild2))
return false;
}
else
return false;
}
else if (grandChild1->getLocalIndex() == 0)
return false;
}
}
}
else
return false;
}
else if (node1->getChild(i)->getLocalIndex() == 0)
return false;
}
}
return true;
}
int32_t TR_LocalAnalysisInfo::HashTable::hash(TR::Node *node)
{
// Hash on the opcode and value numbers of the children
//
uint32_t h, g;
int32_t numChildren = node->getNumChildren();
h = (node->getOpCodeValue() << 4) + numChildren;
g = 0;
for (int32_t i = numChildren-1; i >= 0; i--)
{
TR::Node *child = node->getChild(i);
h <<= 4;
if (child->getOpCode().hasSymbolReference())
h += (int32_t)(intptr_t)child->getSymbolReference()->getSymbol();
else
h++;
g = h & 0xF0000000;
h ^= g >> 24;
}
return (h ^ g) % _numBuckets;
}
TR_LocalAnalysisInfo::HashTable::Cursor::Cursor(HashTable *table, int32_t bucket)
: _table(*table), _bucket(bucket), _chunk(table->_buckets[bucket]), _index(0)
{
}
TR::Node *TR_LocalAnalysisInfo::HashTable::Cursor::firstNode()
{
_chunk = _table._buckets[_bucket];
if (!_chunk) return NULL;
_index = 0;
return _chunk->_nodes[_index];
}
TR::Node *TR_LocalAnalysisInfo::HashTable::Cursor::nextNode()
{
while (_chunk)
{
if (_index < NODES_PER_CHUNK-1)
{
_index++;
TR::Node *node = _chunk->_nodes[_index];
if (node)
return node;
}
_chunk = _chunk->_next;
_index = -1;
}
return NULL;
}
// Counts nodes that involved in PRE that are not stores or checks.
// These nodes require temps.
//
bool TR_LocalAnalysisInfo::countSupportedNodes(TR::Node *node, TR::Node *parent, bool &containsCallInStoreLhs)
{
if (_visitCount == node->getVisitCount())
{
return false;
}
node->setVisitCount(_visitCount);
node->setContainsCall(false);
if (isCallLike(node))
{
node->setContainsCall(true);
// would return here
}
bool flag = false;
TR::ILOpCode &opCode = node->getOpCode();
int n = node->getNumChildren();
int32_t i;
for (i = 0; i < n; i++)
{
TR::Node *child = node->getChild(i);
bool childHasCallsInStoreLhs = false;
if (countSupportedNodes(child, node, childHasCallsInStoreLhs))
flag = true;
if (childHasCallsInStoreLhs)
containsCallInStoreLhs = true;
if (child->containsCall())
{
if (node->getOpCode().isStoreIndirect() && (i == 0))
containsCallInStoreLhs = true;
node->setContainsCall(true);
}
}
if (TR_LocalAnalysis::isSupportedNode(node, _compilation, parent))
{
int oldExpressionOnRhs = hasOldExpressionOnRhs(node, false, containsCallInStoreLhs);
if (oldExpressionOnRhs == -1)
{
if (trace())
{
traceMsg(comp(), "\nExpression #%d is : \n",_numNodes);
_compilation->getDebug()->print(_compilation->getOutFile(), node, 6, true);
}
flag = true;
node->setLocalIndex(_numNodes);
_numNodes++;
}
else
node->setLocalIndex(oldExpressionOnRhs);
}
else
node->setLocalIndex(-1);