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GlobalRegisterAllocator.cpp
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GlobalRegisterAllocator.cpp
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/*******************************************************************************
* Copyright IBM Corp. and others 2000
*
* 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] https://openjdk.org/legal/assembly-exception.html
*
* SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0-only WITH Classpath-exception-2.0 OR GPL-2.0-only WITH OpenJDK-assembly-exception-1.0
*******************************************************************************/
#include "optimizer/GlobalRegisterAllocator.hpp"
#include <stdint.h>
#include <string.h>
#include "codegen/CodeGenerator.hpp"
#include "env/FrontEnd.hpp"
#include "codegen/Machine.hpp"
#include "codegen/RegisterConstants.hpp"
#include "compile/Compilation.hpp"
#include "compile/SymbolReferenceTable.hpp"
#include "control/Options.hpp"
#include "control/Options_inlines.hpp"
#include "cs2/bitvectr.h"
#include "cs2/hashtab.h"
#include "cs2/sparsrbit.h"
#include "env/CompilerEnv.hpp"
#include "env/IO.hpp"
#include "env/ObjectModel.hpp"
#include "env/StackMemoryRegion.hpp"
#include "env/TRMemory.hpp"
#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/Node.hpp"
#include "il/Node_inlines.hpp"
#include "il/ParameterSymbol.hpp"
#include "il/RegisterMappedSymbol.hpp"
#include "il/ResolvedMethodSymbol.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/Link.hpp"
#include "infra/List.hpp"
#include "infra/CfgEdge.hpp"
#include "infra/CfgNode.hpp"
#include "optimizer/Optimization.hpp"
#include "optimizer/Optimization_inlines.hpp"
#include "optimizer/OptimizationManager.hpp"
#include "optimizer/Optimizations.hpp"
#include "optimizer/Optimizer.hpp"
#include "optimizer/RegisterCandidate.hpp"
#include "optimizer/Structure.hpp"
#include "optimizer/TransformUtil.hpp"
#include "optimizer/DataFlowAnalysis.hpp"
#include "optimizer/UseDefInfo.hpp"
#include "optimizer/GlobalRegister.hpp"
#include "optimizer/GlobalRegister_inlines.hpp"
#include "ras/Debug.hpp"
#define GRA_COMPLEXITY_LIMIT 1000000000
static bool isHot(TR::Compilation *comp) { return comp->getMethodHotness() >= hot || comp->getOption(TR_NotCompileTimeSensitive); }
#define HAVE_DIFFERENT_MSB_TO_LSB_OFFSETS(r1,r2) \
((((r1)->getHostByteOffset() + (r1)->getSize()) - ((r2)->getHostByteOffset() + (r2)->getSize())) != 0)
static bool dontAssignInColdBlocks(TR::Compilation *comp) { return comp->getMethodHotness() >= hot; }
#define keepAllStores false
//TODO:GRA: if we are going to have two versions of GRA one with Meta Data and one without then we can do someting here
// for different compilation level then we can have two version of this, one using CPIndex and one (i.e. with MetaData)
// using getReferenceNumber
#define GET_INDEX_FOR_CANDIDATE_FOR_SYMREF(S) (S)->getReferenceNumber()
#define CANDIDATE_FOR_SYMREF_SIZE (comp()->getSymRefCount()+1)
//static TR_BitVector *resetExits;
//static TR_BitVector *seenBlocks;
//static TR_BitVector *successorBits;
#define OPT_DETAILS "O^O GLOBAL REGISTER ASSIGNER: "
// For both switch/table instructions and igoto instructions, the
// same sort of processing has to be done for each successor block.
// These classes are meant to allow that work to be independent of
// the way that the successor blocks are actually identified.
class switchSuccessorIterator;
class SuccessorIterator
{
public:
virtual TR::Block *getFirstSuccessor() = 0;
virtual TR::Block *getNextSuccessor() = 0;
virtual switchSuccessorIterator *asSwitchSuccessor() { return NULL; }
};
class switchSuccessorIterator : public SuccessorIterator
{
public:
TR_ALLOC(TR_Memory::RegisterCandidates)
switchSuccessorIterator(TR::Node *node) : node_(node), i_(node_->getCaseIndexUpperBound()) { }
switchSuccessorIterator *asSwitchSuccessor() { return this; }
TR::Block *getFirstSuccessor() { i_ = node_->getCaseIndexUpperBound(); return getNextSuccessor(); }
TR::Block *getNextSuccessor()
{
for (i_ = (i_ > 0) ? i_ - 1 : 0;
i_ > 0 && !node_->getChild((int32_t)i_)->getOpCode().isCase();
--i_);
if (i_ == 0)
{
return NULL;
}
else
{
return node_->getChild((int32_t)i_)->getBranchDestination()->getNode()->getBlock();
}
}
TR::Node *getCaseNode()
{
TR_ASSERT(i_ > 0 && i_ < node_->getCaseIndexUpperBound(), "getCaseNode not called on valid successor");
return node_->getChild((int32_t)i_);
}
private:
TR::Node * node_;
intptr_t i_;
//TR::Compilation * comp_;
};
class multipleJumpSuccessorIterator : public SuccessorIterator
{
public:
TR_ALLOC(TR_Memory::RegisterCandidates)
multipleJumpSuccessorIterator(TR::Block * currBlock)
{
_list = &currBlock->getSuccessors();
_iterator = _list->begin();
}
TR::Block *getFirstSuccessor()
{
_iterator = _list->begin();
return getNextSuccessor_();
}
TR::Block *getNextSuccessor()
{
if (_iterator != _list->end())
++_iterator;
return getNextSuccessor_();
}
private:
TR::Block *getNextSuccessor_()
{
if (_iterator == _list->end())
return NULL;
else
return (*_iterator)->getTo()->asBlock();
}
TR::CFGEdgeList::iterator _iterator;
TR::CFGEdgeList* _list;
};
///////////////////////////////////////////////////////////////////
// TR_GlobalRegisterAllocator
///////////////////////////////////////////////////////////////////
TR_GlobalRegisterAllocator::TR_GlobalRegisterAllocator(TR::OptimizationManager *manager)
: TR::Optimization(manager),
_pairedSymbols(manager->trMemory()),
_newBlocks(manager->trMemory()),
_osrCatchSucc(NULL)
{}
void TR_GlobalRegisterAllocator::populateSymRefNodes(TR::Node *node, vcount_t visitCount)
{
if (node->getVisitCount() == visitCount)
return;
node->setVisitCount(visitCount);
if (node->getOpCode().hasSymbolReference())
_nodesForSymRefs[node->getSymbolReference()->getReferenceNumber()] = node;
for (int32_t i = 0; i < node->getNumChildren(); ++i)
{
TR::Node *child = node->getChild(i);
populateSymRefNodes(child, visitCount);
}
}
/**
* The cg considerTypeForGRA calls below are the functional tests (i.e. avoid BCD and some aggregates)
* The allocateFor checks are for tuning for scalability when running in limited GRA mode
*/
bool TR_GlobalRegisterAllocator::allocateForSymRef(TR::SymbolReference *symRef)
{
return true;
}
bool TR_GlobalRegisterAllocator::isSymRefAvailable(TR::SymbolReference *symRef)
{
if (!comp()->cg()->considerTypeForGRA(symRef))
return false;
return allocateForSymRef(symRef);
}
/**
* For the findLoops case consider the number of blocks too
*/
bool TR_GlobalRegisterAllocator::isSymRefAvailable(TR::SymbolReference *symRef, List<TR::Block> *blocksInLoop)
{
if (!comp()->cg()->considerTypeForGRA(symRef))
return false;
bool loopHasOneBlock = blocksInLoop && (blocksInLoop->getListHead()->getNextElement() == NULL);
return true;
}
bool TR_GlobalRegisterAllocator::allocateForType(TR::DataType dt)
{
return true;
}
bool TR_GlobalRegisterAllocator::isNodeAvailable(TR::Node *node)
{
if (!comp()->cg()->considerTypeForGRA(node))
return false;
return allocateForType(node->getDataType());
}
bool TR_GlobalRegisterAllocator::isTypeAvailable(TR::SymbolReference *symref)
{
if (!comp()->cg()->considerTypeForGRA(symref))
return false;
return allocateForType(symref->getSymbol()->getDataType());
}
void
TR_GlobalRegisterAllocator::visitNodeForDataType(TR::Node *node)
{
if(node->getVisitCount() >= comp()->getVisitCount())
return;
node->setVisitCount(comp()->getVisitCount());
//visit children
for(int32_t i = 0 ; i < node->getNumChildren() ; i++)
{
visitNodeForDataType(node->getChild(i));
}
if(!node->getOpCode().hasSymbolReference())
return;
if(node->getDataType() != node->getSymbol()->getDataType() && node->getSymbol()->getDataType() == TR::Aggregate)
{
comp()->cg()->addSymbolAndDataTypeToMap(node->getSymbol(),node->getDataType());
}
}
void
TR_GlobalRegisterAllocator::walkTreesAndCollectSymbolDataTypes()
{
comp()->incOrResetVisitCount();
for (TR::TreeTop * tt = comp()->getStartTree(); tt; tt = tt->getNextTreeTop())
{
visitNodeForDataType(tt->getNode());
}
}
int32_t
TR_GlobalRegisterAllocator::perform()
{
LexicalTimer t("TR_GlobalRegisterAllocator::perform", comp()->phaseTimer());
if (comp()->hasLargeNumberOfLoops())
{
return 0;
}
comp()->cg()->setGRACompleted(); // means "full GRA"
if (comp()->getOption(TR_MimicInterpreterFrameShape) && ((!comp()->getOption(TR_EnableOSR) && !comp()->getOption(TR_FSDGRA)) || comp()->getJittedMethodSymbol()->sharesStackSlots(comp())))
return 1;
if (comp()->isGPUCompilation())
return 1;
walkTreesAndCollectSymbolDataTypes();
comp()->getOptimizer()->setResetExitsGRA(0);
comp()->getOptimizer()->setSeenBlocksGRA(0);
comp()->getOptimizer()->setSuccessorBitsGRA(0);
bool globalFPAssignmentDone = false;
_appendBlock = 0;
TR::CFG * cfg = comp()->getFlowGraph();
TR::Block * *cfgBlocks = cfg->createArrayOfBlocks();
int32_t numberOfBlocks = cfg->getNextNodeNumber();
TR::RegisterCandidates * candidates = comp()->getGlobalRegisterCandidates();
candidates->initCandidateForSymRefs();
TR::RegisterCandidate *rc = candidates->getFirst();
for (; rc ; rc = rc->getNext())
candidates->setCandidateForSymRefs(GET_INDEX_FOR_CANDIDATE_FOR_SYMREF(rc->getSymbolReference()), rc);
candidates->initStartOfExtendedBBForBB();
TR::Block * lastStartOfExtendedBB = comp()->getStartBlock();
for (TR::Block * b = lastStartOfExtendedBB; b; b = b->getNextBlock())
{
lastStartOfExtendedBB = b->isExtensionOfPreviousBlock() ? lastStartOfExtendedBB : b;
candidates->setStartOfExtendedBBForBB(b->getNumber(), lastStartOfExtendedBB);
}
comp()->getOptimizer()->setCachedExtendedBBInfoValid(true);
if (cg()->getSupportsGlRegDeps() && !debug("disableGRA") && cg()->prepareForGRA())
{
static char *useFreqs = feGetEnv("TR_GRA_UseProfilingFrequencies");
if (useFreqs)
comp()->setUsesBlockFrequencyInGRA();
TR_BitVector *liveVars = NULL;
if (!cg()->getLiveLocals())
{
int32_t numLocals = 0;
TR::AutomaticSymbol *a;
ListIterator<TR::AutomaticSymbol> locals(&comp()->getMethodSymbol()->getAutomaticList());
for (a = locals.getFirst(); a != NULL; a = locals.getNext())
++numLocals;
ListIterator<TR::ParameterSymbol> parms(&comp()->getMethodSymbol()->getParameterList());
for (TR::ParameterSymbol *p = parms.getFirst(); p != NULL; p = parms.getNext())
++numLocals;
const uint64_t MAX_BITVECTOR_MEMORY_USAGE = 1000000000;
uint64_t bitvectorMemoryUsage = numLocals * comp()->getFlowGraph()->getNextNodeNumber();
if (
numLocals > 0 && (!trace() || performTransformation(comp(), "%s Performing liveness for Global Register Allocator\n", OPT_DETAILS)))
{
// Perform liveness analysis
//
TR_Liveness liveLocals(comp(), optimizer(), comp()->getFlowGraph()->getStructure(), false, NULL, false, true);
liveLocals.perform(comp()->getFlowGraph()->getStructure());
if (comp()->getVisitCount() > HIGH_VISIT_COUNT)
{
comp()->resetVisitCounts(1);
}
for (TR::CFGNode *cfgNode = comp()->getFlowGraph()->getFirstNode(); cfgNode; cfgNode = cfgNode->getNext())
{
TR::Block *block = toBlock(cfgNode);
int32_t blockNum = block->getNumber();
if (blockNum > 0 && liveLocals._blockAnalysisInfo[blockNum])
{
liveVars = new (trHeapMemory()) TR_BitVector(numLocals, trMemory());
*liveVars = *liveLocals._blockAnalysisInfo[blockNum];
block->setLiveLocals(liveVars);
}
}
// Make sure the code generator knows there are live locals for blocks, and
// create a bit vector of the correct size for it.
//
liveVars = new (trHeapMemory()) TR_BitVector(numLocals, trMemory());
cg()->setLiveLocals(liveVars);
}
}
if (trace())
comp()->dumpMethodTrees("Trees before tactical global register allocator", comp()->getMethodSymbol());
_candidatesNeedingSignExtension = NULL;
_candidatesSignExtendedInThisLoop = NULL;
_temp = NULL;
_origSymRefCount = comp()->getSymRefCount();
_temp2 = new (trStackMemory()) TR_BitVector(_origSymRefCount, trMemory(), stackAlloc);
if (comp()->target().is64Bit() &&
optimizer()->getUseDefInfo())
{
_temp = new (trStackMemory()) TR_BitVector(optimizer()->getUseDefInfo()->getNumDefNodes(), trMemory(), stackAlloc);
_candidatesNeedingSignExtension = new (trStackMemory()) TR_BitVector(_origSymRefCount, trMemory(), stackAlloc);
_candidatesSignExtendedInThisLoop = new (trStackMemory()) TR_BitVector(_origSymRefCount, trMemory(), stackAlloc);
}
candidates->getReferencedAutoSymRefs(comp()->trMemory()->currentStackRegion());
static const char *skipit = feGetEnv("TR_SkipOfferAllGRA");
if (NULL == skipit)
{
offerAllAutosAndRegisterParmAsCandidates(cfgBlocks, numberOfBlocks);
}
_registerCandidates = new (trStackMemory()) SymRefCandidateMap((SymRefCandidateMapComparator()), SymRefCandidateMapAllocator(trMemory()->currentStackRegion()));
_candidates = comp()->getGlobalRegisterCandidates();
for (TR::RegisterCandidate * rc = _candidates->getFirst(); rc; rc = rc->getNext())
{
(*_registerCandidates)[rc->getSymbolReference()->getReferenceNumber()] = rc;
}
if (comp()->getOptions()->realTimeGC() &&
comp()->compilationShouldBeInterrupted(GRA_AFTER_FIND_LOOP_AUTO_CONTEXT))
{
comp()->failCompilation<TR::CompilationInterrupted>("interrupted during GRA");
}
bool canAffordAssignment = true;
if (!comp()->getOption(TR_ProcessHugeMethods))
{
int32_t numCands = 0;
for (TR::RegisterCandidate * rc = _candidates->getFirst(); rc; rc = rc->getNext())
numCands++;
int32_t hotnessFactor = 1;
if (comp()->getMethodHotness() >= scorching)
hotnessFactor = 4;
else if (comp()->getMethodHotness() >= hot)
hotnessFactor = 2;
// Use double here so we don't need to worry about overflow
//
double complexityEstimate = comp()->getFlowGraph()->getNumberOfNodes() * (double)numCands * numCands;
if (complexityEstimate / hotnessFactor > (double)GRA_COMPLEXITY_LIMIT)
canAffordAssignment = false;
}
_valueModifiedSymRefs = new (trStackMemory()) TR_BitVector(_origSymRefCount, trMemory(), stackAlloc);
TR_BitVector splitSymRefs(_origSymRefCount, trMemory(), stackAlloc);
TR_BitVector nonSplittingCopyStored(_origSymRefCount, trMemory(), stackAlloc);
//
// Assign registers to candidates
//
if (canAffordAssignment)
{
globalFPAssignmentDone = _candidates->assign(cfgBlocks, numberOfBlocks, _firstGlobalRegisterNumber, _lastGlobalRegisterNumber);
if (_lastGlobalRegisterNumber > -1)
{
_visitCount = comp()->incVisitCount();
_signExtAdjustmentReqd = new (trStackMemory()) TR_BitVector(_lastGlobalRegisterNumber+1, trMemory(), stackAlloc);
_signExtAdjustmentNotReqd = new (trStackMemory()) TR_BitVector(_lastGlobalRegisterNumber+1, trMemory(), stackAlloc);
_signExtDifference = new (trStackMemory()) TR_BitVector(_lastGlobalRegisterNumber+1, trMemory(), stackAlloc);
//
// Transform IL
//
for (TR::TreeTop * tt = comp()->getStartTree(); tt; tt = tt->getExtendedBlockExitTreeTop()->getNextTreeTop())
transformBlock(tt);
}
bool mayHaveDeadStore = false;
for (TR::RegisterCandidate * rc = _candidates->getFirst(); rc; rc = rc->getNext())
{
(*_registerCandidates)[rc->getSymbolReference()->getReferenceNumber()] = rc;
TR::SymbolReference *splitSymRef = rc->getSplitSymbolReference();
if (splitSymRef)
{
splitSymRefs.set(splitSymRef->getReferenceNumber());
}
ListIterator<TR::TreeTop> stores(&rc->getStores());
TR::TreeTop * store = stores.getFirst();
if (!rc->getValueModified())
for (; store; store = stores.getNext())
{
TR::TransformUtil::removeTree(comp(), store);
}
else
{
_valueModifiedSymRefs->set(rc->getSymbolReference()->getReferenceNumber());
if (store)
mayHaveDeadStore = true;
}
}
if (mayHaveDeadStore)
{
requestOpt(OMR::isolatedStoreGroup);
requestOpt(OMR::globalDeadStoreElimination);
}
// Post processing to remove redundant stores for live-range splitting.
//
if (!splitSymRefs.isEmpty())
{
bool trace = comp()->getOptions()->trace(OMR::tacticalGlobalRegisterAllocator);
// If a candidate is modified, and it has a restoreSymbolReference,
// then that one will be modified too (by the "restore" instruction
// after the loop). Hence, we propagage the modified info out of
// every level of the loop nest.
//
for (TR::RegisterCandidate * rc = _candidates->getFirst(); rc; rc = rc->getNext())
{
TR::SymbolReference *outerSymRef = rc->getRestoreSymbolReference();
while (outerSymRef)
{
TR::RegisterCandidate *outerRc = (*_registerCandidates)[outerSymRef->getReferenceNumber()];
if (!outerRc)
break;
if (_valueModifiedSymRefs->get(rc->getSymbolReference()->getReferenceNumber()))
_valueModifiedSymRefs->set(outerRc->getSymbolReference()->getReferenceNumber());
if (outerSymRef == rc->getSplitSymbolReference())
break;
outerSymRef = outerRc->getRestoreSymbolReference();
}
}
// Propagate the information about 'valueModified'.
// 'valueModified' flag is not set at the stores (copies) for live-range splitting.
// If source and destination locals of a copy receive registers, in other words, a register-register copy exists,
// and a value is modified in one of locals, another local must be indentified as 'valueModified'.
//
if (trace)
traceMsg(comp(), "\nPropagating value modified information\n");
List<TR::TreeTop> storesFromRegisters(trMemory());
TR::TreeTop *tt = NULL, *nextTreeTop = NULL;
for (tt = comp()->getStartTree(); tt; tt = tt->getNextTreeTop())
{
TR::Node *node = tt->getNode();
if (!node->getOpCode().isStore() &&
(node->getNumChildren() > 0))
node = node->getFirstChild();
if (isSplittingCopy(tt->getNode()))
{
TR::Node *store = tt->getNode(), *load = tt->getNode()->getFirstChild();
if (store->getOpCode().isStoreDirect() && load->getOpCode().isLoadReg()
&& !(*_registerCandidates)[store->getSymbolReference()->getReferenceNumber()]->extendedLiveRange())
{
storesFromRegisters.add(tt);
}
}
else if (node->getOpCode().isStoreDirect() && node->getSymbolReference()->getSymbol()->isAutoOrParm())
nonSplittingCopyStored.set(node->getSymbolReference()->getReferenceNumber());
}
// Restore original symbols. This can reduce the size of the stack area.
// In addition, dead store elimination can remove redundant stores (copies)
// where both of operands (source and destination) do not receive any register.
//
if (performTransformation(comp(), "%s Restoring original symbols from live range splitter\n", OPT_DETAILS))
{
vcount_t visitCount = comp()->incVisitCount();
for (tt = comp()->getStartTree(); tt; tt = tt->getNextTreeTop())
restoreOriginalSymbol(tt->getNode(), visitCount);
}
// Remove a store generated at the end of the live range when a value is not modified in the live range.
// If a value is not modified in a local which receives a register, the stores from the register is redundant.
//
if (trace)
traceMsg(comp(), "\nRemoving redundant stores\n");
ListIterator<TR::TreeTop> itr(&storesFromRegisters);
for (tt = itr.getFirst(); tt; tt = itr.getNext())
{
if (!_valueModifiedSymRefs->isSet(tt->getNode()->getFirstChild()->getRegLoadStoreSymbolReference()->getReferenceNumber()) &&
!nonSplittingCopyStored.isSet(tt->getNode()->getFirstChild()->getRegLoadStoreSymbolReference()->getReferenceNumber()))
{
if (trace) traceMsg(comp(), "Remove a redundant store %p\n", tt->getNode());
TR::TransformUtil::removeTree(comp(), tt);
}
}
}
}
}
cg()->setLiveLocals(NULL);
optimizer()->setUseDefInfo(NULL);
optimizer()->setValueNumberInfo(NULL);
TR::Block * block = comp()->getStartTree()->getNode()->getBlock();
for (; block; block = block->getNextBlock())
block->clearGlobalRegisters();
candidates->releaseCandidates();
return 1; // actual cost
}
bool
TR_GlobalRegisterAllocator::isSplittingCopy(TR::Node *node)
{
bool trace = comp()->getOptions()->trace(OMR::tacticalGlobalRegisterAllocator);
// Check whether or not this store is a copy for live-range splitting
if ((node->getOpCode().isStoreDirect() || node->getOpCode().isStoreReg()) &&
(node->getFirstChild()->getOpCode().isLoadVarDirect() || node->getFirstChild()->getOpCode().isLoadReg()))
{
if (trace) traceMsg(comp(), "Finding a copy at node %p\n", node);
TR::SymbolReference *storeSymRef = node->getSymbolReferenceOfAnyType();
TR::SymbolReference *loadSymRef = node->getFirstChild()->getSymbolReferenceOfAnyType();
if (storeSymRef && loadSymRef && storeSymRef != loadSymRef)
{
TR::RegisterCandidate *storeRc = (*_registerCandidates)[storeSymRef->getReferenceNumber()];
TR::RegisterCandidate *loadRc = (*_registerCandidates)[loadSymRef->getReferenceNumber()];
TR::SymbolReference *origStoreSymRef = storeRc ? storeRc->getSplitSymbolReference() : NULL;
TR::SymbolReference *origLoadSymRef = loadRc ? loadRc->getSplitSymbolReference() : NULL;
if ((origStoreSymRef && origLoadSymRef && origStoreSymRef == origLoadSymRef) ||
(origStoreSymRef && !origLoadSymRef && origStoreSymRef == loadSymRef) ||
(!origStoreSymRef && origLoadSymRef && storeSymRef == origLoadSymRef))
{
//if (trace) traceMsg(comp(), "Found a copy %p\n", node);
return true;
}
}
}
return false;
}
void
TR_GlobalRegisterAllocator::restoreOriginalSymbol(TR::Node *node, vcount_t visitCount)
{
if (node->getVisitCount() == visitCount)
return;
node->setVisitCount(visitCount);
for (int32_t i = 0; i < node->getNumChildren(); i++)
restoreOriginalSymbol(node->getChild(i), visitCount);
bool trace = comp()->getOptions()->trace(OMR::tacticalGlobalRegisterAllocator);
if (node->getOpCode().hasSymbolReference() || node->getOpCode().isLoadReg() || node->getOpCode().isStoreReg())
{
if (node->getSymbolReferenceOfAnyType())
{
int32_t symRefNum = node->getSymbolReferenceOfAnyType()->getReferenceNumber();
TR::RegisterCandidate *rc = (*_registerCandidates)[symRefNum];
TR::SymbolReference *origSymRef = rc ? rc->getRestoreSymbolReference() : NULL;
bool foundChangeSymRef = false;
bool setValueModified = false;
TR::SymbolReference *changeSymRef = rc ? rc->getSplitSymbolReference() : NULL;
while (origSymRef &&
(origSymRef != rc->getSplitSymbolReference()))
{
TR::RegisterCandidate *origRc = (*_registerCandidates)[origSymRef->getReferenceNumber()];
if (setValueModified)
_valueModifiedSymRefs->set(origRc->getSymbolReference()->getReferenceNumber());
if (!origRc ||
origRc->getValueModified() ||
origRc->extendedLiveRange())
{
if (!foundChangeSymRef)
{
if (origRc &&
!origRc->getValueModified() &&
origRc->getRestoreSymbolReference())
{
_valueModifiedSymRefs->set(origRc->getSymbolReference()->getReferenceNumber());
setValueModified = true;
}
foundChangeSymRef = true;
changeSymRef = origSymRef;
}
}
origSymRef = origRc->getRestoreSymbolReference();
}
TR::RegisterCandidate *oldRc = origSymRef ? (*_registerCandidates)[origSymRef->getReferenceNumber()] : 0;
if (oldRc && oldRc->extendedLiveRange())
{
_valueModifiedSymRefs->set(oldRc->getSymbolReference()->getReferenceNumber());
changeSymRef = NULL;
}
if (rc && !rc->extendedLiveRange() && changeSymRef)
{
if (trace) traceMsg(comp(), "Restore an original symbol #%d from #%d at %p\n", changeSymRef->getReferenceNumber(), symRefNum, node);
if(node->getOpCode().isLoadReg() || node->getOpCode().isStoreReg())
node->setRegLoadStoreSymbolReference(changeSymRef);
else
node->setSymbolReference(changeSymRef);
}
else
_valueModifiedSymRefs->set(symRefNum);
}
else if (trace)
traceMsg(comp(), "Node %p has no symbol\n", node);
}
}
/**
* Transforms extended block
* @param tt Is a bbStart
*/
void
TR_GlobalRegisterAllocator::transformBlock(TR::TreeTop * tt)
{
TR::Node * bbStart = tt->getNode();
TR::Block * block = bbStart->getBlock();
TR::Block * origBlock = block;
// Find out if there are any symbols that are in registers on entry and/or exit
//
TR_Array<TR::GlobalRegister> & registers = block->getGlobalRegisters(comp());
bool found = false;
int32_t i;
for (i = _firstGlobalRegisterNumber; i <= _lastGlobalRegisterNumber; ++i)
{
TR::Block * b = block;
while (b)
{
TR_Array<TR::GlobalRegister> & curRegisters = b->getGlobalRegisters(comp());
if (curRegisters[i].getRegisterCandidateOnEntry())
found = true;
if (curRegisters[i].getRegisterCandidateOnExit())
found = true;
b = b->getNextBlock();
if (b && !b->isExtensionOfPreviousBlock())
break;
}
}
if (!found)
{
bbStart->setVisitCount(_visitCount);
return;
}
_newBlocks.deleteAll();
_signExtAdjustmentReqd->empty();
_signExtAdjustmentNotReqd->empty();
_signExtDifference->empty();
//
// Walk the tree changing all load/stores of register candidates to RegLoads and RegStores.
// Also add RegLoads at branch points for registers live across the branch.
//
_storesInBlockInfo.setFirst(0);
TR::Node * node = tt->getNode();
TR_Array<TR::GlobalRegister> * curRegisters = NULL;
TR_NodeMappings extBlockNodeMapping;
do
{
if (node->getOpCodeValue() == TR::BBStart)
{
block = node->getBlock();
curRegisters = &block->getGlobalRegisters(comp());
// Mark all symbols that are in registers on entry and/or exit to this BB
//
for (i = _firstGlobalRegisterNumber; i <= _lastGlobalRegisterNumber; ++i)
{
if ((*curRegisters)[i].getRegisterCandidateOnEntry())
{
(*curRegisters)[i].getRegisterCandidateOnEntry()->getSymbolReference()->getSymbol()->setIsInGlobalRegister(true);
}
if ((*curRegisters)[i].getRegisterCandidateOnExit())
{
(*curRegisters)[i].getRegisterCandidateOnExit()->getSymbolReference()->getSymbol()->setIsInGlobalRegister(true);
}
}
}
else if (node->getOpCodeValue() == TR::BBEnd)
{
block = node->getBlock();
curRegisters = &block->getGlobalRegisters(comp());
// Reset all tagged symbols for this BB
//
for (i = _firstGlobalRegisterNumber; i <= _lastGlobalRegisterNumber; ++i)
{
if ((*curRegisters)[i].getRegisterCandidateOnEntry())
{
(*curRegisters)[i].getRegisterCandidateOnEntry()->getSymbolReference()->getSymbol()->setIsInGlobalRegister(false);
}
if ((*curRegisters)[i].getRegisterCandidateOnExit())
{
(*curRegisters)[i].getRegisterCandidateOnExit()->getSymbolReference()->getSymbol()->setIsInGlobalRegister(false);
}
}
}
transformNode(node, 0, 0, tt, block, *curRegisters, &extBlockNodeMapping);
}
while ((tt = tt->getNextTreeTop()) &&
(node = tt->getNode(), node->getOpCodeValue() != TR::BBStart || node->getBlock()->isExtensionOfPreviousBlock()));
*_signExtDifference = *_signExtAdjustmentNotReqd;
*_signExtDifference &= *_signExtAdjustmentReqd;
if (!_signExtDifference->isEmpty())
{
tt = origBlock->getEntry();
node = tt->getNode();
do
{
if (node->getOpCodeValue() == TR::treetop)
node = node->getFirstChild();
if (node->getOpCodeValue() == TR::iRegStore)
{
if (_signExtDifference->get(node->getGlobalRegisterNumber()))
node->setNeedsSignExtension(true);
}
}
while ((tt = tt->getNextTreeTop()) &&
(node = tt->getNode(), node->getOpCodeValue() != TR::BBStart || node->getBlock()->isExtensionOfPreviousBlock()));
}
if (block == _appendBlock)
_appendBlock = NULL;
}
TR::Node *
TR_GlobalRegisterAllocator::resolveTypeMismatch(TR::DataType oldType, TR::Node *newNode)
{
return resolveTypeMismatch(oldType, NULL, newNode);
}
TR::Node *
TR_GlobalRegisterAllocator::resolveTypeMismatch(TR::Node *oldNode, TR::Node *newNode)
{
return resolveTypeMismatch(TR::NoType, oldNode, newNode);
}
TR::Node *
TR_GlobalRegisterAllocator::resolveTypeMismatch(TR::DataType inputOldType, TR::Node *oldNode, TR::Node *newNode)
{
return newNode;
}
static void setAutoContainsRegisterValue(TR::RegisterCandidate *rc, TR_Array<TR::GlobalRegister> * extRegisters, int32_t i, TR::Compilation *comp)
{
bool needs2Regs = false;
if (rc->rcNeeds2Regs(comp))
needs2Regs = true;
(*extRegisters)[i].setAutoContainsRegisterValue(true);
if (needs2Regs)
{
int32_t highRegNum = rc->getHighGlobalRegisterNumber();
if (i == highRegNum)
{
int32_t lowRegNum = rc->getLowGlobalRegisterNumber();
(*extRegisters)[lowRegNum].setAutoContainsRegisterValue(true);
}
else
{
(*extRegisters)[highRegNum].setAutoContainsRegisterValue(true);
}
}
}
void
TR_GlobalRegisterAllocator::transformNode(
TR::Node * node, TR::Node * parent, int32_t childIndex, TR::TreeTop * tt, TR::Block * & block, TR_Array<TR::GlobalRegister> & registers, TR_NodeMappings *extBlockNodeMapping)
{
TR_ASSERT(comp()->getOptimizer()->cachedExtendedBBInfoValid(), "Incorrect value in _startOfExtendedBBForBB");
TR_Array<TR::GlobalRegister> * extRegisters = &(_candidates->getStartOfExtendedBBForBB()[block->getNumber()]->getGlobalRegisters(comp()));
if (node->getVisitCount() == _visitCount)
return;
node->setVisitCount(_visitCount);
TR::Node* origStoreToMetaData = NULL;
TR::Node* origLoadFromMetaData = NULL;
TR::TreeTop* origLoadFromMetaDataPrevTT = NULL;
TR::ILOpCode opcode = node->getOpCode();
if (opcode.getOpCodeValue() == TR::table) // (opcode.isSwitch() && debug("putGlRegDepOnSwitch"))
{
transformNode(node->getFirstChild(), node, 0, tt, block, registers, extBlockNodeMapping);
transformMultiWayBranch(tt, node, block, registers);
return;
}
int32_t i;
for (i = 0; i < node->getNumChildren(); ++i)
transformNode(node->getChild(i), node, i, tt, block, registers, extBlockNodeMapping);
bool transformDone = false;
if (node->getOpCode().isJumpWithMultipleTargets() && !node->getOpCode().isSwitch() && node->getOpCodeValue() != TR::tstart)
transformMultiWayBranch(tt, node, block, registers, transformDone);
else if (opcode.isBranch())
{
transformBlockExit(tt, node, block, registers, node->getBranchDestination()->getNode()->getBlock());
}
else if (opcode.getOpCodeValue() == TR::BBStart)
{
block = node->getBlock();
addCandidateReloadsToEntry(tt, *extRegisters, block);
if (!block->isExtensionOfPreviousBlock())
addRegLoadsToEntry(tt, registers, block);
_osrCatchSucc = NULL;
addStoresForCatchBlockLoads(tt, *extRegisters, block);
}
else if (opcode.getOpCodeValue() == TR::BBEnd)
{
TR::TreeTop * nextTT = tt->getNextTreeTop();
TR::TreeTop * prevTT = tt->getPrevRealTreeTop();
TR::Block * nextBlock = nextTT ? nextTT->getNode()->getBlock() : 0;
while (prevTT && prevTT->getNode()->getOpCode().isStoreReg())
prevTT = prevTT->getPrevTreeTop();
TR::Node *ttNode = prevTT->getNode();
if(ttNode->getOpCodeValue() == TR::treetop)
ttNode = ttNode->getFirstChild();
if (nextBlock && !nextBlock->isExtensionOfPreviousBlock() && block->hasSuccessor(nextBlock) && !ttNode->getOpCode().isJumpWithMultipleTargets() )
{
transformBlockExit(tt, node, block, registers, nextBlock);
}
}
else if (opcode.isLoadVar() && isNodeAvailable(node))
{
TR::Symbol * symbol = node->getSymbolReference()->getSymbol();
bool changeNode = true;
TR::Node * value = NULL;
TR::GlobalRegister *gr = NULL;
//traceMsg(comp(), "Node %p symbol %p tag %d\n", node, symbol, symbol->isInGlobalRegister());
changeNode = false;
value = extBlockNodeMapping->getTo(node);
if (value)
{
changeNode = true;
}
else if (symbol->isInGlobalRegister())
{
gr = getGlobalRegister(symbol, registers, block);
if (gr)
changeNode = true; // symbol is will be put into register right before exit
}
else
{
TR::GlobalRegister *ptrToGr = getGlobalRegisterWithoutChangingCurrentCandidate(symbol, registers, block);
if (ptrToGr)
{
TR::RegisterCandidate * rc = ptrToGr->getCurrentRegisterCandidate();
if (rc && (rc->getSymbolReference()->getSymbol() == symbol))
{
if (ptrToGr->getValue() &&
!ptrToGr->getAutoContainsRegisterValue())
ptrToGr->createStoreFromRegister(comp()->getVisitCount(), tt->getPrevTreeTop(), 1, comp(), true);
ptrToGr->setAutoContainsRegisterValue(true);
ptrToGr->setValue(0);
bool needs2Regs = false;
if (ptrToGr->getCurrentRegisterCandidate() &&
ptrToGr->getCurrentRegisterCandidate()->rcNeeds2Regs(comp()))
needs2Regs = true;