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OMRMachine.cpp
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OMRMachine.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 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 "p/codegen/OMRMachine.hpp"
#include <stdint.h>
#include <string.h>
#include <algorithm>
#include "codegen/BackingStore.hpp"
#include "codegen/CodeGenerator.hpp"
#include "env/FrontEnd.hpp"
#include "codegen/InstOpCode.hpp"
#include "codegen/Instruction.hpp"
#include "codegen/Linkage.hpp"
#include "codegen/Linkage_inlines.hpp"
#include "codegen/LiveRegister.hpp"
#include "codegen/Machine.hpp"
#include "codegen/Machine_inlines.hpp"
#include "codegen/MemoryReference.hpp"
#include "codegen/RealRegister.hpp"
#include "codegen/Register.hpp"
#include "codegen/RegisterConstants.hpp"
#include "codegen/RegisterDependency.hpp"
#include "compile/Compilation.hpp"
#include "control/Options.hpp"
#include "control/Options_inlines.hpp"
#include "env/ObjectModel.hpp"
#include "env/Processors.hpp"
#include "env/TRMemory.hpp"
#include "il/Block.hpp"
#include "il/ILOpCodes.hpp"
#include "il/LabelSymbol.hpp"
#include "il/Node.hpp"
#include "il/Symbol.hpp"
#include "il/SymbolReference.hpp"
#include "infra/Assert.hpp"
#include "infra/BitVector.hpp"
#include "infra/List.hpp"
#include "p/codegen/GenerateInstructions.hpp"
#include "p/codegen/PPCCRBackingStore.hpp"
#include "p/codegen/PPCInstruction.hpp"
#include "p/codegen/PPCOpsDefines.hpp"
#include "ras/Debug.hpp"
#include "env/IO.hpp"
namespace TR { class AutomaticSymbol; }
static void registerExchange(TR::Instruction *precedingI,
TR_RegisterKinds rk,
TR::RealRegister *tReg,
TR::RealRegister *sReg,
TR::RealRegister *mReg,
TR::CodeGenerator *cg);
static void registerCopy(TR::Instruction *precedingI,
TR_RegisterKinds rk,
TR::RealRegister *tReg,
TR::RealRegister *sReg,
TR::CodeGenerator *cg);
static int32_t spillSizeForRegister(TR::Register *virtReg)
{
switch (virtReg->getKind())
{
case TR_GPR:
return TR::Compiler->om.sizeofReferenceAddress();
case TR_FPR:
return virtReg->isSinglePrecision() ? 4 : 8;
case TR_VSX_SCALAR:
return 8;
case TR_CCR:
return 4;
case TR_VSX_VECTOR:
case TR_VRF:
return 16;
}
TR_ASSERT(false, "Unexpected register kind");
return 0;
}
static const char *
getRegisterName(TR::Register * reg, TR::CodeGenerator * cg)
{
return (reg? cg->getDebug()->getName(reg) : "NULL");
}
static bool boundNext(TR::Instruction *currentInstruction, int32_t realNum, TR::Register *virtReg, bool isOOL)
{
TR::Instruction *cursor = currentInstruction;
TR::RealRegister::RegNum realReg = (TR::RealRegister::RegNum)realNum;
TR::Node *nodeBBStart = NULL;
while (!(isOOL && cursor == NULL) && cursor->getOpCodeValue() != TR::InstOpCode::proc)
{
TR::RegisterDependencyConditions *conditions;
if ((conditions = cursor->getDependencyConditions()) != NULL)
{
TR::Register *boundReg = conditions->searchPostConditionRegister(realReg);
if (boundReg == NULL)
boundReg = conditions->searchPreConditionRegister(realReg);
if (boundReg != NULL)
{
if (boundReg == virtReg)
return true;
return false;
}
}
TR::Node *node = cursor->getNode();
if (nodeBBStart!=NULL && node!=nodeBBStart)
return true;
if (node!=NULL && node->getOpCodeValue()==TR::BBStart)
{
TR::Block *block = node->getBlock();
if (!block->isExtensionOfPreviousBlock())
nodeBBStart = node;
}
cursor = cursor->getPrev();
}
return true;
}
OMR::Power::Machine::Machine(TR::CodeGenerator *cg) :
OMR::Machine(cg)
{
self()->initializeRegisterFile();
memset( _registerAssociations, 0, sizeof(TR::Register*)*TR::RealRegister::NumRegisters );
}
void OMR::Power::Machine::initREGAssociations()
{
// Track the last 4 real GPRs assigned so that we try not to reuse them.
_4thLastGPRAssigned = -1;
_3rdLastGPRAssigned = -1;
_2ndLastGPRAssigned = -1;
_lastGPRAssigned = -1;
int icount;
int nextV = 0;
int lastFPRv, lastVRFv;
const TR::PPCLinkageProperties &linkage = self()->cg()->getProperties();
// We assume the volatile/preserved registers to be consecutive
// because the private linkage will either be a single volatile set or
// end up resembling the system linkage. In both cases all volatiles are together,
// and so are the preserved registers
// pick the volatiles from traditional BFPs
for (icount=TR::RealRegister::FirstFPR; icount<=TR::RealRegister::LastFPR; icount++)
{
if (!linkage.getPreserved((TR::RealRegister::RegNum)icount))
_registerAllocationFPR[nextV++] = icount;
}
lastFPRv = nextV - 1;
// Then, pick the preserves from traditional BFPs
for (icount=TR::RealRegister::LastFPR; icount>=TR::RealRegister::FirstFPR; icount--)
{
if (linkage.getPreserved((TR::RealRegister::RegNum)icount))
_registerAllocationFPR[nextV++] = icount;
}
_lastPreservedFPRAvail = nextV - 1;
// pick all the volatiles from VRF
for (icount=TR::RealRegister::LastFPR+1; icount<=TR::RealRegister::LastVSR; icount++)
{
if (!linkage.getPreserved((TR::RealRegister::RegNum)icount))
_registerAllocationFPR[nextV++] = icount;
}
lastVRFv = nextV - 1;
// Now VRF the preserves
for (icount=TR::RealRegister::LastVSR; icount>=TR::RealRegister::LastFPR+1; icount--)
{
if (linkage.getPreserved((TR::RealRegister::RegNum)icount))
_registerAllocationFPR[nextV++] = icount;
}
_lastPreservedVRFAvail = nextV - 1;
// Power6: roll over the biggest set of registers we can afford, because no renaming
// Power8/SAR: confine to the smallest set of registers we can get away, because map cache
// Others: neutral --- take Power6 way for now
int rollingAllocator = !(self()->cg()->comp()->target().cpu.is(OMR_PROCESSOR_PPC_P8));
_inUseFPREnd = rollingAllocator?lastFPRv:0;
_lastFPRAlloc = _inUseFPREnd;
_inUseVFREnd = rollingAllocator?lastVRFv:(_lastPreservedFPRAvail + 1);
_lastVRFAlloc = _inUseVFREnd;
}
TR::RealRegister *OMR::Power::Machine::findBestFreeRegister(TR::Instruction *currentInstruction,
TR_RegisterKinds rk,
bool excludeGPR0,
bool considerUnlatched,
TR::Register *virtualReg)
{
uint32_t preference = (virtualReg==NULL)?0:virtualReg->getAssociation();
uint64_t interference = 0;
int first, maskI;
int last;
bool liveRegOn = (self()->cg()->getLiveRegisters(rk) != NULL);
if (liveRegOn && virtualReg != NULL)
interference = virtualReg->getInterference();
// After liveReg is used by default, the following code should go away
bool avoidGPR0 = (virtualReg!=NULL ?
virtualReg->containsCollectedReference() || virtualReg->containsInternalPointer() :
false );
if (!liveRegOn && avoidGPR0)
interference |= 1;
switch(rk)
{
case TR_GPR:
maskI = first = TR::RealRegister::FirstGPR;
if (excludeGPR0)
first++;
last = TR::RealRegister::LastGPR;
break;
case TR_FPR:
case TR_VSX_SCALAR:
case TR_VSX_VECTOR:
maskI = TR::RealRegister::FirstFPR;
break;
case TR_CCR:
maskI = first = TR::RealRegister::FirstCCR;
last = TR::RealRegister::LastCCR;
break;
case TR_VRF:
maskI = TR::RealRegister::FirstVRF;
break;
}
if (liveRegOn && preference!=0 && (interference & (1<<(preference-maskI))))
{
if (!boundNext(currentInstruction, preference, virtualReg, (self()->cg()->isOutOfLineColdPath() || self()->cg()->isOutOfLineHotPath())))
preference = 0;
}
if (preference!=0 && (!excludeGPR0 || preference!=TR::RealRegister::gr0) &&
(_registerFile[preference]->getState() == TR::RealRegister::Free ||
(considerUnlatched &&_registerFile[preference]->getState() == TR::RealRegister::Unlatched)))
{
if (_registerFile[preference]->getState() == TR::RealRegister::Unlatched)
{
_registerFile[preference]->setAssignedRegister(NULL);
_registerFile[preference]->setState(TR::RealRegister::Free);
}
return _registerFile[preference];
}
uint32_t bestWeightSoFar = 0xffffffff;
TR::RealRegister *freeRegister = NULL;
uint64_t iOld=0, iNew;
// For FPR/VSR/VRF
if (rk == TR_FPR || rk == TR_VSX_SCALAR || rk == TR_VSX_VECTOR || rk == TR_VRF)
{
int rollingAllocator = !(self()->cg()->comp()->target().cpu.is(OMR_PROCESSOR_PPC_P8));
// Find the best in the used FPR set so far
int i, idx;
if (rk != TR_VRF)
{
i = _lastFPRAlloc;
do {
if (++i > _inUseFPREnd) i = 0;
iNew = interference & (1<<(_registerAllocationFPR[i]-maskI));
if ( ( _registerFile[_registerAllocationFPR[i]]->getState() == TR::RealRegister::Free ||
(considerUnlatched && _registerFile[_registerAllocationFPR[i]]->getState() == TR::RealRegister::Unlatched))
&&
( freeRegister == NULL ||
(iOld && !iNew) ||
((iOld || !iNew) && !rollingAllocator && // Rolling: weight is not considered once used
_registerFile[_registerAllocationFPR[i]]->getWeight()<bestWeightSoFar)
)
)
{
iOld = iNew;
idx = i;
freeRegister = _registerFile[_registerAllocationFPR[i]];
bestWeightSoFar = freeRegister->getWeight();
}
} while (i != _lastFPRAlloc);
if (freeRegister != NULL)
_lastFPRAlloc = idx;
}
// Find the best in the used VRF set so far
if (freeRegister==NULL && rk!=TR_FPR)
{
i = _lastVRFAlloc;
do {
if (++i > _inUseVFREnd) i = _lastPreservedFPRAvail+1; // first VRF
iNew = interference & (1<<(_registerAllocationFPR[i]-maskI));
if ( ( _registerFile[_registerAllocationFPR[i]]->getState() == TR::RealRegister::Free ||
(considerUnlatched && _registerFile[_registerAllocationFPR[i]]->getState() == TR::RealRegister::Unlatched))
&&
( freeRegister == NULL ||
(iOld && !iNew) ||
((iOld || !iNew) && !rollingAllocator && // Rolling: weight is not considered once used
_registerFile[_registerAllocationFPR[i]]->getWeight()<bestWeightSoFar)
)
)
{
iOld = iNew;
idx = i;
freeRegister = _registerFile[_registerAllocationFPR[i]];
bestWeightSoFar = freeRegister->getWeight();
}
} while (i != _lastVRFAlloc);
if (freeRegister != NULL)
_lastVRFAlloc = idx;
}
// If no register was assigned, try the not-used-so-far register set.
// Remember they are already in increasing weight in _registerAllocationFPR
if (freeRegister==NULL && rk!=TR_VRF)
{
for (i = _inUseFPREnd+1; i<=_lastPreservedFPRAvail; i++)
{
iNew = interference & (1<<(_registerAllocationFPR[i]-maskI));
if ( (_registerFile[_registerAllocationFPR[i]]->getState() == TR::RealRegister::Free ||
(considerUnlatched && _registerFile[_registerAllocationFPR[i]]->getState() == TR::RealRegister::Unlatched))
&&
( freeRegister == NULL || !iNew )
)
{
freeRegister = _registerFile[_registerAllocationFPR[i]];
idx = i;
if (!iNew)
break;
}
}
if (freeRegister != NULL) // We have assigned an unused reg, add it to the used set
_inUseFPREnd = _lastFPRAlloc = idx;
}
if (freeRegister==NULL && rk!=TR_FPR)
{
for (i = _inUseVFREnd+1; i<=_lastPreservedVRFAvail; i++)
{
iNew = interference & (1<<(_registerAllocationFPR[i]-maskI));
if ( (_registerFile[_registerAllocationFPR[i]]->getState() == TR::RealRegister::Free ||
(considerUnlatched && _registerFile[_registerAllocationFPR[i]]->getState() == TR::RealRegister::Unlatched))
&&
( freeRegister == NULL || !iNew )
)
{
freeRegister = _registerFile[_registerAllocationFPR[i]];
idx = i;
if (!iNew)
break;
}
}
if (freeRegister != NULL) // We have assigned an unused reg, add it to the used set
_inUseVFREnd = _lastVRFAlloc = idx;
}
}
else
{
int iChosen;
for (int i = first; i <= last; i++)
{
int currentReg = 1<<(i-maskI);
iNew = interference & currentReg;
//Inject interference for last four assignments to prevent write-after-write dependancy in same p6 dispatch group.
if(rk == TR_GPR && (self()->cg()->comp()->target().cpu.is(OMR_PROCESSOR_PPC_P6)))
{
if (_lastGPRAssigned != -1)
iNew |= currentReg & _lastGPRAssigned;
if (_2ndLastGPRAssigned != -1)
iNew |= currentReg & _2ndLastGPRAssigned;
if (_3rdLastGPRAssigned != -1)
iNew |= currentReg & _3rdLastGPRAssigned;
if (_4thLastGPRAssigned != -1)
iNew |= currentReg & _4thLastGPRAssigned;
}
if ( ( _registerFile[i]->getState() == TR::RealRegister::Free ||
(considerUnlatched && _registerFile[i]->getState() == TR::RealRegister::Unlatched))
&& ( freeRegister == NULL ||
(iOld && !iNew) ||
((iOld || !iNew) && _registerFile[i]->getWeight()<bestWeightSoFar))
)
{
iOld = iNew;
freeRegister = _registerFile[i];
iChosen = i;
bestWeightSoFar = freeRegister->getWeight();
}
}
//Track the last four registers used for use in above interference injection.
if ((rk == TR_GPR) && (freeRegister != NULL) && (self()->cg()->comp()->target().cpu.is(OMR_PROCESSOR_PPC_P6)))
{
_4thLastGPRAssigned = _3rdLastGPRAssigned;
_3rdLastGPRAssigned = _2ndLastGPRAssigned;
_2ndLastGPRAssigned = _lastGPRAssigned;
_lastGPRAssigned = 1<<(iChosen-maskI);
}
}
if (freeRegister!=NULL && freeRegister->getState()==TR::RealRegister::Unlatched)
{
freeRegister->setAssignedRegister(NULL);
freeRegister->setState(TR::RealRegister::Free);
}
return freeRegister;
}
TR::RealRegister *OMR::Power::Machine::freeBestRegister(TR::Instruction *currentInstruction,
TR::Register *virtReg,
TR::RealRegister *forced,
bool excludeGPR0)
{
TR::Register *candidates[NUM_PPC_MAXR];
TR::MemoryReference *tmemref;
TR_BackingStore *location;
TR::RealRegister *best, *crtemp=NULL;
TR::Instruction *cursor;
TR::InstOpCode::Mnemonic opCode;
TR::Machine *machine = self()->cg()->machine();
TR::Node *currentNode = currentInstruction->getNode();
TR_RegisterKinds rk = (virtReg==NULL)?TR_GPR:virtReg->getKind();
int32_t numCandidates=0, first, last, maskI;
uint64_t interference=0;
TR::RealRegister::RegState crtemp_state;
TR::Compilation *comp = self()->cg()->comp();
if (forced != NULL)
{
best = forced;
candidates[0] = best->getAssignedRegister();
}
else
{
switch (rk)
{
case TR_GPR:
maskI = first = TR::RealRegister::FirstGPR;
if (excludeGPR0)
first++;
last = TR::RealRegister::LastGPR;
break;
case TR_FPR:
maskI = first = TR::RealRegister::FirstFPR;
last = TR::RealRegister::LastFPR;
break;
case TR_VSX_SCALAR:
maskI = first = TR::RealRegister::FirstFPR;
last = TR::RealRegister::LastVSR;
break;
case TR_VSX_VECTOR:
maskI = first = TR::RealRegister::FirstFPR;
last = TR::RealRegister::LastVSR;
break;
case TR_CCR:
maskI = first = TR::RealRegister::FirstCCR;
last = TR::RealRegister::LastCCR;
break;
case TR_VRF:
maskI = first = TR::RealRegister::FirstVRF;
last = TR::RealRegister::LastVRF;
break;
}
int32_t preference = 0, pref_favored = 0;
if (self()->cg()->getLiveRegisters(rk) != NULL && virtReg != NULL)
{
interference = virtReg->getInterference();
preference = virtReg->getAssociation();
// Consider yielding
if (preference != 0 && boundNext(currentInstruction, preference, virtReg, (self()->cg()->isOutOfLineColdPath() || self()->cg()->isOutOfLineHotPath())))
{
pref_favored = 1;
interference &= ~((uint64_t)(1<<(preference - maskI)));
}
}
uint64_t allInterfere;
for (int i = first; i <= last; i++)
{
uint64_t iInterfere = interference & (1<<(i-maskI));
TR::RealRegister *realReg = machine->getRealRegister((TR::RealRegister::RegNum)i);
if (realReg->getState() == TR::RealRegister::Assigned)
{
TR::Register *associatedVirtual = realReg->getAssignedRegister();
if (numCandidates == 0)
{
candidates[numCandidates++] = associatedVirtual;
allInterfere = iInterfere;
}
else
{
if (iInterfere)
{
if (allInterfere)
candidates[numCandidates++] = associatedVirtual;
}
else
{
if (allInterfere)
{
numCandidates = allInterfere = 0;
candidates[0] = associatedVirtual;
}
else
{
if (i==preference && pref_favored)
{
TR::Register *tempReg = candidates[0];
candidates[0] = associatedVirtual;
associatedVirtual = tempReg;
}
candidates[numCandidates] = associatedVirtual;
}
numCandidates++;
}
}
}
}
TR_ASSERT(numCandidates !=0, "All %s registers are blocked\n", virtReg->getRegisterKindName(comp, rk));
cursor = currentInstruction;
while (numCandidates > 1 &&
cursor != NULL &&
cursor->getOpCodeValue() != TR::InstOpCode::label &&
cursor->getOpCodeValue() != TR::InstOpCode::proc)
{
for (int i = 0; i < numCandidates; i++)
{
if (cursor->refsRegister(candidates[i]))
{
candidates[i] = candidates[--numCandidates];
}
}
cursor = cursor->getPrev();
}
best = toRealRegister(candidates[0]->getAssignedRegister());
}
switch (rk)
{
// XXX: Reusing backing stores here is causing the virtual being spilled to be clobbered
case TR_GPR:
if (false /*!cg()->comp()->getOption(TR_DisableOOL) && (cg()->isOutOfLineColdPath() || cg()->isOutOfLineHotPath()) &&
virtReg->getBackingStorage()*/)
{
location = virtReg->getBackingStorage();
// reuse the spill slot
if (self()->cg()->getDebug())
self()->cg()->traceRegisterAssignment("\nOOL: Reuse backing store (%p) for %s inside OOL\n",
location, self()->cg()->getDebug()->getName(virtReg));
}
else
{
if (candidates[0]->getBackingStorage())
{
// If there is backing storage associated with a register, it means the
// backing store wasn't returned to the free list and it can be used.
//
location = candidates[0]->getBackingStorage();
// If best register already has a backing store it's because we reverse spilled it in an
// OOL region while the free spill list was locked and we didn't clean this up after unlocking
// the list (see TODO in PPCInstruction.cpp). Therefore we need to set the
// occupied flag for this reuse.
if (location->getSymbolReference()->getSymbol()->getSize() > TR::Compiler->om.sizeofReferenceAddress())
location->setFirstHalfIsOccupied();
else
location->setIsOccupied();
}
else
{
if (candidates[0]->containsInternalPointer())
{
TR::AutomaticSymbol *parray = candidates[0]->getPinningArrayPointer();
location = self()->cg()->allocateInternalPointerSpill(parray);
}
else
{
location = self()->cg()->allocateSpill(TR::Compiler->om.sizeofReferenceAddress(), candidates[0]->containsCollectedReference(), NULL);
}
}
}
break;
case TR_FPR:
if (false /*!cg()->comp()->getOption(TR_DisableOOL) && (cg()->isOutOfLineColdPath() || cg()->isOutOfLineHotPath()) &&
virtReg->getBackingStorage()*/)
{
location = virtReg->getBackingStorage();
// reuse the spill slot
if (self()->cg()->getDebug())
self()->cg()->traceRegisterAssignment("\nOOL: Reuse backing store (%p) for %s inside OOL\n",
location, self()->cg()->getDebug()->getName(virtReg));
}
else
{
if (candidates[0]->getBackingStorage())
{
// If there is backing storage associated with a register, it means the
// backing store wasn't returned to the free list and it can be used.
//
location = candidates[0]->getBackingStorage();
// If best register already has a backing store it's because we reverse spilled it in an
// OOL region while the free spill list was locked and we didn't clean this up after unlocking
// the list (see TODO in PPCInstruction.cpp). Therefore we need to set the
// occupied flag for this reuse.
if (candidates[0]->isSinglePrecision() && location->getSymbolReference()->getSymbol()->getSize() > 4)
location->setFirstHalfIsOccupied();
else
location->setIsOccupied();
}
else
{
location = self()->cg()->allocateSpill(candidates[0]->isSinglePrecision()? 4:8, false, NULL);
}
}
break;
case TR_VSX_SCALAR:
if (candidates[0]->getBackingStorage())
{
// If there is backing storage associated with a register, it means the
// backing store wasn't returned to the free list and it can be used.
//
location = candidates[0]->getBackingStorage();
// If best register already has a backing store it's because we reverse spilled it in an
// OOL region while the free spill list was locked and we didn't clean this up after unlocking
// the list (see TODO in PPCInstruction.cpp). Therefore we need to set the
// occupied flag for this reuse.
if (candidates[0]->isSinglePrecision() && location->getSymbolReference()->getSymbol()->getSize() > 4)
location->setFirstHalfIsOccupied();
else
location->setIsOccupied();
}
else
{
location = self()->cg()->allocateSpill(candidates[0]->isSinglePrecision()? 4:8, false, NULL);
}
break;
case TR_CCR:
if (false /*!cg()->comp()->getOption(TR_DisableOOL) && (cg()->isOutOfLineColdPath() || cg()->isOutOfLineHotPath()) &&
virtReg->getBackingStorage()*/)
{
location = virtReg->getBackingStorage();
// reuse the spill slot
if (self()->cg()->getDebug())
self()->cg()->traceRegisterAssignment("\nOOL: Reuse backing store (%p) for %s inside OOL\n",
location, self()->cg()->getDebug()->getName(virtReg));
}
else
{
if (candidates[0]->getBackingStorage())
{
// If there is backing storage associated with a register, it means the
// backing store wasn't returned to the free list and it can be used.
//
location = candidates[0]->getBackingStorage();
// If best register already has a backing store it's because we reverse spilled it in an
// OOL region while the free spill list was locked and we didn't clean this up after unlocking
// the list (see TODO in PPCInstruction.cpp). Therefore we need to set the
// occupied flag for this reuse.
if (location->getSymbolReference()->getSymbol()->getSize() > 4)
location->setFirstHalfIsOccupied();
else
location->setIsOccupied();
}
else
{
location = new (self()->cg()->trHeapMemory()) TR_PPCCRBackingStore(comp, self()->cg()->allocateSpill(4, false, NULL)); // TODO: Could this be 1 byte?
}
}
break;
case TR_VSX_VECTOR:
case TR_VRF:
if (candidates[0]->getBackingStorage())
{
// If there is backing storage associated with a register, it means the
// backing store wasn't returned to the free list and it can be used.
//
location = candidates[0]->getBackingStorage();
// If best register already has a backing store it's because we reverse spilled it in an
// OOL region while the free spill list was locked and we didn't clean this up after unlocking
// the list (see TODO in PPCInstruction.cpp). Therefore we need to set the
// occupied flag for this reuse.
location->setIsOccupied();
}
else
{
location = self()->cg()->allocateSpill(16, false, NULL);
}
break;
}
if (rk == TR_CCR)
toPPCCRBackingStore(location)->setCcrFieldIndex(
best->getRegisterNumber() - TR::RealRegister::FirstCCR);
candidates[0]->setBackingStorage(location);
tmemref = TR::MemoryReference::createWithSymRef(self()->cg(), currentNode, location->getSymbolReference(), TR::Compiler->om.sizeofReferenceAddress());
if (rk == TR_CCR)
{
crtemp = self()->findBestFreeRegister(currentInstruction, TR_GPR);
if (crtemp == NULL)
crtemp = self()->freeBestRegister(currentInstruction, NULL);
else
crtemp->setHasBeenAssignedInMethod(true);
crtemp_state = crtemp->getState();
TR::Instruction *ccrInstr = generateSrc1Instruction(self()->cg(), TR::InstOpCode::mtocrf, currentNode, crtemp, 1<<(7-toPPCCRBackingStore(location)->getCcrFieldIndex()), currentInstruction);
self()->cg()->traceRAInstruction(ccrInstr);
}
if (!comp->getOption(TR_DisableOOL))
{
if (!self()->cg()->isOutOfLineColdPath())
{
TR_Debug *debugObj = self()->cg()->getDebug();
// the spilledRegisterList contains all registers that are spilled before entering
// the OOL cold path, post dependencies will be generated using this list
self()->cg()->getSpilledRegisterList()->push_front(candidates[0]);
// OOL cold path: depth = 3, hot path: depth =2, main line: depth = 1
// if the spill is outside of the OOL cold/hot path, we need to protect the spill slot
// if we reverse spill this register inside the OOL cold/hot path
if (!self()->cg()->isOutOfLineHotPath())
{// main line
location->setMaxSpillDepth(1);
}
else
{
// hot path
// do not overwrite main line spill depth
if (location->getMaxSpillDepth() != 1)
location->setMaxSpillDepth(2);
}
if (debugObj)
self()->cg()->traceRegisterAssignment("OOL: adding %s to the spilledRegisterList, maxSpillDepth = %d\n",
debugObj->getName(candidates[0]), location->getMaxSpillDepth());
}
else
{
// do not overwrite mainline and hot path spill depth
// if this spill is inside OOL cold path, we do not need to protecting the spill slot
// because the post condition at OOL entry does not expect this register to be spilled
if (location->getMaxSpillDepth() != 1 &&
location->getMaxSpillDepth() != 2 )
location->setMaxSpillDepth(3);
}
}
TR::Instruction *reloadInstr = NULL;
TR::RealRegister *tempIndexRegister = NULL;
switch (rk)
{
case TR_GPR:
reloadInstr = generateTrg1MemInstruction(self()->cg(),TR::InstOpCode::Op_load, currentNode, best, tmemref, currentInstruction);
break;
case TR_FPR:
if (candidates[0]->isSinglePrecision())
{
opCode = TR::InstOpCode::lfs;
tmemref->setLength(4);
}
else
{
opCode = TR::InstOpCode::lfd;
tmemref->setLength(8);
}
reloadInstr = generateTrg1MemInstruction(self()->cg(), opCode, currentNode, best, tmemref, currentInstruction);
break;
case TR_VSX_SCALAR:
tempIndexRegister = self()->findBestFreeRegister(currentInstruction, TR_GPR);
if (tempIndexRegister == NULL)
tempIndexRegister = self()->freeBestRegister(currentInstruction, NULL);
tmemref->setUsingDelayedIndexedForm();
tmemref->setIndexRegister(tempIndexRegister);
tmemref->setIndexModifiable();
opCode = TR::InstOpCode::lxsdx;
tmemref->setLength(8);
reloadInstr = generateTrg1MemInstruction(self()->cg(), opCode, currentNode, best, tmemref, currentInstruction);
self()->cg()->stopUsingRegister(tempIndexRegister);
break;
case TR_CCR:
reloadInstr = generateTrg1MemInstruction(self()->cg(),TR::InstOpCode::Op_load, currentNode, crtemp, tmemref, currentInstruction);
break;
case TR_VSX_VECTOR:
tempIndexRegister = self()->findBestFreeRegister(currentInstruction, TR_GPR);
if (tempIndexRegister == NULL)
tempIndexRegister = self()->freeBestRegister(currentInstruction, NULL);
tmemref->setUsingDelayedIndexedForm();
tmemref->setIndexRegister(tempIndexRegister);
tmemref->setIndexModifiable();
opCode = TR::InstOpCode::lxvd2x;
tmemref->setLength(16);
reloadInstr = generateTrg1MemInstruction(self()->cg(), opCode, currentNode, best, tmemref, currentInstruction);
self()->cg()->stopUsingRegister(tempIndexRegister);
break;
case TR_VRF:
// Until stack frame is 16-byte aligned, we cannot use VMX load/store here
// So, we use VSX load/store instead as a work-around
TR_ASSERT(self()->cg()->comp()->target().cpu.supportsFeature(OMR_FEATURE_PPC_HAS_VSX), "VSX support not enabled");
tempIndexRegister = self()->findBestFreeRegister(currentInstruction, TR_GPR);
if (tempIndexRegister == NULL)
tempIndexRegister = self()->freeBestRegister(currentInstruction, NULL);
tmemref->setUsingDelayedIndexedForm();
tmemref->setIndexRegister(tempIndexRegister);
tmemref->setIndexModifiable();
opCode = TR::InstOpCode::lxvd2x;
tmemref->setLength(16);
reloadInstr = generateTrg1MemInstruction(self()->cg(), opCode, currentNode, best, tmemref, currentInstruction);
self()->cg()->stopUsingRegister(tempIndexRegister);
break;
}
self()->cg()->traceRegFreed(candidates[0], best);
self()->cg()->traceRAInstruction(reloadInstr);
best->setAssignedRegister(NULL);
best->setState(TR::RealRegister::Free);
candidates[0]->setAssignedRegister(NULL);
return best;
}
// Sets the register association of a real register to a virtual register
// Used to track the old real register association
TR::Register *OMR::Power::Machine::setVirtualAssociatedWithReal(TR::RealRegister::RegNum regNum, TR::Register * virtReg)
{
if (virtReg)
{
// disable previous association
if (virtReg->getAssociation())
_registerAssociations[virtReg->getAssociation()] = 0;
virtReg->setAssociation(regNum);
}
return (_registerAssociations[regNum] = virtReg);
}
TR::Register *OMR::Power::Machine::getVirtualAssociatedWithReal(TR::RealRegister::RegNum regNum)
{
return(_registerAssociations[regNum]);
}
TR::RealRegister *OMR::Power::Machine::reverseSpillState(TR::Instruction *currentInstruction,
TR::Register *spilledRegister,
TR::RealRegister *targetRegister,
bool excludeGPR0)
{
TR::MemoryReference *tmemref;
TR::Compilation *comp = self()->cg()->comp();
TR::RealRegister *sameReg, *crtemp = NULL;
TR_BackingStore *location = spilledRegister->getBackingStorage();
TR::Node *currentNode = currentInstruction->getNode();
TR_RegisterKinds rk = spilledRegister->getKind();
TR::InstOpCode::Mnemonic opCode;
TR_Debug *debugObj = self()->cg()->getDebug();
if (targetRegister == NULL)
{
if ((rk == TR_CCR) && (!self()->cg()->isOutOfLineColdPath() && !self()->cg()->isOutOfLineHotPath()) && ((sameReg=self()->cg()->machine()->getRealRegister((TR::RealRegister::RegNum)(TR::RealRegister::FirstCCR+toPPCCRBackingStore(location)->getCcrFieldIndex())))->getState() == TR::RealRegister::Free))
{
targetRegister = sameReg;
}
else
{
targetRegister = self()->findBestFreeRegister(currentInstruction, rk, excludeGPR0, false, spilledRegister);
}
if (targetRegister == NULL)
{
targetRegister = self()->freeBestRegister(currentInstruction,
spilledRegister, NULL, excludeGPR0);
}
targetRegister->setState(TR::RealRegister::Assigned);
}
if (self()->cg()->isOutOfLineColdPath())
{
// the future and total use count might not always reflect register spill state
// for example a new register assignment in the hot path would cause FC != TC
// in this case, assign a new register and return
if (!location)
{
if (debugObj)
self()->cg()->traceRegisterAssignment("OOL: Not generating reverse spill for (%s)\n", debugObj->getName(spilledRegister));
return targetRegister;
}
}
if (rk == TR_CCR)
{
crtemp = self()->findBestFreeRegister(currentInstruction, TR_GPR);
if (crtemp == NULL)
crtemp = self()->freeBestRegister(currentInstruction, NULL);
else
crtemp->setHasBeenAssignedInMethod(true);
}
tmemref = TR::MemoryReference::createWithSymRef(self()->cg(), currentNode, location->getSymbolReference(), TR::Compiler->om.sizeofReferenceAddress());
TR::Instruction *spillInstr = NULL;
int32_t dataSize = spillSizeForRegister(spilledRegister);
if (comp->getOption(TR_DisableOOL))
{
self()->cg()->freeSpill(location, dataSize, 0);
}
else
{
if (self()->cg()->isOutOfLineColdPath())
{
bool isOOLentryReverseSpill = false;
if (currentInstruction->isLabel())
{
if (((TR::PPCLabelInstruction*)currentInstruction)->getLabelSymbol()->isStartOfColdInstructionStream())
{
// indicates that we are at OOL entry point post conditions. Since
// we are now exiting the OOL cold path (going reverse order)
// and we called reverseSpillState(), the main line path
// expects the Virt reg to be assigned to a real register
// we can now safely unlock the protected backing storage
// This prevents locking backing storage for future OOL blocks
isOOLentryReverseSpill = true;
}
}
// OOL: only free the spill slot if the register was spilled in the same or less dominant path
// ex: spilled in cold path, reverse spill in hot path or main line
// we have to spill this register again when we reach OOL entry point due to post
// conditions. We want to guarantee that the same spill slot will be protected and reused.
// maxSpillDepth: 3:cold path, 2:hot path, 1:main line
// Also free the spill if maxSpillDepth==0, which will be the case if the reverse spill also occured on the hot path.
// If the reverse spill occured on both paths then this is the last chance we have to free the spill slot.
if (location->getMaxSpillDepth() == 3 || location->getMaxSpillDepth() == 0 || isOOLentryReverseSpill)
{
if (location->getMaxSpillDepth() != 0)
location->setMaxSpillDepth(0);
else if (debugObj)
self()->cg()->traceRegisterAssignment("\nOOL: reverse spill %s in less dominant path (%d / 3), reverse spill on both paths indicated, free spill slot (%p)\n",
debugObj->getName(spilledRegister), location->getMaxSpillDepth(), location);
self()->cg()->freeSpill(location, dataSize, 0);
if (!self()->cg()->isFreeSpillListLocked())
{
spilledRegister->setBackingStorage(NULL);
}
}
else
{
if (debugObj)
self()->cg()->traceRegisterAssignment("\nOOL: reverse spill %s in less dominant path (%d / 3), protect spill slot (%p)\n",
debugObj->getName(spilledRegister), location->getMaxSpillDepth(), location);
}
}
else if (self()->cg()->isOutOfLineHotPath())
{
// the spilledRegisterList contains all registers that are spilled before entering
// the OOL path (in backwards RA). Post dependencies will be generated using this list.
// Any registers reverse spilled before entering OOL should be removed from the spilled list
if (debugObj)
self()->cg()->traceRegisterAssignment("\nOOL: removing %s from the spilledRegisterList\n", debugObj->getName(spilledRegister));
self()->cg()->getSpilledRegisterList()->remove(spilledRegister);