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BackwardPass.cpp
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//-------------------------------------------------------------------------------------------------------
// Copyright (C) Microsoft. All rights reserved.
// Licensed under the MIT license. See LICENSE.txt file in the project root for full license information.
//-------------------------------------------------------------------------------------------------------
#include "Backend.h"
#define INLINEEMETAARG_COUNT 3
BackwardPass::BackwardPass(Func * func, GlobOpt * globOpt, Js::Phase tag)
: func(func), globOpt(globOpt), tag(tag), currentPrePassLoop(nullptr), tempAlloc(nullptr),
preOpBailOutInstrToProcess(nullptr),
isCollectionPass(false), currentRegion(nullptr),
collectionPassSubPhase(CollectionPassSubPhase::None),
isLoopPrepass(false)
{
// Those are the only three phases BackwardPass will use currently
Assert(tag == Js::BackwardPhase || tag == Js::DeadStorePhase || tag == Js::CaptureByteCodeRegUsePhase);
#if DBG
// The CaptureByteCodeRegUse phase is just a collection phase, no mutations should occur
this->isCollectionPass = tag == Js::CaptureByteCodeRegUsePhase;
#endif
this->implicitCallBailouts = 0;
this->fieldOpts = 0;
#if DBG_DUMP
this->numDeadStore = 0;
this->numMarkTempNumber = 0;
this->numMarkTempNumberTransferred = 0;
this->numMarkTempObject = 0;
#endif
}
void
BackwardPass::DoSetDead(IR::Opnd * opnd, bool isDead) const
{
// Note: Dead bit on the Opnd records flow-based liveness.
// This is distinct from isLastUse, which records lexical last-ness.
if (isDead && this->tag == Js::BackwardPhase && !this->IsPrePass())
{
opnd->SetIsDead();
}
else if (this->tag == Js::DeadStorePhase)
{
// Set or reset in DeadStorePhase.
// CSE could make previous dead operand not the last use, so reset it.
opnd->SetIsDead(isDead);
}
}
bool
BackwardPass::DoByteCodeUpwardExposedUsed() const
{
return (
(this->tag == Js::DeadStorePhase && this->func->hasBailout) ||
(this->tag == Js::BackwardPhase && this->func->HasTry() && this->func->DoOptimizeTry())
#if DBG
|| tag == Js::CaptureByteCodeRegUsePhase
#endif
);
}
bool BackwardPass::DoCaptureByteCodeUpwardExposedUsed() const
{
#if DBG
return (this->tag == Js::CaptureByteCodeRegUsePhase || this->tag == Js::DeadStorePhase) &&
this->DoByteCodeUpwardExposedUsed() &&
!func->IsJitInDebugMode() &&
!this->func->GetJITFunctionBody()->IsAsmJsMode() &&
this->func->DoGlobOpt();
#else
return false;
#endif
}
bool
BackwardPass::DoMarkTempNumbers() const
{
#if FLOATVAR
return false;
#else
// only mark temp number on the dead store phase
return (tag == Js::DeadStorePhase) && !PHASE_OFF(Js::MarkTempPhase, this->func) &&
!PHASE_OFF(Js::MarkTempNumberPhase, this->func) && func->DoFastPaths() && (!this->func->HasTry());
#endif
}
bool
BackwardPass::SatisfyMarkTempObjectsConditions() const {
return !PHASE_OFF(Js::MarkTempPhase, this->func) &&
!PHASE_OFF(Js::MarkTempObjectPhase, this->func) &&
func->DoGlobOpt() && func->GetHasTempObjectProducingInstr() &&
!func->IsJitInDebugMode();
// Why MarkTempObject is disabled under debugger:
// We add 'identified so far dead non-temp locals' to byteCodeUpwardExposedUsed in ProcessBailOutInfo,
// this may cause MarkTempObject to convert some temps back to non-temp when it sees a 'transferred exposed use'
// from a temp to non-temp. That's in general not a supported conversion (while non-temp -> temp is fine).
}
bool
BackwardPass::DoMarkTempObjects() const
{
// only mark temp object on the backward store phase
return (tag == Js::BackwardPhase) && SatisfyMarkTempObjectsConditions();
}
bool
BackwardPass::DoMarkTempNumbersOnTempObjects() const
{
return !PHASE_OFF(Js::MarkTempNumberOnTempObjectPhase, this->func) && DoMarkTempNumbers() && this->func->GetHasMarkTempObjects();
}
#if DBG
bool
BackwardPass::DoMarkTempObjectVerify() const
{
// only mark temp object on the backward store phase
return (tag == Js::DeadStorePhase) && SatisfyMarkTempObjectsConditions();
}
#endif
// static
bool
BackwardPass::DoDeadStore(Func* func)
{
return
!PHASE_OFF(Js::DeadStorePhase, func) &&
(!func->HasTry() || func->DoOptimizeTry());
}
bool
BackwardPass::DoDeadStore() const
{
return
this->tag == Js::DeadStorePhase &&
DoDeadStore(this->func);
}
bool
BackwardPass::DoDeadStoreSlots() const
{
// only dead store fields if glob opt is on to generate the trackable fields bitvector
return (tag == Js::DeadStorePhase && this->func->DoGlobOpt()
&& (!this->func->HasTry()));
}
// Whether dead store is enabled for given func and sym.
// static
bool
BackwardPass::DoDeadStore(Func* func, StackSym* sym)
{
// Dead store is disabled under debugger for non-temp local vars.
return
DoDeadStore(func) &&
!(func->IsJitInDebugMode() && sym->HasByteCodeRegSlot() && func->IsNonTempLocalVar(sym->GetByteCodeRegSlot()));
}
bool
BackwardPass::DoTrackNegativeZero() const
{
return
!PHASE_OFF(Js::TrackIntUsagePhase, func) &&
!PHASE_OFF(Js::TrackNegativeZeroPhase, func) &&
func->DoGlobOpt() &&
!IsPrePass() &&
!func->IsJitInDebugMode();
}
bool
BackwardPass::DoTrackBitOpsOrNumber() const
{
#if defined(_WIN32) && defined(TARGET_64)
return
!PHASE_OFF1(Js::TypedArrayVirtualPhase) &&
tag == Js::BackwardPhase &&
func->DoGlobOpt() &&
!IsPrePass() &&
!func->IsJitInDebugMode();
#else
return false;
#endif
}
bool
BackwardPass::DoTrackIntOverflow() const
{
return
!PHASE_OFF(Js::TrackIntUsagePhase, func) &&
!PHASE_OFF(Js::TrackIntOverflowPhase, func) &&
tag == Js::BackwardPhase &&
!IsPrePass() &&
globOpt->DoLossyIntTypeSpec() &&
!func->IsJitInDebugMode();
}
bool
BackwardPass::DoTrackCompoundedIntOverflow() const
{
return
!PHASE_OFF(Js::TrackCompoundedIntOverflowPhase, func) &&
DoTrackIntOverflow() && !func->IsTrackCompoundedIntOverflowDisabled();
}
bool
BackwardPass::DoTrackNon32BitOverflow() const
{
// enabled only for IA
#if defined(_M_IX86) || defined(_M_X64)
return true;
#else
return false;
#endif
}
void
BackwardPass::CleanupBackwardPassInfoInFlowGraph()
{
if (!this->func->m_fg->hasBackwardPassInfo)
{
// No information to clean up
return;
}
// The backward pass temp arena has already been deleted, we can just reset the data
FOREACH_BLOCK_IN_FUNC_DEAD_OR_ALIVE(block, this->func)
{
block->upwardExposedUses = nullptr;
block->upwardExposedFields = nullptr;
block->typesNeedingKnownObjectLayout = nullptr;
block->slotDeadStoreCandidates = nullptr;
block->byteCodeUpwardExposedUsed = nullptr;
block->liveFixedFields = nullptr;
#if DBG
block->byteCodeRestoreSyms = nullptr;
block->excludeByteCodeUpwardExposedTracking = nullptr;
#endif
block->tempNumberTracker = nullptr;
block->tempObjectTracker = nullptr;
#if DBG
block->tempObjectVerifyTracker = nullptr;
#endif
block->stackSymToFinalType = nullptr;
block->stackSymToGuardedProperties = nullptr;
block->stackSymToWriteGuardsMap = nullptr;
block->cloneStrCandidates = nullptr;
block->noImplicitCallUses = nullptr;
block->noImplicitCallNoMissingValuesUses = nullptr;
block->noImplicitCallNativeArrayUses = nullptr;
block->noImplicitCallJsArrayHeadSegmentSymUses = nullptr;
block->noImplicitCallArrayLengthSymUses = nullptr;
block->couldRemoveNegZeroBailoutForDef = nullptr;
if (block->loop != nullptr)
{
block->loop->hasDeadStoreCollectionPass = false;
block->loop->hasDeadStorePrepass = false;
}
}
NEXT_BLOCK_IN_FUNC_DEAD_OR_ALIVE;
}
/*
* We Insert ArgIns at the start of the function for all the formals.
* Unused formals will be deadstored during the deadstore pass.
* We need ArgIns only for the outermost function(inliner).
*/
void
BackwardPass::InsertArgInsForFormals()
{
if (func->IsStackArgsEnabled() && !func->GetJITFunctionBody()->HasImplicitArgIns())
{
IR::Instr * insertAfterInstr = func->m_headInstr->m_next;
AssertMsg(insertAfterInstr->IsLabelInstr(), "First Instr of the first block should always have a label");
Js::ArgSlot paramsCount = insertAfterInstr->m_func->GetJITFunctionBody()->GetInParamsCount() - 1;
IR::Instr * argInInstr = nullptr;
for (Js::ArgSlot argumentIndex = 1; argumentIndex <= paramsCount; argumentIndex++)
{
IR::SymOpnd * srcOpnd;
StackSym * symSrc = StackSym::NewParamSlotSym(argumentIndex + 1, func);
StackSym * symDst = StackSym::New(func);
IR::RegOpnd * dstOpnd = IR::RegOpnd::New(symDst, TyVar, func);
func->SetArgOffset(symSrc, (argumentIndex + LowererMD::GetFormalParamOffset()) * MachPtr);
srcOpnd = IR::SymOpnd::New(symSrc, TyVar, func);
argInInstr = IR::Instr::New(Js::OpCode::ArgIn_A, dstOpnd, srcOpnd, func);
insertAfterInstr->InsertAfter(argInInstr);
insertAfterInstr = argInInstr;
AssertMsg(!func->HasStackSymForFormal(argumentIndex - 1), "Already has a stack sym for this formal?");
this->func->TrackStackSymForFormalIndex(argumentIndex - 1, symDst);
}
if (PHASE_VERBOSE_TRACE1(Js::StackArgFormalsOptPhase) && paramsCount > 0)
{
Output::Print(_u("StackArgFormals : %s (%d) :Inserting ArgIn_A for LdSlot (formals) in the start of Deadstore pass. \n"), func->GetJITFunctionBody()->GetDisplayName(), func->GetFunctionNumber());
Output::Flush();
}
}
}
void
BackwardPass::MarkScopeObjSymUseForStackArgOpt()
{
IR::Instr * instr = this->currentInstr;
BasicBlock *block = this->currentBlock;
if (tag == Js::DeadStorePhase)
{
if (instr->DoStackArgsOpt() && !block->IsLandingPad() && instr->m_func->GetScopeObjSym() != nullptr && this->DoByteCodeUpwardExposedUsed())
{
this->currentBlock->byteCodeUpwardExposedUsed->Set(instr->m_func->GetScopeObjSym()->m_id);
}
}
}
void
BackwardPass::ProcessBailOnStackArgsOutOfActualsRange()
{
IR::Instr * instr = this->currentInstr;
if (tag == Js::DeadStorePhase &&
(instr->m_opcode == Js::OpCode::LdElemI_A || instr->m_opcode == Js::OpCode::TypeofElem) &&
instr->HasBailOutInfo() && !IsPrePass())
{
if (instr->DoStackArgsOpt())
{
AssertMsg(instr->GetBailOutKind() & IR::BailOnStackArgsOutOfActualsRange, "Stack args bail out is not set when the optimization is turned on? ");
if (instr->GetBailOutKind() & ~IR::BailOnStackArgsOutOfActualsRange)
{
//Make sure that in absence of potential LazyBailOut and BailOutOnImplicitCallsPreOp, we only have BailOnStackArgsOutOfActualsRange bit set
Assert((BailOutInfo::WithoutLazyBailOut(instr->GetBailOutKind() & ~IR::BailOutOnImplicitCallsPreOp)) == IR::BailOnStackArgsOutOfActualsRange);
//We are sure at this point, that we will not have any implicit calls as we wouldn't have done this optimization in the first place.
instr->SetBailOutKind(IR::BailOnStackArgsOutOfActualsRange);
}
}
else if (instr->GetBailOutKind() & IR::BailOnStackArgsOutOfActualsRange)
{
//If we don't decide to do StackArgs, then remove the bail out at this point.
//We would have optimistically set the bailout in the forward pass, and by the end of forward pass - we
//turned off stack args for some reason. So we are removing it in the deadstore pass.
IR::BailOutKind bailOutKind = instr->GetBailOutKind() & ~IR::BailOnStackArgsOutOfActualsRange;
if (bailOutKind == IR::BailOutInvalid)
{
instr->ClearBailOutInfo();
}
else
{
instr->SetBailOutKind(bailOutKind);
}
}
}
}
void
BackwardPass::Optimize()
{
if (tag == Js::BackwardPhase && PHASE_OFF(tag, this->func))
{
return;
}
if (tag == Js::CaptureByteCodeRegUsePhase && (!PHASE_ENABLED(CaptureByteCodeRegUsePhase, this->func) || !DoCaptureByteCodeUpwardExposedUsed()))
{
return;
}
if (tag == Js::DeadStorePhase)
{
if (!this->func->DoLoopFastPaths() || !this->func->DoFastPaths())
{
//arguments[] access is similar to array fast path hence disable when array fastpath is disabled.
//loopFastPath is always true except explicitly disabled
//defaultDoFastPath can be false when we the source code size is huge
func->SetHasStackArgs(false);
}
InsertArgInsForFormals();
}
NoRecoverMemoryJitArenaAllocator localAlloc(tag == Js::BackwardPhase? _u("BE-Backward") : _u("BE-DeadStore"),
this->func->m_alloc->GetPageAllocator(), Js::Throw::OutOfMemory);
this->tempAlloc = &localAlloc;
#if DBG_DUMP
if (this->IsTraceEnabled())
{
this->func->DumpHeader();
}
#endif
this->CleanupBackwardPassInfoInFlowGraph();
// Info about whether a sym is used in a way in which -0 differs from +0, or whether the sym is used in a way in which an
// int32 overflow when generating the value of the sym matters, in the current block. The info is transferred to
// instructions that define the sym in the current block as they are encountered. The info in these bit vectors is discarded
// after optimizing each block, so the only info that remains for GlobOpt is that which is transferred to instructions.
BVSparse<JitArenaAllocator> localNegativeZeroDoesNotMatterBySymId(tempAlloc);
negativeZeroDoesNotMatterBySymId = &localNegativeZeroDoesNotMatterBySymId;
BVSparse<JitArenaAllocator> localSymUsedOnlyForBitOpsBySymId(tempAlloc);
symUsedOnlyForBitOpsBySymId = &localSymUsedOnlyForBitOpsBySymId;
BVSparse<JitArenaAllocator> localSymUsedOnlyForNumberBySymId(tempAlloc);
symUsedOnlyForNumberBySymId = &localSymUsedOnlyForNumberBySymId;
BVSparse<JitArenaAllocator> localIntOverflowDoesNotMatterBySymId(tempAlloc);
intOverflowDoesNotMatterBySymId = &localIntOverflowDoesNotMatterBySymId;
BVSparse<JitArenaAllocator> localIntOverflowDoesNotMatterInRangeBySymId(tempAlloc);
intOverflowDoesNotMatterInRangeBySymId = &localIntOverflowDoesNotMatterInRangeBySymId;
BVSparse<JitArenaAllocator> localCandidateSymsRequiredToBeInt(tempAlloc);
candidateSymsRequiredToBeInt = &localCandidateSymsRequiredToBeInt;
BVSparse<JitArenaAllocator> localCandidateSymsRequiredToBeLossyInt(tempAlloc);
candidateSymsRequiredToBeLossyInt = &localCandidateSymsRequiredToBeLossyInt;
BVSparse<JitArenaAllocator> localConsiderSymsAsRealUsesInNoImplicitCallUses(tempAlloc);
considerSymsAsRealUsesInNoImplicitCallUses = &localConsiderSymsAsRealUsesInNoImplicitCallUses;
intOverflowCurrentlyMattersInRange = true;
FloatSymEquivalenceMap localFloatSymEquivalenceMap(tempAlloc);
floatSymEquivalenceMap = &localFloatSymEquivalenceMap;
NumberTempRepresentativePropertySymMap localNumberTempRepresentativePropertySym(tempAlloc);
numberTempRepresentativePropertySym = &localNumberTempRepresentativePropertySym;
FOREACH_BLOCK_BACKWARD_IN_FUNC_DEAD_OR_ALIVE(block, this->func)
{
this->OptBlock(block);
}
NEXT_BLOCK_BACKWARD_IN_FUNC_DEAD_OR_ALIVE;
if (this->tag == Js::DeadStorePhase && !PHASE_OFF(Js::MemOpPhase, this->func))
{
this->RemoveEmptyLoops();
}
this->func->m_fg->hasBackwardPassInfo = true;
if(DoTrackCompoundedIntOverflow())
{
// Tracking int overflow makes use of a scratch field in stack syms, which needs to be cleared
func->m_symTable->ClearStackSymScratch();
}
#if DBG_DUMP
if (PHASE_STATS(this->tag, this->func))
{
this->func->DumpHeader();
Output::Print(this->tag == Js::BackwardPhase? _u("Backward Phase Stats:\n") : _u("Deadstore Phase Stats:\n"));
if (this->DoDeadStore())
{
Output::Print(_u(" Deadstore : %3d\n"), this->numDeadStore);
}
if (this->DoMarkTempNumbers())
{
Output::Print(_u(" Temp Number : %3d\n"), this->numMarkTempNumber);
Output::Print(_u(" Transferred Temp Number: %3d\n"), this->numMarkTempNumberTransferred);
}
if (this->DoMarkTempObjects())
{
Output::Print(_u(" Temp Object : %3d\n"), this->numMarkTempObject);
}
}
#endif
}
void
BackwardPass::MergeSuccBlocksInfo(BasicBlock * block)
{
// Can't reuse the bv in the current block, because its successor can be itself.
TempNumberTracker * tempNumberTracker = nullptr;
TempObjectTracker * tempObjectTracker = nullptr;
#if DBG
TempObjectVerifyTracker * tempObjectVerifyTracker = nullptr;
#endif
HashTable<AddPropertyCacheBucket> * stackSymToFinalType = nullptr;
HashTable<ObjTypeGuardBucket> * stackSymToGuardedProperties = nullptr;
HashTable<ObjWriteGuardBucket> * stackSymToWriteGuardsMap = nullptr;
BVSparse<JitArenaAllocator> * cloneStrCandidates = nullptr;
BVSparse<JitArenaAllocator> * noImplicitCallUses = nullptr;
BVSparse<JitArenaAllocator> * noImplicitCallNoMissingValuesUses = nullptr;
BVSparse<JitArenaAllocator> * noImplicitCallNativeArrayUses = nullptr;
BVSparse<JitArenaAllocator> * noImplicitCallJsArrayHeadSegmentSymUses = nullptr;
BVSparse<JitArenaAllocator> * noImplicitCallArrayLengthSymUses = nullptr;
BVSparse<JitArenaAllocator> * upwardExposedUses = nullptr;
BVSparse<JitArenaAllocator> * upwardExposedFields = nullptr;
BVSparse<JitArenaAllocator> * typesNeedingKnownObjectLayout = nullptr;
BVSparse<JitArenaAllocator> * slotDeadStoreCandidates = nullptr;
BVSparse<JitArenaAllocator> * byteCodeUpwardExposedUsed = nullptr;
BVSparse<JitArenaAllocator> * couldRemoveNegZeroBailoutForDef = nullptr;
BVSparse<JitArenaAllocator> * liveFixedFields = nullptr;
#if DBG
uint byteCodeLocalsCount = func->GetJITFunctionBody()->GetLocalsCount();
StackSym ** byteCodeRestoreSyms = nullptr;
BVSparse<JitArenaAllocator> * excludeByteCodeUpwardExposedTracking = nullptr;
#endif
Assert(!block->isDead || block->GetSuccList()->Empty());
if (this->DoByteCodeUpwardExposedUsed())
{
byteCodeUpwardExposedUsed = JitAnew(this->tempAlloc, BVSparse<JitArenaAllocator>, this->tempAlloc);
#if DBG
byteCodeRestoreSyms = JitAnewArrayZ(this->tempAlloc, StackSym *, byteCodeLocalsCount);
excludeByteCodeUpwardExposedTracking = JitAnew(this->tempAlloc, BVSparse<JitArenaAllocator>, this->tempAlloc);
#endif
}
#if DBG
if (!IsCollectionPass() && this->DoMarkTempObjectVerify())
{
tempObjectVerifyTracker = JitAnew(this->tempAlloc, TempObjectVerifyTracker, this->tempAlloc, block->loop != nullptr);
}
#endif
if (!block->isDead)
{
bool keepUpwardExposed = (this->tag == Js::BackwardPhase);
JitArenaAllocator *upwardExposedArena = nullptr;
if(!IsCollectionPass())
{
upwardExposedArena = keepUpwardExposed ? this->globOpt->alloc : this->tempAlloc;
upwardExposedUses = JitAnew(upwardExposedArena, BVSparse<JitArenaAllocator>, upwardExposedArena);
upwardExposedFields = JitAnew(upwardExposedArena, BVSparse<JitArenaAllocator>, upwardExposedArena);
if (this->tag == Js::DeadStorePhase)
{
liveFixedFields = JitAnew(this->tempAlloc, BVSparse<JitArenaAllocator>, this->tempAlloc);
typesNeedingKnownObjectLayout = JitAnew(this->tempAlloc, BVSparse<JitArenaAllocator>, this->tempAlloc);
}
if (this->DoDeadStoreSlots())
{
slotDeadStoreCandidates = JitAnew(this->tempAlloc, BVSparse<JitArenaAllocator>, this->tempAlloc);
}
if (this->DoMarkTempNumbers())
{
tempNumberTracker = JitAnew(this->tempAlloc, TempNumberTracker, this->tempAlloc, block->loop != nullptr);
}
if (this->DoMarkTempObjects())
{
tempObjectTracker = JitAnew(this->tempAlloc, TempObjectTracker, this->tempAlloc, block->loop != nullptr);
}
noImplicitCallUses = JitAnew(this->tempAlloc, BVSparse<JitArenaAllocator>, this->tempAlloc);
noImplicitCallNoMissingValuesUses = JitAnew(this->tempAlloc, BVSparse<JitArenaAllocator>, this->tempAlloc);
noImplicitCallNativeArrayUses = JitAnew(this->tempAlloc, BVSparse<JitArenaAllocator>, this->tempAlloc);
noImplicitCallJsArrayHeadSegmentSymUses = JitAnew(this->tempAlloc, BVSparse<JitArenaAllocator>, this->tempAlloc);
noImplicitCallArrayLengthSymUses = JitAnew(this->tempAlloc, BVSparse<JitArenaAllocator>, this->tempAlloc);
if (this->tag == Js::BackwardPhase)
{
cloneStrCandidates = JitAnew(this->globOpt->alloc, BVSparse<JitArenaAllocator>, this->globOpt->alloc);
}
else
{
couldRemoveNegZeroBailoutForDef = JitAnew(this->tempAlloc, BVSparse<JitArenaAllocator>, this->tempAlloc);
}
}
bool firstSucc = true;
FOREACH_SUCCESSOR_BLOCK(blockSucc, block)
{
#if defined(DBG_DUMP) || defined(ENABLE_DEBUG_CONFIG_OPTIONS)
char16 debugStringBuffer[MAX_FUNCTION_BODY_DEBUG_STRING_SIZE];
#endif
// save the byteCodeUpwardExposedUsed from deleting for the block right after the memop loop
if (this->tag == Js::DeadStorePhase && !this->IsPrePass() && globOpt->HasMemOp(block->loop) && blockSucc->loop != block->loop)
{
Assert(block->loop->memOpInfo->inductionVariablesUsedAfterLoop == nullptr);
block->loop->memOpInfo->inductionVariablesUsedAfterLoop = JitAnew(this->tempAlloc, BVSparse<JitArenaAllocator>, this->tempAlloc);
block->loop->memOpInfo->inductionVariablesUsedAfterLoop->Or(blockSucc->byteCodeUpwardExposedUsed);
block->loop->memOpInfo->inductionVariablesUsedAfterLoop->Or(blockSucc->upwardExposedUses);
}
bool deleteData = false;
if (!blockSucc->isLoopHeader && blockSucc->backwardPassCurrentLoop == this->currentPrePassLoop)
{
Assert(blockSucc->GetDataUseCount() != 0);
deleteData = (blockSucc->DecrementDataUseCount() == 0);
if (blockSucc->GetFirstInstr()->m_next->m_opcode == Js::OpCode::SpeculatedLoadFence)
{
// We hold on to data for these blocks until the arena gets cleared due to unusual data lifetimes.
deleteData = false;
blockSucc->IncrementDataUseCount();
}
}
#if DBG
if (excludeByteCodeUpwardExposedTracking && blockSucc->excludeByteCodeUpwardExposedTracking)
{
excludeByteCodeUpwardExposedTracking->Or(blockSucc->excludeByteCodeUpwardExposedTracking);
}
#endif
Assert((byteCodeUpwardExposedUsed == nullptr) == !this->DoByteCodeUpwardExposedUsed());
if (byteCodeUpwardExposedUsed && blockSucc->byteCodeUpwardExposedUsed)
{
byteCodeUpwardExposedUsed->Or(blockSucc->byteCodeUpwardExposedUsed);
if (this->tag == Js::DeadStorePhase)
{
#if DBG
for (uint i = 0; i < byteCodeLocalsCount; i++)
{
if (byteCodeRestoreSyms[i] == nullptr)
{
byteCodeRestoreSyms[i] = blockSucc->byteCodeRestoreSyms[i];
}
else
{
Assert(blockSucc->byteCodeRestoreSyms[i] == nullptr
|| byteCodeRestoreSyms[i] == blockSucc->byteCodeRestoreSyms[i]);
}
}
#endif
if (deleteData)
{
// byteCodeUpwardExposedUsed is required to populate the writeThroughSymbolsSet for the try region. So, don't delete it in the backwards pass.
JitAdelete(this->tempAlloc, blockSucc->byteCodeUpwardExposedUsed);
blockSucc->byteCodeUpwardExposedUsed = nullptr;
}
}
#if DBG
if (deleteData)
{
JitAdeleteArray(this->tempAlloc, byteCodeLocalsCount, blockSucc->byteCodeRestoreSyms);
blockSucc->byteCodeRestoreSyms = nullptr;
JitAdelete(this->tempAlloc, blockSucc->excludeByteCodeUpwardExposedTracking);
blockSucc->excludeByteCodeUpwardExposedTracking = nullptr;
}
#endif
}
else
{
Assert(blockSucc->byteCodeUpwardExposedUsed == nullptr);
Assert(blockSucc->byteCodeRestoreSyms == nullptr);
Assert(blockSucc->excludeByteCodeUpwardExposedTracking == nullptr);
}
if(IsCollectionPass())
{
continue;
}
Assert((blockSucc->upwardExposedUses != nullptr)
|| (blockSucc->isLoopHeader && (this->IsPrePass() || blockSucc->loop->IsDescendentOrSelf(block->loop))));
Assert((blockSucc->upwardExposedFields != nullptr)
|| (blockSucc->isLoopHeader && (this->IsPrePass() || blockSucc->loop->IsDescendentOrSelf(block->loop))));
Assert((blockSucc->typesNeedingKnownObjectLayout != nullptr)
|| (blockSucc->isLoopHeader && (this->IsPrePass() || blockSucc->loop->IsDescendentOrSelf(block->loop)))
|| this->tag != Js::DeadStorePhase);
Assert((blockSucc->slotDeadStoreCandidates != nullptr)
|| (blockSucc->isLoopHeader && (this->IsPrePass() || blockSucc->loop->IsDescendentOrSelf(block->loop)))
|| !this->DoDeadStoreSlots());
Assert((blockSucc->tempNumberTracker != nullptr)
|| (blockSucc->isLoopHeader && (this->IsPrePass() || blockSucc->loop->IsDescendentOrSelf(block->loop)))
|| !this->DoMarkTempNumbers());
Assert((blockSucc->tempObjectTracker != nullptr)
|| (blockSucc->isLoopHeader && (this->IsPrePass() || blockSucc->loop->IsDescendentOrSelf(block->loop)))
|| !this->DoMarkTempObjects());
Assert((blockSucc->tempObjectVerifyTracker != nullptr)
|| (blockSucc->isLoopHeader && (this->IsPrePass() || blockSucc->loop->IsDescendentOrSelf(block->loop)))
|| !this->DoMarkTempObjectVerify());
if (this->tag == Js::DeadStorePhase && blockSucc->liveFixedFields != nullptr)
{
liveFixedFields->Or(blockSucc->liveFixedFields);
JitAdelete(this->tempAlloc, blockSucc->liveFixedFields);
blockSucc->liveFixedFields = nullptr;
}
if (blockSucc->upwardExposedUses != nullptr)
{
upwardExposedUses->Or(blockSucc->upwardExposedUses);
if (deleteData && (!keepUpwardExposed
|| (this->IsPrePass() && blockSucc->backwardPassCurrentLoop == this->currentPrePassLoop)))
{
JitAdelete(upwardExposedArena, blockSucc->upwardExposedUses);
blockSucc->upwardExposedUses = nullptr;
}
}
if (blockSucc->upwardExposedFields != nullptr)
{
upwardExposedFields->Or(blockSucc->upwardExposedFields);
if (deleteData && (!keepUpwardExposed
|| (this->IsPrePass() && blockSucc->backwardPassCurrentLoop == this->currentPrePassLoop)))
{
JitAdelete(upwardExposedArena, blockSucc->upwardExposedFields);
blockSucc->upwardExposedFields = nullptr;
}
}
if (blockSucc->typesNeedingKnownObjectLayout != nullptr)
{
typesNeedingKnownObjectLayout->Or(blockSucc->typesNeedingKnownObjectLayout);
if (deleteData)
{
JitAdelete(this->tempAlloc, blockSucc->typesNeedingKnownObjectLayout);
blockSucc->typesNeedingKnownObjectLayout = nullptr;
}
}
if (blockSucc->slotDeadStoreCandidates != nullptr)
{
slotDeadStoreCandidates->And(blockSucc->slotDeadStoreCandidates);
if (deleteData)
{
JitAdelete(this->tempAlloc, blockSucc->slotDeadStoreCandidates);
blockSucc->slotDeadStoreCandidates = nullptr;
}
}
if (blockSucc->tempNumberTracker != nullptr)
{
Assert((blockSucc->loop != nullptr) == blockSucc->tempNumberTracker->HasTempTransferDependencies());
tempNumberTracker->MergeData(blockSucc->tempNumberTracker, deleteData);
if (deleteData)
{
blockSucc->tempNumberTracker = nullptr;
}
}
if (blockSucc->tempObjectTracker != nullptr)
{
Assert((blockSucc->loop != nullptr) == blockSucc->tempObjectTracker->HasTempTransferDependencies());
tempObjectTracker->MergeData(blockSucc->tempObjectTracker, deleteData);
if (deleteData)
{
blockSucc->tempObjectTracker = nullptr;
}
}
#if DBG
if (blockSucc->tempObjectVerifyTracker != nullptr)
{
Assert((blockSucc->loop != nullptr) == blockSucc->tempObjectVerifyTracker->HasTempTransferDependencies());
tempObjectVerifyTracker->MergeData(blockSucc->tempObjectVerifyTracker, deleteData);
if (deleteData)
{
blockSucc->tempObjectVerifyTracker = nullptr;
}
}
#endif
PHASE_PRINT_TRACE(Js::ObjTypeSpecStorePhase, this->func,
_u("ObjTypeSpecStore: func %s, edge %d => %d: "),
this->func->GetDebugNumberSet(debugStringBuffer),
block->GetBlockNum(), blockSucc->GetBlockNum());
auto fixupFrom = [block, blockSucc, upwardExposedUses, this](Bucket<AddPropertyCacheBucket> &bucket)
{
AddPropertyCacheBucket *fromData = &bucket.element;
if (fromData->GetInitialType() == nullptr ||
fromData->GetFinalType() == fromData->GetInitialType())
{
return;
}
this->InsertTypeTransitionsAtPriorSuccessors(block, blockSucc, bucket.value, fromData, upwardExposedUses);
};
auto fixupTo = [blockSucc, upwardExposedUses, this](Bucket<AddPropertyCacheBucket> &bucket)
{
AddPropertyCacheBucket *toData = &bucket.element;
if (toData->GetInitialType() == nullptr ||
toData->GetFinalType() == toData->GetInitialType())
{
return;
}
this->InsertTypeTransitionAtBlock(blockSucc, bucket.value, toData, upwardExposedUses);
};
if (blockSucc->stackSymToFinalType != nullptr)
{
#if DBG_DUMP
if (PHASE_TRACE(Js::ObjTypeSpecStorePhase, this->func))
{
blockSucc->stackSymToFinalType->Dump();
}
#endif
if (firstSucc)
{
stackSymToFinalType = blockSucc->stackSymToFinalType->Copy();
}
else if (stackSymToFinalType != nullptr)
{
if (this->IsPrePass())
{
stackSymToFinalType->And(blockSucc->stackSymToFinalType);
}
else
{
// Insert any type transitions that can't be merged past this point.
stackSymToFinalType->AndWithFixup(blockSucc->stackSymToFinalType, fixupFrom, fixupTo);
}
}
else if (!this->IsPrePass())
{
FOREACH_HASHTABLE_ENTRY(AddPropertyCacheBucket, bucket, blockSucc->stackSymToFinalType)
{
fixupTo(bucket);
}
NEXT_HASHTABLE_ENTRY;
}
if (deleteData)
{
blockSucc->stackSymToFinalType->Delete();
blockSucc->stackSymToFinalType = nullptr;
}
}
else
{
PHASE_PRINT_TRACE(Js::ObjTypeSpecStorePhase, this->func, _u("null\n"));
if (stackSymToFinalType)
{
if (!this->IsPrePass())
{
FOREACH_HASHTABLE_ENTRY(AddPropertyCacheBucket, bucket, stackSymToFinalType)
{
fixupFrom(bucket);
}
NEXT_HASHTABLE_ENTRY;
}
stackSymToFinalType->Delete();
stackSymToFinalType = nullptr;
}
}
if (tag == Js::BackwardPhase)
{
if (blockSucc->cloneStrCandidates != nullptr)
{
Assert(cloneStrCandidates != nullptr);
cloneStrCandidates->Or(blockSucc->cloneStrCandidates);
if (deleteData)
{
JitAdelete(this->globOpt->alloc, blockSucc->cloneStrCandidates);
blockSucc->cloneStrCandidates = nullptr;
}
}
#if DBG_DUMP
if (PHASE_VERBOSE_TRACE(Js::TraceObjTypeSpecWriteGuardsPhase, this->func))
{
char16 debugStringBuffer2[MAX_FUNCTION_BODY_DEBUG_STRING_SIZE];
Output::Print(_u("ObjTypeSpec: top function %s (%s), function %s (%s), write guard symbols on edge %d => %d: "),
this->func->GetTopFunc()->GetJITFunctionBody()->GetDisplayName(),
this->func->GetTopFunc()->GetDebugNumberSet(debugStringBuffer),
this->func->GetJITFunctionBody()->GetDisplayName(),
this->func->GetDebugNumberSet(debugStringBuffer2), block->GetBlockNum(),
blockSucc->GetBlockNum());
}
#endif
if (blockSucc->stackSymToWriteGuardsMap != nullptr)
{
#if DBG_DUMP
if (PHASE_VERBOSE_TRACE(Js::TraceObjTypeSpecWriteGuardsPhase, this->func))
{
Output::Print(_u("\n"));
blockSucc->stackSymToWriteGuardsMap->Dump();
}
#endif
if (stackSymToWriteGuardsMap == nullptr)
{
stackSymToWriteGuardsMap = blockSucc->stackSymToWriteGuardsMap->Copy();
}
else
{
stackSymToWriteGuardsMap->Or(
blockSucc->stackSymToWriteGuardsMap, &BackwardPass::MergeWriteGuards);
}
if (deleteData)
{
blockSucc->stackSymToWriteGuardsMap->Delete();
blockSucc->stackSymToWriteGuardsMap = nullptr;
}
}
else
{
#if DBG_DUMP
if (PHASE_VERBOSE_TRACE(Js::TraceObjTypeSpecWriteGuardsPhase, this->func))
{
Output::Print(_u("null\n"));
}
#endif
}
}
else
{
#if DBG_DUMP
if (PHASE_VERBOSE_TRACE(Js::TraceObjTypeSpecTypeGuardsPhase, this->func))
{
char16 debugStringBuffer2[MAX_FUNCTION_BODY_DEBUG_STRING_SIZE];
Output::Print(_u("ObjTypeSpec: top function %s (%s), function %s (%s), guarded property operations on edge %d => %d: \n"),
this->func->GetTopFunc()->GetJITFunctionBody()->GetDisplayName(),
this->func->GetTopFunc()->GetDebugNumberSet(debugStringBuffer),
this->func->GetJITFunctionBody()->GetDisplayName(),
this->func->GetDebugNumberSet(debugStringBuffer2),
block->GetBlockNum(), blockSucc->GetBlockNum());
}
#endif
if (blockSucc->stackSymToGuardedProperties != nullptr)
{
#if DBG_DUMP
if (PHASE_VERBOSE_TRACE(Js::TraceObjTypeSpecTypeGuardsPhase, this->func))
{
blockSucc->stackSymToGuardedProperties->Dump();
Output::Print(_u("\n"));
}
#endif
if (stackSymToGuardedProperties == nullptr)
{
stackSymToGuardedProperties = blockSucc->stackSymToGuardedProperties->Copy();
}
else
{
stackSymToGuardedProperties->Or(
blockSucc->stackSymToGuardedProperties, &BackwardPass::MergeGuardedProperties);
}
if (deleteData)
{
blockSucc->stackSymToGuardedProperties->Delete();
blockSucc->stackSymToGuardedProperties = nullptr;
}
}
else
{
#if DBG_DUMP
if (PHASE_VERBOSE_TRACE(Js::TraceObjTypeSpecTypeGuardsPhase, this->func))
{
Output::Print(_u("null\n"));
}
#endif
}
if (blockSucc->couldRemoveNegZeroBailoutForDef != nullptr)
{
couldRemoveNegZeroBailoutForDef->And(blockSucc->couldRemoveNegZeroBailoutForDef);
if (deleteData)
{
JitAdelete(this->tempAlloc, blockSucc->couldRemoveNegZeroBailoutForDef);
blockSucc->couldRemoveNegZeroBailoutForDef = nullptr;
}
}
this->CombineTypeIDsWithFinalType(block, blockSucc);
}
if (blockSucc->noImplicitCallUses != nullptr)
{
noImplicitCallUses->Or(blockSucc->noImplicitCallUses);
if (deleteData)
{
JitAdelete(this->tempAlloc, blockSucc->noImplicitCallUses);
blockSucc->noImplicitCallUses = nullptr;
}
}
if (blockSucc->noImplicitCallNoMissingValuesUses != nullptr)
{
noImplicitCallNoMissingValuesUses->Or(blockSucc->noImplicitCallNoMissingValuesUses);
if (deleteData)
{
JitAdelete(this->tempAlloc, blockSucc->noImplicitCallNoMissingValuesUses);
blockSucc->noImplicitCallNoMissingValuesUses = nullptr;
}
}
if (blockSucc->noImplicitCallNativeArrayUses != nullptr)
{
noImplicitCallNativeArrayUses->Or(blockSucc->noImplicitCallNativeArrayUses);
if (deleteData)
{
JitAdelete(this->tempAlloc, blockSucc->noImplicitCallNativeArrayUses);
blockSucc->noImplicitCallNativeArrayUses = nullptr;
}
}
if (blockSucc->noImplicitCallJsArrayHeadSegmentSymUses != nullptr)
{
noImplicitCallJsArrayHeadSegmentSymUses->Or(blockSucc->noImplicitCallJsArrayHeadSegmentSymUses);
if (deleteData)
{
JitAdelete(this->tempAlloc, blockSucc->noImplicitCallJsArrayHeadSegmentSymUses);
blockSucc->noImplicitCallJsArrayHeadSegmentSymUses = nullptr;
}
}
if (blockSucc->noImplicitCallArrayLengthSymUses != nullptr)
{
noImplicitCallArrayLengthSymUses->Or(blockSucc->noImplicitCallArrayLengthSymUses);
if (deleteData)
{
JitAdelete(this->tempAlloc, blockSucc->noImplicitCallArrayLengthSymUses);
blockSucc->noImplicitCallArrayLengthSymUses = nullptr;
}
}