DenseMap<BasicBlock *, Value *> &Loads, Function &F);
void demoteNonlocalUses(Value *V, std::set<BasicBlock *> &ColorsForBB,
Function &F);
- bool prepareExplicitEH(Function &F);
- void numberFunclet(BasicBlock *InitialBB, BasicBlock *FuncletBB);
+ bool prepareExplicitEH(Function &F,
+ SmallVectorImpl<BasicBlock *> &EntryBlocks);
+ void colorFunclets(Function &F, SmallVectorImpl<BasicBlock *> &EntryBlocks);
Triple TheTriple;
std::map<BasicBlock *, std::set<BasicBlock *>> BlockColors;
std::map<BasicBlock *, std::set<BasicBlock *>> FuncletBlocks;
+ std::map<BasicBlock *, std::set<BasicBlock *>> FuncletChildren;
};
class WinEHFrameVariableMaterializer : public ValueMaterializer {
SmallVector<LandingPadInst *, 4> LPads;
SmallVector<ResumeInst *, 4> Resumes;
+ SmallVector<BasicBlock *, 4> EntryBlocks;
bool ForExplicitEH = false;
for (BasicBlock &BB : Fn) {
- if (auto *LP = BB.getLandingPadInst()) {
+ Instruction *First = BB.getFirstNonPHI();
+ if (auto *LP = dyn_cast<LandingPadInst>(First)) {
LPads.push_back(LP);
- } else if (BB.getFirstNonPHI()->isEHPad()) {
+ } else if (First->isEHPad()) {
+ if (!ForExplicitEH)
+ EntryBlocks.push_back(&Fn.getEntryBlock());
+ if (!isa<CatchEndPadInst>(First) && !isa<CleanupEndPadInst>(First))
+ EntryBlocks.push_back(&BB);
ForExplicitEH = true;
- break;
}
if (auto *Resume = dyn_cast<ResumeInst>(BB.getTerminator()))
Resumes.push_back(Resume);
}
if (ForExplicitEH)
- return prepareExplicitEH(Fn);
+ return prepareExplicitEH(Fn, EntryBlocks);
// No need to prepare functions that lack landing pads.
if (LPads.empty())
};
}
-void WinEHNumbering::createUnwindMapEntry(int ToState, ActionHandler *AH) {
+static int addUnwindMapEntry(WinEHFuncInfo &FuncInfo, int ToState,
+ const Value *V) {
WinEHUnwindMapEntry UME;
UME.ToState = ToState;
- if (auto *CH = dyn_cast_or_null<CleanupHandler>(AH))
- UME.Cleanup = cast<Function>(CH->getHandlerBlockOrFunc());
- else
- UME.Cleanup = nullptr;
+ UME.Cleanup = V;
FuncInfo.UnwindMap.push_back(UME);
+ return FuncInfo.getLastStateNumber();
+}
+
+static void addTryBlockMapEntry(WinEHFuncInfo &FuncInfo, int TryLow,
+ int TryHigh, int CatchHigh,
+ ArrayRef<const CatchPadInst *> Handlers) {
+ WinEHTryBlockMapEntry TBME;
+ TBME.TryLow = TryLow;
+ TBME.TryHigh = TryHigh;
+ TBME.CatchHigh = CatchHigh;
+ assert(TBME.TryLow <= TBME.TryHigh);
+ for (const CatchPadInst *CPI : Handlers) {
+ WinEHHandlerType HT;
+ Constant *TypeInfo = cast<Constant>(CPI->getArgOperand(0));
+ if (TypeInfo->isNullValue()) {
+ HT.Adjectives = 0x40;
+ HT.TypeDescriptor = nullptr;
+ } else {
+ auto *GV = cast<GlobalVariable>(TypeInfo->stripPointerCasts());
+ // Selectors are always pointers to GlobalVariables with 'struct' type.
+ // The struct has two fields, adjectives and a type descriptor.
+ auto *CS = cast<ConstantStruct>(GV->getInitializer());
+ HT.Adjectives =
+ cast<ConstantInt>(CS->getAggregateElement(0U))->getZExtValue();
+ HT.TypeDescriptor =
+ cast<GlobalVariable>(CS->getAggregateElement(1)->stripPointerCasts());
+ }
+ HT.Handler = CPI->getNormalDest();
+ // FIXME: Pass CPI->getArgOperand(1).
+ HT.CatchObjRecoverIdx = -1;
+ TBME.HandlerArray.push_back(HT);
+ }
+ FuncInfo.TryBlockMap.push_back(TBME);
+}
+
+void WinEHNumbering::createUnwindMapEntry(int ToState, ActionHandler *AH) {
+ Value *V = nullptr;
+ if (auto *CH = dyn_cast_or_null<CleanupHandler>(AH))
+ V = cast<Function>(CH->getHandlerBlockOrFunc());
+ addUnwindMapEntry(FuncInfo, ToState, V);
}
void WinEHNumbering::createTryBlockMapEntry(int TryLow, int TryHigh,
continue;
int N;
for (N = 0; N < NumHandlers; ++N) {
- if (Entry.HandlerArray[N].Handler != Handlers[N]->getHandlerBlockOrFunc())
+ if (Entry.HandlerArray[N].Handler.get<const Value *>() !=
+ Handlers[N]->getHandlerBlockOrFunc())
break; // breaks out of inner loop
}
// If all the handlers match, this is what we were looking for.
continue;
processCallSite(ActionList, II);
ActionList.clear();
- FuncInfo.LandingPadStateMap[LPI] = currentEHNumber();
+ FuncInfo.EHPadStateMap[LPI] = currentEHNumber();
DEBUG(dbgs() << "Assigning state " << currentEHNumber()
<< " to landing pad at " << LPI->getParent()->getName()
<< '\n');
}
}
+static const CatchPadInst *getSingleCatchPadPredecessor(const BasicBlock *BB) {
+ for (const BasicBlock *PredBlock : predecessors(BB))
+ if (auto *CPI = dyn_cast<CatchPadInst>(PredBlock->getFirstNonPHI()))
+ return CPI;
+ return nullptr;
+}
+
+/// Find all the catchpads that feed directly into the catchendpad. Frontends
+/// using this personality should ensure that each catchendpad and catchpad has
+/// one or zero catchpad predecessors.
+///
+/// The following C++ generates the IR after it:
+/// try {
+/// } catch (A) {
+/// } catch (B) {
+/// }
+///
+/// IR:
+/// %catchpad.A
+/// catchpad [i8* A typeinfo]
+/// to label %catch.A unwind label %catchpad.B
+/// %catchpad.B
+/// catchpad [i8* B typeinfo]
+/// to label %catch.B unwind label %endcatches
+/// %endcatches
+/// catchendblock unwind to caller
+void findCatchPadsForCatchEndPad(
+ const BasicBlock *CatchEndBB,
+ SmallVectorImpl<const CatchPadInst *> &Handlers) {
+ const CatchPadInst *CPI = getSingleCatchPadPredecessor(CatchEndBB);
+ while (CPI) {
+ Handlers.push_back(CPI);
+ CPI = getSingleCatchPadPredecessor(CPI->getParent());
+ }
+ // We've pushed these back into reverse source order. Reverse them to get
+ // the list back into source order.
+ std::reverse(Handlers.begin(), Handlers.end());
+}
+
+// Given BB which ends in an unwind edge, return the EHPad that this BB belongs
+// to. If the unwind edge came from an invoke, return null.
+static const BasicBlock *getEHPadFromPredecessor(const BasicBlock *BB) {
+ const TerminatorInst *TI = BB->getTerminator();
+ if (isa<InvokeInst>(TI))
+ return nullptr;
+ if (TI->isEHPad())
+ return BB;
+ return cast<CleanupReturnInst>(TI)->getCleanupPad()->getParent();
+}
+
+static void calculateExplicitCXXStateNumbers(WinEHFuncInfo &FuncInfo,
+ const BasicBlock &BB,
+ int ParentState) {
+ assert(BB.isEHPad());
+ const Instruction *FirstNonPHI = BB.getFirstNonPHI();
+ // All catchpad instructions will be handled when we process their
+ // respective catchendpad instruction.
+ if (isa<CatchPadInst>(FirstNonPHI))
+ return;
+
+ if (isa<CatchEndPadInst>(FirstNonPHI)) {
+ SmallVector<const CatchPadInst *, 2> Handlers;
+ findCatchPadsForCatchEndPad(&BB, Handlers);
+ const BasicBlock *FirstTryPad = Handlers.front()->getParent();
+ int TryLow = addUnwindMapEntry(FuncInfo, ParentState, nullptr);
+ FuncInfo.EHPadStateMap[Handlers.front()] = TryLow;
+ for (const BasicBlock *PredBlock : predecessors(FirstTryPad))
+ if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
+ calculateExplicitCXXStateNumbers(FuncInfo, *PredBlock, TryLow);
+ int CatchLow = addUnwindMapEntry(FuncInfo, ParentState, nullptr);
+
+ // catchpads are separate funclets in C++ EH due to the way rethrow works.
+ // In SEH, they aren't, so no invokes will unwind to the catchendpad.
+ FuncInfo.EHPadStateMap[FirstNonPHI] = CatchLow;
+ int TryHigh = CatchLow - 1;
+ for (const BasicBlock *PredBlock : predecessors(&BB))
+ if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
+ calculateExplicitCXXStateNumbers(FuncInfo, *PredBlock, CatchLow);
+ int CatchHigh = FuncInfo.getLastStateNumber();
+ addTryBlockMapEntry(FuncInfo, TryLow, TryHigh, CatchHigh, Handlers);
+ DEBUG(dbgs() << "TryLow[" << FirstTryPad->getName() << "]: " << TryLow
+ << '\n');
+ DEBUG(dbgs() << "TryHigh[" << FirstTryPad->getName() << "]: " << TryHigh
+ << '\n');
+ DEBUG(dbgs() << "CatchHigh[" << FirstTryPad->getName() << "]: " << CatchHigh
+ << '\n');
+ } else if (isa<CleanupPadInst>(FirstNonPHI)) {
+ int CleanupState = addUnwindMapEntry(FuncInfo, ParentState, &BB);
+ FuncInfo.EHPadStateMap[FirstNonPHI] = CleanupState;
+ DEBUG(dbgs() << "Assigning state #" << CleanupState << " to BB "
+ << BB.getName() << '\n');
+ for (const BasicBlock *PredBlock : predecessors(&BB))
+ if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
+ calculateExplicitCXXStateNumbers(FuncInfo, *PredBlock, CleanupState);
+ } else if (isa<TerminatePadInst>(FirstNonPHI)) {
+ report_fatal_error("Not yet implemented!");
+ } else {
+ llvm_unreachable("unexpected EH Pad!");
+ }
+}
+
+static int addSEHHandler(WinEHFuncInfo &FuncInfo, int ParentState,
+ const Function *Filter, const BasicBlock *Handler) {
+ SEHUnwindMapEntry Entry;
+ Entry.ToState = ParentState;
+ Entry.Filter = Filter;
+ Entry.Handler = Handler;
+ FuncInfo.SEHUnwindMap.push_back(Entry);
+ return FuncInfo.SEHUnwindMap.size() - 1;
+}
+
+static void calculateExplicitSEHStateNumbers(WinEHFuncInfo &FuncInfo,
+ const BasicBlock &BB,
+ int ParentState) {
+ assert(BB.isEHPad());
+ const Instruction *FirstNonPHI = BB.getFirstNonPHI();
+ // All catchpad instructions will be handled when we process their
+ // respective catchendpad instruction.
+ if (isa<CatchPadInst>(FirstNonPHI))
+ return;
+
+ if (isa<CatchEndPadInst>(FirstNonPHI)) {
+ // Extract the filter function and the __except basic block and create a
+ // state for them.
+ SmallVector<const CatchPadInst *, 1> Handlers;
+ findCatchPadsForCatchEndPad(&BB, Handlers);
+ assert(Handlers.size() == 1 &&
+ "SEH doesn't have multiple handlers per __try");
+ const CatchPadInst *CPI = Handlers.front();
+ const BasicBlock *CatchPadBB = CPI->getParent();
+ const Function *Filter =
+ cast<Function>(CPI->getArgOperand(0)->stripPointerCasts());
+ int TryState =
+ addSEHHandler(FuncInfo, ParentState, Filter, CPI->getNormalDest());
+
+ // Everything in the __try block uses TryState as its parent state.
+ FuncInfo.EHPadStateMap[CPI] = TryState;
+ DEBUG(dbgs() << "Assigning state #" << TryState << " to BB "
+ << CatchPadBB->getName() << '\n');
+ for (const BasicBlock *PredBlock : predecessors(CatchPadBB))
+ if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
+ calculateExplicitSEHStateNumbers(FuncInfo, *PredBlock, TryState);
+
+ // Everything in the __except block unwinds to ParentState, just like code
+ // outside the __try.
+ FuncInfo.EHPadStateMap[FirstNonPHI] = ParentState;
+ DEBUG(dbgs() << "Assigning state #" << ParentState << " to BB "
+ << BB.getName() << '\n');
+ for (const BasicBlock *PredBlock : predecessors(&BB))
+ if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
+ calculateExplicitSEHStateNumbers(FuncInfo, *PredBlock, ParentState);
+ } else if (isa<CleanupPadInst>(FirstNonPHI)) {
+ int CleanupState =
+ addSEHHandler(FuncInfo, ParentState, /*Filter=*/nullptr, &BB);
+ FuncInfo.EHPadStateMap[FirstNonPHI] = CleanupState;
+ DEBUG(dbgs() << "Assigning state #" << CleanupState << " to BB "
+ << BB.getName() << '\n');
+ for (const BasicBlock *PredBlock : predecessors(&BB))
+ if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
+ calculateExplicitSEHStateNumbers(FuncInfo, *PredBlock, CleanupState);
+ } else if (isa<CleanupEndPadInst>(FirstNonPHI)) {
+ // Anything unwinding through CleanupEndPadInst is in ParentState.
+ FuncInfo.EHPadStateMap[FirstNonPHI] = ParentState;
+ DEBUG(dbgs() << "Assigning state #" << ParentState << " to BB "
+ << BB.getName() << '\n');
+ for (const BasicBlock *PredBlock : predecessors(&BB))
+ if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
+ calculateExplicitSEHStateNumbers(FuncInfo, *PredBlock, ParentState);
+ } else if (isa<TerminatePadInst>(FirstNonPHI)) {
+ report_fatal_error("Not yet implemented!");
+ } else {
+ llvm_unreachable("unexpected EH Pad!");
+ }
+}
+
+/// Check if the EH Pad unwinds to caller. Cleanups are a little bit of a
+/// special case because we have to look at the cleanupret instruction that uses
+/// the cleanuppad.
+static bool doesEHPadUnwindToCaller(const Instruction *EHPad) {
+ auto *CPI = dyn_cast<CleanupPadInst>(EHPad);
+ if (!CPI)
+ return EHPad->mayThrow();
+
+ // This cleanup does not return or unwind, so we say it unwinds to caller.
+ if (CPI->use_empty())
+ return true;
+
+ const Instruction *User = CPI->user_back();
+ if (auto *CRI = dyn_cast<CleanupReturnInst>(User))
+ return CRI->unwindsToCaller();
+ return cast<CleanupEndPadInst>(User)->unwindsToCaller();
+}
+
+void llvm::calculateSEHStateNumbers(const Function *ParentFn,
+ WinEHFuncInfo &FuncInfo) {
+ // Don't compute state numbers twice.
+ if (!FuncInfo.SEHUnwindMap.empty())
+ return;
+
+ for (const BasicBlock &BB : *ParentFn) {
+ if (!BB.isEHPad() || !doesEHPadUnwindToCaller(BB.getFirstNonPHI()))
+ continue;
+ calculateExplicitSEHStateNumbers(FuncInfo, BB, -1);
+ }
+}
+
void llvm::calculateWinCXXEHStateNumbers(const Function *ParentFn,
WinEHFuncInfo &FuncInfo) {
// Return if it's already been done.
- if (!FuncInfo.LandingPadStateMap.empty())
+ if (!FuncInfo.EHPadStateMap.empty())
+ return;
+
+ bool IsExplicit = false;
+ for (const BasicBlock &BB : *ParentFn) {
+ if (!BB.isEHPad())
+ continue;
+ const Instruction *FirstNonPHI = BB.getFirstNonPHI();
+ // Skip cleanupendpads; they are exits, not entries.
+ if (isa<CleanupEndPadInst>(FirstNonPHI))
+ continue;
+ if (!doesEHPadUnwindToCaller(FirstNonPHI))
+ continue;
+ calculateExplicitCXXStateNumbers(FuncInfo, BB, -1);
+ IsExplicit = true;
+ }
+
+ if (IsExplicit)
return;
WinEHNumbering Num(FuncInfo);
Num.processCallSite(None, ImmutableCallSite());
}
-void WinEHPrepare::numberFunclet(BasicBlock *InitialBB, BasicBlock *FuncletBB) {
- Instruction *FirstNonPHI = FuncletBB->getFirstNonPHI();
- bool IsCatch = isa<CatchPadInst>(FirstNonPHI);
- bool IsCleanup = isa<CleanupPadInst>(FirstNonPHI);
+void WinEHPrepare::colorFunclets(Function &F,
+ SmallVectorImpl<BasicBlock *> &EntryBlocks) {
+ SmallVector<std::pair<BasicBlock *, BasicBlock *>, 16> Worklist;
+ BasicBlock *EntryBlock = &F.getEntryBlock();
- // Initialize the worklist with the funclet's entry point.
- std::vector<BasicBlock *> Worklist;
- Worklist.push_back(InitialBB);
+ // Build up the color map, which maps each block to its set of 'colors'.
+ // For any block B, the "colors" of B are the set of funclets F (possibly
+ // including a root "funclet" representing the main function), such that
+ // F will need to directly contain B or a copy of B (where the term "directly
+ // contain" is used to distinguish from being "transitively contained" in
+ // a nested funclet).
+ // Use a CFG walk driven by a worklist of (block, color) pairs. The "color"
+ // sets attached during this processing to a block which is the entry of some
+ // funclet F is actually the set of F's parents -- i.e. the union of colors
+ // of all predecessors of F's entry. For all other blocks, the color sets
+ // are as defined above. A post-pass fixes up the block color map to reflect
+ // the same sense of "color" for funclet entries as for other blocks.
+
+ Worklist.push_back({EntryBlock, EntryBlock});
while (!Worklist.empty()) {
- BasicBlock *BB = Worklist.back();
- Worklist.pop_back();
-
- // There can be only one "pad" basic block in the funclet: the initial one.
- if (BB != FuncletBB && BB->isEHPad())
- continue;
-
- // Add 'FuncletBB' as a possible color for 'BB'.
- if (BlockColors[BB].insert(FuncletBB).second == false) {
- // Skip basic blocks which we have already visited.
- continue;
+ BasicBlock *Visiting;
+ BasicBlock *Color;
+ std::tie(Visiting, Color) = Worklist.pop_back_val();
+ Instruction *VisitingHead = Visiting->getFirstNonPHI();
+ if (VisitingHead->isEHPad() && !isa<CatchEndPadInst>(VisitingHead) &&
+ !isa<CleanupEndPadInst>(VisitingHead)) {
+ // Mark this as a funclet head as a member of itself.
+ FuncletBlocks[Visiting].insert(Visiting);
+ // Queue exits with the parent color.
+ for (User *Exit : VisitingHead->users()) {
+ for (BasicBlock *Succ :
+ successors(cast<Instruction>(Exit)->getParent())) {
+ if (BlockColors[Succ].insert(Color).second) {
+ Worklist.push_back({Succ, Color});
+ }
+ }
+ }
+ // Handle CatchPad specially since its successors need different colors.
+ if (CatchPadInst *CatchPad = dyn_cast<CatchPadInst>(VisitingHead)) {
+ // Visit the normal successor with the color of the new EH pad, and
+ // visit the unwind successor with the color of the parent.
+ BasicBlock *NormalSucc = CatchPad->getNormalDest();
+ if (BlockColors[NormalSucc].insert(Visiting).second) {
+ Worklist.push_back({NormalSucc, Visiting});
+ }
+ BasicBlock *UnwindSucc = CatchPad->getUnwindDest();
+ if (BlockColors[UnwindSucc].insert(Color).second) {
+ Worklist.push_back({UnwindSucc, Color});
+ }
+ continue;
+ }
+ // Switch color to the current node, except for terminate pads which
+ // have no bodies and only unwind successors and so need their successors
+ // visited with the color of the parent.
+ if (!isa<TerminatePadInst>(VisitingHead))
+ Color = Visiting;
+ } else {
+ // Note that this is a member of the given color.
+ FuncletBlocks[Color].insert(Visiting);
}
- FuncletBlocks[FuncletBB].insert(BB);
-
- Instruction *Terminator = BB->getTerminator();
- // The catchret's successors cannot be part of the funclet.
- if (IsCatch && isa<CatchReturnInst>(Terminator))
- continue;
- // The cleanupret's successors cannot be part of the funclet.
- if (IsCleanup && isa<CleanupReturnInst>(Terminator))
+ TerminatorInst *Terminator = Visiting->getTerminator();
+ if (isa<CleanupReturnInst>(Terminator) ||
+ isa<CatchReturnInst>(Terminator) ||
+ isa<CleanupEndPadInst>(Terminator)) {
+ // These blocks' successors have already been queued with the parent
+ // color.
continue;
+ }
+ for (BasicBlock *Succ : successors(Visiting)) {
+ if (isa<CatchEndPadInst>(Succ->getFirstNonPHI())) {
+ // The catchendpad needs to be visited with the parent's color, not
+ // the current color. This will happen in the code above that visits
+ // any catchpad unwind successor with the parent color, so we can
+ // safely skip this successor here.
+ continue;
+ }
+ if (BlockColors[Succ].insert(Color).second) {
+ Worklist.push_back({Succ, Color});
+ }
+ }
+ }
- Worklist.insert(Worklist.end(), succ_begin(BB), succ_end(BB));
+ // The processing above actually accumulated the parent set for this
+ // funclet into the color set for its entry; use the parent set to
+ // populate the children map, and reset the color set to include just
+ // the funclet itself (no instruction can target a funclet entry except on
+ // that transitions to the child funclet).
+ for (BasicBlock *FuncletEntry : EntryBlocks) {
+ std::set<BasicBlock *> &ColorMapItem = BlockColors[FuncletEntry];
+ for (BasicBlock *Parent : ColorMapItem)
+ FuncletChildren[Parent].insert(FuncletEntry);
+ ColorMapItem.clear();
+ ColorMapItem.insert(FuncletEntry);
}
}
-bool WinEHPrepare::prepareExplicitEH(Function &F) {
+bool WinEHPrepare::prepareExplicitEH(
+ Function &F, SmallVectorImpl<BasicBlock *> &EntryBlocks) {
// Remove unreachable blocks. It is not valuable to assign them a color and
// their existence can trick us into thinking values are alive when they are
// not.
removeUnreachableBlocks(F);
- BasicBlock *EntryBlock = &F.getEntryBlock();
-
- // Number everything starting from the entry block.
- numberFunclet(EntryBlock, EntryBlock);
-
- for (BasicBlock &BB : F) {
- // Remove single entry PHIs to simplify preparation.
- if (auto *PN = dyn_cast<PHINode>(BB.begin()))
- if (PN->getNumIncomingValues() == 1)
- FoldSingleEntryPHINodes(&BB);
-
- // EH pad instructions are always the first non-PHI nodes in a block if they
- // are at all present.
- Instruction *I = BB.getFirstNonPHI();
- if (I->isEHPad())
- numberFunclet(&BB, &BB);
-
- // It is possible for a normal basic block to only be reachable via an
- // exceptional basic block. The successor of a catchret is the only case
- // where this is possible.
- if (auto *CRI = dyn_cast<CatchReturnInst>(BB.getTerminator()))
- numberFunclet(CRI->getSuccessor(), EntryBlock);
- }
+ // Determine which blocks are reachable from which funclet entries.
+ colorFunclets(F, EntryBlocks);
// Strip PHI nodes off of EH pads.
SmallVector<PHINode *, 16> PHINodes;
// We need to clone all blocks which belong to multiple funclets. Values are
// remapped throughout the funclet to propogate both the new instructions
// *and* the new basic blocks themselves.
- for (auto &Funclet : FuncletBlocks) {
- BasicBlock *FuncletPadBB = Funclet.first;
- std::set<BasicBlock *> &BlocksInFunclet = Funclet.second;
+ for (BasicBlock *FuncletPadBB : EntryBlocks) {
+ std::set<BasicBlock *> &BlocksInFunclet = FuncletBlocks[FuncletPadBB];
std::map<BasicBlock *, BasicBlock *> Orig2Clone;
ValueToValueMapTy VMap;
if (NumColorsForBB == 1)
continue;
- assert(!isa<PHINode>(BB->front()) &&
- "Polychromatic PHI nodes should have been demoted!");
-
// Create a new basic block and copy instructions into it!
- BasicBlock *CBB = CloneBasicBlock(
- BB, VMap, Twine(".for.", FuncletPadBB->getName()), &F);
+ BasicBlock *CBB =
+ CloneBasicBlock(BB, VMap, Twine(".for.", FuncletPadBB->getName()));
+ // Insert the clone immediately after the original to ensure determinism
+ // and to keep the same relative ordering of any funclet's blocks.
+ CBB->insertInto(&F, BB->getNextNode());
// Add basic block mapping.
VMap[BB] = CBB;
RemapInstruction(&I, VMap, RF_IgnoreMissingEntries);
}
+ // Remove implausible terminators and replace them with UnreachableInst.
+ for (auto &Funclet : FuncletBlocks) {
+ BasicBlock *FuncletPadBB = Funclet.first;
+ std::set<BasicBlock *> &BlocksInFunclet = Funclet.second;
+ Instruction *FirstNonPHI = FuncletPadBB->getFirstNonPHI();
+ auto *CatchPad = dyn_cast<CatchPadInst>(FirstNonPHI);
+ auto *CleanupPad = dyn_cast<CleanupPadInst>(FirstNonPHI);
+
+ for (BasicBlock *BB : BlocksInFunclet) {
+ TerminatorInst *TI = BB->getTerminator();
+ // CatchPadInst and CleanupPadInst can't transfer control to a ReturnInst.
+ bool IsUnreachableRet = isa<ReturnInst>(TI) && (CatchPad || CleanupPad);
+ // The token consumed by a CatchReturnInst must match the funclet token.
+ bool IsUnreachableCatchret = false;
+ if (auto *CRI = dyn_cast<CatchReturnInst>(TI))
+ IsUnreachableCatchret = CRI->getCatchPad() != CatchPad;
+ // The token consumed by a CleanupReturnInst must match the funclet token.
+ bool IsUnreachableCleanupret = false;
+ if (auto *CRI = dyn_cast<CleanupReturnInst>(TI))
+ IsUnreachableCleanupret = CRI->getCleanupPad() != CleanupPad;
+ // The token consumed by a CleanupEndPadInst must match the funclet token.
+ bool IsUnreachableCleanupendpad = false;
+ if (auto *CEPI = dyn_cast<CleanupEndPadInst>(TI))
+ IsUnreachableCleanupendpad = CEPI->getCleanupPad() != CleanupPad;
+ if (IsUnreachableRet || IsUnreachableCatchret ||
+ IsUnreachableCleanupret || IsUnreachableCleanupendpad) {
+ new UnreachableInst(BB->getContext(), TI);
+ TI->eraseFromParent();
+ }
+ }
+ }
+
// Clean-up some of the mess we made by removing useles PHI nodes, trivial
// branches, etc.
for (Function::iterator FI = F.begin(), FE = F.end(); FI != FE;) {
MergeBlockIntoPredecessor(BB);
}
- // TODO: Do something about cleanupblocks which branch to implausible
- // cleanuprets.
-
// We might have some unreachable blocks after cleaning up some impossible
// control flow.
removeUnreachableBlocks(F);
BlockColors.clear();
FuncletBlocks.clear();
+ FuncletChildren.clear();
+
return true;
}
void WinEHPrepare::demoteNonlocalUses(Value *V,
std::set<BasicBlock *> &ColorsForBB,
Function &F) {
+ // Tokens can only be used non-locally due to control flow involving
+ // unreachable edges. Don't try to demote the token usage, we'll simply
+ // delete the cloned user later.
+ if (isa<CatchPadInst>(V) || isa<CleanupPadInst>(V))
+ return;
+
DenseMap<BasicBlock *, Value *> Loads;
AllocaInst *SpillSlot = nullptr;
for (Value::use_iterator UI = V->use_begin(), UE = V->use_end(); UI != UE;) {
auto *UsingInst = cast<Instruction>(U.getUser());
BasicBlock *UsingBB = UsingInst->getParent();
- // Is the Use inside a block which is colored with a subset of the Def?
+ // Is the Use inside a block which is colored the same as the Def?
// If so, we don't need to escape the Def because we will clone
// ourselves our own private copy.
std::set<BasicBlock *> &ColorsForUsingBB = BlockColors[UsingBB];
- if (std::includes(ColorsForBB.begin(), ColorsForBB.end(),
- ColorsForUsingBB.begin(), ColorsForUsingBB.end()))
+ if (ColorsForUsingBB == ColorsForBB)
continue;
replaceUseWithLoad(V, U, SpillSlot, Loads, F);
// coming in from the same block, which is illegal SSA form.
// For this reason, we keep track of and reuse loads we insert.
BasicBlock *IncomingBlock = UsingPHI->getIncomingBlock(U);
+ if (auto *CatchRet =
+ dyn_cast<CatchReturnInst>(IncomingBlock->getTerminator())) {
+ // Putting a load above a catchret and use on the phi would still leave
+ // a cross-funclet def/use. We need to split the edge, change the
+ // catchret to target the new block, and put the load there.
+ BasicBlock *PHIBlock = UsingInst->getParent();
+ BasicBlock *NewBlock = SplitEdge(IncomingBlock, PHIBlock);
+ // SplitEdge gives us:
+ // IncomingBlock:
+ // ...
+ // br label %NewBlock
+ // NewBlock:
+ // catchret label %PHIBlock
+ // But we need:
+ // IncomingBlock:
+ // ...
+ // catchret label %NewBlock
+ // NewBlock:
+ // br label %PHIBlock
+ // So move the terminators to each others' blocks and swap their
+ // successors.
+ BranchInst *Goto = cast<BranchInst>(IncomingBlock->getTerminator());
+ Goto->removeFromParent();
+ CatchRet->removeFromParent();
+ IncomingBlock->getInstList().push_back(CatchRet);
+ NewBlock->getInstList().push_back(Goto);
+ Goto->setSuccessor(0, PHIBlock);
+ CatchRet->setSuccessor(NewBlock);
+ // Update the color mapping for the newly split edge.
+ std::set<BasicBlock *> &ColorsForPHIBlock = BlockColors[PHIBlock];
+ BlockColors[NewBlock] = ColorsForPHIBlock;
+ for (BasicBlock *FuncletPad : ColorsForPHIBlock)
+ FuncletBlocks[FuncletPad].insert(NewBlock);
+ // Treat the new block as incoming for load insertion.
+ IncomingBlock = NewBlock;
+ }
Value *&Load = Loads[IncomingBlock];
// Insert the load into the predecessor block
if (!Load)
projects / oota-llvm.git / blobdiff