[cfe-commits] r109274 - in /cfe/trunk: lib/CodeGen/CGException.cpp lib/CodeGen/CGException.h lib/CodeGen/CGObjC.cpp lib/CodeGen/CGObjCGNU.cpp lib/CodeGen/CGObjCMac.cpp lib/CodeGen/CGStmt.cpp lib/CodeGen/CodeGenFunction.cpp lib/CodeGen/CodeGenFunction.h test/CodeGenCXX/condition.cpp test/CodeGenCXX/eh.cpp test/CodeGenObjC/gnu-exceptions.m
John McCall
rjmccall at apple.com
Fri Jul 23 14:56:41 PDT 2010
Author: rjmccall
Date: Fri Jul 23 16:56:41 2010
New Revision: 109274
URL: http://llvm.org/viewvc/llvm-project?rev=109274&view=rev
Log:
Revise cleanup IR generation to fix a major bug with cleanups (PR7686)
as well as some significant asymptotic inefficiencies with threading
multiple jumps through deep cleanups.
Modified:
cfe/trunk/lib/CodeGen/CGException.cpp
cfe/trunk/lib/CodeGen/CGException.h
cfe/trunk/lib/CodeGen/CGObjC.cpp
cfe/trunk/lib/CodeGen/CGObjCGNU.cpp
cfe/trunk/lib/CodeGen/CGObjCMac.cpp
cfe/trunk/lib/CodeGen/CGStmt.cpp
cfe/trunk/lib/CodeGen/CodeGenFunction.cpp
cfe/trunk/lib/CodeGen/CodeGenFunction.h
cfe/trunk/test/CodeGenCXX/condition.cpp
cfe/trunk/test/CodeGenCXX/eh.cpp
cfe/trunk/test/CodeGenObjC/gnu-exceptions.m
Modified: cfe/trunk/lib/CodeGen/CGException.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGException.cpp?rev=109274&r1=109273&r2=109274&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGException.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGException.cpp Fri Jul 23 16:56:41 2010
@@ -98,6 +98,11 @@
InnermostEHCleanup = Cleanup.getEnclosingEHCleanup();
StartOfData += Cleanup.getAllocatedSize();
+ if (empty()) NextEHDestIndex = FirstEHDestIndex;
+
+ // Destroy the cleanup.
+ Cleanup.~EHCleanupScope();
+
// Check whether we can shrink the branch-fixups stack.
if (!BranchFixups.empty()) {
// If we no longer have any normal cleanups, all the fixups are
@@ -123,6 +128,8 @@
EHFilterScope &Filter = cast<EHFilterScope>(*begin());
StartOfData += EHFilterScope::getSizeForNumFilters(Filter.getNumFilters());
+ if (empty()) NextEHDestIndex = FirstEHDestIndex;
+
assert(CatchDepth > 0 && "mismatched filter push/pop");
CatchDepth--;
}
@@ -130,13 +137,16 @@
EHCatchScope *EHScopeStack::pushCatch(unsigned NumHandlers) {
char *Buffer = allocate(EHCatchScope::getSizeForNumHandlers(NumHandlers));
CatchDepth++;
- return new (Buffer) EHCatchScope(NumHandlers);
+ EHCatchScope *Scope = new (Buffer) EHCatchScope(NumHandlers);
+ for (unsigned I = 0; I != NumHandlers; ++I)
+ Scope->getHandlers()[I].Index = getNextEHDestIndex();
+ return Scope;
}
void EHScopeStack::pushTerminate() {
char *Buffer = allocate(EHTerminateScope::getSize());
CatchDepth++;
- new (Buffer) EHTerminateScope();
+ new (Buffer) EHTerminateScope(getNextEHDestIndex());
}
/// Remove any 'null' fixups on the stack. However, we can't pop more
@@ -158,20 +168,6 @@
BranchFixups.pop_back();
}
-void EHScopeStack::resolveBranchFixups(llvm::BasicBlock *Dest) {
- assert(Dest && "null block passed to resolveBranchFixups");
-
- if (BranchFixups.empty()) return;
- assert(hasNormalCleanups() &&
- "branch fixups exist with no normal cleanups on stack");
-
- for (unsigned I = 0, E = BranchFixups.size(); I != E; ++I)
- if (BranchFixups[I].Destination == Dest)
- BranchFixups[I].Destination = 0;
-
- popNullFixups();
-}
-
static llvm::Constant *getAllocateExceptionFn(CodeGenFunction &CGF) {
// void *__cxa_allocate_exception(size_t thrown_size);
const llvm::Type *SizeTy = CGF.ConvertType(CGF.getContext().getSizeType());
@@ -756,8 +752,8 @@
EHSelector.push_back(getPersonalityFn(*this, Personality));
// Accumulate all the handlers in scope.
- llvm::DenseMap<llvm::Value*, JumpDest> EHHandlers;
- JumpDest CatchAll;
+ llvm::DenseMap<llvm::Value*, UnwindDest> EHHandlers;
+ UnwindDest CatchAll;
bool HasEHCleanup = false;
bool HasEHFilter = false;
llvm::SmallVector<llvm::Value*, 8> EHFilters;
@@ -773,7 +769,7 @@
case EHScope::Filter: {
assert(I.next() == EHStack.end() && "EH filter is not end of EH stack");
- assert(!CatchAll.Block && "EH filter reached after catch-all");
+ assert(!CatchAll.isValid() && "EH filter reached after catch-all");
// Filter scopes get added to the selector in wierd ways.
EHFilterScope &Filter = cast<EHFilterScope>(*I);
@@ -791,9 +787,10 @@
case EHScope::Terminate:
// Terminate scopes are basically catch-alls.
- assert(!CatchAll.Block);
- CatchAll.Block = getTerminateHandler();
- CatchAll.ScopeDepth = EHStack.getEnclosingEHCleanup(I);
+ assert(!CatchAll.isValid());
+ CatchAll = UnwindDest(getTerminateHandler(),
+ EHStack.getEnclosingEHCleanup(I),
+ cast<EHTerminateScope>(*I).getDestIndex());
goto done;
case EHScope::Catch:
@@ -806,30 +803,32 @@
// Catch-all. We should only have one of these per catch.
if (!Handler.Type) {
- assert(!CatchAll.Block);
- CatchAll.Block = Handler.Block;
- CatchAll.ScopeDepth = EHStack.getEnclosingEHCleanup(I);
+ assert(!CatchAll.isValid());
+ CatchAll = UnwindDest(Handler.Block,
+ EHStack.getEnclosingEHCleanup(I),
+ Handler.Index);
continue;
}
// Check whether we already have a handler for this type.
- JumpDest &Dest = EHHandlers[Handler.Type];
- if (Dest.Block) continue;
+ UnwindDest &Dest = EHHandlers[Handler.Type];
+ if (Dest.isValid()) continue;
EHSelector.push_back(Handler.Type);
- Dest.Block = Handler.Block;
- Dest.ScopeDepth = EHStack.getEnclosingEHCleanup(I);
+ Dest = UnwindDest(Handler.Block,
+ EHStack.getEnclosingEHCleanup(I),
+ Handler.Index);
}
// Stop if we found a catch-all.
- if (CatchAll.Block) break;
+ if (CatchAll.isValid()) break;
}
done:
unsigned LastToEmitInLoop = EHSelector.size();
// If we have a catch-all, add null to the selector.
- if (CatchAll.Block) {
+ if (CatchAll.isValid()) {
EHSelector.push_back(getCatchAllValue(CGF));
// If we have an EH filter, we need to add those handlers in the
@@ -878,14 +877,15 @@
// filter (possibly with a cleanup), a catch-all, or another catch).
for (unsigned I = 2; I != LastToEmitInLoop; ++I) {
llvm::Value *Type = EHSelector[I];
- JumpDest Dest = EHHandlers[Type];
- assert(Dest.Block && "no handler entry for value in selector?");
+ UnwindDest Dest = EHHandlers[Type];
+ assert(Dest.isValid() && "no handler entry for value in selector?");
// Figure out where to branch on a match. As a debug code-size
// optimization, if the scope depth matches the innermost cleanup,
// we branch directly to the catch handler.
- llvm::BasicBlock *Match = Dest.Block;
- bool MatchNeedsCleanup = Dest.ScopeDepth != EHStack.getInnermostEHCleanup();
+ llvm::BasicBlock *Match = Dest.getBlock();
+ bool MatchNeedsCleanup =
+ Dest.getScopeDepth() != EHStack.getInnermostEHCleanup();
if (MatchNeedsCleanup)
Match = createBasicBlock("eh.match");
@@ -911,7 +911,7 @@
// Emit the final case in the selector.
// This might be a catch-all....
- if (CatchAll.Block) {
+ if (CatchAll.isValid()) {
assert(isa<llvm::ConstantPointerNull>(EHSelector.back()));
EmitBranchThroughEHCleanup(CatchAll);
@@ -930,7 +930,8 @@
}
llvm::BasicBlock *CleanupContBB = createBasicBlock("ehspec.cleanup.cont");
- EmitBranchThroughEHCleanup(JumpDest(CleanupContBB, EHStack.stable_end()));
+ EmitBranchThroughEHCleanup(UnwindDest(CleanupContBB, EHStack.stable_end(),
+ EHStack.getNextEHDestIndex()));
EmitBlock(CleanupContBB);
if (HasEHCleanup)
@@ -975,26 +976,7 @@
// ...or a cleanup.
} else {
- // We emit a jump to a notional label at the outermost unwind state.
- llvm::BasicBlock *Unwind = createBasicBlock("eh.resume");
- JumpDest Dest(Unwind, EHStack.stable_end());
- EmitBranchThroughEHCleanup(Dest);
-
- // The unwind block. We have to reload the exception here because
- // we might have unwound through arbitrary blocks, so the landing
- // pad might not dominate.
- EmitBlock(Unwind);
-
- // This can always be a call because we necessarily didn't find
- // anything on the EH stack which needs our help.
- llvm::Constant *RethrowFn;
- if (const char *RethrowName = Personality.getCatchallRethrowFnName())
- RethrowFn = getCatchallRethrowFn(CGF, RethrowName);
- else
- RethrowFn = getUnwindResumeOrRethrowFn();
- Builder.CreateCall(RethrowFn, Builder.CreateLoad(getExceptionSlot()))
- ->setDoesNotReturn();
- Builder.CreateUnreachable();
+ EmitBranchThroughEHCleanup(getRethrowDest());
}
// Restore the old IR generation state.
@@ -1537,6 +1519,35 @@
return TerminateHandler;
}
+CodeGenFunction::UnwindDest CodeGenFunction::getRethrowDest() {
+ if (RethrowBlock.isValid()) return RethrowBlock;
+
+ CGBuilderTy::InsertPoint SavedIP = Builder.saveIP();
+
+ // We emit a jump to a notional label at the outermost unwind state.
+ llvm::BasicBlock *Unwind = createBasicBlock("eh.resume");
+ Builder.SetInsertPoint(Unwind);
+
+ const EHPersonality &Personality = EHPersonality::get(CGM.getLangOptions());
+
+ // This can always be a call because we necessarily didn't find
+ // anything on the EH stack which needs our help.
+ llvm::Constant *RethrowFn;
+ if (const char *RethrowName = Personality.getCatchallRethrowFnName())
+ RethrowFn = getCatchallRethrowFn(*this, RethrowName);
+ else
+ RethrowFn = getUnwindResumeOrRethrowFn();
+
+ Builder.CreateCall(RethrowFn, Builder.CreateLoad(getExceptionSlot()))
+ ->setDoesNotReturn();
+ Builder.CreateUnreachable();
+
+ Builder.restoreIP(SavedIP);
+
+ RethrowBlock = UnwindDest(Unwind, EHStack.stable_end(), 0);
+ return RethrowBlock;
+}
+
EHScopeStack::Cleanup::~Cleanup() {
llvm_unreachable("Cleanup is indestructable");
}
Modified: cfe/trunk/lib/CodeGen/CGException.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGException.h?rev=109274&r1=109273&r2=109274&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGException.h (original)
+++ cfe/trunk/lib/CodeGen/CGException.h Fri Jul 23 16:56:41 2010
@@ -100,15 +100,13 @@
/// The catch handler for this type.
llvm::BasicBlock *Block;
- static Handler make(llvm::Value *Type, llvm::BasicBlock *Block) {
- Handler Temp;
- Temp.Type = Type;
- Temp.Block = Block;
- return Temp;
- }
+ /// The unwind destination index for this handler.
+ unsigned Index;
};
private:
+ friend class EHScopeStack;
+
Handler *getHandlers() {
return reinterpret_cast<Handler*>(this+1);
}
@@ -136,7 +134,8 @@
void setHandler(unsigned I, llvm::Value *Type, llvm::BasicBlock *Block) {
assert(I < getNumHandlers());
- getHandlers()[I] = Handler::make(Type, Block);
+ getHandlers()[I].Type = Type;
+ getHandlers()[I].Block = Block;
}
const Handler &getHandler(unsigned I) const {
@@ -184,6 +183,39 @@
/// created if needed before the cleanup is popped.
llvm::BasicBlock *EHBlock;
+ /// Extra information required for cleanups that have resolved
+ /// branches through them. This has to be allocated on the side
+ /// because everything on the cleanup stack has be trivially
+ /// movable.
+ struct ExtInfo {
+ /// The destinations of normal branch-afters and branch-throughs.
+ llvm::SmallPtrSet<llvm::BasicBlock*, 4> Branches;
+
+ /// Normal branch-afters.
+ llvm::SmallVector<std::pair<llvm::BasicBlock*,llvm::ConstantInt*>, 4>
+ BranchAfters;
+
+ /// The destinations of EH branch-afters and branch-throughs.
+ /// TODO: optimize for the extremely common case of a single
+ /// branch-through.
+ llvm::SmallPtrSet<llvm::BasicBlock*, 4> EHBranches;
+
+ /// EH branch-afters.
+ llvm::SmallVector<std::pair<llvm::BasicBlock*,llvm::ConstantInt*>, 4>
+ EHBranchAfters;
+ };
+ mutable struct ExtInfo *ExtInfo;
+
+ struct ExtInfo &getExtInfo() {
+ if (!ExtInfo) ExtInfo = new struct ExtInfo();
+ return *ExtInfo;
+ }
+
+ const struct ExtInfo &getExtInfo() const {
+ if (!ExtInfo) ExtInfo = new struct ExtInfo();
+ return *ExtInfo;
+ }
+
public:
/// Gets the size required for a lazy cleanup scope with the given
/// cleanup-data requirements.
@@ -203,8 +235,14 @@
IsNormalCleanup(IsNormal), IsEHCleanup(IsEH),
CleanupSize(CleanupSize), FixupDepth(FixupDepth),
EnclosingNormal(EnclosingNormal), EnclosingEH(EnclosingEH),
- NormalBlock(0), EHBlock(0)
- {}
+ NormalBlock(0), EHBlock(0), ExtInfo(0)
+ {
+ assert(this->CleanupSize == CleanupSize && "cleanup size overflow");
+ }
+
+ ~EHCleanupScope() {
+ delete ExtInfo;
+ }
bool isNormalCleanup() const { return IsNormalCleanup; }
llvm::BasicBlock *getNormalBlock() const { return NormalBlock; }
@@ -229,6 +267,102 @@
return reinterpret_cast<EHScopeStack::Cleanup*>(getCleanupBuffer());
}
+ /// True if this cleanup scope has any branch-afters or branch-throughs.
+ bool hasBranches() const { return ExtInfo && !ExtInfo->Branches.empty(); }
+
+ /// Add a branch-after to this cleanup scope. A branch-after is a
+ /// branch from a point protected by this (normal) cleanup to a
+ /// point in the normal cleanup scope immediately containing it.
+ /// For example,
+ /// for (;;) { A a; break; }
+ /// contains a branch-after.
+ ///
+ /// Branch-afters each have their own destination out of the
+ /// cleanup, guaranteed distinct from anything else threaded through
+ /// it. Therefore branch-afters usually force a switch after the
+ /// cleanup.
+ void addBranchAfter(llvm::ConstantInt *Index,
+ llvm::BasicBlock *Block) {
+ struct ExtInfo &ExtInfo = getExtInfo();
+ if (ExtInfo.Branches.insert(Block))
+ ExtInfo.BranchAfters.push_back(std::make_pair(Block, Index));
+ }
+
+ /// Return the number of unique branch-afters on this scope.
+ unsigned getNumBranchAfters() const {
+ return ExtInfo ? ExtInfo->BranchAfters.size() : 0;
+ }
+
+ llvm::BasicBlock *getBranchAfterBlock(unsigned I) const {
+ assert(I < getNumBranchAfters());
+ return ExtInfo->BranchAfters[I].first;
+ }
+
+ llvm::ConstantInt *getBranchAfterIndex(unsigned I) const {
+ assert(I < getNumBranchAfters());
+ return ExtInfo->BranchAfters[I].second;
+ }
+
+ /// Add a branch-through to this cleanup scope. A branch-through is
+ /// a branch from a scope protected by this (normal) cleanup to an
+ /// enclosing scope other than the immediately-enclosing normal
+ /// cleanup scope.
+ ///
+ /// In the following example, the branch through B's scope is a
+ /// branch-through, while the branch through A's scope is a
+ /// branch-after:
+ /// for (;;) { A a; B b; break; }
+ ///
+ /// All branch-throughs have a common destination out of the
+ /// cleanup, one possibly shared with the fall-through. Therefore
+ /// branch-throughs usually don't force a switch after the cleanup.
+ ///
+ /// \return true if the branch-through was new to this scope
+ bool addBranchThrough(llvm::BasicBlock *Block) {
+ return getExtInfo().Branches.insert(Block);
+ }
+
+ /// Determines if this cleanup scope has any branch throughs.
+ bool hasBranchThroughs() const {
+ if (!ExtInfo) return false;
+ return (ExtInfo->BranchAfters.size() != ExtInfo->Branches.size());
+ }
+
+ // Same stuff, only for EH branches instead of normal branches.
+ // It's quite possible that we could find a better representation
+ // for this.
+
+ bool hasEHBranches() const { return ExtInfo && !ExtInfo->EHBranches.empty(); }
+ void addEHBranchAfter(llvm::ConstantInt *Index,
+ llvm::BasicBlock *Block) {
+ struct ExtInfo &ExtInfo = getExtInfo();
+ if (ExtInfo.EHBranches.insert(Block))
+ ExtInfo.EHBranchAfters.push_back(std::make_pair(Block, Index));
+ }
+
+ unsigned getNumEHBranchAfters() const {
+ return ExtInfo ? ExtInfo->EHBranchAfters.size() : 0;
+ }
+
+ llvm::BasicBlock *getEHBranchAfterBlock(unsigned I) const {
+ assert(I < getNumEHBranchAfters());
+ return ExtInfo->EHBranchAfters[I].first;
+ }
+
+ llvm::ConstantInt *getEHBranchAfterIndex(unsigned I) const {
+ assert(I < getNumEHBranchAfters());
+ return ExtInfo->EHBranchAfters[I].second;
+ }
+
+ bool addEHBranchThrough(llvm::BasicBlock *Block) {
+ return getExtInfo().EHBranches.insert(Block);
+ }
+
+ bool hasEHBranchThroughs() const {
+ if (!ExtInfo) return false;
+ return (ExtInfo->EHBranchAfters.size() != ExtInfo->EHBranches.size());
+ }
+
static bool classof(const EHScope *Scope) {
return (Scope->getKind() == Cleanup);
}
@@ -281,10 +415,13 @@
/// An exceptions scope which calls std::terminate if any exception
/// reaches it.
class EHTerminateScope : public EHScope {
+ unsigned DestIndex : BitsRemaining;
public:
- EHTerminateScope() : EHScope(Terminate) {}
+ EHTerminateScope(unsigned Index) : EHScope(Terminate), DestIndex(Index) {}
static size_t getSize() { return sizeof(EHTerminateScope); }
+ unsigned getDestIndex() const { return DestIndex; }
+
static bool classof(const EHScope *Scope) {
return Scope->getKind() == Terminate;
}
@@ -344,6 +481,9 @@
return copy;
}
+ bool encloses(iterator other) const { return Ptr >= other.Ptr; }
+ bool strictlyEncloses(iterator other) const { return Ptr > other.Ptr; }
+
bool operator==(iterator other) const { return Ptr == other.Ptr; }
bool operator!=(iterator other) const { return Ptr != other.Ptr; }
};
@@ -363,6 +503,8 @@
StartOfData += EHCatchScope::getSizeForNumHandlers(
cast<EHCatchScope>(*begin()).getNumHandlers());
+ if (empty()) NextEHDestIndex = FirstEHDestIndex;
+
assert(CatchDepth > 0 && "mismatched catch/terminate push/pop");
CatchDepth--;
}
@@ -373,6 +515,8 @@
assert(isa<EHTerminateScope>(*begin()));
StartOfData += EHTerminateScope::getSize();
+ if (empty()) NextEHDestIndex = FirstEHDestIndex;
+
assert(CatchDepth > 0 && "mismatched catch/terminate push/pop");
CatchDepth--;
}
Modified: cfe/trunk/lib/CodeGen/CGObjC.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGObjC.cpp?rev=109274&r1=109273&r2=109274&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGObjC.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGObjC.cpp Fri Jul 23 16:56:41 2010
@@ -793,7 +793,7 @@
BreakContinueStack.pop_back();
- EmitBlock(AfterBody.Block);
+ EmitBlock(AfterBody.getBlock());
llvm::BasicBlock *FetchMore = createBasicBlock("fetchmore");
@@ -829,7 +829,7 @@
LV.getAddress());
}
- EmitBlock(LoopEnd.Block);
+ EmitBlock(LoopEnd.getBlock());
}
void CodeGenFunction::EmitObjCAtTryStmt(const ObjCAtTryStmt &S) {
Modified: cfe/trunk/lib/CodeGen/CGObjCGNU.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGObjCGNU.cpp?rev=109274&r1=109273&r2=109274&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGObjCGNU.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGObjCGNU.cpp Fri Jul 23 16:56:41 2010
@@ -2016,13 +2016,11 @@
if (S.getFinallyStmt())
CGF.ExitFinallyBlock(FinallyInfo);
- if (Cont.Block) {
- if (Cont.Block->use_empty())
- delete Cont.Block;
- else {
- CGF.EmitBranch(Cont.Block);
- CGF.EmitBlock(Cont.Block);
- }
+ if (Cont.isValid()) {
+ if (Cont.getBlock()->use_empty())
+ delete Cont.getBlock();
+ else
+ CGF.EmitBlock(Cont.getBlock());
}
}
Modified: cfe/trunk/lib/CodeGen/CGObjCMac.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGObjCMac.cpp?rev=109274&r1=109273&r2=109274&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGObjCMac.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGObjCMac.cpp Fri Jul 23 16:56:41 2010
@@ -2953,11 +2953,11 @@
// Pop the cleanup.
CGF.PopCleanupBlock();
- CGF.EmitBlock(FinallyEnd.Block);
+ CGF.EmitBlock(FinallyEnd.getBlock());
// Emit the rethrow block.
CGF.Builder.ClearInsertionPoint();
- CGF.EmitBlock(FinallyRethrow.Block, true);
+ CGF.EmitBlock(FinallyRethrow.getBlock(), true);
if (CGF.HaveInsertPoint()) {
CGF.Builder.CreateCall(ObjCTypes.getExceptionThrowFn(),
CGF.Builder.CreateLoad(RethrowPtr))
@@ -2965,7 +2965,7 @@
CGF.Builder.CreateUnreachable();
}
- CGF.Builder.SetInsertPoint(FinallyEnd.Block);
+ CGF.Builder.SetInsertPoint(FinallyEnd.getBlock());
}
void CGObjCMac::EmitThrowStmt(CodeGen::CodeGenFunction &CGF,
@@ -5895,8 +5895,8 @@
if (S.getFinallyStmt())
CGF.ExitFinallyBlock(FinallyInfo);
- if (Cont.Block)
- CGF.EmitBlock(Cont.Block);
+ if (Cont.isValid())
+ CGF.EmitBlock(Cont.getBlock());
}
/// EmitThrowStmt - Generate code for a throw statement.
Modified: cfe/trunk/lib/CodeGen/CGStmt.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGStmt.cpp?rev=109274&r1=109273&r2=109274&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGStmt.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGStmt.cpp Fri Jul 23 16:56:41 2010
@@ -248,32 +248,35 @@
CodeGenFunction::JumpDest
CodeGenFunction::getJumpDestForLabel(const LabelStmt *S) {
JumpDest &Dest = LabelMap[S];
- if (Dest.Block) return Dest;
+ if (Dest.isValid()) return Dest;
// Create, but don't insert, the new block.
- Dest.Block = createBasicBlock(S->getName());
- Dest.ScopeDepth = EHScopeStack::stable_iterator::invalid();
+ Dest = JumpDest(createBasicBlock(S->getName()),
+ EHScopeStack::stable_iterator::invalid(),
+ NextCleanupDestIndex++);
return Dest;
}
void CodeGenFunction::EmitLabel(const LabelStmt &S) {
JumpDest &Dest = LabelMap[&S];
- // If we didn't needed a forward reference to this label, just go
+ // If we didn't need a forward reference to this label, just go
// ahead and create a destination at the current scope.
- if (!Dest.Block) {
+ if (!Dest.isValid()) {
Dest = getJumpDestInCurrentScope(S.getName());
// Otherwise, we need to give this label a target depth and remove
// it from the branch-fixups list.
} else {
- assert(!Dest.ScopeDepth.isValid() && "already emitted label!");
- Dest.ScopeDepth = EHStack.stable_begin();
+ assert(!Dest.getScopeDepth().isValid() && "already emitted label!");
+ Dest = JumpDest(Dest.getBlock(),
+ EHStack.stable_begin(),
+ Dest.getDestIndex());
- EHStack.resolveBranchFixups(Dest.Block);
+ ResolveBranchFixups(Dest.getBlock());
}
- EmitBlock(Dest.Block);
+ EmitBlock(Dest.getBlock());
}
@@ -373,7 +376,7 @@
// Emit the header for the loop, which will also become
// the continue target.
JumpDest LoopHeader = getJumpDestInCurrentScope("while.cond");
- EmitBlock(LoopHeader.Block);
+ EmitBlock(LoopHeader.getBlock());
// Create an exit block for when the condition fails, which will
// also become the break target.
@@ -409,13 +412,13 @@
// As long as the condition is true, go to the loop body.
llvm::BasicBlock *LoopBody = createBasicBlock("while.body");
if (EmitBoolCondBranch) {
- llvm::BasicBlock *ExitBlock = LoopExit.Block;
+ llvm::BasicBlock *ExitBlock = LoopExit.getBlock();
if (ConditionScope.requiresCleanups())
ExitBlock = createBasicBlock("while.exit");
Builder.CreateCondBr(BoolCondVal, LoopBody, ExitBlock);
- if (ExitBlock != LoopExit.Block) {
+ if (ExitBlock != LoopExit.getBlock()) {
EmitBlock(ExitBlock);
EmitBranchThroughCleanup(LoopExit);
}
@@ -435,15 +438,15 @@
ConditionScope.ForceCleanup();
// Branch to the loop header again.
- EmitBranch(LoopHeader.Block);
+ EmitBranch(LoopHeader.getBlock());
// Emit the exit block.
- EmitBlock(LoopExit.Block, true);
+ EmitBlock(LoopExit.getBlock(), true);
// The LoopHeader typically is just a branch if we skipped emitting
// a branch, try to erase it.
if (!EmitBoolCondBranch)
- SimplifyForwardingBlocks(LoopHeader.Block);
+ SimplifyForwardingBlocks(LoopHeader.getBlock());
}
void CodeGenFunction::EmitDoStmt(const DoStmt &S) {
@@ -463,7 +466,7 @@
BreakContinueStack.pop_back();
- EmitBlock(LoopCond.Block);
+ EmitBlock(LoopCond.getBlock());
// C99 6.8.5.2: "The evaluation of the controlling expression takes place
// after each execution of the loop body."
@@ -482,15 +485,15 @@
// As long as the condition is true, iterate the loop.
if (EmitBoolCondBranch)
- Builder.CreateCondBr(BoolCondVal, LoopBody, LoopExit.Block);
+ Builder.CreateCondBr(BoolCondVal, LoopBody, LoopExit.getBlock());
// Emit the exit block.
- EmitBlock(LoopExit.Block);
+ EmitBlock(LoopExit.getBlock());
// The DoCond block typically is just a branch if we skipped
// emitting a branch, try to erase it.
if (!EmitBoolCondBranch)
- SimplifyForwardingBlocks(LoopCond.Block);
+ SimplifyForwardingBlocks(LoopCond.getBlock());
}
void CodeGenFunction::EmitForStmt(const ForStmt &S) {
@@ -506,7 +509,7 @@
// If there's an increment, the continue scope will be overwritten
// later.
JumpDest Continue = getJumpDestInCurrentScope("for.cond");
- llvm::BasicBlock *CondBlock = Continue.Block;
+ llvm::BasicBlock *CondBlock = Continue.getBlock();
EmitBlock(CondBlock);
// Create a cleanup scope for the condition variable cleanups.
@@ -516,7 +519,7 @@
if (S.getCond()) {
// If the for statement has a condition scope, emit the local variable
// declaration.
- llvm::BasicBlock *ExitBlock = LoopExit.Block;
+ llvm::BasicBlock *ExitBlock = LoopExit.getBlock();
if (S.getConditionVariable()) {
EmitLocalBlockVarDecl(*S.getConditionVariable());
}
@@ -534,7 +537,7 @@
BoolCondVal = EvaluateExprAsBool(S.getCond());
Builder.CreateCondBr(BoolCondVal, ForBody, ExitBlock);
- if (ExitBlock != LoopExit.Block) {
+ if (ExitBlock != LoopExit.getBlock()) {
EmitBlock(ExitBlock);
EmitBranchThroughCleanup(LoopExit);
}
@@ -570,7 +573,7 @@
// If there is an increment, emit it next.
if (S.getInc()) {
- EmitBlock(Continue.Block);
+ EmitBlock(Continue.getBlock());
EmitStmt(S.getInc());
}
@@ -587,7 +590,7 @@
}
// Emit the fall-through block.
- EmitBlock(LoopExit.Block, true);
+ EmitBlock(LoopExit.getBlock(), true);
}
void CodeGenFunction::EmitReturnOfRValue(RValue RV, QualType Ty) {
@@ -840,13 +843,15 @@
// Otherwise, just forward the default block to the switch end.
} else {
- DefaultBlock->replaceAllUsesWith(SwitchExit.Block);
+ DefaultBlock->replaceAllUsesWith(SwitchExit.getBlock());
delete DefaultBlock;
}
}
+ ConditionScope.ForceCleanup();
+
// Emit continuation.
- EmitBlock(SwitchExit.Block, true);
+ EmitBlock(SwitchExit.getBlock(), true);
SwitchInsn = SavedSwitchInsn;
CaseRangeBlock = SavedCRBlock;
Modified: cfe/trunk/lib/CodeGen/CodeGenFunction.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenFunction.cpp?rev=109274&r1=109273&r2=109274&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenFunction.cpp (original)
+++ cfe/trunk/lib/CodeGen/CodeGenFunction.cpp Fri Jul 23 16:56:41 2010
@@ -31,8 +31,9 @@
: BlockFunction(cgm, *this, Builder), CGM(cgm),
Target(CGM.getContext().Target),
Builder(cgm.getModule().getContext()),
+ NormalCleanupDest(0), EHCleanupDest(0), NextCleanupDestIndex(1),
ExceptionSlot(0), DebugInfo(0), IndirectBranch(0),
- SwitchInsn(0), CaseRangeBlock(0), InvokeDest(0),
+ SwitchInsn(0), CaseRangeBlock(0),
DidCallStackSave(false), UnreachableBlock(0),
CXXThisDecl(0), CXXThisValue(0), CXXVTTDecl(0), CXXVTTValue(0),
ConditionalBranchLevel(0), TerminateLandingPad(0), TerminateHandler(0),
@@ -89,26 +90,26 @@
// We have a valid insert point, reuse it if it is empty or there are no
// explicit jumps to the return block.
- if (CurBB->empty() || ReturnBlock.Block->use_empty()) {
- ReturnBlock.Block->replaceAllUsesWith(CurBB);
- delete ReturnBlock.Block;
+ if (CurBB->empty() || ReturnBlock.getBlock()->use_empty()) {
+ ReturnBlock.getBlock()->replaceAllUsesWith(CurBB);
+ delete ReturnBlock.getBlock();
} else
- EmitBlock(ReturnBlock.Block);
+ EmitBlock(ReturnBlock.getBlock());
return;
}
// Otherwise, if the return block is the target of a single direct
// branch then we can just put the code in that block instead. This
// cleans up functions which started with a unified return block.
- if (ReturnBlock.Block->hasOneUse()) {
+ if (ReturnBlock.getBlock()->hasOneUse()) {
llvm::BranchInst *BI =
- dyn_cast<llvm::BranchInst>(*ReturnBlock.Block->use_begin());
+ dyn_cast<llvm::BranchInst>(*ReturnBlock.getBlock()->use_begin());
if (BI && BI->isUnconditional() &&
- BI->getSuccessor(0) == ReturnBlock.Block) {
+ BI->getSuccessor(0) == ReturnBlock.getBlock()) {
// Reset insertion point and delete the branch.
Builder.SetInsertPoint(BI->getParent());
BI->eraseFromParent();
- delete ReturnBlock.Block;
+ delete ReturnBlock.getBlock();
return;
}
}
@@ -117,7 +118,7 @@
// unless it has uses. However, we still need a place to put the debug
// region.end for now.
- EmitBlock(ReturnBlock.Block);
+ EmitBlock(ReturnBlock.getBlock());
}
static void EmitIfUsed(CodeGenFunction &CGF, llvm::BasicBlock *BB) {
@@ -170,6 +171,7 @@
}
}
+ EmitIfUsed(*this, RethrowBlock.getBlock());
EmitIfUsed(*this, TerminateLandingPad);
EmitIfUsed(*this, TerminateHandler);
EmitIfUsed(*this, UnreachableBlock);
@@ -585,7 +587,7 @@
if (IndirectBranch == 0)
GetIndirectGotoBlock();
- llvm::BasicBlock *BB = getJumpDestForLabel(L).Block;
+ llvm::BasicBlock *BB = getJumpDestForLabel(L).getBlock();
// Make sure the indirect branch includes all of the address-taken blocks.
IndirectBranch->addDestination(BB);
@@ -666,41 +668,75 @@
void CodeGenFunction::PopCleanupBlocks(EHScopeStack::stable_iterator Old) {
assert(Old.isValid());
- EHScopeStack::iterator E = EHStack.find(Old);
- while (EHStack.begin() != E)
- PopCleanupBlock();
-}
+ while (EHStack.stable_begin() != Old) {
+ EHCleanupScope &Scope = cast<EHCleanupScope>(*EHStack.begin());
-/// Creates a switch instruction to thread branches out of the given
-/// block (which is the exit block of a cleanup).
-static void CreateCleanupSwitch(CodeGenFunction &CGF,
- llvm::BasicBlock *Block) {
- if (Block->getTerminator()) {
- assert(isa<llvm::SwitchInst>(Block->getTerminator()) &&
- "cleanup block already has a terminator, but it isn't a switch");
- return;
+ // As long as Old strictly encloses the scope's enclosing normal
+ // cleanup, we're going to emit another normal cleanup which
+ // fallthrough can propagate through.
+ bool FallThroughIsBranchThrough =
+ Old.strictlyEncloses(Scope.getEnclosingNormalCleanup());
+
+ PopCleanupBlock(FallThroughIsBranchThrough);
}
+}
- llvm::Value *DestCodePtr
- = CGF.CreateTempAlloca(CGF.Builder.getInt32Ty(), "cleanup.dst");
- CGBuilderTy Builder(Block);
- llvm::Value *DestCode = Builder.CreateLoad(DestCodePtr, "tmp");
-
- // Create a switch instruction to determine where to jump next.
- Builder.CreateSwitch(DestCode, CGF.getUnreachableBlock());
+static llvm::BasicBlock *CreateNormalEntry(CodeGenFunction &CGF,
+ EHCleanupScope &Scope) {
+ assert(Scope.isNormalCleanup());
+ llvm::BasicBlock *Entry = Scope.getNormalBlock();
+ if (!Entry) {
+ Entry = CGF.createBasicBlock("cleanup");
+ Scope.setNormalBlock(Entry);
+ }
+ return Entry;
+}
+
+static llvm::BasicBlock *CreateEHEntry(CodeGenFunction &CGF,
+ EHCleanupScope &Scope) {
+ assert(Scope.isEHCleanup());
+ llvm::BasicBlock *Entry = Scope.getEHBlock();
+ if (!Entry) {
+ Entry = CGF.createBasicBlock("eh.cleanup");
+ Scope.setEHBlock(Entry);
+ }
+ return Entry;
+}
+
+/// Transitions the terminator of the given exit-block of a cleanup to
+/// be a cleanup switch.
+static llvm::SwitchInst *TransitionToCleanupSwitch(CodeGenFunction &CGF,
+ llvm::BasicBlock *Block) {
+ // If it's a branch, turn it into a switch whose default
+ // destination is its original target.
+ llvm::TerminatorInst *Term = Block->getTerminator();
+ assert(Term && "can't transition block without terminator");
+
+ if (llvm::BranchInst *Br = dyn_cast<llvm::BranchInst>(Term)) {
+ assert(Br->isUnconditional());
+ llvm::LoadInst *Load =
+ new llvm::LoadInst(CGF.getNormalCleanupDestSlot(), "cleanup.dest", Term);
+ llvm::SwitchInst *Switch =
+ llvm::SwitchInst::Create(Load, Br->getSuccessor(0), 4, Block);
+ Br->eraseFromParent();
+ return Switch;
+ } else {
+ return cast<llvm::SwitchInst>(Term);
+ }
}
/// Attempts to reduce a cleanup's entry block to a fallthrough. This
/// is basically llvm::MergeBlockIntoPredecessor, except
-/// simplified/optimized for the tighter constraints on cleanup
-/// blocks.
-static void SimplifyCleanupEntry(CodeGenFunction &CGF,
- llvm::BasicBlock *Entry) {
+/// simplified/optimized for the tighter constraints on cleanup blocks.
+///
+/// Returns the new block, whatever it is.
+static llvm::BasicBlock *SimplifyCleanupEntry(CodeGenFunction &CGF,
+ llvm::BasicBlock *Entry) {
llvm::BasicBlock *Pred = Entry->getSinglePredecessor();
- if (!Pred) return;
+ if (!Pred) return Entry;
llvm::BranchInst *Br = dyn_cast<llvm::BranchInst>(Pred->getTerminator());
- if (!Br || Br->isConditional()) return;
+ if (!Br || Br->isConditional()) return Entry;
assert(Br->getSuccessor(0) == Entry);
// If we were previously inserting at the end of the cleanup entry
@@ -720,80 +756,8 @@
if (WasInsertBlock)
CGF.Builder.SetInsertPoint(Pred);
-}
-
-/// Attempts to reduce an cleanup's exit switch to an unconditional
-/// branch.
-static void SimplifyCleanupExit(llvm::BasicBlock *Exit) {
- llvm::TerminatorInst *Terminator = Exit->getTerminator();
- assert(Terminator && "completed cleanup exit has no terminator");
-
- llvm::SwitchInst *Switch = dyn_cast<llvm::SwitchInst>(Terminator);
- if (!Switch) return;
- if (Switch->getNumCases() != 2) return; // default + 1
-
- llvm::LoadInst *Cond = cast<llvm::LoadInst>(Switch->getCondition());
- llvm::AllocaInst *CondVar = cast<llvm::AllocaInst>(Cond->getPointerOperand());
-
- // Replace the switch instruction with an unconditional branch.
- llvm::BasicBlock *Dest = Switch->getSuccessor(1); // default is 0
- Switch->eraseFromParent();
- llvm::BranchInst::Create(Dest, Exit);
-
- // Delete all uses of the condition variable.
- Cond->eraseFromParent();
- while (!CondVar->use_empty())
- cast<llvm::StoreInst>(*CondVar->use_begin())->eraseFromParent();
-
- // Delete the condition variable itself.
- CondVar->eraseFromParent();
-}
-
-/// Threads a branch fixup through a cleanup block.
-static void ThreadFixupThroughCleanup(CodeGenFunction &CGF,
- BranchFixup &Fixup,
- llvm::BasicBlock *Entry,
- llvm::BasicBlock *Exit) {
- if (!Exit->getTerminator())
- CreateCleanupSwitch(CGF, Exit);
-
- // Find the switch and its destination index alloca.
- llvm::SwitchInst *Switch = cast<llvm::SwitchInst>(Exit->getTerminator());
- llvm::Value *DestCodePtr =
- cast<llvm::LoadInst>(Switch->getCondition())->getPointerOperand();
-
- // Compute the index of the new case we're adding to the switch.
- unsigned Index = Switch->getNumCases();
-
- const llvm::IntegerType *i32 = llvm::Type::getInt32Ty(CGF.getLLVMContext());
- llvm::ConstantInt *IndexV = llvm::ConstantInt::get(i32, Index);
-
- // Set the index in the origin block.
- new llvm::StoreInst(IndexV, DestCodePtr, Fixup.Origin);
-
- // Add a case to the switch.
- Switch->addCase(IndexV, Fixup.Destination);
-
- // Change the last branch to point to the cleanup entry block.
- Fixup.LatestBranch->setSuccessor(Fixup.LatestBranchIndex, Entry);
-
- // And finally, update the fixup.
- Fixup.LatestBranch = Switch;
- Fixup.LatestBranchIndex = Index;
-}
-
-/// Try to simplify both the entry and exit edges of a cleanup.
-static void SimplifyCleanupEdges(CodeGenFunction &CGF,
- llvm::BasicBlock *Entry,
- llvm::BasicBlock *Exit) {
-
- // Given their current implementations, it's important to run these
- // in this order: SimplifyCleanupEntry will delete Entry if it can
- // be merged into its predecessor, which will then break
- // SimplifyCleanupExit if (as is common) Entry == Exit.
- SimplifyCleanupExit(Exit);
- SimplifyCleanupEntry(CGF, Entry);
+ return Pred;
}
static void EmitCleanup(CodeGenFunction &CGF,
@@ -805,42 +769,10 @@
assert(CGF.HaveInsertPoint() && "cleanup ended with no insertion point?");
}
-static void SplitAndEmitCleanup(CodeGenFunction &CGF,
- EHScopeStack::Cleanup *Fn,
- bool ForEH,
- llvm::BasicBlock *Entry) {
- assert(Entry && "no entry block for cleanup");
-
- // Remove the switch and load from the end of the entry block.
- llvm::Instruction *Switch = &Entry->getInstList().back();
- Entry->getInstList().remove(Switch);
- assert(isa<llvm::SwitchInst>(Switch));
- llvm::Instruction *Load = &Entry->getInstList().back();
- Entry->getInstList().remove(Load);
- assert(isa<llvm::LoadInst>(Load));
-
- assert(Entry->getInstList().empty() &&
- "lazy cleanup block not empty after removing load/switch pair?");
-
- // Emit the actual cleanup at the end of the entry block.
- CGF.Builder.SetInsertPoint(Entry);
- EmitCleanup(CGF, Fn, ForEH);
-
- // Put the load and switch at the end of the exit block.
- llvm::BasicBlock *Exit = CGF.Builder.GetInsertBlock();
- Exit->getInstList().push_back(Load);
- Exit->getInstList().push_back(Switch);
-
- // Clean up the edges if possible.
- SimplifyCleanupEdges(CGF, Entry, Exit);
-
- CGF.Builder.ClearInsertionPoint();
-}
-
/// Pops a cleanup block. If the block includes a normal cleanup, the
/// current insertion point is threaded through the cleanup, as are
/// any branch fixups on the cleanup.
-void CodeGenFunction::PopCleanupBlock() {
+void CodeGenFunction::PopCleanupBlock(bool FallthroughIsBranchThrough) {
assert(!EHStack.empty() && "cleanup stack is empty!");
assert(isa<EHCleanupScope>(*EHStack.begin()) && "top not a cleanup!");
EHCleanupScope &Scope = cast<EHCleanupScope>(*EHStack.begin());
@@ -848,8 +780,7 @@
// Check whether we need an EH cleanup. This is only true if we've
// generated a lazy EH cleanup block.
- llvm::BasicBlock *EHEntry = Scope.getEHBlock();
- bool RequiresEHCleanup = (EHEntry != 0);
+ bool RequiresEHCleanup = Scope.hasEHBranches();
// Check the three conditions which might require a normal cleanup:
@@ -857,9 +788,8 @@
unsigned FixupDepth = Scope.getFixupDepth();
bool HasFixups = EHStack.getNumBranchFixups() != FixupDepth;
- // - whether control has already been threaded through this cleanup
- llvm::BasicBlock *NormalEntry = Scope.getNormalBlock();
- bool HasExistingBranches = (NormalEntry != 0);
+ // - whether there are branch-throughs or branch-afters
+ bool HasExistingBranches = Scope.hasBranches();
// - whether there's a fallthrough
llvm::BasicBlock *FallthroughSource = Builder.GetInsertBlock();
@@ -873,7 +803,7 @@
// If we don't need the cleanup at all, we're done.
if (!RequiresNormalCleanup && !RequiresEHCleanup) {
- EHStack.popCleanup();
+ EHStack.popCleanup(); // safe because there are no fixups
assert(EHStack.getNumBranchFixups() == 0 ||
EHStack.hasNormalCleanups());
return;
@@ -890,157 +820,440 @@
EHScopeStack::Cleanup *Fn =
reinterpret_cast<EHScopeStack::Cleanup*>(CleanupBuffer.data());
- // We're done with the scope; pop it off so we can emit the cleanups.
- EHStack.popCleanup();
+ // We want to emit the EH cleanup after the normal cleanup, but go
+ // ahead and do the setup for the EH cleanup while the scope is still
+ // alive.
+ llvm::BasicBlock *EHEntry = 0;
+ llvm::SmallVector<llvm::Instruction*, 2> EHInstsToAppend;
+ if (RequiresEHCleanup) {
+ EHEntry = CreateEHEntry(*this, Scope);
+
+ // Figure out the branch-through dest if necessary.
+ llvm::BasicBlock *EHBranchThroughDest = 0;
+ if (Scope.hasEHBranchThroughs()) {
+ assert(Scope.getEnclosingEHCleanup() != EHStack.stable_end());
+ EHScope &S = *EHStack.find(Scope.getEnclosingEHCleanup());
+ EHBranchThroughDest = CreateEHEntry(*this, cast<EHCleanupScope>(S));
+ }
+
+ // If we have exactly one branch-after and no branch-throughs, we
+ // can dispatch it without a switch.
+ if (!Scope.hasBranchThroughs() &&
+ Scope.getNumEHBranchAfters() == 1) {
+ assert(!EHBranchThroughDest);
+
+ // TODO: remove the spurious eh.cleanup.dest stores if this edge
+ // never went through any switches.
+ llvm::BasicBlock *BranchAfterDest = Scope.getEHBranchAfterBlock(0);
+ EHInstsToAppend.push_back(llvm::BranchInst::Create(BranchAfterDest));
+
+ // Otherwise, if we have any branch-afters, we need a switch.
+ } else if (Scope.getNumEHBranchAfters()) {
+ // The default of the switch belongs to the branch-throughs if
+ // they exist.
+ llvm::BasicBlock *Default =
+ (EHBranchThroughDest ? EHBranchThroughDest : getUnreachableBlock());
+
+ const unsigned SwitchCapacity = Scope.getNumEHBranchAfters();
+
+ llvm::LoadInst *Load =
+ new llvm::LoadInst(getEHCleanupDestSlot(), "cleanup.dest");
+ llvm::SwitchInst *Switch =
+ llvm::SwitchInst::Create(Load, Default, SwitchCapacity);
+
+ EHInstsToAppend.push_back(Load);
+ EHInstsToAppend.push_back(Switch);
+
+ for (unsigned I = 0, E = Scope.getNumEHBranchAfters(); I != E; ++I)
+ Switch->addCase(Scope.getEHBranchAfterIndex(I),
+ Scope.getEHBranchAfterBlock(I));
+
+ // Otherwise, we have only branch-throughs; jump to the next EH
+ // cleanup.
+ } else {
+ assert(EHBranchThroughDest);
+ EHInstsToAppend.push_back(llvm::BranchInst::Create(EHBranchThroughDest));
+ }
+ }
+
+ if (!RequiresNormalCleanup) {
+ EHStack.popCleanup();
+ } else {
+ // As a kindof crazy internal case, branch-through fall-throughs
+ // leave the insertion point set to the end of the last cleanup.
+ bool HasPrebranchedFallthrough =
+ (HasFallthrough && FallthroughSource->getTerminator());
+ assert(!HasPrebranchedFallthrough ||
+ FallthroughSource->getTerminator()->getSuccessor(0)
+ == Scope.getNormalBlock());
- if (RequiresNormalCleanup) {
// If we have a fallthrough and no other need for the cleanup,
// emit it directly.
- if (HasFallthrough && !HasFixups && !HasExistingBranches) {
+ if (HasFallthrough && !HasPrebranchedFallthrough &&
+ !HasFixups && !HasExistingBranches) {
+
+ // Fixups can cause us to optimistically create a normal block,
+ // only to later have no real uses for it. Just delete it in
+ // this case.
+ // TODO: we can potentially simplify all the uses after this.
+ if (Scope.getNormalBlock()) {
+ Scope.getNormalBlock()->replaceAllUsesWith(getUnreachableBlock());
+ delete Scope.getNormalBlock();
+ }
+
+ EHStack.popCleanup();
+
EmitCleanup(*this, Fn, /*ForEH*/ false);
// Otherwise, the best approach is to thread everything through
// the cleanup block and then try to clean up after ourselves.
} else {
// Force the entry block to exist.
- if (!HasExistingBranches) {
- NormalEntry = createBasicBlock("cleanup");
- CreateCleanupSwitch(*this, NormalEntry);
- }
+ llvm::BasicBlock *NormalEntry = CreateNormalEntry(*this, Scope);
+ // If there's a fallthrough, we need to store the cleanup
+ // destination index. For fall-throughs this is always zero.
+ if (HasFallthrough && !HasPrebranchedFallthrough)
+ Builder.CreateStore(Builder.getInt32(0), getNormalCleanupDestSlot());
+
+ // Emit the entry block. This implicitly branches to it if we
+ // have fallthrough. All the fixups and existing branches should
+ // already be branched to it.
EmitBlock(NormalEntry);
- // Thread the fallthrough edge through the (momentarily trivial)
- // cleanup.
- llvm::BasicBlock *FallthroughDestination = 0;
- if (HasFallthrough) {
- assert(isa<llvm::BranchInst>(FallthroughSource->getTerminator()));
- FallthroughDestination = createBasicBlock("cleanup.cont");
-
- BranchFixup Fix;
- Fix.Destination = FallthroughDestination;
- Fix.LatestBranch = FallthroughSource->getTerminator();
- Fix.LatestBranchIndex = 0;
- Fix.Origin = Fix.LatestBranch;
-
- // Restore fixup invariant. EmitBlock added a branch to the
- // cleanup which we need to redirect to the destination.
- cast<llvm::BranchInst>(Fix.LatestBranch)
- ->setSuccessor(0, Fix.Destination);
+ bool HasEnclosingCleanups =
+ (Scope.getEnclosingNormalCleanup() != EHStack.stable_end());
- ThreadFixupThroughCleanup(*this, Fix, NormalEntry, NormalEntry);
+ // Compute the branch-through dest if we need it:
+ // - if there are branch-throughs threaded through the scope
+ // - if fall-through is a branch-through
+ // - if there are fixups that will be optimistically forwarded
+ // to the enclosing cleanup
+ llvm::BasicBlock *BranchThroughDest = 0;
+ if (Scope.hasBranchThroughs() ||
+ (HasFallthrough && FallthroughIsBranchThrough) ||
+ (HasFixups && HasEnclosingCleanups)) {
+ assert(HasEnclosingCleanups);
+ EHScope &S = *EHStack.find(Scope.getEnclosingNormalCleanup());
+ BranchThroughDest = CreateNormalEntry(*this, cast<EHCleanupScope>(S));
}
- // Thread any "real" fixups we need to thread.
- for (unsigned I = FixupDepth, E = EHStack.getNumBranchFixups();
- I != E; ++I)
- if (CGF.EHStack.getBranchFixup(I).Destination)
- ThreadFixupThroughCleanup(*this, EHStack.getBranchFixup(I),
- NormalEntry, NormalEntry);
+ llvm::BasicBlock *FallthroughDest = 0;
+ llvm::SmallVector<llvm::Instruction*, 2> InstsToAppend;
+
+ // If there's exactly one branch-after and no other threads,
+ // we can route it without a switch.
+ if (!Scope.hasBranchThroughs() && !HasFixups && !HasFallthrough &&
+ Scope.getNumBranchAfters() == 1) {
+ assert(!BranchThroughDest);
+
+ // TODO: clean up the possibly dead stores to the cleanup dest slot.
+ llvm::BasicBlock *BranchAfter = Scope.getBranchAfterBlock(0);
+ InstsToAppend.push_back(llvm::BranchInst::Create(BranchAfter));
+
+ // Build a switch-out if we need it:
+ // - if there are branch-afters threaded through the scope
+ // - if fall-through is a branch-after
+ // - if there are fixups that have nowhere left to go and
+ // so must be immediately resolved
+ } else if (Scope.getNumBranchAfters() ||
+ (HasFallthrough && !FallthroughIsBranchThrough) ||
+ (HasFixups && !HasEnclosingCleanups)) {
+
+ llvm::BasicBlock *Default =
+ (BranchThroughDest ? BranchThroughDest : getUnreachableBlock());
+
+ // TODO: base this on the number of branch-afters and fixups
+ const unsigned SwitchCapacity = 10;
+
+ llvm::LoadInst *Load =
+ new llvm::LoadInst(getNormalCleanupDestSlot(), "cleanup.dest");
+ llvm::SwitchInst *Switch =
+ llvm::SwitchInst::Create(Load, Default, SwitchCapacity);
+
+ InstsToAppend.push_back(Load);
+ InstsToAppend.push_back(Switch);
+
+ // Branch-after fallthrough.
+ if (HasFallthrough && !FallthroughIsBranchThrough) {
+ FallthroughDest = createBasicBlock("cleanup.cont");
+ Switch->addCase(Builder.getInt32(0), FallthroughDest);
+ }
+
+ for (unsigned I = 0, E = Scope.getNumBranchAfters(); I != E; ++I) {
+ Switch->addCase(Scope.getBranchAfterIndex(I),
+ Scope.getBranchAfterBlock(I));
+ }
- SplitAndEmitCleanup(*this, Fn, /*ForEH*/ false, NormalEntry);
+ if (HasFixups && !HasEnclosingCleanups)
+ ResolveAllBranchFixups(Switch);
+ } else {
+ // We should always have a branch-through destination in this case.
+ assert(BranchThroughDest);
+ InstsToAppend.push_back(llvm::BranchInst::Create(BranchThroughDest));
+ }
+
+ // We're finally ready to pop the cleanup.
+ EHStack.popCleanup();
+ assert(EHStack.hasNormalCleanups() == HasEnclosingCleanups);
- if (HasFallthrough)
- EmitBlock(FallthroughDestination);
+ EmitCleanup(*this, Fn, /*ForEH*/ false);
+
+ // Append the prepared cleanup prologue from above.
+ llvm::BasicBlock *NormalExit = Builder.GetInsertBlock();
+ for (unsigned I = 0, E = InstsToAppend.size(); I != E; ++I)
+ NormalExit->getInstList().push_back(InstsToAppend[I]);
+
+ // Optimistically hope that any fixups will continue falling through.
+ for (unsigned I = FixupDepth, E = EHStack.getNumBranchFixups();
+ I < E; ++I) {
+ BranchFixup &Fixup = CGF.EHStack.getBranchFixup(I);
+ if (!Fixup.Destination) continue;
+ if (!Fixup.OptimisticBranchBlock) {
+ new llvm::StoreInst(Builder.getInt32(Fixup.DestinationIndex),
+ getNormalCleanupDestSlot(),
+ Fixup.InitialBranch);
+ Fixup.InitialBranch->setSuccessor(0, NormalEntry);
+ }
+ Fixup.OptimisticBranchBlock = NormalExit;
+ }
+
+ if (FallthroughDest)
+ EmitBlock(FallthroughDest);
+ else if (!HasFallthrough)
+ Builder.ClearInsertionPoint();
+
+ // Check whether we can merge NormalEntry into a single predecessor.
+ // This might invalidate (non-IR) pointers to NormalEntry.
+ llvm::BasicBlock *NewNormalEntry =
+ SimplifyCleanupEntry(*this, NormalEntry);
+
+ // If it did invalidate those pointers, and NormalEntry was the same
+ // as NormalExit, go back and patch up the fixups.
+ if (NewNormalEntry != NormalEntry && NormalEntry == NormalExit)
+ for (unsigned I = FixupDepth, E = EHStack.getNumBranchFixups();
+ I < E; ++I)
+ CGF.EHStack.getBranchFixup(I).OptimisticBranchBlock = NewNormalEntry;
}
}
+ assert(EHStack.hasNormalCleanups() || EHStack.getNumBranchFixups() == 0);
+
// Emit the EH cleanup if required.
if (RequiresEHCleanup) {
CGBuilderTy::InsertPoint SavedIP = Builder.saveAndClearIP();
+
EmitBlock(EHEntry);
- SplitAndEmitCleanup(*this, Fn, /*ForEH*/ true, EHEntry);
+ EmitCleanup(*this, Fn, /*ForEH*/ true);
+
+ // Append the prepared cleanup prologue from above.
+ llvm::BasicBlock *EHExit = Builder.GetInsertBlock();
+ for (unsigned I = 0, E = EHInstsToAppend.size(); I != E; ++I)
+ EHExit->getInstList().push_back(EHInstsToAppend[I]);
+
Builder.restoreIP(SavedIP);
+
+ SimplifyCleanupEntry(*this, EHEntry);
}
}
+/// Terminate the current block by emitting a branch which might leave
+/// the current cleanup-protected scope. The target scope may not yet
+/// be known, in which case this will require a fixup.
+///
+/// As a side-effect, this method clears the insertion point.
void CodeGenFunction::EmitBranchThroughCleanup(JumpDest Dest) {
if (!HaveInsertPoint())
return;
// Create the branch.
- llvm::BranchInst *BI = Builder.CreateBr(Dest.Block);
+ llvm::BranchInst *BI = Builder.CreateBr(Dest.getBlock());
- // If we're not in a cleanup scope, we don't need to worry about
+ // If we're not in a cleanup scope, or if the destination scope is
+ // the current normal-cleanup scope, we don't need to worry about
// fixups.
- if (!EHStack.hasNormalCleanups()) {
+ if (!EHStack.hasNormalCleanups() ||
+ Dest.getScopeDepth() == EHStack.getInnermostNormalCleanup()) {
Builder.ClearInsertionPoint();
return;
}
- // Initialize a fixup.
- BranchFixup Fixup;
- Fixup.Destination = Dest.Block;
- Fixup.Origin = BI;
- Fixup.LatestBranch = BI;
- Fixup.LatestBranchIndex = 0;
-
// If we can't resolve the destination cleanup scope, just add this
- // to the current cleanup scope.
- if (!Dest.ScopeDepth.isValid()) {
- EHStack.addBranchFixup() = Fixup;
+ // to the current cleanup scope as a branch fixup.
+ if (!Dest.getScopeDepth().isValid()) {
+ BranchFixup &Fixup = EHStack.addBranchFixup();
+ Fixup.Destination = Dest.getBlock();
+ Fixup.DestinationIndex = Dest.getDestIndex();
+ Fixup.InitialBranch = BI;
+ Fixup.OptimisticBranchBlock = 0;
+
Builder.ClearInsertionPoint();
return;
}
- for (EHScopeStack::iterator I = EHStack.begin(),
- E = EHStack.find(Dest.ScopeDepth); I != E; ++I) {
- if (isa<EHCleanupScope>(*I)) {
- EHCleanupScope &Scope = cast<EHCleanupScope>(*I);
- if (Scope.isNormalCleanup()) {
- llvm::BasicBlock *Block = Scope.getNormalBlock();
- if (!Block) {
- Block = createBasicBlock("cleanup");
- Scope.setNormalBlock(Block);
- }
- ThreadFixupThroughCleanup(*this, Fixup, Block, Block);
+ // Otherwise, thread through all the normal cleanups in scope.
+
+ // Store the index at the start.
+ llvm::ConstantInt *Index = Builder.getInt32(Dest.getDestIndex());
+ new llvm::StoreInst(Index, getNormalCleanupDestSlot(), BI);
+
+ // Adjust BI to point to the first cleanup block.
+ {
+ EHCleanupScope &Scope =
+ cast<EHCleanupScope>(*EHStack.find(EHStack.getInnermostNormalCleanup()));
+ BI->setSuccessor(0, CreateNormalEntry(*this, Scope));
+ }
+
+ // Add this destination to all the scopes involved.
+ EHScopeStack::stable_iterator I = EHStack.getInnermostNormalCleanup();
+ EHScopeStack::stable_iterator E = Dest.getScopeDepth();
+ if (E.strictlyEncloses(I)) {
+ while (true) {
+ EHCleanupScope &Scope = cast<EHCleanupScope>(*EHStack.find(I));
+ assert(Scope.isNormalCleanup());
+ I = Scope.getEnclosingNormalCleanup();
+
+ // If this is the last cleanup we're propagating through, tell it
+ // that there's a resolved jump moving through it.
+ if (!E.strictlyEncloses(I)) {
+ Scope.addBranchAfter(Index, Dest.getBlock());
+ break;
}
+
+ // Otherwise, tell the scope that there's a jump propoagating
+ // through it. If this isn't new information, all the rest of
+ // the work has been done before.
+ if (!Scope.addBranchThrough(Dest.getBlock()))
+ break;
}
}
Builder.ClearInsertionPoint();
}
-void CodeGenFunction::EmitBranchThroughEHCleanup(JumpDest Dest) {
+void CodeGenFunction::EmitBranchThroughEHCleanup(UnwindDest Dest) {
+ // We should never get invalid scope depths for an UnwindDest; that
+ // implies that the destination wasn't set up correctly.
+ assert(Dest.getScopeDepth().isValid() && "invalid scope depth on EH dest?");
+
if (!HaveInsertPoint())
return;
// Create the branch.
- llvm::BranchInst *BI = Builder.CreateBr(Dest.Block);
+ llvm::BranchInst *BI = Builder.CreateBr(Dest.getBlock());
- // If we're not in a cleanup scope, we don't need to worry about
- // fixups.
- if (!EHStack.hasEHCleanups()) {
+ // If the destination is in the same EH cleanup scope as us, we
+ // don't need to thread through anything.
+ if (Dest.getScopeDepth() == EHStack.getInnermostEHCleanup()) {
Builder.ClearInsertionPoint();
return;
}
+ assert(EHStack.hasEHCleanups());
- // Initialize a fixup.
- BranchFixup Fixup;
- Fixup.Destination = Dest.Block;
- Fixup.Origin = BI;
- Fixup.LatestBranch = BI;
- Fixup.LatestBranchIndex = 0;
-
- // We should never get invalid scope depths for these: invalid scope
- // depths only arise for as-yet-unemitted labels, and we can't do an
- // EH-unwind to one of those.
- assert(Dest.ScopeDepth.isValid() && "invalid scope depth on EH dest?");
-
- for (EHScopeStack::iterator I = EHStack.begin(),
- E = EHStack.find(Dest.ScopeDepth); I != E; ++I) {
- if (isa<EHCleanupScope>(*I)) {
- EHCleanupScope &Scope = cast<EHCleanupScope>(*I);
- if (Scope.isEHCleanup()) {
- llvm::BasicBlock *Block = Scope.getEHBlock();
- if (!Block) {
- Block = createBasicBlock("eh.cleanup");
- Scope.setEHBlock(Block);
- }
- ThreadFixupThroughCleanup(*this, Fixup, Block, Block);
- }
+ // Store the index at the start.
+ llvm::ConstantInt *Index = Builder.getInt32(Dest.getDestIndex());
+ new llvm::StoreInst(Index, getEHCleanupDestSlot(), BI);
+
+ // Adjust BI to point to the first cleanup block.
+ {
+ EHCleanupScope &Scope =
+ cast<EHCleanupScope>(*EHStack.find(EHStack.getInnermostEHCleanup()));
+ BI->setSuccessor(0, CreateEHEntry(*this, Scope));
+ }
+
+ // Add this destination to all the scopes involved.
+ for (EHScopeStack::stable_iterator
+ I = EHStack.getInnermostEHCleanup(),
+ E = Dest.getScopeDepth(); ; ) {
+ assert(E.strictlyEncloses(I));
+ EHCleanupScope &Scope = cast<EHCleanupScope>(*EHStack.find(I));
+ assert(Scope.isEHCleanup());
+ I = Scope.getEnclosingEHCleanup();
+
+ // If this is the last cleanup we're propagating through, add this
+ // as a branch-after.
+ if (I == E) {
+ Scope.addEHBranchAfter(Index, Dest.getBlock());
+ break;
}
+
+ // Otherwise, add it as a branch-through. If this isn't new
+ // information, all the rest of the work has been done before.
+ if (!Scope.addEHBranchThrough(Dest.getBlock()))
+ break;
}
Builder.ClearInsertionPoint();
}
+
+/// All the branch fixups on the EH stack have propagated out past the
+/// outermost normal cleanup; resolve them all by adding cases to the
+/// given switch instruction.
+void CodeGenFunction::ResolveAllBranchFixups(llvm::SwitchInst *Switch) {
+ llvm::SmallPtrSet<llvm::BasicBlock*, 4> CasesAdded;
+
+ for (unsigned I = 0, E = EHStack.getNumBranchFixups(); I != E; ++I) {
+ // Skip this fixup if its destination isn't set or if we've
+ // already treated it.
+ BranchFixup &Fixup = EHStack.getBranchFixup(I);
+ if (Fixup.Destination == 0) continue;
+ if (!CasesAdded.insert(Fixup.Destination)) continue;
+
+ Switch->addCase(Builder.getInt32(Fixup.DestinationIndex),
+ Fixup.Destination);
+ }
+
+ EHStack.clearFixups();
+}
+
+void CodeGenFunction::ResolveBranchFixups(llvm::BasicBlock *Block) {
+ assert(Block && "resolving a null target block");
+ if (!EHStack.getNumBranchFixups()) return;
+
+ assert(EHStack.hasNormalCleanups() &&
+ "branch fixups exist with no normal cleanups on stack");
+
+ llvm::SmallPtrSet<llvm::BasicBlock*, 4> ModifiedOptimisticBlocks;
+ bool ResolvedAny = false;
+
+ for (unsigned I = 0, E = EHStack.getNumBranchFixups(); I != E; ++I) {
+ // Skip this fixup if its destination doesn't match.
+ BranchFixup &Fixup = EHStack.getBranchFixup(I);
+ if (Fixup.Destination != Block) continue;
+
+ Fixup.Destination = 0;
+ ResolvedAny = true;
+
+ // If it doesn't have an optimistic branch block, LatestBranch is
+ // already pointing to the right place.
+ llvm::BasicBlock *BranchBB = Fixup.OptimisticBranchBlock;
+ if (!BranchBB)
+ continue;
+
+ // Don't process the same optimistic branch block twice.
+ if (!ModifiedOptimisticBlocks.insert(BranchBB))
+ continue;
+
+ llvm::SwitchInst *Switch = TransitionToCleanupSwitch(*this, BranchBB);
+
+ // Add a case to the switch.
+ Switch->addCase(Builder.getInt32(Fixup.DestinationIndex), Block);
+ }
+
+ if (ResolvedAny)
+ EHStack.popNullFixups();
+}
+
+llvm::Value *CodeGenFunction::getNormalCleanupDestSlot() {
+ if (!NormalCleanupDest)
+ NormalCleanupDest =
+ CreateTempAlloca(Builder.getInt32Ty(), "cleanup.dest.slot");
+ return NormalCleanupDest;
+}
+
+llvm::Value *CodeGenFunction::getEHCleanupDestSlot() {
+ if (!EHCleanupDest)
+ EHCleanupDest =
+ CreateTempAlloca(Builder.getInt32Ty(), "eh.cleanup.dest.slot");
+ return EHCleanupDest;
+}
Modified: cfe/trunk/lib/CodeGen/CodeGenFunction.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenFunction.h?rev=109274&r1=109273&r2=109274&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenFunction.h (original)
+++ cfe/trunk/lib/CodeGen/CodeGenFunction.h Fri Jul 23 16:56:41 2010
@@ -77,22 +77,22 @@
/// the innermost cleanup. When a (normal) cleanup is popped, any
/// unresolved fixups in that scope are threaded through the cleanup.
struct BranchFixup {
- /// The origin of the branch. Any switch-index stores required by
- /// cleanup threading are added before this instruction.
- llvm::Instruction *Origin;
+ /// The block containing the terminator which needs to be modified
+ /// into a switch if this fixup is resolved into the current scope.
+ /// If null, LatestBranch points directly to the destination.
+ llvm::BasicBlock *OptimisticBranchBlock;
- /// The destination of the branch.
+ /// The ultimate destination of the branch.
///
/// This can be set to null to indicate that this fixup was
/// successfully resolved.
llvm::BasicBlock *Destination;
- /// The last branch of the fixup. It is an invariant that
- /// LatestBranch->getSuccessor(LatestBranchIndex) == Destination.
- ///
- /// The branch is always either a BranchInst or a SwitchInst.
- llvm::TerminatorInst *LatestBranch;
- unsigned LatestBranchIndex;
+ /// The destination index value.
+ unsigned DestinationIndex;
+
+ /// The initial branch of the fixup.
+ llvm::BranchInst *InitialBranch;
};
enum CleanupKind { NormalAndEHCleanup, EHCleanup, NormalCleanup };
@@ -117,9 +117,8 @@
bool isValid() const { return Size >= 0; }
- /// \return true if this scope is (non-strictly) nested within the
- /// given scope, assuming they're both valid
- bool isWithin(stable_iterator I) const { return Size <= I.Size; }
+ bool encloses(stable_iterator I) const { return Size <= I.Size; }
+ bool strictlyEncloses(stable_iterator I) const { return Size < I.Size; }
friend bool operator==(stable_iterator A, stable_iterator B) {
return A.Size == B.Size;
@@ -182,6 +181,11 @@
/// The number of catches on the stack.
unsigned CatchDepth;
+ /// The current EH destination index. Reset to FirstCatchIndex
+ /// whenever the last EH cleanup is popped.
+ unsigned NextEHDestIndex;
+ enum { FirstEHDestIndex = 1 };
+
/// The current set of branch fixups. A branch fixup is a jump to
/// an as-yet unemitted label, i.e. a label for which we don't yet
/// know the EH stack depth. Whenever we pop a cleanup, we have
@@ -203,15 +207,13 @@
char *allocate(size_t Size);
- void popNullFixups();
-
void *pushCleanup(CleanupKind K, size_t DataSize);
public:
EHScopeStack() : StartOfBuffer(0), EndOfBuffer(0), StartOfData(0),
InnermostNormalCleanup(stable_end()),
InnermostEHCleanup(stable_end()),
- CatchDepth(0) {}
+ CatchDepth(0), NextEHDestIndex(FirstEHDestIndex) {}
~EHScopeStack() { delete[] StartOfBuffer; }
// Variadic templates would make this not terrible.
@@ -366,8 +368,17 @@
return BranchFixups[I];
}
- /// Mark any branch fixups leading to the given block as resolved.
- void resolveBranchFixups(llvm::BasicBlock *Dest);
+ /// Pops lazily-removed fixups from the end of the list. This
+ /// should only be called by procedures which have just popped a
+ /// cleanup or resolved one or more fixups.
+ void popNullFixups();
+
+ /// Clears the branch-fixups list. This should only be called by
+ /// CodeGenFunction::ResolveAllBranchFixups.
+ void clearFixups() { BranchFixups.clear(); }
+
+ /// Gets the next EH destination index.
+ unsigned getNextEHDestIndex() { return NextEHDestIndex++; }
};
/// CodeGenFunction - This class organizes the per-function state that is used
@@ -376,16 +387,44 @@
CodeGenFunction(const CodeGenFunction&); // DO NOT IMPLEMENT
void operator=(const CodeGenFunction&); // DO NOT IMPLEMENT
public:
- /// A jump destination is a pair of a basic block and a cleanup
- /// depth. They are used to implement direct jumps across cleanup
- /// scopes, e.g. goto, break, continue, and return.
+ /// A jump destination is an abstract label, branching to which may
+ /// require a jump out through normal cleanups.
struct JumpDest {
- JumpDest() : Block(0), ScopeDepth() {}
- JumpDest(llvm::BasicBlock *Block, EHScopeStack::stable_iterator Depth)
- : Block(Block), ScopeDepth(Depth) {}
+ JumpDest() : Block(0), ScopeDepth(), Index(0) {}
+ JumpDest(llvm::BasicBlock *Block,
+ EHScopeStack::stable_iterator Depth,
+ unsigned Index)
+ : Block(Block), ScopeDepth(Depth), Index(Index) {}
+
+ bool isValid() const { return Block != 0; }
+ llvm::BasicBlock *getBlock() const { return Block; }
+ EHScopeStack::stable_iterator getScopeDepth() const { return ScopeDepth; }
+ unsigned getDestIndex() const { return Index; }
+ private:
+ llvm::BasicBlock *Block;
+ EHScopeStack::stable_iterator ScopeDepth;
+ unsigned Index;
+ };
+
+ /// An unwind destination is an abstract label, branching to which
+ /// may require a jump out through EH cleanups.
+ struct UnwindDest {
+ UnwindDest() : Block(0), ScopeDepth(), Index(0) {}
+ UnwindDest(llvm::BasicBlock *Block,
+ EHScopeStack::stable_iterator Depth,
+ unsigned Index)
+ : Block(Block), ScopeDepth(Depth), Index(Index) {}
+
+ bool isValid() const { return Block != 0; }
+ llvm::BasicBlock *getBlock() const { return Block; }
+ EHScopeStack::stable_iterator getScopeDepth() const { return ScopeDepth; }
+ unsigned getDestIndex() const { return Index; }
+
+ private:
llvm::BasicBlock *Block;
EHScopeStack::stable_iterator ScopeDepth;
+ unsigned Index;
};
CodeGenModule &CGM; // Per-module state.
@@ -413,6 +452,9 @@
/// iff the function has no return value.
llvm::Value *ReturnValue;
+ /// RethrowBlock - Unified rethrow block.
+ UnwindDest RethrowBlock;
+
/// AllocaInsertPoint - This is an instruction in the entry block before which
/// we prefer to insert allocas.
llvm::AssertingVH<llvm::Instruction> AllocaInsertPt;
@@ -430,6 +472,12 @@
EHScopeStack EHStack;
+ /// i32s containing the indexes of the cleanup destinations.
+ llvm::AllocaInst *NormalCleanupDest;
+ llvm::AllocaInst *EHCleanupDest;
+
+ unsigned NextCleanupDestIndex;
+
/// The exception slot. All landing pads write the current
/// exception pointer into this alloca.
llvm::Value *ExceptionSlot;
@@ -469,7 +517,7 @@
/// PopCleanupBlock - Will pop the cleanup entry on the stack and
/// process all branch fixups.
- void PopCleanupBlock();
+ void PopCleanupBlock(bool FallThroughIsBranchThrough = false);
/// \brief Enters a new scope for capturing cleanups, all of which
/// will be executed once the scope is exited.
@@ -520,18 +568,21 @@
/// the cleanup blocks that have been added.
void PopCleanupBlocks(EHScopeStack::stable_iterator OldCleanupStackSize);
+ void ResolveAllBranchFixups(llvm::SwitchInst *Switch);
+ void ResolveBranchFixups(llvm::BasicBlock *Target);
+
/// The given basic block lies in the current EH scope, but may be a
/// target of a potentially scope-crossing jump; get a stable handle
/// to which we can perform this jump later.
- JumpDest getJumpDestInCurrentScope(llvm::BasicBlock *Target) const {
- return JumpDest(Target, EHStack.stable_begin());
+ JumpDest getJumpDestInCurrentScope(llvm::BasicBlock *Target) {
+ return JumpDest(Target, EHStack.stable_begin(), NextCleanupDestIndex++);
}
/// The given basic block lies in the current EH scope, but may be a
/// target of a potentially scope-crossing jump; get a stable handle
/// to which we can perform this jump later.
JumpDest getJumpDestInCurrentScope(const char *Name = 0) {
- return JumpDest(createBasicBlock(Name), EHStack.stable_begin());
+ return getJumpDestInCurrentScope(createBasicBlock(Name));
}
/// EmitBranchThroughCleanup - Emit a branch from the current insert
@@ -542,7 +593,11 @@
/// EmitBranchThroughEHCleanup - Emit a branch from the current
/// insert block through the EH cleanup handling code (if any) and
/// then on to \arg Dest.
- void EmitBranchThroughEHCleanup(JumpDest Dest);
+ void EmitBranchThroughEHCleanup(UnwindDest Dest);
+
+ /// getRethrowDest - Returns the unified outermost-scope rethrow
+ /// destination.
+ UnwindDest getRethrowDest();
/// BeginConditionalBranch - Should be called before a conditional part of an
/// expression is emitted. For example, before the RHS of the expression below
@@ -600,10 +655,6 @@
/// statement range in current switch instruction.
llvm::BasicBlock *CaseRangeBlock;
- /// InvokeDest - This is the nearest exception target for calls
- /// which can unwind, when exceptions are being used.
- llvm::BasicBlock *InvokeDest;
-
// VLASizeMap - This keeps track of the associated size for each VLA type.
// We track this by the size expression rather than the type itself because
// in certain situations, like a const qualifier applied to an VLA typedef,
@@ -660,6 +711,9 @@
/// is assigned in every landing pad.
llvm::Value *getExceptionSlot();
+ llvm::Value *getNormalCleanupDestSlot();
+ llvm::Value *getEHCleanupDestSlot();
+
llvm::BasicBlock *getUnreachableBlock() {
if (!UnreachableBlock) {
UnreachableBlock = createBasicBlock("unreachable");
Modified: cfe/trunk/test/CodeGenCXX/condition.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/condition.cpp?rev=109274&r1=109273&r2=109274&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/condition.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/condition.cpp Fri Jul 23 16:56:41 2010
@@ -105,12 +105,12 @@
// CHECK-NEXT: br i1 [[COND]]
// Loop-exit staging block.
- // CHECK: store i32 1, i32* [[CLEANUPDEST]]
+ // CHECK: store i32 3, i32* [[CLEANUPDEST]]
// CHECK-NEXT: br
// While body.
// CHECK: store i32 21, i32* [[Z]]
- // CHECK: store i32 2, i32* [[CLEANUPDEST]]
+ // CHECK: store i32 0, i32* [[CLEANUPDEST]]
// CHECK-NEXT: br
z = 21;
@@ -138,7 +138,7 @@
// CHECK: define void @_Z12for_destructi(
void for_destruct(int z) {
// CHECK: [[Z:%.*]] = alloca i32
- // CHECK: [[XDEST:%.*]] = alloca i32
+ // CHECK: [[CLEANUPDEST:%.*]] = alloca i32
// CHECK: [[I:%.*]] = alloca i32
// CHECK: call void @_ZN1YC1Ev
// CHECK-NEXT: br
@@ -152,7 +152,7 @@
// -> %for.body, %for.cond.cleanup
// %for.cond.cleanup: Exit cleanup staging.
- // CHECK: store i32 1, i32* [[XDEST]]
+ // CHECK: store i32 2, i32* [[CLEANUPDEST]]
// CHECK-NEXT: br
// -> %cleanup
@@ -166,21 +166,21 @@
// CHECK: [[TMP:%.*]] = load i32* [[Z]]
// CHECK-NEXT: [[INC:%.*]] = add nsw i32 [[TMP]], 1
// CHECK-NEXT: store i32 [[INC]], i32* [[Z]]
- // CHECK-NEXT: store i32 2, i32* [[XDEST]]
+ // CHECK-NEXT: store i32 0, i32* [[CLEANUPDEST]]
// CHECK-NEXT: br
// -> %cleanup
// %cleanup: Destroys X.
// CHECK: call void @_ZN1XD1Ev
- // CHECK-NEXT: [[YDESTTMP:%.*]] = load i32* [[XDEST]]
+ // CHECK-NEXT: [[YDESTTMP:%.*]] = load i32* [[CLEANUPDEST]]
// CHECK-NEXT: switch i32 [[YDESTTMP]]
- // 1 -> %cleanup4, 2 -> %cleanup.cont
+ // 0 -> %cleanup.cont, default -> %cleanup1
// %cleanup.cont: (eliminable)
// CHECK: br
// -> %for.cond
- // %cleanup4: Destroys Y.
+ // %cleanup1: Destroys Y.
// CHECK: call void @_ZN1YD1Ev(
// CHECK-NEXT: br
// -> %for.end
Modified: cfe/trunk/test/CodeGenCXX/eh.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/eh.cpp?rev=109274&r1=109273&r2=109274&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/eh.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/eh.cpp Fri Jul 23 16:56:41 2010
@@ -39,6 +39,7 @@
// CHECK: [[FREEVAR:%.*]] = alloca i1
// CHECK-NEXT: [[EXNOBJVAR:%.*]] = alloca i8*
// CHECK-NEXT: [[EXNSLOTVAR:%.*]] = alloca i8*
+// CHECK-NEXT: [[CLEANUPDESTVAR:%.*]] = alloca i32
// CHECK-NEXT: store i1 false, i1* [[FREEVAR]]
// CHECK-NEXT: [[EXNOBJ:%.*]] = call i8* @__cxa_allocate_exception(i64 16)
// CHECK-NEXT: store i8* [[EXNOBJ]], i8** [[EXNOBJVAR]]
@@ -124,6 +125,7 @@
// CHECK-NEXT: [[EXNALLOCVAR:%.*]] = alloca i8*
// CHECK-NEXT: [[CAUGHTEXNVAR:%.*]] = alloca i8*
// CHECK-NEXT: [[INTCATCHVAR:%.*]] = alloca i32
+// CHECK-NEXT: [[EHCLEANUPDESTVAR:%.*]] = alloca i32
// CHECK-NEXT: store i1 false, i1* [[FREEEXNOBJ]]
try {
try {
@@ -153,6 +155,7 @@
// CHECK: [[CAUGHTEXN:%.*]] = call i8* @llvm.eh.exception()
// CHECK-NEXT: store i8* [[CAUGHTEXN]], i8** [[CAUGHTEXNVAR]]
// CHECK-NEXT: call i32 (i8*, i8*, ...)* @llvm.eh.selector(i8* [[CAUGHTEXN]], i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*), i8* null)
+// CHECK-NEXT: store i32 1, i32* [[EHCLEANUPDESTVAR]]
// CHECK-NEXT: call void @__cxa_end_catch()
// CHECK-NEXT: br label
// CHECK: load i8** [[CAUGHTEXNVAR]]
@@ -290,3 +293,71 @@
}
}
}
+
+// PR7686
+namespace test12 {
+ struct A { ~A(); };
+ bool opaque(const A&);
+
+ // CHECK: define void @_ZN6test124testEv()
+ void test() {
+ // CHECK: [[X:%.*]] = alloca [[A:%.*]],
+ // CHECK: [[EHCLEANUPDEST:%.*]] = alloca i32
+ // CHECK: [[Y:%.*]] = alloca [[A]]
+ // CHECK: [[Z:%.*]] = alloca [[A]]
+ // CHECK: [[CLEANUPDEST:%.*]] = alloca i32
+
+ A x;
+ // CHECK: invoke zeroext i1 @_ZN6test126opaqueERKNS_1AE(
+ if (opaque(x)) {
+ A y;
+ A z;
+
+ // CHECK: invoke void @_ZN6test121AD1Ev([[A]]* [[Z]])
+ // CHECK: invoke void @_ZN6test121AD1Ev([[A]]* [[Y]])
+
+ // It'd be great if something eliminated this switch.
+ // CHECK: load i32* [[CLEANUPDEST]]
+ // CHECK-NEXT: switch i32
+ goto success;
+ }
+
+ success:
+ bool _ = true;
+
+ // CHECK: call void @_ZN6test121AD1Ev([[A]]* [[X]])
+ // CHECK-NEXT: ret void
+ }
+}
+
+// Reduced from some TableGen code that was causing a self-host crash.
+namespace test13 {
+ struct A { ~A(); };
+
+ void test0(int x) {
+ try {
+ switch (x) {
+ case 0:
+ break;
+ case 1:{
+ A a;
+ break;
+ }
+ default:
+ return;
+ }
+ return;
+ } catch (int x) {
+ }
+ return;
+ }
+
+ void test1(int x) {
+ A y;
+ try {
+ switch (x) {
+ default: break;
+ }
+ } catch (int x) {}
+ }
+}
Modified: cfe/trunk/test/CodeGenObjC/gnu-exceptions.m
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenObjC/gnu-exceptions.m?rev=109274&r1=109273&r2=109274&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenObjC/gnu-exceptions.m (original)
+++ cfe/trunk/test/CodeGenObjC/gnu-exceptions.m Fri Jul 23 16:56:41 2010
@@ -10,16 +10,20 @@
@try {
// CHECK: invoke void @opaque()
opaque();
+
+ // CHECK: call void @log(i32 1)
+
} @catch (C *c) {
// CHECK: call i8* @llvm.eh.exception()
// CHECK: call i32 (i8*, i8*, ...)* @llvm.eh.selector({{.*}} @__gnu_objc_personality_v0
// CHECK: br i1
- // CHECK: call void @objc_exception_throw
// CHECK: call void @log(i32 0)
+
+ // CHECK: call void @objc_exception_throw
+
log(0);
}
- // CHECK: call void @log(i32 1)
log(1);
}
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