[llvm-commits] [llvm] r138990 - /llvm/trunk/lib/VMCore/AutoUpgrade.cpp
Bill Wendling
isanbard at gmail.com
Thu Sep 1 18:30:08 PDT 2011
Author: void
Date: Thu Sep 1 20:30:08 2011
New Revision: 138990
URL: http://llvm.org/viewvc/llvm-project?rev=138990&view=rev
Log:
Perform the upgrading of the old EH to the new EH in a more sane manner.
Perform the upgrading in steps.
* First, create a map of the invokes to the EH intrinsics.
* Next, take that mapping and determine if the invoke's unwind destination has a
single predecessor. If not, then create a new empty block to hold the new
landingpad instruction.
* Create a landingpad instruction into the uwnind destination. Fill it with the
values from the old selector. Map the old intrinsic calls to the new
landingpad values (there may be multiple landingpad instructions per instrinic
call pairs).
* Go through the old intrinsic calls, create a PHI node when necessary, and then
replace their values with the new values from the landingpad instructions.
* Delete all dead instructions.
* ???
* Profit!
Modified:
llvm/trunk/lib/VMCore/AutoUpgrade.cpp
Modified: llvm/trunk/lib/VMCore/AutoUpgrade.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/VMCore/AutoUpgrade.cpp?rev=138990&r1=138989&r2=138990&view=diff
==============================================================================
--- llvm/trunk/lib/VMCore/AutoUpgrade.cpp (original)
+++ llvm/trunk/lib/VMCore/AutoUpgrade.cpp Thu Sep 1 20:30:08 2011
@@ -387,10 +387,9 @@
Type *SelTy = Type::getInt32Ty(Context);
Type *LPadSlotTy = StructType::get(ExnTy, SelTy, NULL);
- // This map stores the slots where the exception object and selector value are
- // stored within a function.
- SmallPtrSet<Instruction*, 32> DeadInsts;
- DenseMap<Function*, std::pair<Value*, Value*> > FnToLPadSlotMap;
+ // This map links the invoke instruction with the eh.exception and eh.selector
+ // calls associated with it.
+ DenseMap<InvokeInst*, std::pair<Value*, Value*> > InvokeToIntrinsicsMap;
for (Module::iterator
I = M->begin(), E = M->end(); I != E; ++I) {
Function &F = *I;
@@ -401,47 +400,127 @@
InvokeInst *Inst = dyn_cast<InvokeInst>(BB->getTerminator());
if (!Inst) continue;
BasicBlock *UnwindDest = Inst->getUnwindDest();
- if (UnwindDest->isLandingPad()) continue; // All ready converted.
-
- // Store the exception object and selector value in the entry block.
- Value *ExnSlot = 0;
- Value *SelSlot = 0;
- if (!FnToLPadSlotMap[&F].first) {
- BasicBlock *Entry = &F.front();
- ExnSlot = new AllocaInst(ExnTy, "exn", Entry->getTerminator());
- SelSlot = new AllocaInst(SelTy, "sel", Entry->getTerminator());
- FnToLPadSlotMap[&F] = std::make_pair(ExnSlot, SelSlot);
- } else {
- ExnSlot = FnToLPadSlotMap[&F].first;
- SelSlot = FnToLPadSlotMap[&F].second;
- }
-
- // We're in an unwind block. Try to find the eh.exception and eh.selector
- // calls.
- IRBuilder<> Builder(Context);
- Builder.SetInsertPoint(UnwindDest, UnwindDest->getFirstNonPHI());
+ if (UnwindDest->isLandingPad()) continue; // Already converted.
SmallPtrSet<BasicBlock*, 8> Visited;
CallInst *Exn = 0;
CallInst *Sel = 0;
FindExnAndSelIntrinsics(UnwindDest, Exn, Sel, Visited);
assert(Exn && Sel && "Cannot find eh.exception and eh.selector calls!");
+ InvokeToIntrinsicsMap[Inst] = std::make_pair(Exn, Sel);
+ }
+ }
+
+ // This map stores the slots where the exception object and selector value are
+ // stored within a function.
+ DenseMap<Function*, std::pair<Value*, Value*> > FnToLPadSlotMap;
+
+ // This maps the old intrinsic calls (eh.exception & eh.selector) to the new
+ // landingpad instruction(s).
+ DenseMap<std::pair<CallInst*, CallInst*>,
+ SmallVector<std::pair<Value*, Value*>, 8> > OldExnToNewExnMap;
+
+ SmallPtrSet<Instruction*, 32> DeadInsts;
+ for (DenseMap<InvokeInst*, std::pair<Value*, Value*> >::iterator
+ I = InvokeToIntrinsicsMap.begin(), E = InvokeToIntrinsicsMap.end();
+ I != E; ++I) {
+ InvokeInst *Invoke = I->first;
+ BasicBlock *UnwindDest = Invoke->getUnwindDest();
+ Function *F = UnwindDest->getParent();
+ std::pair<Value*, Value*> EHIntrinsics = I->second;
+ CallInst *Exn = cast<CallInst>(EHIntrinsics.first);
+ CallInst *Sel = cast<CallInst>(EHIntrinsics.second);
+
+ // Store the exception object and selector value in the entry block.
+ Value *ExnSlot = 0;
+ Value *SelSlot = 0;
+ if (!FnToLPadSlotMap[F].first) {
+ BasicBlock *Entry = &F->front();
+ ExnSlot = new AllocaInst(ExnTy, "exn", Entry->getTerminator());
+ SelSlot = new AllocaInst(SelTy, "sel", Entry->getTerminator());
+ FnToLPadSlotMap[F] = std::make_pair(ExnSlot, SelSlot);
+ } else {
+ ExnSlot = FnToLPadSlotMap[F].first;
+ SelSlot = FnToLPadSlotMap[F].second;
+ }
- Value *PersFn = Sel->getArgOperand(1);
- LandingPadInst *LPI = Builder.CreateLandingPad(LPadSlotTy, PersFn, 0);
- Value *LPExn = Builder.CreateExtractValue(LPI, 0);
- Value *LPSel = Builder.CreateExtractValue(LPI, 1);
- Builder.CreateStore(LPExn, ExnSlot);
- Builder.CreateStore(LPSel, SelSlot);
+ if (!UnwindDest->getSinglePredecessor()) {
+ // The unwind destination doesn't have a single predecessor. Create an
+ // unwind destination which has only one predecessor.
+ BasicBlock *NewBB = BasicBlock::Create(Context, "new.lpad",
+ UnwindDest->getParent());
+ BranchInst::Create(UnwindDest, NewBB);
+ Invoke->setUnwindDest(NewBB);
+
+ // Fix up any PHIs in the original unwind destination block.
+ for (BasicBlock::iterator
+ II = UnwindDest->begin(); isa<PHINode>(II); ++II) {
+ PHINode *PN = cast<PHINode>(II);
+ int Idx = PN->getBasicBlockIndex(Invoke->getParent());
+ if (Idx == -1) continue;
+ PN->setIncomingBlock(Idx, NewBB);
+ }
- TransferClausesToLandingPadInst(LPI, Sel);
+ UnwindDest = NewBB;
+ }
+
+ IRBuilder<> Builder(Context);
+ Builder.SetInsertPoint(UnwindDest, UnwindDest->getFirstInsertionPt());
- Exn->replaceAllUsesWith(LPExn);
- Sel->replaceAllUsesWith(LPSel);
+ Value *PersFn = Sel->getArgOperand(1);
+ LandingPadInst *LPI = Builder.CreateLandingPad(LPadSlotTy, PersFn, 0);
+ Value *LPExn = Builder.CreateExtractValue(LPI, 0);
+ Value *LPSel = Builder.CreateExtractValue(LPI, 1);
+ Builder.CreateStore(LPExn, ExnSlot);
+ Builder.CreateStore(LPSel, SelSlot);
+
+ TransferClausesToLandingPadInst(LPI, Sel);
+
+ OldExnToNewExnMap[std::make_pair(Exn, Sel)].
+ push_back(std::make_pair(LPExn, LPSel));
+
+ DeadInsts.insert(Exn);
+ DeadInsts.insert(Sel);
+ }
- DeadInsts.insert(Exn);
- DeadInsts.insert(Sel);
+ // Replace the old intrinsic calls with the new (possibly PHI'ed) values.
+ for (DenseMap<std::pair<CallInst*, CallInst*>,
+ SmallVector<std::pair<Value*, Value*>, 8> >::iterator
+ I = OldExnToNewExnMap.begin(), E = OldExnToNewExnMap.end();
+ I != E; ++I) {
+ std::pair<CallInst*, CallInst*> OldExnSel = I->first;
+ CallInst *Exn = OldExnSel.first;
+ CallInst *Sel = OldExnSel.second;
+ SmallVector<std::pair<Value*, Value*>, 8> &LPExnSel = I->second;
+ unsigned Size = LPExnSel.size();
+ Value *LPExn = LPExnSel[0].first;
+ Value *LPSel = LPExnSel[0].second;
+
+ if (Size != 1) {
+ BasicBlock *Parent = Exn->getParent();
+ IRBuilder<> Builder(Context);
+ Builder.SetInsertPoint(Parent, Parent->getFirstInsertionPt());
+
+ PHINode *PN = Builder.CreatePHI(Exn->getType(), Size, "exn.phi");
+ for (SmallVector<std::pair<Value*, Value*>, 8>::iterator
+ II = LPExnSel.begin(), IE = LPExnSel.end(); II != IE; ++II)
+ PN->addIncoming(II->first, cast<Instruction>(II->first)->getParent());
+
+ LPExn = PN;
+
+ Parent = Sel->getParent();
+ Builder.SetInsertPoint(Parent, Parent->getFirstInsertionPt());
+
+ PN = Builder.CreatePHI(Sel->getType(), Size, "sel.phi");
+ for (SmallVector<std::pair<Value*, Value*>, 8>::iterator
+ II = LPExnSel.begin(), IE = LPExnSel.end(); II != IE; ++II)
+ PN->addIncoming(II->second, cast<Instruction>(II->second)->getParent());
+
+ LPSel = PN;
}
+
+ Exn->replaceAllUsesWith(LPExn);
+ Sel->replaceAllUsesWith(LPSel);
}
// Remove the dead instructions.
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