[WinEH] Split the landingpad BB instead of cloning it
This means we don't have to RAUW the landingpad instruction and
landingpad BB, which is a nice win.
llvm-svn: 235725
diff --git a/llvm/lib/CodeGen/WinEHPrepare.cpp b/llvm/lib/CodeGen/WinEHPrepare.cpp
index 09f3e13..8a0fb7f 100644
--- a/llvm/lib/CodeGen/WinEHPrepare.cpp
+++ b/llvm/lib/CodeGen/WinEHPrepare.cpp
@@ -670,25 +670,13 @@
outlineHandler(Action, &F, LPad, StartBB, FrameVarInfo);
}
- // Replace the landing pad with a new llvm.eh.action based landing pad.
- BasicBlock *NewLPadBB = BasicBlock::Create(Context, "lpad", &F, LPadBB);
- assert(!isa<PHINode>(LPadBB->begin()));
- auto *NewLPad = cast<LandingPadInst>(LPad->clone());
- NewLPadBB->getInstList().push_back(NewLPad);
- while (!pred_empty(LPadBB)) {
- auto *pred = *pred_begin(LPadBB);
- InvokeInst *Invoke = cast<InvokeInst>(pred->getTerminator());
- Invoke->setUnwindDest(NewLPadBB);
- }
-
- // Replace the mapping of any nested landing pad that previously mapped
- // to this landing pad with a referenced to the cloned version.
- for (auto &LPadPair : NestedLPtoOriginalLP) {
- const LandingPadInst *OriginalLPad = LPadPair.second;
- if (OriginalLPad == LPad) {
- LPadPair.second = NewLPad;
- }
- }
+ // Split the block after the landingpad instruction so that it is just a
+ // call to llvm.eh.actions followed by indirectbr.
+ assert(!isa<PHINode>(LPadBB->begin()) && "lpad phi not removed");
+ LPadBB->splitBasicBlock(LPad->getNextNode(),
+ LPadBB->getName() + ".prepsplit");
+ // Erase the branch inserted by the split so we can insert indirectbr.
+ LPadBB->getTerminator()->eraseFromParent();
// Replace all extracted values with undef and ultimately replace the
// landingpad with undef.
@@ -733,7 +721,7 @@
ActionArgs.push_back(Action->getHandlerBlockOrFunc());
}
CallInst *Recover =
- CallInst::Create(ActionIntrin, ActionArgs, "recover", NewLPadBB);
+ CallInst::Create(ActionIntrin, ActionArgs, "recover", LPadBB);
// Add an indirect branch listing possible successors of the catch handlers.
SetVector<BasicBlock *> ReturnTargets;
@@ -744,7 +732,7 @@
}
}
IndirectBrInst *Branch =
- IndirectBrInst::Create(Recover, ReturnTargets.size(), NewLPadBB);
+ IndirectBrInst::Create(Recover, ReturnTargets.size(), LPadBB);
for (BasicBlock *Target : ReturnTargets)
Branch->addDestination(Target);
} // End for each landingpad
