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[SimplifyCFG] markAliveBlocks(): catchswitch: preserve PostDomTree 

When removing catchpad's from catchswitch, if that removes a successor,
we need to record that in DomTreeUpdater.

This fixes PostDomTree preservation failure in an existing test.
This appears to be the single issue that i see in my current test coverage.
This commit is contained in:
Roman Lebedev 2021-01-16 21:42:40 +03:00
parent 1454724215
commit 32fc32317a
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GPG Key ID: 083C3EBB4A1689E0
1 changed files with 9 additions and 0 deletions
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9
llvm/lib/Transforms/Utils/Local.cpp
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@ -2286,6 +2286,7 @@ static bool markAliveBlocks(Function &F,
}
};
SmallMapVector<BasicBlock *, int, 8> NumPerSuccessorCases;
// Set of unique CatchPads.
SmallDenseMap<CatchPadInst *, detail::DenseSetEmpty, 4,
CatchPadDenseMapInfo, detail::DenseSetPair<CatchPadInst *>>
@ -2295,14 +2296,22 @@ static bool markAliveBlocks(Function &F,
E = CatchSwitch->handler_end();
I != E; ++I) {
BasicBlock *HandlerBB = *I;
++NumPerSuccessorCases[HandlerBB];
auto *CatchPad = cast<CatchPadInst>(HandlerBB->getFirstNonPHI());
if (!HandlerSet.insert({CatchPad, Empty}).second) {
--NumPerSuccessorCases[HandlerBB];
CatchSwitch->removeHandler(I);
--I;
--E;
Changed = true;
}
}
std::vector<DominatorTree::UpdateType> Updates;
for (const std::pair<BasicBlock *, int> &I : NumPerSuccessorCases)
if (I.second == 0)
Updates.push_back({DominatorTree::Delete, BB, I.first});
if (DTU)
DTU->applyUpdates(Updates);
}
Changed |= ConstantFoldTerminator(BB, true, nullptr, DTU);