From a8ba2c25e9ea7b0d213b485debe5d044efde66a4 Mon Sep 17 00:00:00 2001 From: Eli Friedman Date: Wed, 3 Jun 2009 21:42:06 +0000 Subject: [PATCH] PR4317: Handle splits where the new block is unreachable correctly in DominatorTreeBase::Split. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72810 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/Analysis/Dominators.h | 9 +++++++-- .../Generic/2009-06-03-UnreachableSplitPad.ll | 15 +++++++++++++++ 2 files changed, 22 insertions(+), 2 deletions(-) create mode 100644 test/CodeGen/Generic/2009-06-03-UnreachableSplitPad.ll diff --git a/include/llvm/Analysis/Dominators.h b/include/llvm/Analysis/Dominators.h index b405f5b71ed..347e239d8ea 100644 --- a/include/llvm/Analysis/Dominators.h +++ b/include/llvm/Analysis/Dominators.h @@ -270,12 +270,17 @@ protected: NewBBIDom = PredBlocks[i]; break; } - assert(i != PredBlocks.size() && "No reachable preds?"); + + // It's possible that none of the predecessors of NewBB are reachable; + // in that case, NewBB itself is unreachable, so nothing needs to be + // changed. + if (!NewBBIDom) + return; + for (i = i + 1; i < PredBlocks.size(); ++i) { if (DT.isReachableFromEntry(PredBlocks[i])) NewBBIDom = DT.findNearestCommonDominator(NewBBIDom, PredBlocks[i]); } - assert(NewBBIDom && "No immediate dominator found??"); // Create the new dominator tree node... and set the idom of NewBB. DomTreeNodeBase *NewBBNode = DT.addNewBlock(NewBB, NewBBIDom); diff --git a/test/CodeGen/Generic/2009-06-03-UnreachableSplitPad.ll b/test/CodeGen/Generic/2009-06-03-UnreachableSplitPad.ll new file mode 100644 index 00000000000..59e7d0c7a8f --- /dev/null +++ b/test/CodeGen/Generic/2009-06-03-UnreachableSplitPad.ll @@ -0,0 +1,15 @@ +; RUN: llvm-as < %s | llc +; PR4317 + +declare i32 @b() + +define void @a() { +entry: + ret void + +dummy: + invoke i32 @b() to label %reg unwind label %reg + +reg: + ret void +} -- 2.34.1