diff options
| -rw-r--r-- | lib/Transforms/Utils/SSI.cpp | 8 | ||||
| -rw-r--r-- | test/Transforms/SSI/2009-08-15-UnreachableBB.ll | 19 |
2 files changed, 25 insertions, 2 deletions
diff --git a/lib/Transforms/Utils/SSI.cpp b/lib/Transforms/Utils/SSI.cpp index 63ca354793..7736f08768 100644 --- a/lib/Transforms/Utils/SSI.cpp +++ b/lib/Transforms/Utils/SSI.cpp @@ -39,7 +39,7 @@ STATISTIC(NumPhiInserted, "Number of phi functions inserted"); void SSI::getAnalysisUsage(AnalysisUsage &AU) const { AU.addRequired<DominanceFrontier>(); AU.addRequired<DominatorTree>(); - AU.setPreservesAll(); + AU.setPreservesCFG(); } bool SSI::runOnFunction(Function &F) { @@ -121,7 +121,7 @@ void SSI::insertPhiFunctions(SmallVectorImpl<Instruction *> &value) { // Test if there were any sigmas for this variable if (needConstruction[i]) { - SmallPtrSet<BasicBlock *, 1> BB_visited; + SmallPtrSet<BasicBlock *, 16> BB_visited; // Insert phi functions if there is any sigma function while (!defsites[i].empty()) { @@ -131,6 +131,10 @@ void SSI::insertPhiFunctions(SmallVectorImpl<Instruction *> &value) { defsites[i].pop_back(); DominanceFrontier::iterator DF_BB = DF->find(BB); + // The BB is unreachable. Skip it. + if (DF_BB == DF->end()) + continue; + // Iterates through all the dominance frontier of BB for (std::set<BasicBlock *>::iterator DF_BB_begin = DF_BB->second.begin(), DF_BB_end = DF_BB->second.end(); diff --git a/test/Transforms/SSI/2009-08-15-UnreachableBB.ll b/test/Transforms/SSI/2009-08-15-UnreachableBB.ll new file mode 100644 index 0000000000..11a4f60b15 --- /dev/null +++ b/test/Transforms/SSI/2009-08-15-UnreachableBB.ll @@ -0,0 +1,19 @@ +; RUN: llvm-as < %s | opt -ssi-everything -disable-output + +declare fastcc i32 @ras_Empty(i8** nocapture) nounwind readonly + +define i32 @cc_Tautology() nounwind { +entry: + unreachable + +cc_InitData.exit: ; No predecessors! + %0 = call fastcc i32 @ras_Empty(i8** undef) nounwind ; <i32> [#uses=1] + %1 = icmp eq i32 %0, 0 ; <i1> [#uses=1] + br i1 %1, label %bb2, label %bb6 + +bb2: ; preds = %cc_InitData.exit + unreachable + +bb6: ; preds = %cc_InitData.exit + ret i32 undef +} |