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| author | Owen Anderson <resistor@mac.com> | 2008-07-02 17:20:16 +0000 |
|---|---|---|
| committer | Owen Anderson <resistor@mac.com> | 2008-07-02 17:20:16 +0000 |
| commit | f2aa160b357c98d8c37b69ea9775aa3e097d1319 (patch) | |
| tree | bad306be76337b3a4dac25790e1644b4682642cb /lib/Transforms | |
| parent | bee98c66c0c3d1f43244cdf237e572a9df031e40 (diff) | |
A better fix for PR2503 that doesn't pessimize GVN in the presence of unreachable blocks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53032 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms')
| -rw-r--r-- | lib/Transforms/Scalar/GVN.cpp | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/lib/Transforms/Scalar/GVN.cpp b/lib/Transforms/Scalar/GVN.cpp index 5564dbde1b..590227c27f 100644 --- a/lib/Transforms/Scalar/GVN.cpp +++ b/lib/Transforms/Scalar/GVN.cpp @@ -808,6 +808,11 @@ Value *GVN::GetValueForBlock(BasicBlock *BB, LoadInst* orig, DenseMap<BasicBlock*, Value*>::iterator V = Phis.find(BB); if (V != Phis.end() && !top_level) return V->second; + if (!getAnalysis<DominatorTree>().isReachableFromEntry(BB)) { + Phis[BB] = UndefValue::get(orig->getType()); + return UndefValue::get(orig->getType()); + } + BasicBlock* singlePred = BB->getSinglePredecessor(); if (singlePred) { Value *ret = GetValueForBlock(singlePred, orig, Phis); |