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| author | Benjamin Kramer <benny.kra@googlemail.com> | 2012-10-19 16:37:30 +0000 |
|---|---|---|
| committer | Benjamin Kramer <benny.kra@googlemail.com> | 2012-10-19 16:37:30 +0000 |
| commit | 239fd44f7a68aae4b2e8b6f1738ef9e8fd4ddc01 (patch) | |
| tree | f8f67d4ffc122a3bf495e0b6bda03fdb6d55a5da /lib/Analysis/ScalarEvolutionExpander.cpp | |
| parent | 34674fea970b20dde4336a06a12732211d1cfa04 (diff) | |
SCEVExpander: Don't crash when trying to merge two constant phis.
Just constant fold them so they can't cause any trouble. Fixes PR12627.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166286 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Analysis/ScalarEvolutionExpander.cpp')
| -rw-r--r-- | lib/Analysis/ScalarEvolutionExpander.cpp | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/lib/Analysis/ScalarEvolutionExpander.cpp b/lib/Analysis/ScalarEvolutionExpander.cpp index 5c2a49e767..f18c50e070 100644 --- a/lib/Analysis/ScalarEvolutionExpander.cpp +++ b/lib/Analysis/ScalarEvolutionExpander.cpp @@ -1618,6 +1618,17 @@ unsigned SCEVExpander::replaceCongruentIVs(Loop *L, const DominatorTree *DT, PEnd = Phis.end(); PIter != PEnd; ++PIter) { PHINode *Phi = *PIter; + // Fold constant phis. They may be congruent to other constant phis and + // would confuse the logic below that expects proper IVs. + if (Value *V = Phi->hasConstantValue()) { + Phi->replaceAllUsesWith(V); + DeadInsts.push_back(Phi); + ++NumElim; + DEBUG_WITH_TYPE(DebugType, dbgs() + << "INDVARS: Eliminated constant iv: " << *Phi << '\n'); + continue; + } + if (!SE.isSCEVable(Phi->getType())) continue; |