diff options
| -rw-r--r-- | llvm/lib/Analysis/ScalarEvolutionExpander.cpp | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/llvm/lib/Analysis/ScalarEvolutionExpander.cpp b/llvm/lib/Analysis/ScalarEvolutionExpander.cpp index f95e191e5ee..86cfe2d00ab 100644 --- a/llvm/lib/Analysis/ScalarEvolutionExpander.cpp +++ b/llvm/lib/Analysis/ScalarEvolutionExpander.cpp @@ -1652,10 +1652,17 @@ Value *SCEVExpander::expand(const SCEV *S) { // If S is scConstant, it may be worse to reuse an existing Value. if (S->getSCEVType() != scConstant && Set) { // Choose a Value from the set which dominates the insertPt. + // insertPt should be inside the Value's parent loop so as not to break + // the LCSSA form. for (auto const &Ent : *Set) { - if (Ent && isa<Instruction>(Ent) && S->getType() == Ent->getType() && - cast<Instruction>(Ent)->getFunction() == InsertPt->getFunction() && - SE.DT.dominates(cast<Instruction>(Ent), InsertPt)) { + Instruction *EntInst = nullptr; + if (Ent && isa<Instruction>(Ent) && + (EntInst = cast<Instruction>(Ent)) && + S->getType() == Ent->getType() && + EntInst->getFunction() == InsertPt->getFunction() && + SE.DT.dominates(EntInst, InsertPt) && + (SE.LI.getLoopFor(EntInst->getParent()) == nullptr || + SE.LI.getLoopFor(EntInst->getParent())->contains(InsertPt))) { V = Ent; break; } |
