diff options
Diffstat (limited to 'lib/Analysis/ScalarEvolution.cpp')
| -rw-r--r-- | lib/Analysis/ScalarEvolution.cpp | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp index 7f63217925..42d2fdd362 100644 --- a/lib/Analysis/ScalarEvolution.cpp +++ b/lib/Analysis/ScalarEvolution.cpp @@ -812,11 +812,14 @@ SCEVHandle ScalarEvolution::getSignExtendExpr(const SCEVHandle &Op, SCEVHandle Step = AR->getStepRecurrence(*this); // Check whether the backedge-taken count can be losslessly casted to - // the addrec's type. The count is always unsigned. + // the addrec's type. The count needs to be the same whether sign + // extended or zero extended. SCEVHandle CastedBECount = getTruncateOrZeroExtend(BECount, Start->getType()); if (BECount == - getTruncateOrZeroExtend(CastedBECount, BECount->getType())) { + getTruncateOrZeroExtend(CastedBECount, BECount->getType()) && + BECount == + getTruncateOrSignExtend(CastedBECount, BECount->getType())) { const Type *WideTy = IntegerType::get(getTypeSizeInBits(Start->getType()) * 2); SCEVHandle SMul = |