aboutsummaryrefslogtreecommitdiff
path: root/lib/Analysis/ScalarEvolution.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'lib/Analysis/ScalarEvolution.cpp')
-rw-r--r--lib/Analysis/ScalarEvolution.cpp7
1 files changed, 5 insertions, 2 deletions
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 3e06298882..148912b766 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -3979,8 +3979,11 @@ getSmallConstantTripMultiple(Loop *L, BasicBlock *ExitingBlock) {
ConstantInt *Result = MulC->getValue();
- // Guard against huge trip counts.
- if (!Result || Result->getValue().getActiveBits() > 32)
+ // Guard against huge trip counts (this requires checking
+ // for zero to handle the case where the trip count == -1 and the
+ // addition wraps).
+ if (!Result || Result->getValue().getActiveBits() > 32 ||
+ Result->getValue().getActiveBits() == 0)
return 1;
return (unsigned)Result->getZExtValue();