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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142592 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineLICM.cpp b/lib/CodeGen/MachineLICM.cpp
index 969a9b0..c693386 100644
--- a/lib/CodeGen/MachineLICM.cpp
+++ b/lib/CodeGen/MachineLICM.cpp
@@ -788,7 +788,9 @@
// If it is load then check if it is guaranteed to execute by making sure that
// it dominates all exiting blocks. If it doesn't, then there is a path out of
- // the loop which does not execute this load, so we can't hoist it.
+ // the loop which does not execute this load, so we can't hoist it. Loads
+ // from constant memory are not safe to speculate all the time, for example
+ // indexed load from a jump table.
// Stores and side effects are already checked by isSafeToMove.
if (I.getDesc().mayLoad() && !isLoadFromGOT(I) &&
!IsGuaranteedToExecute(I.getParent()))