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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100459 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 9b1e963..4570c4d 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -3518,6 +3518,12 @@
true, DstSV, DstSVOff, SrcSV, SrcSVOff);
}
+ // FIXME: If the memcpy is volatile (isVol), lowering it to a plain libc
+ // memcpy is not guaranteed to be safe. libc memcpys aren't required to
+ // respect volatile, so they may do things like read or write memory
+ // beyond the given memory regions. But fixing this isn't easy, and most
+ // people don't care.
+
// Emit a library call.
TargetLowering::ArgListTy Args;
TargetLowering::ArgListEntry Entry;