Initialize the IndexedModeActions array with memset before
updating it with calls to setIndexedLoadAction/setIndexedStoreAction,
which only update a few bits at a time. This avoids ostensible
undefined behavior of operationg on values which may be
trap-representations, and as a practical matter fixes errors from
valgrind, which doesn't track uninitialized memory with bit
granularity.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@38468 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 44faf24..1b7b436 100644
--- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -128,7 +128,9 @@
   memset(OpActions, 0, sizeof(OpActions));
   memset(LoadXActions, 0, sizeof(LoadXActions));
   memset(&StoreXActions, 0, sizeof(StoreXActions));
-  // Initialize all indexed load / store to expand.
+  memset(&IndexedModeActions, 0, sizeof(IndexedModeActions));
+
+  // Set all indexed load / store to expand.
   for (unsigned VT = 0; VT != (unsigned)MVT::LAST_VALUETYPE; ++VT) {
     for (unsigned IM = (unsigned)ISD::PRE_INC;
          IM != (unsigned)ISD::LAST_INDEXED_MODE; ++IM) {