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.
llvm-svn: 38468
diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 44faf24..1b7b436 100644
--- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/llvm/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) {