When transforming sext(trunc(load(x))) into sext(smaller load(x)),
the trunc is directly replaced with the smaller load, so don't
try to create a new sext node. This fixes PR4050.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70179 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index b937eaf..bd4b10e 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -2962,7 +2962,7 @@
if (NarrowLoad.getNode()) {
if (NarrowLoad.getNode() != N0.getNode())
CombineTo(N0.getNode(), NarrowLoad);
- return DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(), VT, NarrowLoad);
+ return SDValue(N, 0); // Return N so it doesn't get rechecked!
}
// See if the value being truncated is already sign extended. If so, just