[SDAG] Fix zeroExtend assertion error

Move CombineTo preventing deleted node from being returned in
visitZERO_EXTEND.

Fixes PR32284.

Reviewers: RKSimon, bogner

Reviewed By: RKSimon

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D31254

llvm-svn: 298604

1 files changed, 2 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index dd0abd15daf..d527a0e15af 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -7277,13 +7277,14 @@ SDValue DAGCombiner::visitZERO_EXTEND(SDNode *N) {
                                        LN0->getChain(),
                                        LN0->getBasePtr(), N0.getValueType(),
                                        LN0->getMemOperand());
-      CombineTo(N, ExtLoad);
+
       SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
                                   N0.getValueType(), ExtLoad);
       CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
 
       ExtendSetCCUses(SetCCs, Trunc, ExtLoad, SDLoc(N),
                       ISD::ZERO_EXTEND);
+      CombineTo(N, ExtLoad);
       return SDValue(N, 0);   // Return N so it doesn't get rechecked!
     }
   }