From: Nirav Dave <niravd@google.com>
Date: Thu, 31 Jan 2019 19:35:14 +0000 (+0000)
Subject: [DAG] Aggressively cleanup dangling node in CombineZExtLogicopShiftLoad.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=6980a884f19f17bea78f1f2921f1c1197a1195ed;p=llvm

[DAG] Aggressively cleanup dangling node in CombineZExtLogicopShiftLoad.

While dangling nodes will eventually be pruned when they are
considered, leaving them disables combines requiring single-use.

Reviewers: Carrot, spatel, craig.topper, RKSimon, efriedma

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D57520

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@352784 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index d2e235189ec..1f05a435bbe 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -8465,6 +8465,10 @@ SDValue DAGCombiner::CombineZExtLogicopShiftLoad(SDNode *N) {
                                 Load->getValueType(0), ExtLoad);
     CombineTo(Load, Trunc, ExtLoad.getValue(1));
   }
+
+  // N0 is dead at this point.
+  recursivelyDeleteUnusedNodes(N0.getNode());
+
   return SDValue(N,0); // Return N so it doesn't get rechecked!
 }