[DAG] Cleanup unused node in SimplifySelectCC.

Delete temporarily constructed node uses for analysis after it's use,
holding onto original input nodes. Ideally this would be rewritten
without making nodes, but this appears relatively complex.

Reviewers: spatel, RKSimon, craig.topper

Subscribers: jdoerfert, hiraditya, deadalnix, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D57921

llvm-svn: 356382

1 files changed, 7 insertions, 8 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 43a1005d84a..4ff48732ef6 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -18934,14 +18934,13 @@ SDValue DAGCombiner::SimplifySelectCC(const SDLoc &DL, SDValue N0, SDValue N1,
   auto *N3C = dyn_cast<ConstantSDNode>(N3.getNode());
 
   // Determine if the condition we're dealing with is constant.
-  SDValue SCC = SimplifySetCC(getSetCCResultType(CmpOpVT), N0, N1, CC, DL,
-                              false);
-  if (SCC.getNode()) AddToWorklist(SCC.getNode());
-
-  if (auto *SCCC = dyn_cast_or_null<ConstantSDNode>(SCC.getNode())) {
-    // fold select_cc true, x, y -> x
-    // fold select_cc false, x, y -> y
-    return !SCCC->isNullValue() ? N2 : N3;
+  if (SDValue SCC = DAG.FoldSetCC(VT, N0, N1, CC, DL)) {
+    AddToWorklist(SCC.getNode());
+    if (auto *SCCC = dyn_cast<ConstantSDNode>(SCC)) {
+      // fold select_cc true, x, y -> x
+      // fold select_cc false, x, y -> y
+      return !(SCCC->isNullValue()) ? N2 : N3;
+    }
   }
 
   if (SDValue V =