From 13aee345cae5ba7016d32c23685910607698c404 Mon Sep 17 00:00:00 2001
From: Sanjay Patel <spatel@rotateright.com>
Date: Sun, 30 Oct 2016 18:13:30 +0000
Subject: [DAG] x & x --> x

llvm-svn: 285521
---
 llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 4 ++++
 1 file changed, 4 insertions(+)

(limited to 'llvm/lib/CodeGen')

diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index f5aeb8cb533..e78a3562a05 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -3134,6 +3134,10 @@ SDValue DAGCombiner::visitAND(SDNode *N) {
   SDValue N1 = N->getOperand(1);
   EVT VT = N1.getValueType();
 
+  // x & x --> x
+  if (N0 == N1)
+    return N0;
+
   // fold vector ops
   if (VT.isVector()) {
     if (SDValue FoldedVOp = SimplifyVBinOp(N))
-- 
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