From 3f74a116c80b483ffc7c2e6922ff62f0f73d83f5 Mon Sep 17 00:00:00 2001
From: Devang Patel <dpatel@apple.com>
Date: Thu, 2 Sep 2010 21:29:42 +0000
Subject: [PATCH] Detect undef value early and save unnecessary NodeMap query.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112864 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 08d2e9337b7..e65744592c8 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -4074,6 +4074,17 @@ SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I, unsigned Intrinsic) {
     // absolute, but not relative, values are different depending on whether
     // debug info exists.
     ++SDNodeOrder;
+
+    // Check if address has undef value.
+    if (isa<UndefValue>(Address) ||
+        (Address->use_empty() && !isa<Argument>(Address))) {
+      SDDbgValue*SDV = 
+        DAG.getDbgValue(Variable, UndefValue::get(Address->getType()),
+                        0, dl, SDNodeOrder);
+      DAG.AddDbgValue(SDV, 0, false);
+      return 0;
+    }
+
     SDValue &N = NodeMap[Address];
     if (!N.getNode() && isa<Argument>(Address))
       // Check unused arguments map.