[llvm-commits] [llvm] r112864 - /llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

[Devang Patel]

Author: dpatel
Date: Thu Sep  2 16:29:42 2010
New Revision: 112864

URL: http://llvm.org/viewvc/llvm-project?rev=112864&view=rev
Log:
Detect undef value early and save unnecessary NodeMap query.

Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp?rev=112864&r1=112863&r2=112864&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp Thu Sep  2 16:29:42 2010
@@ -4074,6 +4074,17 @@
     // 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.