commit aad753bbbd98c952f7e65246af2faf5c7d5a850b
author Evan Cheng <evan.cheng@apple.com> Mon May 10 19:03:57 2010 +0000
committer Evan Cheng <evan.cheng@apple.com> Mon May 10 19:03:57 2010 +0000
tree 56b8ac3cef2c55af0b8ac483936ac15afd534b3a
parent 1deea21e3512e8c41b5145711019048d39d1cb0b

Be careful with operand promotion. For a binary operation, the source operands may be the same. PR7018. rdar://7939869.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@103419 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/SelectionDAG/DAGCombiner.cpp

diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 3639f80..c8d3e0d 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -760,12 +760,18 @@
 
     bool Replace1 = false;
     SDValue N1 = Op.getOperand(1);
-    SDValue NN1 = PromoteOperand(N1, PVT, Replace1);
-    if (NN1.getNode() == 0)
-      return SDValue();
+    SDValue NN1;
+    if (N0 == N1)
+      NN1 = NN0;
+    else {
+      NN1 = PromoteOperand(N1, PVT, Replace1);
+      if (NN1.getNode() == 0)
+        return SDValue();
+    }
 
     AddToWorkList(NN0.getNode());
-    AddToWorkList(NN1.getNode());
+    if (NN1.getNode())
+      AddToWorkList(NN1.getNode());
 
     if (Replace0)
       ReplaceLoadWithPromotedLoad(N0.getNode(), NN0.getNode());