Use separate named MDNode to hold each function's local variable info.
This speeds up local variable handling in DwarfDebug.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106075 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/DebugInfo.cpp b/lib/Analysis/DebugInfo.cpp
index 774dce0..6ef160b 100644
--- a/lib/Analysis/DebugInfo.cpp
+++ b/lib/Analysis/DebugInfo.cpp
@@ -1053,8 +1053,12 @@
     // The optimizer may remove local variable. If there is an interest
     // to preserve variable info in such situation then stash it in a
     // named mdnode.
-    NamedMDNode *NMD = M.getOrInsertNamedMetadata("llvm.dbg.lv");
-    NMD->addOperand(Node);
+    DISubprogram Fn(getDISubprogram(Context));
+    const Twine FnLVName = Twine("llvm.dbg.lv.", Fn.getName());
+    NamedMDNode *FnLocals = M.getNamedMetadataUsingTwine(FnLVName);
+    if (!FnLocals)
+      FnLocals = NamedMDNode::Create(VMContext, FnLVName, NULL, 0, &M);
+    FnLocals->addOperand(Node);
   }
   return DIVariable(Node);
 }