Totally gut mergeInGraph. There is absolutely no reason to be merging

global roots in from callees to callers.  The BU graphs do not have accurate
globals information and all of the clients know it.  Instead, just make sure
the GG is up-to-date, and they will be perfectly satiated.

This speeds up the BU pass on 176.gcc from 5.5s to 1.5s, and Loc+BU+TD
from 7s to 2.7s.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20786 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Analysis/DataStructure/DataStructure.cpp b/lib/Analysis/DataStructure/DataStructure.cpp
index 2f6fde89033a34083102fe1cfeea674d57eb8556..a84c4fe0322301e79888f11baf175e275987389a 100644 (file)
--- a/lib/Analysis/DataStructure/DataStructure.cpp
+++ b/lib/Analysis/DataStructure/DataStructure.cpp
@@ -1348,95 +1348,69 @@ void DSGraph::mergeInGraph(const DSCallSite &CS,
   TIME_REGION(X, "mergeInGraph");
 
   // If this is not a recursive call, clone the graph into this graph...
-  if (&Graph != this) {
-    // Clone the callee's graph into the current graph, keeping track of where
-    // scalars in the old graph _used_ to point, and of the new nodes matching
-    // nodes of the old graph.
-    ReachabilityCloner RC(*this, Graph, CloneFlags);
+  if (&Graph == this) {
+    // Merge the return value with the return value of the context.
+    Args[0].mergeWith(CS.getRetVal());
     
-    // Map the return node pointer over.
-    if (!CS.getRetVal().isNull())
-      RC.merge(CS.getRetVal(), Args[0]);
-
-    // Map over all of the arguments.
+    // Resolve all of the function arguments.
     for (unsigned i = 0, e = CS.getNumPtrArgs(); i != e; ++i) {
       if (i == Args.size()-1)
         break;
       
       // Add the link from the argument scalar to the provided value.
-      RC.merge(CS.getPtrArg(i), Args[i+1]);
+      Args[i+1].mergeWith(CS.getPtrArg(i));
     }
+    return;
+  }
+
+  // Clone the callee's graph into the current graph, keeping track of where
+  // scalars in the old graph _used_ to point, and of the new nodes matching
+  // nodes of the old graph.
+  ReachabilityCloner RC(*this, Graph, CloneFlags);
     
-    // If requested, copy all of the calls.
-    if (!(CloneFlags & DontCloneCallNodes)) {
-      // Copy the function calls list.
-      for (fc_iterator I = Graph.fc_begin(), E = Graph.fc_end(); I != E; ++I)
-        FunctionCalls.push_back(DSCallSite(*I, RC));
-    }
+  // Map the return node pointer over.
+  if (!CS.getRetVal().isNull())
+    RC.merge(CS.getRetVal(), Args[0]);
 
-    // If the user has us copying aux calls (the normal case), set up a data
-    // structure to keep track of which ones we've copied over.
-    std::set<const DSCallSite*> CopiedAuxCall;
+  // Map over all of the arguments.
+  for (unsigned i = 0, e = CS.getNumPtrArgs(); i != e; ++i) {
+    if (i == Args.size()-1)
+      break;
+      
+    // Add the link from the argument scalar to the provided value.
+    RC.merge(CS.getPtrArg(i), Args[i+1]);
+  }
     
-    // Clone over all globals that appear in the caller and callee graphs.
-    hash_set<GlobalVariable*> NonCopiedGlobals;
-    for (DSScalarMap::global_iterator GI = Graph.getScalarMap().global_begin(),
-           E = Graph.getScalarMap().global_end(); GI != E; ++GI)
-      if (GlobalVariable *GV = dyn_cast<GlobalVariable>(*GI))
-        if (ScalarMap.count(GV))
-          RC.merge(ScalarMap[GV], Graph.getNodeForValue(GV));
-        else
-          NonCopiedGlobals.insert(GV);
+  // If requested, copy all of the calls.
+  if (!(CloneFlags & DontCloneCallNodes)) {
+    // Copy the function calls list.
+    for (fc_iterator I = Graph.fc_begin(), E = Graph.fc_end(); I != E; ++I)
+      FunctionCalls.push_back(DSCallSite(*I, RC));
+  }
+
+  // If the user has us copying aux calls (the normal case), set up a data
+  // structure to keep track of which ones we've copied over.
+  std::set<const DSCallSite*> CopiedAuxCall;
     
-    // If the global does not appear in the callers graph we generally don't
-    // want to copy the node.  However, if there is a path from the node global
-    // node to a node that we did copy in the graph, we *must* copy it to
-    // maintain the connection information.  Every time we decide to include a
-    // new global, this might make other globals live, so we must iterate
-    // unfortunately.
-    bool MadeChange = true;
+  // If the global does not appear in the callers graph we generally don't
+  // want to copy the node.  However, if there is a path from the node global
+  // node to a node that we did copy in the graph, we *must* copy it to
+  // maintain the connection information.  Every time we decide to include a
+  // new global, this might make other globals live, so we must iterate
+  // unfortunately.
+  bool MadeChange = true;
+  if (!(CloneFlags & DontCloneAuxCallNodes))
     while (MadeChange) {
       MadeChange = false;
-      for (hash_set<GlobalVariable*>::iterator I = NonCopiedGlobals.begin();
-           I != NonCopiedGlobals.end();) {
-        DSNode *GlobalNode = Graph.getNodeForValue(*I).getNode();
-        if (RC.hasClonedNode(GlobalNode)) {
-          // Already cloned it, remove from set.
-          NonCopiedGlobals.erase(I++);
-          MadeChange = true;
-        } else if (PathExistsToClonedNode(GlobalNode, RC)) {
-          RC.getClonedNH(Graph.getNodeForValue(*I));
-          NonCopiedGlobals.erase(I++);
-          MadeChange = true;
-        } else {
-          ++I;
-        }
-      }
 
       // If requested, copy any aux calls that can reach copied nodes.
-      if (!(CloneFlags & DontCloneAuxCallNodes)) {
-        for (afc_iterator I = Graph.afc_begin(), E = Graph.afc_end(); I!=E; ++I)
-          if (CopiedAuxCall.insert(&*I).second &&
-              PathExistsToClonedNode(*I, RC)) {
-            AuxFunctionCalls.push_back(DSCallSite(*I, RC));
-            MadeChange = true;
-          }
-      }
-    }
-    
-  } else {
-    // Merge the return value with the return value of the context.
-    Args[0].mergeWith(CS.getRetVal());
-    
-    // Resolve all of the function arguments.
-    for (unsigned i = 0, e = CS.getNumPtrArgs(); i != e; ++i) {
-      if (i == Args.size()-1)
-        break;
-      
-      // Add the link from the argument scalar to the provided value.
-      Args[i+1].mergeWith(CS.getPtrArg(i));
+      for (afc_iterator I = Graph.afc_begin(), E = Graph.afc_end(); I!=E; ++I)
+        if (CopiedAuxCall.insert(&*I).second &&
+            PathExistsToClonedNode(*I, RC)) {
+          AuxFunctionCalls.push_back(DSCallSite(*I, RC));
+          MadeChange = true;
+        }
     }
-  }
 }