[llvm-commits] CVS: llvm/lib/Analysis/DataStructure/TopDownClosure.cpp

[Chris Lattner]

Changes in directory llvm/lib/Analysis/DataStructure:

TopDownClosure.cpp updated: 1.16 -> 1.17

---
Log message:

  - Make sure to only keep track of mappings that the TD pass may need in the
    future.  This prevents having spurious map entries to nodes that we really
    don't care about.  This allows us to reenable the DeadNodeElim, which was
    disabled.


---
Diffs of the changes:

Index: llvm/lib/Analysis/DataStructure/TopDownClosure.cpp
diff -u llvm/lib/Analysis/DataStructure/TopDownClosure.cpp:1.16 llvm/lib/Analysis/DataStructure/TopDownClosure.cpp:1.17
--- llvm/lib/Analysis/DataStructure/TopDownClosure.cpp:1.16	Mon Oct 21 14:50:29 2002
+++ llvm/lib/Analysis/DataStructure/TopDownClosure.cpp	Tue Oct 22 11:01:03 2002
@@ -12,6 +12,7 @@
 #include "llvm/Module.h"
 #include "llvm/DerivedTypes.h"
 #include "Support/Statistic.h"
+#include <set>
 
 static RegisterAnalysis<TDDataStructures>
 Y("tddatastructure", "Top-down Data Structure Analysis Closure");
@@ -34,10 +35,23 @@
 // program.
 //
 bool TDDataStructures::run(Module &M) {
-  // Simply calculate the graphs for each function...
+  BUDataStructures &BU = getAnalysis<BUDataStructures>();
+
+  // Calculate the CallSitesForFunction mapping from the BU info...
+  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
+    if (!I->isExternal())
+      if (const std::vector<DSCallSite> *CS = BU.getCallSites(*I))
+        for (unsigned i = 0, e = CS->size(); i != e; ++i)
+          if (Function *F = (*CS)[i].getResolvingCaller())
+            CallSitesForFunction[F].push_back(&(*CS)[i]);
+
+  // Next calculate the graphs for each function...
   for (Module::reverse_iterator I = M.rbegin(), E = M.rend(); I != E; ++I)
     if (!I->isExternal())
       calculateGraph(*I);
+
+  // Destroy the temporary mapping...
+  CallSitesForFunction.clear();
   return false;
 }
 
@@ -82,8 +96,37 @@
   std::map<const DSNode*, DSNode*> BUNodeMap;
   Graph = new DSGraph(BUGraph, BUNodeMap);
 
+  // We only need the BUMap entries for the nodes that are used in call sites.
+  // Calculate which nodes are needed.
+  std::set<const DSNode*> NeededNodes;
+  std::map<const Function*, std::vector<const DSCallSite*> >::iterator CSFFI
+    = CallSitesForFunction.find(&F);
+  if (CSFFI == CallSitesForFunction.end()) {
+    BUNodeMap.clear();  // No nodes are neccesary
+  } else {
+    std::vector<const DSCallSite*> &CSV = CSFFI->second;
+    for (unsigned i = 0, e = CSV.size(); i != e; ++i) {
+      NeededNodes.insert(CSV[i]->getRetVal().getNode());
+      for (unsigned j = 0, je = CSV[i]->getNumPtrArgs(); j != je; ++j)
+        NeededNodes.insert(CSV[i]->getPtrArg(j).getNode());
+    }
+  }
+
+  // Loop through te BUNodeMap, keeping only the nodes that are "Needed"
+  for (std::map<const DSNode*, DSNode*>::iterator I = BUNodeMap.begin();
+       I != BUNodeMap.end(); )
+    if (NeededNodes.count(I->first) && I->first)  // Keep needed nodes...
+      ++I;
+    else {
+      std::map<const DSNode*, DSNode*>::iterator J = I++;
+      BUNodeMap.erase(J);
+    }
+
+  NeededNodes.clear();  // We are done with this temporary data structure
+
   // Convert the mapping from a node-to-node map into a node-to-nodehandle map
-  BUMaps[&F].insert(BUNodeMap.begin(), BUNodeMap.end());
+  BUNodeMapTy &BUMap = BUMaps[&F];
+  BUMap.insert(BUNodeMap.begin(), BUNodeMap.end());
   BUNodeMap.clear();   // We are done with the temporary map.
 
   const std::vector<DSCallSite> *CallSitesP = BU.getCallSites(F);
@@ -140,12 +183,11 @@
   }
 
   // Recompute the Incomplete markers and eliminate unreachable nodes.
-#if 0
   Graph->maskIncompleteMarkers();
   Graph->markIncompleteNodes(/*markFormals*/ !F.hasInternalLinkage()
                              /*&& FIXME: NEED TO CHECK IF ALL CALLERS FOUND!*/);
   Graph->removeDeadNodes(/*KeepAllGlobals*/ false, /*KeepCalls*/ false);
-#endif
+
   DEBUG(std::cerr << "  [TD] Done inlining callers for: " << F.getName() << " ["
         << Graph->getGraphSize() << "+" << Graph->getFunctionCalls().size()
         << "]\n");