Lots of bug fixes, add BottomUpClosure, which has bugs, but is a start.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@2945 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 216 insertions, 12 deletions

diff --git a/lib/Analysis/DataStructure/DataStructure.cpp b/lib/Analysis/DataStructure/DataStructure.cpp
index dd0b52a438..800c82ad98 100644
--- a/lib/Analysis/DataStructure/DataStructure.cpp
+++ b/lib/Analysis/DataStructure/DataStructure.cpp
@@ -4,11 +4,12 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "llvm/Analysis/DataStructure.h"
 #include "llvm/Module.h"
 #include "llvm/DerivedTypes.h"
-#include <algorithm>
 #include "Support/STLExtras.h"
+#include "Support/StatisticReporter.h"
+#include <algorithm>
+#include "llvm/Analysis/DataStructure.h"
 
 AnalysisID LocalDataStructures::ID(AnalysisID::create<LocalDataStructures>());
 
@@ -28,6 +29,11 @@ DSNode::DSNode(enum NodeTy NT, const Type *T) : Ty(T), NodeType(NT) {
   }
 }
 
+// DSNode copy constructor... do not copy over the referrers list!
+DSNode::DSNode(const DSNode &N)
+  : Ty(N.Ty), Links(N.Links), Globals(N.Globals), NodeType(N.NodeType) {
+}
+
 void DSNode::removeReferrer(DSNodeHandle *H) {
   // Search backwards, because we depopulate the list from the back for
   // efficiency (because it's a vector).
@@ -41,9 +47,15 @@ void DSNode::removeReferrer(DSNodeHandle *H) {
 // marks the node with the 'G' flag if it does not already have it.
 //
 void DSNode::addGlobal(GlobalValue *GV) {
-  assert(GV->getType()->getElementType() == Ty);
-  Globals.push_back(GV);
-  NodeType |= GlobalNode;
+  // Keep the list sorted.
+  std::vector<GlobalValue*>::iterator I =
+    std::lower_bound(Globals.begin(), Globals.end(), GV);
+
+  if (I == Globals.end() || *I != GV) {
+    assert(GV->getType()->getElementType() == Ty);
+    Globals.insert(I, GV);
+    NodeType |= GlobalNode;
+  }
 }
 
 
@@ -89,14 +101,33 @@ void DSNode::mergeWith(DSNode *N) {
   N->NodeType = 0;   // N is now a dead node.
 
   // Merge the globals list...
-  Globals.insert(Globals.end(), N->Globals.begin(), N->Globals.end());
-  N->Globals.clear();
+  if (!N->Globals.empty()) {
+    // Save the current globals off to the side...
+    std::vector<GlobalValue*> OldGlobals(Globals);
+
+    // Resize the globals vector to be big enough to hold both of them...
+    Globals.resize(Globals.size()+N->Globals.size());
+
+    // Merge the two sorted globals lists together...
+    std::merge(OldGlobals.begin(), OldGlobals.end(),
+               N->Globals.begin(), N->Globals.end(), Globals.begin());
+
+    // Erase duplicate entries from the globals list...
+    Globals.erase(std::unique(Globals.begin(), Globals.end()), Globals.end());
+
+    // Delete the globals from the old node...
+    N->Globals.clear();
+  }
 }
 
 //===----------------------------------------------------------------------===//
 // DSGraph Implementation
 //===----------------------------------------------------------------------===//
 
+DSGraph::DSGraph(const DSGraph &G) : Func(G.Func) {
+  RetNode = cloneInto(G, ValueMap, false);
+}
+
 DSGraph::~DSGraph() {
   FunctionCalls.clear();
   ValueMap.clear();
@@ -112,6 +143,182 @@ DSGraph::~DSGraph() {
   std::for_each(Nodes.begin(), Nodes.end(), deleter<DSNode>);
 }
 
+// dump - Allow inspection of graph in a debugger.
+void DSGraph::dump() const { print(std::cerr); }
+
+// cloneInto - Clone the specified DSGraph into the current graph, returning the
+// Return node of the graph.  The translated ValueMap for the old function is
+// filled into the OldValMap member.  If StripLocals is set to true, Scalar and
+// Alloca markers are removed from the graph, as the graph is being cloned into
+// a calling function's graph.
+//
+DSNode *DSGraph::cloneInto(const DSGraph &G, 
+                           std::map<Value*, DSNodeHandle> &OldValMap,
+                           bool StripLocals) {
+  std::map<const DSNode*, DSNode*> NodeMap;
+  NodeMap[0] = 0;  // Null pointer maps to null
+
+  unsigned FN = Nodes.size();  // FirstNode...
+
+  // Duplicate all of the nodes, populating the node map...
+  Nodes.reserve(FN+G.Nodes.size());
+  for (unsigned i = 0, e = G.Nodes.size(); i != e; ++i) {
+    DSNode *Old = G.Nodes[i], *New = new DSNode(*Old);
+    Nodes.push_back(New);
+    NodeMap[Old] = New;
+  }
+
+  // Rewrite the links in the nodes to point into the current graph now.
+  for (unsigned i = FN, e = Nodes.size(); i != e; ++i)
+    for (unsigned j = 0, e = Nodes[i]->getNumLinks(); j != e; ++j)
+      Nodes[i]->setLink(j, NodeMap[Nodes[i]->getLink(j)]);
+
+  // If we are inlining this graph into the called function graph, remove local
+  // markers.
+  if (StripLocals)
+    for (unsigned i = FN, e = Nodes.size(); i != e; ++i)
+      Nodes[i]->NodeType &= ~(DSNode::AllocaNode | DSNode::ScalarNode);
+
+  // Copy the value map...
+  for (std::map<Value*, DSNodeHandle>::const_iterator I = G.ValueMap.begin(),
+         E = G.ValueMap.end(); I != E; ++I)
+    OldValMap[I->first] = NodeMap[I->second];
+
+  // Copy the function calls list...
+  unsigned FC = FunctionCalls.size();  // FirstCall
+  FunctionCalls.reserve(FC+G.FunctionCalls.size());
+  for (unsigned i = 0, e = G.FunctionCalls.size(); i != e; ++i) {
+    FunctionCalls.push_back(std::vector<DSNodeHandle>());
+    FunctionCalls[FC+i].reserve(G.FunctionCalls[i].size());
+    for (unsigned j = 0, e = G.FunctionCalls[i].size(); j != e; ++j)
+      FunctionCalls[FC+i].push_back(NodeMap[G.FunctionCalls[i][j]]);
+  }
+
+  // Return the returned node pointer...
+  return NodeMap[G.RetNode];
+}
+
+
+// markIncompleteNodes - Mark the specified node as having contents that are not
+// known with the current analysis we have performed.  Because a node makes all
+// of the nodes it can reach imcomplete if the node itself is incomplete, we
+// must recursively traverse the data structure graph, marking all reachable
+// nodes as incomplete.
+//
+static void markIncompleteNode(DSNode *N) {
+  // Stop recursion if no node, or if node already marked...
+  if (N == 0 || (N->NodeType & DSNode::Incomplete)) return;
+
+  // Actually mark the node
+  N->NodeType |= DSNode::Incomplete;
+
+  // Recusively process children...
+  for (unsigned i = 0, e = N->getNumLinks(); i != e; ++i)
+    markIncompleteNode(N->getLink(i));
+}
+
+
+// markIncompleteNodes - Traverse the graph, identifying nodes that may be
+// modified by other functions that have not been resolved yet.  This marks
+// nodes that are reachable through three sources of "unknownness":
+//
+//  Global Variables, Function Calls, and Incoming Arguments
+//
+// For any node that may have unknown components (because something outside the
+// scope of current analysis may have modified it), the 'Incomplete' flag is
+// added to the NodeType.
+//
+void DSGraph::markIncompleteNodes() {
+  // Mark any incoming arguments as incomplete...
+  for (Function::aiterator I = Func.abegin(), E = Func.aend(); I != E; ++I)
+    if (isa<PointerType>(I->getType()))
+      markIncompleteNode(ValueMap[I]->getLink(0));
+
+  // Mark stuff passed into functions calls as being incomplete...
+  for (unsigned i = 0, e = FunctionCalls.size(); i != e; ++i) {
+    std::vector<DSNodeHandle> &Args = FunctionCalls[i];
+    if (Args[0])                // If the call returns a pointer...
+      // Then the return value is certainly incomplete!
+      markIncompleteNode(Args[0]);
+
+    // The call does not make the function argument incomplete...
+ 
+    // All arguments to the function call are incomplete though!
+    for (unsigned i = 2, e = Args.size(); i != e; ++i)
+      markIncompleteNode(Args[i]);
+  }
+
+  // Mark all of the nodes pointed to by global nodes as incomplete...
+  for (unsigned i = 0, e = Nodes.size(); i != e; ++i)
+    if (Nodes[i]->NodeType & DSNode::GlobalNode) {
+      DSNode *N = Nodes[i];
+      for (unsigned i = 0, e = N->getNumLinks(); i != e; ++i)
+        markIncompleteNode(N->getLink(i));
+    }
+}
+
+// isNodeDead - This method checks to see if a node is dead, and if it isn't, it
+// checks to see if there are simple transformations that it can do to make it
+// dead.
+//
+bool DSGraph::isNodeDead(DSNode *N) {
+  // Is it a trivially dead shadow node...
+  if (N->getReferrers().empty() && N->NodeType == 0)
+    return true;
+
+  // Is it a function node or some other trivially unused global?
+  if ((N->NodeType & ~DSNode::GlobalNode) == 0 && 
+      N->getNumLinks() == 0 &&
+      N->getReferrers().size() == N->getGlobals().size()) {
+
+    // Remove the globals from the valuemap, so that the referrer count will go
+    // down to zero.
+    while (!N->getGlobals().empty()) {
+      GlobalValue *GV = N->getGlobals().back();
+      N->getGlobals().pop_back();      
+      ValueMap.erase(GV);
+    }
+    assert(N->getReferrers().empty() && "Referrers should all be gone now!");
+    return true;
+  }
+
+  return false;
+}
+
+
+// removeDeadNodes - After the graph has been constructed, this method removes
+// all unreachable nodes that are created because they got merged with other
+// nodes in the graph.  These nodes will all be trivially unreachable, so we
+// don't have to perform any non-trivial analysis here.
+//
+void DSGraph::removeDeadNodes() {
+  for (unsigned i = 0; i != Nodes.size(); ++i)
+    if (isNodeDead(Nodes[i])) {               // This node is dead!
+      delete Nodes[i];                        // Free memory...
+      Nodes.erase(Nodes.begin()+i--);         // Remove from node list...
+    }
+
+  // Remove identical function calls
+  unsigned NumFns = FunctionCalls.size();
+  std::sort(FunctionCalls.begin(), FunctionCalls.end());
+  FunctionCalls.erase(std::unique(FunctionCalls.begin(), FunctionCalls.end()),
+                      FunctionCalls.end());
+
+  DEBUG(if (NumFns != FunctionCalls.size())
+        std::cerr << "Merged " << (NumFns-FunctionCalls.size())
+        << " call nodes in " << Func.getName() << "\n";);
+}
+
+
+// maskNodeTypes - Apply a mask to all of the node types in the graph.  This
+// is useful for clearing out markers like Scalar or Incomplete.
+//
+void DSGraph::maskNodeTypes(unsigned char Mask) {
+  for (unsigned i = 0, e = Nodes.size(); i != e; ++i)
+    Nodes[i]->NodeType &= Mask;
+}
+
+
 //===----------------------------------------------------------------------===//
 // LocalDataStructures Implementation
 //===----------------------------------------------------------------------===//
@@ -132,11 +339,8 @@ void LocalDataStructures::releaseMemory() {
 bool LocalDataStructures::run(Module &M) {
   // Calculate all of the graphs...
   for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
-    if (!I->isExternal()) {
-      std::map<Function*, DSGraph*>::iterator DI = DSInfo.find(I);
-      if (DI == DSInfo.end() || DI->second == 0)
-        DSInfo.insert(std::make_pair(&*I, new DSGraph(*I)));
-    }
+    if (!I->isExternal())
+      DSInfo.insert(std::make_pair(&*I, new DSGraph(*I)));
 
   return false;
 }