Two bug fixes:

(1) Make entries for Constant values in the ScalarMap.
(2) Set MOD bit for the node pointed to by the
    argument of a free instruction.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@4948 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Analysis/DataStructure/Local.cpp

@@ -92,7 +92,7 @@ namespace {
     void visitStoreInst(StoreInst &SI);
     void visitCallInst(CallInst &CI);
     void visitSetCondInst(SetCondInst &SCI) {}  // SetEQ & friends are ignored
-    void visitFreeInst(FreeInst &FI) {}         // Ignore free instructions
+    void visitFreeInst(FreeInst &FI);
     void visitCastInst(CastInst &CI);
     void visitInstruction(Instruction &I) {}
 
@@ -154,34 +154,35 @@ DSNodeHandle GraphBuilder::getValueDest(Value &Val) {
   if (V == Constant::getNullValue(V->getType()))
     return 0;  // Null doesn't point to anything, don't add to ScalarMap!
 
+  DSNodeHandle &NH = ScalarMap[V];
+  if (NH.getNode())
+    return NH;     // Already have a node?  Just return it...
+
+  // Otherwise we need to create a new node to point to.
+  // Check first for constant expressions that must be traversed to
+  // extract the actual value.
   if (Constant *C = dyn_cast<Constant>(V))
     if (ConstantPointerRef *CPR = dyn_cast<ConstantPointerRef>(C)) {
-      return getValueDest(*CPR->getValue());
+      return NH = getValueDest(*CPR->getValue());
     } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
       if (CE->getOpcode() == Instruction::Cast)
-        return getValueDest(*CE->getOperand(0));
+        return NH = getValueDest(*CE->getOperand(0));
       if (CE->getOpcode() == Instruction::GetElementPtr) {
         visitGetElementPtrInst(*CE);
         std::map<Value*, DSNodeHandle>::iterator I = ScalarMap.find(CE);
         assert(I != ScalarMap.end() && "GEP didn't get processed right?");
-        DSNodeHandle NH = I->second;
+        return NH = I->second;
-        ScalarMap.erase(I);           // Remove constant from scalarmap
-        return NH;
       }
 
       // This returns a conservative unknown node for any unhandled ConstExpr
-      return createNode(DSNode::UnknownNode);
+      return NH = createNode(DSNode::UnknownNode);
     } else if (ConstantIntegral *CI = dyn_cast<ConstantIntegral>(C)) {
       // Random constants are unknown mem
-      return createNode(DSNode::UnknownNode);
+      return NH = createNode(DSNode::UnknownNode);
     } else {
       assert(0 && "Unknown constant type!");
     }
 
-  DSNodeHandle &NH = ScalarMap[V];
-  if (NH.getNode())
-    return NH;     // Already have a node?  Just return it...
-
   // Otherwise we need to create a new node to point to...
   DSNode *N;
   if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
@@ -355,7 +356,7 @@ void GraphBuilder::visitStoreInst(StoreInst &SI) {
   DSNodeHandle Dest = getValueDest(*SI.getOperand(1));
   if (Dest.getNode() == 0) return;
 
-  // Make that the node is written to...
+  // Mark that the node is written to...
   Dest.getNode()->NodeType |= DSNode::Modified;
 
   // Ensure a typerecord exists...
@@ -391,6 +392,14 @@ void GraphBuilder::visitCallInst(CallInst &CI) {
   FunctionCalls.push_back(DSCallSite(CI, RetVal, Callee, Args));
 }
 
+void GraphBuilder::visitFreeInst(FreeInst &FI) {
+  DSNodeHandle Dest = getValueDest(*FI.getOperand(0));
+  if (Dest.getNode() == 0) return;
+
+  // Mark that the node is written to...
+  Dest.getNode()->NodeType |= DSNode::Modified;
+}
+
 /// Handle casts...
 void GraphBuilder::visitCastInst(CastInst &CI) {
   if (isPointerType(CI.getType()))