Preserve logic of adding weak edges

This change preserves logic of adding weak edges in augmentation.
Current logic implies duplicate weak edges are added causing pessimistic
degree computation. But in order to keep the larger change NFC, we
preserve this logic. Later (non-NFC) change will modify logic so we don't add
duplicate weak edges.

Author: pratikashar

visa/FlowGraph.cpp

@@ -4622,18 +4622,18 @@ void RelocationEntry::dump(std::ostream &os) const {
   os << "  symbol = " << symName << "; src" << opndPos << "\n";
 }
 
-void FuncInfo::dump() const {
-  std::cerr << "subroutine " << getId() << "("
+void FuncInfo::dump(std::ostream &os) const {
+  os << "subroutine " << getId() << "("
             << getInitBB()->front()->getLabelStr() << ")\n";
-  std::cerr << "\tentryBB=" << getInitBB()->getId()
+  os << "\tentryBB=" << getInitBB()->getId()
             << ", exitBB=" << getExitBB()->getId() << "\n";
-  std::cerr << "\tCallees: ";
+  os << "\tCallees: ";
   for (auto callee : callees) {
-    std::cerr << callee->getId() << " ";
+    os << callee->getId() << " ";
   }
-  std::cerr << "\n\tBB list: ";
+  os << "\n\tBB list: ";
   for (auto bb : BBList) {
-    std::cerr << bb->getId() << " ";
+    os << bb->getId() << " ";
   }
-  std::cerr << "\n";
+  os << "\n";
 }

visa/FlowGraph.h

@@ -88,6 +88,12 @@ class FuncInfo {
   void addCallee(FuncInfo *fn) { callees.push_back(fn); }
   std::list<FuncInfo *> &getCallees() { return callees; }
 
+  // const version that does O(n) lookup.
+  bool contains(G4_BB *bb) const {
+    auto it = std::find(BBList.begin(), BBList.end(), bb);
+    return it != BBList.end();
+  }
+
   bool contains(G4_BB *bb) {
     if (BBSet.size() != BBList.size()) {
       BBSet.clear();
@@ -120,7 +126,7 @@ class FuncInfo {
   unsigned getPostID() const { return postID; }
   void setPostID(unsigned id) { postID = id; }
 
-  void dump() const;
+  void dump(std::ostream &os = std::cerr) const;
 }; // FuncInfo
 
 //