[turbofan] Dump graph in RPO order as text.

R=bmeurer@chromium.org
BUG=

Review URL: https://codereview.chromium.org/754803002

Cr-Commit-Position: refs/heads/master@{#25477}

src/compiler/graph-visualizer.cc

@@ -27,6 +27,9 @@ namespace internal {
 namespace compiler {
 
 static int SafeId(Node* node) { return node == NULL ? -1 : node->id(); }
+static const char* SafeMnemonic(Node* node) {
+  return node == NULL ? "null" : node->op()->mnemonic();
+}
 
 #define DEAD_COLOR "#999999"
 
@@ -790,6 +793,43 @@ std::ostream& operator<<(std::ostream& os, const AsC1VAllocator& ac) {
   GraphC1Visualizer(os, &tmp_zone).PrintAllocator(ac.phase_, ac.allocator_);
   return os;
 }
+
+const int kUnvisited = 0;
+const int kOnStack = 1;
+const int kVisited = 2;
+
+std::ostream& operator<<(std::ostream& os, const AsRPO& ar) {
+  Zone local_zone(ar.graph.zone()->isolate());
+  ZoneVector<byte> state(ar.graph.NodeCount(), kUnvisited, &local_zone);
+  ZoneStack<Node*> stack(&local_zone);
+
+  stack.push(ar.graph.end());
+  state[ar.graph.end()->id()] = kOnStack;
+  while (!stack.empty()) {
+    Node* n = stack.top();
+    bool pop = true;
+    for (Node* const i : n->inputs()) {
+      if (state[i->id()] == kUnvisited) {
+        state[i->id()] = kOnStack;
+        stack.push(i);
+        pop = false;
+        break;
+      }
+    }
+    if (pop) {
+      state[n->id()] = kVisited;
+      stack.pop();
+      os << "#" << SafeId(n) << ":" << SafeMnemonic(n) << "(";
+      int j = 0;
+      for (Node* const i : n->inputs()) {
+        if (j++ > 0) os << ", ";
+        os << "#" << SafeId(i) << ":" << SafeMnemonic(i);
+      }
+      os << ")" << std::endl;
+    }
+  }
+  return os;
+}
 }
 }
 }  // namespace v8::internal::compiler

src/compiler/graph-visualizer.h

@@ -36,6 +36,14 @@ struct AsJSON {
 
 std::ostream& operator<<(std::ostream& os, const AsJSON& ad);
 
+struct AsRPO {
+  explicit AsRPO(const Graph& g) : graph(g) {}
+  const Graph& graph;
+};
+
+std::ostream& operator<<(std::ostream& os, const AsRPO& ad);
+
+
 struct AsC1VCompilation {
   explicit AsC1VCompilation(const CompilationInfo* info) : info_(info) {}
   const CompilationInfo* info_;

src/compiler/pipeline.cc

@@ -611,25 +611,34 @@ struct PrintGraphPhase {
     std::replace(filename.start(), filename.start() + filename.length(), ' ',
                  '_');
 
-    char dot_buffer[256];
-    Vector<char> dot_filename(dot_buffer, sizeof(dot_buffer));
-    SNPrintF(dot_filename, "%s.dot", filename.start());
-    FILE* dot_file = base::OS::FOpen(dot_filename.start(), "w+");
-    OFStream dot_of(dot_file);
-    dot_of << AsDOT(*graph);
-    fclose(dot_file);
+    {  // Print dot.
+      char dot_buffer[256];
+      Vector<char> dot_filename(dot_buffer, sizeof(dot_buffer));
+      SNPrintF(dot_filename, "%s.dot", filename.start());
+      FILE* dot_file = base::OS::FOpen(dot_filename.start(), "w+");
+      OFStream dot_of(dot_file);
+      dot_of << AsDOT(*graph);
+      fclose(dot_file);
+    }
 
-    char json_buffer[256];
-    Vector<char> json_filename(json_buffer, sizeof(json_buffer));
-    SNPrintF(json_filename, "%s.json", filename.start());
-    FILE* json_file = base::OS::FOpen(json_filename.start(), "w+");
-    OFStream json_of(json_file);
-    json_of << AsJSON(*graph);
-    fclose(json_file);
+    {  // Print JSON.
+      char json_buffer[256];
+      Vector<char> json_filename(json_buffer, sizeof(json_buffer));
+      SNPrintF(json_filename, "%s.json", filename.start());
+      FILE* json_file = base::OS::FOpen(json_filename.start(), "w+");
+      OFStream json_of(json_file);
+      json_of << AsJSON(*graph);
+      fclose(json_file);
+    }
 
     OFStream os(stdout);
+    if (FLAG_trace_turbo_graph) {  // Simple textual RPO.
+      os << "-- Graph after " << phase << " -- " << std::endl;
+      os << AsRPO(*graph);
+    }
+
     os << "-- " << phase << " graph printed to file " << filename.start()
-       << "\n";
+       << std::endl;
   }
 };
 

src/flag-definitions.h

@@ -366,6 +366,8 @@ DEFINE_BOOL(omit_map_checks_for_leaf_maps, true,
 // Flags for TurboFan.
 DEFINE_STRING(turbo_filter, "~", "optimization filter for TurboFan compiler")
 DEFINE_BOOL(trace_turbo, false, "trace generated TurboFan IR")
+DEFINE_BOOL(trace_turbo_graph, false, "trace generated TurboFan graphs")
+DEFINE_IMPLICATION(trace_turbo_graph, trace_turbo)
 DEFINE_STRING(trace_turbo_cfg_file, NULL,
               "trace turbo cfg graph (for C1 visualizer) to a given file name")
 DEFINE_BOOL(trace_turbo_types, true, "trace TurboFan's types")