Optimizing: Add debugging output for HInstruction.

Allow printing individual instruction and its arguments with
the HGraphVisualizer. Arguments are dumped "recursively"
(but implemented with a queue instead of actual recursion).

For example, printing the Return instruction from the method
Main.testLoop17 in 530-checker-lse yields

v28 Return [i27] dex_pc:23 loop:none
  i27 Add [i24,i26] dex_pc:22 loop:none
    i24 Phi [i5,i15] dex_pc:n/a reg:0 is_catch_phi:false loop:none
      i5 IntConstant dex_pc:0 1 loop:none
      i15 IntConstant dex_pc:5 2 loop:none
    i26 InstanceFieldGet [l6] dex_pc:20 field_name:TestClass.i field_type:Int32 loop:none
      l6 NullCheck [l1] dex_pc:1 env:[[i5,_,_,l1,i2]] loop:none
        l1 ParameterValue dex_pc:n/a loop:none

Test: Manual; modify LSE to print the instruction above.
Change-Id: Iaf41ba62cd6a5a36236ad0abca082ebffcf6a20e

1 files changed, 4 insertions, 2 deletions

diff --git a/compiler/optimizing/graph_visualizer.h b/compiler/optimizing/graph_visualizer.h
index e01d03c19c..b83e88740c 100644
--- a/compiler/optimizing/graph_visualizer.h
+++ b/compiler/optimizing/graph_visualizer.h
@@ -101,7 +101,7 @@ class HGraphVisualizer : public ValueObject {
  public:
   HGraphVisualizer(std::ostream* output,
                    HGraph* graph,
-                   const CodeGenerator& codegen);
+                   const CodeGenerator* codegen);
 
   void PrintHeader(const char* method_name) const;
   void DumpGraph(const char* pass_name, bool is_after_pass, bool graph_in_bad_state) const;
@@ -112,10 +112,12 @@ class HGraphVisualizer : public ValueObject {
   // method attributes is used. Such empty blocks don't break the c1visualizer parser.
   static std::string InsertMetaDataAsCompilationBlock(const std::string& meta_data);
 
+  static void DumpInstruction(std::ostream* output, HGraph* graph, HInstruction* instruction);
+
  private:
   std::ostream* const output_;
   HGraph* const graph_;
-  const CodeGenerator& codegen_;
+  const CodeGenerator* codegen_;
 
   DISALLOW_COPY_AND_ASSIGN(HGraphVisualizer);
 };