Add higher-level accesses to Environment. Print flow graph after register allocation. Most interest…

runtime/vm/compiler.cc

Index: runtime/vm/compiler.cc
===================================================================
--- runtime/vm/compiler.cc	(revision 9819)
+++ runtime/vm/compiler.cc	(working copy)
@@ -34,6 +34,7 @@
     "How many times we allow deoptimization before we disallow"
     " certain optimizations");
 DEFINE_FLAG(bool, trace_bailout, false, "Print bailout from ssa compiler.");
+DECLARE_FLAG(bool, print_flow_graph);
 DECLARE_FLAG(bool, use_ssa);
 
 
@@ -172,6 +173,11 @@
           FlowGraphAllocator allocator(block_order, &graph_builder);
           allocator.AllocateRegisters();
         }
+        if (FLAG_print_flow_graph) {
+          OS::Print("After Optimizations:\n");
+          FlowGraphPrinter printer(Function::Handle(), block_order);
+          printer.PrintBlocks();
+        }
       }
     }