Collect edge count profiling data and reorder basic blocks.

runtime/vm/compiler.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/compiler.h"
 
 #include "vm/assembler.h"
 
 #include "vm/ast_printer.h"
+#include "vm/block_scheduler.h"
 #include "vm/code_generator.h"
 #include "vm/code_patcher.h"
 #include "vm/dart_entry.h"
 #include "vm/debugger.h"
 #include "vm/deopt_instructions.h"
 #include "vm/exceptions.h"
 #include "vm/flags.h"
 #include "vm/flow_graph.h"
 #include "vm/flow_graph_allocator.h"
 #include "vm/flow_graph_builder.h"
@@ skipping 267 matching lines @@
 
     if (FLAG_print_flow_graph ||
         (optimized && FLAG_print_flow_graph_optimized)) {
       if (osr_id == Isolate::kNoDeoptId) {
         FlowGraphPrinter::PrintGraph("Before Optimizations", flow_graph);
       } else {
         FlowGraphPrinter::PrintGraph("For OSR", flow_graph);
       }
     }
 
+    BlockScheduler block_scheduler(flow_graph);

[Florian Schneider, 2013/08/12 11:30:09]

Maybe add a flag FLAG_reorder_basic_blocks to control reordering.

[Kevin Millikin (Google), 2013/08/13 11:14:57]

Done.

+    if (optimized) {
+      block_scheduler.AssignEdgeWeights();
+    }
+
     if (optimized) {
       TimerScope timer(FLAG_compiler_stats,
                        &CompilerStats::ssa_timer,
                        isolate);
       // Transform to SSA (virtual register 0 and no inlining arguments).
       flow_graph->ComputeSSA(0, NULL);
       DEBUG_ASSERT(flow_graph->VerifyUseLists());
       if (FLAG_print_flow_graph || FLAG_print_flow_graph_optimized) {
         FlowGraphPrinter::PrintGraph("After SSA", flow_graph);
       }
     }
 
-
     // Collect all instance fields that are loaded in the graph and
     // have non-generic type feedback attached to them that can
     // potentially affect optimizations.
     GrowableArray<const Field*> guarded_fields(10);
     if (optimized) {
       TimerScope timer(FLAG_compiler_stats,
                        &CompilerStats::graphoptimizer_timer,
                        isolate);
 
       FlowGraphOptimizer optimizer(flow_graph, &guarded_fields);
@@ skipping 154 matching lines @@
         // sinking from the flow graph and let them float on the side referenced
         // only from environments. Register allocator will consider them
         // as part of a deoptimization environment.
         sinking->DetachMaterializations();
       }
 
       // Perform register allocation on the SSA graph.
       FlowGraphAllocator allocator(*flow_graph);
       allocator.AllocateRegisters();
 
+      block_scheduler.ReorderBlocks();
+
       if (FLAG_print_flow_graph || FLAG_print_flow_graph_optimized) {
         FlowGraphPrinter::PrintGraph("After Optimizations", flow_graph);
       }
     }
 
     Assembler assembler;
-    FlowGraphCompiler graph_compiler(&assembler,
-                                     *flow_graph,
-                                     optimized);
+    FlowGraphCompiler graph_compiler(&assembler, flow_graph, optimized);
     {
       TimerScope timer(FLAG_compiler_stats,
                        &CompilerStats::graphcompiler_timer,
                        isolate);
       graph_compiler.CompileGraph();
     }
     {
       TimerScope timer(FLAG_compiler_stats,
                        &CompilerStats::codefinalizer_timer,
                        isolate);
@@ skipping 376 matching lines @@
       Object::Handle(isolate->object_store()->sticky_error());
     isolate->object_store()->clear_sticky_error();
     isolate->set_long_jump_base(base);
     return result.raw();
   }
   UNREACHABLE();
   return Object::null();
 }
 
 }  // namespace dart