Skeleton of a linear scan register allocator.

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/code_generator.h"
 #include "vm/code_patcher.h"
 #include "vm/dart_entry.h"
 #include "vm/debugger.h"
 #include "vm/disassembler.h"
 #include "vm/exceptions.h"
 #include "vm/flags.h"
 #include "vm/flow_graph_allocator.h"
 #include "vm/flow_graph_builder.h"
 #include "vm/flow_graph_compiler.h"
 #include "vm/flow_graph_optimizer.h"
+#include "vm/il_printer.h"
 #include "vm/longjump.h"
 #include "vm/object.h"
 #include "vm/object_store.h"
 #include "vm/os.h"
 #include "vm/parser.h"
 #include "vm/scanner.h"
 #include "vm/timer.h"
 
 namespace dart {
 
@@ skipping 131 matching lines @@
       intptr_t length = graph_builder.postorder_block_entries().length();
       for (intptr_t i = length - 1; i >= 0; --i) {
         block_order.Add(graph_builder.postorder_block_entries()[i]);
       }
       if (optimized) {
         FlowGraphOptimizer optimizer(block_order);
         optimizer.ApplyICData();
 
         if (use_ssa) {
           // Perform register allocation on the SSA graph.
-          FlowGraphAllocator allocator(graph_builder.postorder_block_entries(),
-                                       graph_builder.current_ssa_temp_index());
-          allocator.ResolveConstraints();
-          allocator.AnalyzeLiveness();
-
-          // Temporary bailout until we support code generation from SSA form.
-          graph_builder.Bailout("No SSA code generation support.");
+          FlowGraphAllocator allocator(block_order, &graph_builder);
+          allocator.AllocateRegisters();
         }
       }
     }
 
     bool is_leaf = false;
     if (optimized) {
       FlowGraphAnalyzer analyzer(block_order);
       analyzer.Analyze();
       is_leaf = analyzer.is_leaf();
     }
     Assembler assembler;
-    FlowGraphCompiler graph_compiler(&assembler, parsed_function,
-                                     block_order, optimized, is_leaf);
+    FlowGraphCompiler graph_compiler(&assembler,
+                                     parsed_function,
+                                     block_order,
+                                     optimized,
+                                     optimized && use_ssa,
+                                     is_leaf);
     {
       TimerScope timer(FLAG_compiler_stats,
                        &CompilerStats::graphcompiler_timer,
                        isolate);
       graph_compiler.CompileGraph();
     }
     {
       TimerScope timer(FLAG_compiler_stats,
                        &CompilerStats::codefinalizer_timer,
                        isolate);
@@ skipping 275 matching lines @@
     isolate->object_store()->clear_sticky_error();
     isolate->set_long_jump_base(base);
     return result.raw();
   }
   UNREACHABLE();
   return Object::null();
 }
 
 
 }  // namespace dart