Make CTX allocatable by the register allocator.

runtime/vm/flow_graph.h

 // Copyright (c) 2013, 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.
 
 #ifndef VM_FLOW_GRAPH_H_
 #define VM_FLOW_GRAPH_H_
 
 #include "vm/bit_vector.h"
 #include "vm/growable_array.h"
 #include "vm/hash_map.h"
@@ skipping 93 matching lines @@
   intptr_t num_stack_locals() const {
     return num_stack_locals_;
   }
   intptr_t num_copied_params() const {
     return num_copied_params_;
   }
   intptr_t num_non_copied_params() const {
     return num_non_copied_params_;
   }
 
+  LocalVariable* CurrentContextVar() const {
+    return parsed_function().saved_current_context_var();
+  }
+
+  intptr_t CurrentContextEnvIndex() const {
+    return parsed_function().saved_current_context_var()->BitIndexIn(
+        num_non_copied_params_);
+  }
+
   // Flow graph orders.
   const GrowableArray<BlockEntryInstr*>& preorder() const {
     return preorder_;
   }
   const GrowableArray<BlockEntryInstr*>& postorder() const {
     return postorder_;
   }
   const GrowableArray<BlockEntryInstr*>& reverse_postorder() const {
     return reverse_postorder_;
   }
@@ skipping 28 matching lines @@
   }
 
   ConstantInstr* constant_null() const {
     return constant_null_;
   }
 
   ConstantInstr* constant_dead() const {
     return constant_dead_;
   }
 
+  ConstantInstr* constant_empty_context() const {
+    return constant_empty_context_;
+  }
+
+  Definition* CurrentContext(Environment* env) const {
+    while (env->outer() != NULL) env = env->outer();

[Vyacheslav Egorov (Google), 2014/10/28 13:44:58]

Kill this function. It's also a bit suspicious.

[Florian Schneider, 2014/10/28 19:04:31]

Done.

+    return env->ValueAt(CurrentContextEnvIndex())->definition();
+  }
+
   intptr_t alloc_ssa_temp_index() { return current_ssa_temp_index_++; }
 
   void AllocateSSAIndexes(Definition* def) {
     ASSERT(def);
     def->set_ssa_temp_index(alloc_ssa_temp_index());
     // Always allocate a second index. This index is unused except
     // for Definitions with register pair outputs.
     alloc_ssa_temp_index();
   }
 
@@ skipping 154 matching lines @@
   const intptr_t num_copied_params_;
   const intptr_t num_non_copied_params_;
   const intptr_t num_stack_locals_;
   GraphEntryInstr* graph_entry_;
   GrowableArray<BlockEntryInstr*> preorder_;
   GrowableArray<BlockEntryInstr*> postorder_;
   GrowableArray<BlockEntryInstr*> reverse_postorder_;
   GrowableArray<BlockEntryInstr*> optimized_block_order_;
   ConstantInstr* constant_null_;
   ConstantInstr* constant_dead_;
+  ConstantInstr* constant_empty_context_;
+  Definition* current_context_;

[Vyacheslav Egorov (Google), 2014/10/28 13:44:58]

Kill this with fire.

[Florian Schneider, 2014/10/28 19:04:31]

Done.

 
   BlockEffects* block_effects_;
   bool licm_allowed_;
 
   ZoneGrowableArray<BlockEntryInstr*>* loop_headers_;
   ZoneGrowableArray<BitVector*>* loop_invariant_loads_;
   ZoneGrowableArray<const Field*>* guarded_fields_;
   ZoneGrowableArray<const LibraryPrefix*>* deferred_prefixes_;
   DirectChainedHashMap<ConstantPoolTrait> constant_instr_pool_;
   BitVector* captured_parameters_;
@@ skipping 145 matching lines @@
 
  private:
   GrowableArray<Definition*> defs_;
   BitVector* contains_vector_;
 };
 
 
 }  // namespace dart
 
 #endif  // VM_FLOW_GRAPH_H_