Use enums for the index of IL operands.

runtime/vm/flow_graph_optimizer.cc

 // 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.
 
 #include "vm/flow_graph_optimizer.h"
 
 #include "vm/bit_vector.h"
 #include "vm/cha.h"
 #include "vm/dart_entry.h"
 #include "vm/flow_graph_builder.h"
@@ skipping 4143 matching lines @@
           offset_in_bytes_ = load_field->offset_in_bytes();
         }
         *is_load = true;
         break;
       }
 
       case Instruction::kStoreInstanceField: {
         StoreInstanceFieldInstr* store_instance_field =
             instr->AsStoreInstanceField();
         kind_ = kField;
-        // Value is at input index 1.
-        representation_ = store_instance_field->RequiredInputRepresentation(1);
+        representation_ = store_instance_field->
+            RequiredInputRepresentation(StoreInstanceFieldInstr::kValuePos);
         instance_ =
             OriginalDefinition(store_instance_field->instance()->definition());
         field_ = &store_instance_field->field();
         break;
       }
 
       case Instruction::kStoreVMField: {
         StoreVMFieldInstr* store_vm_field = instr->AsStoreVMField();
         kind_ = kVMField;
-        // Value is at input index 0.
-        representation_ = store_vm_field->RequiredInputRepresentation(0);
+        representation_ = store_vm_field->
+            RequiredInputRepresentation(StoreVMFieldInstr::kValuePos);
         instance_ = OriginalDefinition(store_vm_field->dest()->definition());
         offset_in_bytes_ = store_vm_field->offset_in_bytes();
         break;
       }
 
       case Instruction::kLoadStaticField:
         kind_ = kField;
         representation_ = instr->AsLoadStaticField()->representation();
         field_ = &instr->AsLoadStaticField()->StaticField();
         *is_load = true;
         break;
 
       case Instruction::kStoreStaticField:
         kind_ = kField;
-        // Value is at input index 0.
-        representation_ =
-            instr->AsStoreStaticField()->RequiredInputRepresentation(0);
+        representation_ = instr->AsStoreStaticField()->
+            RequiredInputRepresentation(StoreStaticFieldInstr::kValuePos);
         field_ = &instr->AsStoreStaticField()->field();
         break;
 
       case Instruction::kLoadIndexed: {
         LoadIndexedInstr* load_indexed = instr->AsLoadIndexed();
         kind_ = kIndexed;
         representation_ = load_indexed->representation();
         instance_ = OriginalDefinition(load_indexed->array()->definition());
         index_ = load_indexed->index()->definition();
         *is_load = true;
         break;
       }
 
       case Instruction::kStoreIndexed: {
         StoreIndexedInstr* store_indexed = instr->AsStoreIndexed();
         kind_ = kIndexed;
-        // Value is at input index 2.
-        representation_ = store_indexed->RequiredInputRepresentation(2);
+        representation_ = store_indexed->
+            RequiredInputRepresentation(StoreIndexedInstr::kValuePos);
         instance_ = OriginalDefinition(store_indexed->array()->definition());
         index_ = store_indexed->index()->definition();
         break;
       }
 
       case Instruction::kCurrentContext:
         kind_ = kContext;
         ASSERT(instr->AsCurrentContext()->representation() == kTagged);
         representation_ = kTagged;
         *is_load = true;
         break;
 
       case Instruction::kStoreContext:
         kind_ = kContext;
-        ASSERT(instr->AsStoreContext()->RequiredInputRepresentation(0) ==
-               kTagged);
+        ASSERT(instr->AsStoreContext()->RequiredInputRepresentation(
+            StoreContextInstr::kValuePos) == kTagged);
         representation_ = kTagged;
         break;
 
       default:
         break;
     }
   }
 
   intptr_t id() const { return id_; }
   void set_id(intptr_t id) { id_ = id; }
@@ skipping 3526 matching lines @@
   }
 
   // Insert materializations at environment uses.
   for (intptr_t i = 0; i < exits.length(); i++) {
     CreateMaterializationAt(exits[i], alloc, alloc->cls(), *fields);
   }
 }
 
 
 }  // namespace dart