Add more spcific ranges for String length and charCode methods.

runtime/vm/intermediate_language.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/intermediate_language.h"
 
 #include "vm/bit_vector.h"
 #include "vm/dart_entry.h"
 #include "vm/flow_graph_allocator.h"
 #include "vm/flow_graph_builder.h"
@@ skipping 2442 matching lines @@
 
 
 void LoadFieldInstr::InferRange() {
   if ((range_ == NULL) &&
       ((recognized_kind() == MethodRecognizer::kObjectArrayLength) ||
        (recognized_kind() == MethodRecognizer::kImmutableArrayLength))) {
     range_ = new Range(RangeBoundary::FromConstant(0),
                        RangeBoundary::FromConstant(Array::kMaxElements));
     return;
   }
+  if ((range_ == NULL) &&
+      (recognized_kind() == MethodRecognizer::kStringBaseLength)) {
+    range_ = new Range(RangeBoundary::FromConstant(0),
+                       RangeBoundary::FromConstant(String::kMaxElements));
+    return;
+  }
   Definition::InferRange();
 }
 
 
+
+void StringCharCodeAtInstr::InferRange() {
+  switch (class_id_) {
+    case kOneByteStringCid:
+      range_ = new Range(RangeBoundary::FromConstant(0),
+                         RangeBoundary::FromConstant(0xFF));
+      break;
+    case kTwoByteStringCid:
+      range_ = new Range(RangeBoundary::FromConstant(0),
+                         RangeBoundary::FromConstant(0xFFFF));
+      break;
+    default:
+      UNIMPLEMENTED();
+  }
+}
+
+
 void LoadIndexedInstr::InferRange() {
   switch (class_id()) {
     case kExternalUint8ArrayCid:
     case kUint8ArrayCid:
       range_ = new Range(RangeBoundary::FromConstant(0),
                          RangeBoundary::FromConstant(255));
       break;
     default:
       Definition::InferRange();
       break;
@@ skipping 233 matching lines @@
     default:
       UNREACHABLE();
       return -1;
   }
 }
 
 
 #undef __
 
 }  // namespace dart