Improve compilation speed on a pathological case > 2x (7 sec -> 2.7 sec) by improving local lookups.

runtime/vm/object.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/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/bigint_operations.h"
@@ skipping 10162 matching lines @@
     hash_ += hash_ << 15;
     hash_ = hash_ & ((static_cast<intptr_t>(1) << bits) - 1);
     ASSERT(hash_ <= static_cast<uint32_t>(kMaxInt32));
     return hash_ == 0 ? 1 : hash_;
   }
  private:
   uint32_t hash_;
 };
 
 
-intptr_t String::Hash() const {
-  intptr_t result = Smi::Value(raw_ptr()->hash_);
-  if (result != 0) {
-    return result;
-  }
-  result = String::Hash(*this, 0, this->Length());
-  this->SetHash(result);
-  return result;
-}
-
-
 intptr_t String::Hash(const String& str, intptr_t begin_index, intptr_t len) {
   ASSERT(begin_index >= 0);
   ASSERT(len >= 0);
   ASSERT((begin_index + len) <= str.Length());
   StringHasher hasher;
   CodePointIterator it(str, begin_index, len);
   while (it.Next()) {
     hasher.Add(it.Current());
   }
   return hasher.Finalize(String::kHashBits);
@@ skipping 75 matching lines @@
     // Both handles point to the same raw instance.
     return true;
   }
 
   if (!other.IsString() || other.IsNull()) {
     return false;
   }
 
   const String& other_string = String::Cast(other);
   if (this->HasHash() && other_string.HasHash() &&
-      (this->Hash() != other_string.Hash())) {
+      (this->StringHash() != other_string.StringHash())) {
     return false;  // Both sides have a hash code and it does not match.
   }
   return Equals(other_string, 0, other_string.Length());
 }
 
 
 bool String::Equals(const char* cstr) const {
   ASSERT(cstr != NULL);
   CodePointIterator it(*this);
   intptr_t len = strlen(cstr);
@@ skipping 2196 matching lines @@
   }
   return result.raw();
 }
 
 
 const char* WeakProperty::ToCString() const {
   return "_WeakProperty";
 }
 
 }  // namespace dart