Serializer: Cache FlagList::Hash result.

src/flags.cc

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <cctype>
 #include <cstdlib>
 #include <sstream>
 
 #include "src/v8.h"
 
@@ skipping 525 matching lines @@
      << "Options:\n";
   for (size_t i = 0; i < num_flags; ++i) {
     Flag* f = &flags[i];
     os << "  --" << f->name() << " (" << f->comment() << ")\n"
        << "        type: " << Type2String(f->type()) << "  default: " << *f
        << "\n";
   }
 }
 
 
-// static
-void FlagList::EnforceFlagImplications() {
-#define FLAG_MODE_DEFINE_IMPLICATIONS
-#include "src/flag-definitions.h"
-#undef FLAG_MODE_DEFINE_IMPLICATIONS
-}
+static uint32_t flag_hash = 0;
 
 
-uint32_t FlagList::Hash() {
+void ComputeFlagListHash() {
   std::ostringstream modified_args_as_string;
 #ifdef DEBUG
   modified_args_as_string << "debug";
 #endif  // DEBUG
   for (size_t i = 0; i < num_flags; ++i) {
     Flag* current = &flags[i];
     if (!current->IsDefault()) {
       modified_args_as_string << i;
       modified_args_as_string << *current;
     }
   }
   std::string args(modified_args_as_string.str());
-  return static_cast<uint32_t>(
+  flag_hash = static_cast<uint32_t>(
       base::hash_range(args.c_str(), args.c_str() + args.length()));
 }
+
+
+// static
+void FlagList::EnforceFlagImplications() {
+#define FLAG_MODE_DEFINE_IMPLICATIONS
+#include "src/flag-definitions.h"
+#undef FLAG_MODE_DEFINE_IMPLICATIONS
+  ComputeFlagListHash();
+}
+
+
+uint32_t FlagList::Hash() { return flag_hash; }
 } }  // namespace v8::internal