RFC: Try to be much more careful with where we skip the write barrier by:...

src/dateparser.cc

 // Copyright 2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 54 matching lines @@
       day = comp_[0];
       year = comp_[1];
     }
   }
 
   if (Between(year, 0, 49)) year += 2000;
   else if (Between(year, 50, 99)) year += 1900;
 
   if (!Smi::IsValid(year) || !IsMonth(month) || !IsDay(day)) return false;
 
-  output->set(YEAR,
-              Smi::FromInt(year),
-              SKIP_WRITE_BARRIER);
-  output->set(MONTH,
-              Smi::FromInt(month - 1),
-              SKIP_WRITE_BARRIER);  // 0-based
-  output->set(DAY,
-              Smi::FromInt(day),
-              SKIP_WRITE_BARRIER);
+  output->set(YEAR, Smi::FromInt(year));
+  output->set(MONTH, Smi::FromInt(month - 1));  // 0-based
+  output->set(DAY, Smi::FromInt(day));
   return true;
 }
 
 
 bool DateParser::TimeComposer::Write(FixedArray* output) {
   // All time slots default to 0
   while (index_ < kSize) {
     comp_[index_++] = 0;
   }
 
   int& hour = comp_[0];
   int& minute = comp_[1];
   int& second = comp_[2];
 
   if (hour_offset_ != kNone) {
     if (!IsHour12(hour)) return false;
     hour %= 12;
     hour += hour_offset_;
   }
 
   if (!IsHour(hour) || !IsMinute(minute) || !IsSecond(second)) return false;
 
-  output->set(HOUR,
-              Smi::FromInt(hour),
-              SKIP_WRITE_BARRIER);
-  output->set(MINUTE,
-              Smi::FromInt(minute),
-              SKIP_WRITE_BARRIER);
-  output->set(SECOND,
-              Smi::FromInt(second),
-              SKIP_WRITE_BARRIER);
+  output->set(HOUR, Smi::FromInt(hour));
+  output->set(MINUTE, Smi::FromInt(minute));
+  output->set(SECOND, Smi::FromInt(second));
   return true;
 }
 
 bool DateParser::TimeZoneComposer::Write(FixedArray* output) {
   if (sign_ != kNone) {
     if (hour_ == kNone) hour_ = 0;
     if (minute_ == kNone) minute_ = 0;
     int total_seconds = sign_ * (hour_ * 3600 + minute_ * 60);
     if (!Smi::IsValid(total_seconds)) return false;
-    output->set(UTC_OFFSET,
-                Smi::FromInt(total_seconds),
-                SKIP_WRITE_BARRIER);
+    output->set(UTC_OFFSET, Smi::FromInt(total_seconds));
   } else {
-    output->set(UTC_OFFSET,
-                Heap::null_value(),
-                SKIP_WRITE_BARRIER);
+    output->set_null(UTC_OFFSET);
   }
   return true;
 }
 
 const int8_t DateParser::KeywordTable::
     array[][DateParser::KeywordTable::kEntrySize] = {
   {'j', 'a', 'n', DateParser::MONTH_NAME, 1},
   {'f', 'e', 'b', DateParser::MONTH_NAME, 2},
   {'m', 'a', 'r', DateParser::MONTH_NAME, 3},
   {'a', 'p', 'r', DateParser::MONTH_NAME, 4},
@@ skipping 36 matching lines @@
     if (j == kPrefixLength &&
         (len <= kPrefixLength || array[i][kTypeOffset] == MONTH_NAME)) {
       return i;
     }
   }
   return i;
 }
 
 
 } }  // namespace v8::internal