VM: Speed up output of UTF8 for 1-byte strings.

runtime/vm/symbols.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/symbols.h"
 
 #include "vm/handles.h"
 #include "vm/hash_table.h"
 #include "vm/isolate.h"
 #include "vm/object.h"
@@ skipping 488 matching lines @@
   if (is_one_byte_string) {
     uint8_t* buffer = zone->Alloc<uint8_t>(len_sum);
     const uint8_t* const orig_buffer = buffer;
     for (intptr_t i = 0; i < strs_length; i++) {
       NoSafepointScope no_safepoint;
       intptr_t str_len = lengths[i];
       if (str_len > 0) {
         const String& str = strs[i];
         ASSERT(str.IsOneByteString() || str.IsExternalOneByteString());
         const uint8_t* src_p = str.IsOneByteString()
-                                   ? OneByteString::CharAddr(str, 0)
-                                   : ExternalOneByteString::CharAddr(str, 0);
+                                   ? OneByteString::DataStart(str)
+                                   : ExternalOneByteString::DataStart(str);
         memmove(buffer, src_p, str_len);
         buffer += str_len;
       }
     }
     ASSERT(len_sum == buffer - orig_buffer);
     return Symbols::FromLatin1(thread, orig_buffer, len_sum);
   } else {
     uint16_t* buffer = zone->Alloc<uint16_t>(len_sum);
     const uint16_t* const orig_buffer = buffer;
     for (intptr_t i = 0; i < strs_length; i++) {
       NoSafepointScope no_safepoint;
       intptr_t str_len = lengths[i];
       if (str_len > 0) {
         const String& str = strs[i];
         if (str.IsTwoByteString()) {
-          memmove(buffer, TwoByteString::CharAddr(str, 0), str_len * 2);
+          memmove(buffer, TwoByteString::DataStart(str), str_len * 2);
         } else if (str.IsExternalTwoByteString()) {
-          memmove(buffer, ExternalTwoByteString::CharAddr(str, 0), str_len * 2);
+          memmove(buffer, ExternalTwoByteString::DataStart(str), str_len * 2);
         } else {
           // One-byte to two-byte string copy.
           ASSERT(str.IsOneByteString() || str.IsExternalOneByteString());
           const uint8_t* src_p = str.IsOneByteString()
-                                     ? OneByteString::CharAddr(str, 0)
-                                     : ExternalOneByteString::CharAddr(str, 0);
+                                     ? OneByteString::DataStart(str)
+                                     : ExternalOneByteString::DataStart(str);
           for (int n = 0; n < str_len; n++) {
             buffer[n] = src_p[n];
           }
         }
         buffer += str_len;
       }
     }
     ASSERT(len_sum == buffer - orig_buffer);
     return Symbols::FromUTF16(thread, orig_buffer, len_sum);
   }
@@ skipping 154 matching lines @@
 RawObject* Symbols::GetPredefinedSymbol(intptr_t object_id) {
   ASSERT(IsPredefinedSymbolId(object_id));
   intptr_t i = (object_id - kMaxPredefinedObjectIds);
   if ((i > kIllegal) && (i < Symbols::kMaxPredefinedId)) {
     return symbol_handles_[i]->raw();
   }
   return Object::null();
 }
 
 }  // namespace dart