Use direct jump and call instruction for X64 when the deoptimization entries are in the code range

src/objects.cc

 // Copyright 2012 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 8606 matching lines @@
     } else if (mode == RelocInfo::GLOBAL_PROPERTY_CELL) {
       Handle<JSGlobalPropertyCell> cell  = it.rinfo()->target_cell_handle();
       it.rinfo()->set_target_cell(*cell, SKIP_WRITE_BARRIER);
     } else if (RelocInfo::IsCodeTarget(mode)) {
       // rewrite code handles in inline cache targets to direct
       // pointers to the first instruction in the code object
       Handle<Object> p = it.rinfo()->target_object_handle(origin);
       Code* code = Code::cast(*p);
       it.rinfo()->set_target_address(code->instruction_start(),
                                      SKIP_WRITE_BARRIER);
+#if defined(V8_TARGET_ARCH_X64)

[danno, 2013/02/06 15:00:38]

I would very much like to avoid having platform #ifdefs in shared code. I think
a better solution is to add a new method of RelocInfo, something like
set_runtime_entry_address, which has a platform-specific implementation and
makes the offset relative on platforms that support it, just like
set_target_address does. With that in place, you could always execute the code
below, getting the "raw" address using a specialized call similar to what code
targets do above, e.g.:

 Address p = it.rinfo()->absolute_runtime_entry_address(origin);
it.rinfo()->set_target_runtime_entry_address(origin);

[haitao.feng, 2013/02/07 05:08:05]

Done.

+    } else if (RelocInfo::IsRuntimeEntry(mode)) {
+      // rewrite runtime entries in optimized codes to direct
+      // pointers to the entry
+      Address p = it.rinfo()->target_runtime_entry(origin);
+      it.rinfo()->set_target_address(p, SKIP_WRITE_BARRIER);
+#endif
     } else {
       it.rinfo()->apply(delta);
     }
   }
   CPU::FlushICache(instruction_start(), instruction_size());
 }
 
 
 // Locate the source position which is closest to the address in the code. This
 // is using the source position information embedded in the relocation info.
@@ skipping 5218 matching lines @@
   set_year(Smi::FromInt(year), SKIP_WRITE_BARRIER);
   set_month(Smi::FromInt(month), SKIP_WRITE_BARRIER);
   set_day(Smi::FromInt(day), SKIP_WRITE_BARRIER);
   set_weekday(Smi::FromInt(weekday), SKIP_WRITE_BARRIER);
   set_hour(Smi::FromInt(hour), SKIP_WRITE_BARRIER);
   set_min(Smi::FromInt(min), SKIP_WRITE_BARRIER);
   set_sec(Smi::FromInt(sec), SKIP_WRITE_BARRIER);
 }
 
 } }  // namespace v8::internal