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 8585 matching lines @@
   // copy reloc info
   memmove(relocation_start(),
           desc.buffer + desc.buffer_size - desc.reloc_size,
           desc.reloc_size);
 
   // unbox handles and relocate
   intptr_t delta = instruction_start() - desc.buffer;
   int mode_mask = RelocInfo::kCodeTargetMask |
                   RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT) |
                   RelocInfo::ModeMask(RelocInfo::GLOBAL_PROPERTY_CELL) |
+                  RelocInfo::ModeMask(RelocInfo::RUNTIME_ENTRY) |
                   RelocInfo::kApplyMask;
-  Assembler* origin = desc.origin;  // Needed to find target_object on X64.
+  // Needed to find target_object and runtime_entry on X64
+  Assembler* origin = desc.origin;
   for (RelocIterator it(this, mode_mask); !it.done(); it.next()) {
     RelocInfo::Mode mode = it.rinfo()->rmode();
     if (mode == RelocInfo::EMBEDDED_OBJECT) {
       Handle<Object> p = it.rinfo()->target_object_handle(origin);
       it.rinfo()->set_target_object(*p, SKIP_WRITE_BARRIER);
     } 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);
+    } else if (RelocInfo::IsRuntimeEntry(mode) &&
+               RelocInfo::NeedsInitializeRuntimeEntry()) {
+      Address p = it.rinfo()->target_runtime_entry(origin);

[danno, 2013/03/07 14:57:23]

Why do you need NeedsInitializeRuntimeEntry at all? If you make
target_runtime_entry always return the right thing (platform specific), then
this can be executed on all platforms. For platforms that don't change the
address because it is an absolute address, the set_target_address should do
nothing (it checks the current value and doesn't store if there is no change). 

[haitao.feng, 2013/03/08 05:30:05]

Done.

+      it.rinfo()->set_target_address(p, SKIP_WRITE_BARRIER);
     } 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 5349 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