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

src/objects.cc

Index: src/objects.cc
===================================================================
--- src/objects.cc	(revision 13740)
+++ src/objects.cc	(working copy)
@@ -8603,8 +8603,10 @@
   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) {
@@ -8620,6 +8622,10 @@
       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);
     }