This patch is the propagation version of https://codereview.chromium.org/10824032 patch

src/ia32/lithium-codegen-ia32.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 302 matching lines @@
           } else {
             Comment(";;; @%d: %s. <#%d>", current_instruction_,
                     instr->Mnemonic(), hydrogen->id());
           }
         } else {
           Comment(";;; @%d: %s.", current_instruction_, instr->Mnemonic());
         }
       }
       instr->CompileToNative(this);
     }
+
+    if (instr->HasPointerMap()) {

[danno, 2012/12/20 16:27:20]

Why do you need to add this? I would think that this duplicates a lot of
position information for instructions that already output position information,
and don't understand the motivation behind the change. And if you do make this
change, you need to make it for ARM as well.

+      LPointerMap* pointers = instr->pointer_map();
+      if (pointers->position() != RelocInfo::kNoPosition) {
+        RecordPosition(pointers->position());
+      }
+    }
   }
   EnsureSpaceForLazyDeopt();
   return !is_aborted();
 }
 
 
 bool LCodeGen::GenerateDeferredCode() {
   ASSERT(is_generating());
   if (deferred_.length() > 0) {
     for (int i = 0; !is_aborted() && i < deferred_.length(); i++) {
@@ skipping 5325 matching lines @@
                               FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32