Share optimized code for closures.

src/ia32/deoptimizer-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 99 matching lines @@
     }
     // Replace relocation information on the code object.
     code->set_relocation_info(*new_reloc);
   }
 }
 
 
 void Deoptimizer::DeoptimizeFunction(JSFunction* function) {
   if (!function->IsOptimized()) return;
 
+  // The optimized code is going to be patched, so we cannot use it
+  // any more.  Play safe and reset the whole cache.
+  function->shared()->set_optimized_code_map(Smi::FromInt(0));

[Michael Starzinger, 2012/05/23 11:16:29]

I think it would make sense to have shared->ClearOptimizedCodeMap() as a helper.

[fschneider, 2012/06/14 11:08:23]

Done.

+
   Isolate* isolate = function->GetIsolate();
   HandleScope scope(isolate);
   AssertNoAllocation no_allocation;
 
   // Get the optimized code.
   Code* code = function->code();
   Address code_start_address = code->instruction_start();
 
   // We will overwrite the code's relocation info in-place. Relocation info
   // is written backward. The relocation info is the payload of a byte
@@ skipping 57 matching lines @@
   DeoptimizingCodeListNode* node = new DeoptimizingCodeListNode(code);
   DeoptimizerData* data = isolate->deoptimizer_data();
   node->set_next(data->deoptimizing_code_list_);
   data->deoptimizing_code_list_ = node;
 
   // We might be in the middle of incremental marking with compaction.
   // Tell collector to treat this code object in a special way and
   // ignore all slots that might have been recorded on it.
   isolate->heap()->mark_compact_collector()->InvalidateCode(code);
 
-  // Set the code for the function to non-optimized version.
-  function->ReplaceCode(function->shared()->code());
+  // Iterate over all the functions which share the same code object
+  // and make them use unoptimized version.
+  Context* context = function->context()->global_context();
+  Object* element = context->get(Context::OPTIMIZED_FUNCTIONS_LIST);
+  SharedFunctionInfo* shared = function->shared();
+  while (!element->IsUndefined()) {
+    JSFunction* func = JSFunction::cast(element);
+    // Grab element before code replacement as ReplaceCode alters the list.
+    element = func->next_function_link();
+    if (func->code() == code) {
+      func->ReplaceCode(shared->code());
+    }
+  }
 
   if (FLAG_trace_deopt) {
     PrintF("[forced deoptimization: ");
     function->PrintName();
     PrintF(" / %x]\n", reinterpret_cast<uint32_t>(function));
   }
 }
 
 
 static const byte kJnsInstruction = 0x79;
@@ skipping 114 matching lines @@
   iterator.Next();  // Drop JS frames count.
   ASSERT(count == 1);
   USE(count);
 
   opcode = static_cast<Translation::Opcode>(iterator.Next());
   USE(opcode);
   ASSERT(Translation::JS_FRAME == opcode);
   unsigned node_id = iterator.Next();
   USE(node_id);
   ASSERT(node_id == ast_id);
-  JSFunction* function = JSFunction::cast(ComputeLiteral(iterator.Next()));
-  USE(function);
-  ASSERT(function == function_);
+  int closure_id = iterator.Next();
+  USE(closure_id);
+  ASSERT_EQ(Translation::kSelfLiteralId, closure_id);
   unsigned height = iterator.Next();
   unsigned height_in_bytes = height * kPointerSize;
   USE(height_in_bytes);
 
   unsigned fixed_size = ComputeFixedSize(function_);
   unsigned input_frame_size = input_->GetFrameSize();
   ASSERT(fixed_size + height_in_bytes == input_frame_size);
 
   unsigned stack_slot_size = optimized_code_->stack_slots() * kPointerSize;
   unsigned outgoing_height = data->ArgumentsStackHeight(bailout_id)->value();
@@ skipping 83 matching lines @@
     // Set up the frame pointer and the context pointer.
     output_[0]->SetRegister(ebp.code(), input_->GetRegister(ebp.code()));
     output_[0]->SetRegister(esi.code(), input_->GetRegister(esi.code()));
 
     unsigned pc_offset = data->OsrPcOffset()->value();
     uint32_t pc = reinterpret_cast<uint32_t>(
         optimized_code_->entry() + pc_offset);
     output_[0]->SetPc(pc);
   }
   Code* continuation =
-      function->GetIsolate()->builtins()->builtin(Builtins::kNotifyOSR);
+      function_->GetIsolate()->builtins()->builtin(Builtins::kNotifyOSR);
   output_[0]->SetContinuation(
       reinterpret_cast<uint32_t>(continuation->entry()));
 
   if (FLAG_trace_osr) {
     PrintF("[on-stack replacement translation %s: 0x%08" V8PRIxPTR " ",
            ok ? "finished" : "aborted",
-           reinterpret_cast<intptr_t>(function));
-    function->PrintName();
+           reinterpret_cast<intptr_t>(function_));
+    function_->PrintName();
     PrintF(" => pc=0x%0x]\n", output_[0]->GetPc());
   }
 }
 
 
 void Deoptimizer::DoComputeArgumentsAdaptorFrame(TranslationIterator* iterator,
                                                  int frame_index) {
   JSFunction* function = JSFunction::cast(ComputeLiteral(iterator->Next()));
   unsigned height = iterator->Next();
   unsigned height_in_bytes = height * kPointerSize;
@@ skipping 197 matching lines @@
   uint32_t pc = reinterpret_cast<uint32_t>(
       construct_stub->instruction_start() +
       isolate_->heap()->construct_stub_deopt_pc_offset()->value());
   output_frame->SetPc(pc);
 }
 
 
 void Deoptimizer::DoComputeJSFrame(TranslationIterator* iterator,
                                    int frame_index) {
   int node_id = iterator->Next();
-  JSFunction* function = JSFunction::cast(ComputeLiteral(iterator->Next()));
+  JSFunction* function;
+  if (frame_index != 0) {
+    function = JSFunction::cast(ComputeLiteral(iterator->Next()));
+  } else {
+    int closure_id = iterator->Next();
+    USE(closure_id);
+    ASSERT_EQ(Translation::kSelfLiteralId, closure_id);
+    function = function_;
+  }
   unsigned height = iterator->Next();
   unsigned height_in_bytes = height * kPointerSize;
   if (FLAG_trace_deopt) {
     PrintF("  translating ");
     function->PrintName();
     PrintF(" => node=%d, height=%d\n", node_id, height_in_bytes);
   }
 
   // The 'fixed' part of the frame consists of the incoming parameters and
   // the part described by JavaScriptFrameConstants.
@@ skipping 335 matching lines @@
   }
   __ bind(&done);
 }
 
 #undef __
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32