Cache optimized code for OSR.

src/code-stubs-hydrogen.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 1176 matching lines @@
   }
   is_optimized.Else();
   {
     AddIncrementCounter(counters->fast_new_closure_try_optimized());
     // optimized_map points to fixed array of 3-element entries
     // (native context, optimized code, literals).
     // Map must never be empty, so check the first elements.
     Label install_optimized;
     HValue* first_context_slot = Add<HLoadNamedField>(optimized_map,
         HObjectAccess::ForFirstContextSlot());
+    HValue* first_osr_ast_slot = Add<HLoadNamedField>(optimized_map,
+        HObjectAccess::ForFirstOsrAstIdSlot());
+    HValue* osr_ast_id_none = Add<HConstant>(BailoutId::None().ToInt(),
+                                            Representation::Smi());

[Toon Verwaest, 2013/12/11 12:40:29]

Any reason why you manually set the representation to Smi? That should be done
automatically in HConstant?

[Yang, 2013/12/11 13:11:15]

Yep, this was not necessary.

     IfBuilder already_in(this);
     already_in.If<HCompareObjectEqAndBranch>(native_context,
                                              first_context_slot);
+    already_in.AndIf<HCompareObjectEqAndBranch>(first_osr_ast_slot,
+                                                osr_ast_id_none);
     already_in.Then();
     {
       HValue* code_object = Add<HLoadNamedField>(optimized_map,
         HObjectAccess::ForFirstCodeSlot());
       BuildInstallOptimizedCode(js_function, native_context, code_object);
     }
     already_in.Else();
     {
       HValue* shared_function_entry_length =
           Add<HConstant>(SharedFunctionInfo::kEntryLength);
       LoopBuilder loop_builder(this,
                                context(),
                                LoopBuilder::kPostDecrement,
                                shared_function_entry_length);
       HValue* array_length = Add<HLoadNamedField>(optimized_map,
           HObjectAccess::ForFixedArrayLength());
-      HValue* key = loop_builder.BeginBody(array_length,
+      HValue* slot_iterator = loop_builder.BeginBody(array_length,
                                            graph()->GetConstant0(),
                                            Token::GT);
       {
         // Iterate through the rest of map backwards.
         // Do not double check first entry.
         HValue* second_entry_index =
             Add<HConstant>(SharedFunctionInfo::kSecondEntryIndex);
         IfBuilder restore_check(this);
-        restore_check.If<HCompareNumericAndBranch>(key, second_entry_index,
-                                                   Token::EQ);
+        restore_check.If<HCompareNumericAndBranch>(
+            slot_iterator, second_entry_index, Token::EQ);
         restore_check.Then();
         {
           // Store the unoptimized code
           BuildInstallCode(js_function, shared_info);
           loop_builder.Break();
         }
         restore_check.Else();
         {
-          HValue* keyed_minus = AddUncasted<HSub>(
-              key, shared_function_entry_length);
-          HInstruction* keyed_lookup = Add<HLoadKeyed>(optimized_map,
-              keyed_minus, static_cast<HValue*>(NULL), FAST_ELEMENTS);
+          HValue* native_context_slot = AddUncasted<HSub>(
+              slot_iterator, shared_function_entry_length);
+          HValue* osr_ast_id_slot = AddUncasted<HSub>(
+              slot_iterator, graph()->GetConstant1());

[Toon Verwaest, 2013/12/11 12:40:29]

Can you add STATIC_ASSERTs here that native_context_slot is the first entry, and
OSR_AST_ID is the last entry?

[Yang, 2013/12/11 13:11:15]

Done.

+          HInstruction* native_context_entry = Add<HLoadKeyed>(optimized_map,
+              native_context_slot, static_cast<HValue*>(NULL), FAST_ELEMENTS);
+          HInstruction* osr_ast_id_entry = Add<HLoadKeyed>(optimized_map,
+              osr_ast_id_slot, static_cast<HValue*>(NULL), FAST_ELEMENTS);
           IfBuilder done_check(this);
           done_check.If<HCompareObjectEqAndBranch>(native_context,
-                                                   keyed_lookup);
+                                                   native_context_entry);
+          done_check.AndIf<HCompareObjectEqAndBranch>(osr_ast_id_entry,
+                                                      osr_ast_id_none);
           done_check.Then();
           {
             // Hit: fetch the optimized code.
-            HValue* keyed_plus = AddUncasted<HAdd>(
-                keyed_minus, graph()->GetConstant1());
+            HValue* code_slot = AddUncasted<HAdd>(
+                native_context_slot, graph()->GetConstant1());
             HValue* code_object = Add<HLoadKeyed>(optimized_map,
-                keyed_plus, static_cast<HValue*>(NULL), FAST_ELEMENTS);
+                code_slot, static_cast<HValue*>(NULL), FAST_ELEMENTS);
             BuildInstallOptimizedCode(js_function, native_context, code_object);
 
             // Fall out of the loop
             loop_builder.Break();
           }
           done_check.Else();
           done_check.End();
         }
         restore_check.End();
       }
@@ skipping 73 matching lines @@
   return BuildUncheckedDictionaryElementLoad(receiver, key);
 }
 
 
 Handle<Code> KeyedLoadDictionaryElementStub::GenerateCode(Isolate* isolate) {
   return DoGenerateCode(isolate, this);
 }
 
 
 } }  // namespace v8::internal