Simplify and unify PolymorphicStoreNameFeild

src/hydrogen.cc

 // Copyright 2013 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 5766 matching lines @@
       true);
   Push(value);
   store->set_position(position);
   AddInstruction(store);
   AddSimulate(assignment_id);
   ast_context()->ReturnValue(Pop());
   return true;
 }
 
 
+void HOptimizedGraphBuilder::HandlePolymorphicStoreNamedFieldHelper(
+    HValue* object,
+    Handle<String> name,
+    HValue* value,
+    SmallMapList* types,
+    int current_type,
+    int stored_count,
+    int position) {
+  HInstruction* instr = NULL;
+  if (stored_count == kMaxStorePolymorphism ||
+      (current_type == types->length() - 1)) {

[Toon Verwaest, 2013/07/08 16:49:00]

remove the - 1

+    if (FLAG_deoptimize_uncommon_cases) {
+      AddSoftDeoptimize(MUST_EMIT_SOFT_DEOPT);

[Toon Verwaest, 2013/07/08 16:49:00]

Soft deopts aren't counted towards MaxDeopt to stop attempting to optimize. We
should use a hard deopt instead.

+    } else {
+      instr = BuildStoreNamedGeneric(object, name, value);
+      instr->set_position(position);
+      AddInstruction(instr);
+    }
+    return;
+  }
+
+  Handle<Map> map = types->at(current_type);
+  LookupResult lookup(isolate());
+  if (!ComputeLoadStoreField(map, name, &lookup, true)) {
+    HandlePolymorphicStoreNamedFieldHelper(object, name, value, types,
+                                           current_type + 1, stored_count,
+                                           position);
+    return;
+  }
+
+  IfBuilder builder(this);
+  builder.If<HCompareMap>(object, map);
+
+  builder.Then();
+  CHECK_ALIVE(instr = BuildStoreNamedField(object, name, value, map, &lookup));
+  instr->set_position(position);
+  AddInstruction(instr);
+
+  builder.Else();
+  HandlePolymorphicStoreNamedFieldHelper(object, name, value, types,
+                                         current_type + 1, stored_count + 1,
+                                         position);
+  builder.End();
+}
+
+
 void HOptimizedGraphBuilder::HandlePolymorphicStoreNamedField(
     BailoutId id,
     int position,
     BailoutId assignment_id,
     HValue* object,
     HValue* value,
     SmallMapList* types,
     Handle<String> name) {
   if (TryStorePolymorphicAsMonomorphic(
           position, assignment_id, object, value, types, name)) {
     return;
   }
 
-  // TODO(ager): We should recognize when the prototype chains for different
-  // maps are identical. In that case we can avoid repeatedly generating the
-  // same prototype map checks.
-  int count = 0;
-  HBasicBlock* join = NULL;
-  for (int i = 0; i < types->length() && count < kMaxStorePolymorphism; ++i) {
-    Handle<Map> map = types->at(i);
-    LookupResult lookup(isolate());
-    if (ComputeLoadStoreField(map, name, &lookup, true)) {
-      if (count == 0) {
-        BuildCheckHeapObject(object);
-        join = graph()->CreateBasicBlock();
-      }
-      ++count;
-      HBasicBlock* if_true = graph()->CreateBasicBlock();
-      HBasicBlock* if_false = graph()->CreateBasicBlock();
-      HCompareMap* compare =
-          new(zone()) HCompareMap(object, map,  if_true, if_false);
-      current_block()->Finish(compare);
-
-      set_current_block(if_true);
-      HInstruction* instr;
-      CHECK_ALIVE(
-          instr = BuildStoreNamedField(object, name, value, map, &lookup));
-      instr->set_position(position);
-      // Goto will add the HSimulate for the store.
-      AddInstruction(instr);
-      if (!ast_context()->IsEffect()) Push(value);
-      current_block()->Goto(join);
-
-      set_current_block(if_false);
-    }
+  {
+    Add<HCheckHeapObject>(object);
+    NoObservableSideEffectsScope no_effects(this);
+    HandlePolymorphicStoreNamedFieldHelper(object, name, value, types,
+                                           0, 0, position);
   }
 
-  // Finish up.  Unconditionally deoptimize if we've handled all the maps we
-  // know about and do not want to handle ones we've never seen.  Otherwise
-  // use a generic IC.
-  if (count == types->length() && FLAG_deoptimize_uncommon_cases) {
-    current_block()->FinishExitWithDeoptimization(HDeoptimize::kNoUses);
+  if (ast_context()->IsEffect()) {
+    AddSimulate(id, REMOVABLE_SIMULATE);
   } else {
-    HInstruction* instr = BuildStoreNamedGeneric(object, name, value);
-    instr->set_position(position);
-    AddInstruction(instr);
-
-    if (join != NULL) {
-      if (!ast_context()->IsEffect()) Push(value);
-      current_block()->Goto(join);
-    } else {
-      // The HSimulate for the store should not see the stored value in
-      // effect contexts (it is not materialized at expr->id() in the
-      // unoptimized code).
-      if (instr->HasObservableSideEffects()) {
-        if (ast_context()->IsEffect()) {
-          AddSimulate(id, REMOVABLE_SIMULATE);
-        } else {
-          Push(value);
-          AddSimulate(id, REMOVABLE_SIMULATE);
-          Drop(1);
-        }
-      }
-      return ast_context()->ReturnValue(value);
-    }
+    Push(value);
+    AddSimulate(id, REMOVABLE_SIMULATE);
+    ast_context()->ReturnValue(Pop());
   }
-
-  ASSERT(join != NULL);
-  join->SetJoinId(id);
-  set_current_block(join);
-  if (!ast_context()->IsEffect()) ast_context()->ReturnValue(Pop());
 }
 
 
 void HOptimizedGraphBuilder::HandlePropertyAssignment(Assignment* expr) {
   Property* prop = expr->target()->AsProperty();
   ASSERT(prop != NULL);
   CHECK_ALIVE(VisitForValue(prop->obj()));
 
   if (prop->key()->IsPropertyName()) {
     // Named store.
@@ skipping 4959 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal