Refactor polymorphic load and inline function graph construction.

src/hydrogen.cc

 // Copyright 2011 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 518 matching lines @@
 
 void HBasicBlock::FinishExit(HControlInstruction* instruction) {
   Finish(instruction);
   ClearEnvironment();
 }
 
 
 HGraph::HGraph(CompilationInfo* info)
     : HSubgraph(this),
       next_block_id_(0),
-      info_(info),
       blocks_(8),
       values_(16),
       phi_list_(NULL) {
   start_environment_ = new HEnvironment(NULL, info->scope(), info->closure());
   start_environment_->set_ast_id(info->function()->id());
 }
 
 
-bool HGraph::AllowCodeMotion() const {
-  return info()->shared_info()->opt_count() + 1 < Compiler::kDefaultMaxOptCount;
-}
-
-
-Handle<Code> HGraph::Compile() {
+Handle<Code> HGraph::Compile(CompilationInfo* info) {
   int values = GetMaximumValueID();
   if (values > LAllocator::max_initial_value_ids()) {
     if (FLAG_trace_bailout) PrintF("Function is too big\n");
     return Handle<Code>::null();
   }
 
   LAllocator allocator(values, this);
-  LChunkBuilder builder(this, &allocator);
+  LChunkBuilder builder(info, this, &allocator);
   LChunk* chunk = builder.Build();
   if (chunk == NULL) return Handle<Code>::null();
 
   if (!FLAG_alloc_lithium) return Handle<Code>::null();
 
   allocator.Allocate(chunk);
 
   if (!FLAG_use_lithium) return Handle<Code>::null();
 
   MacroAssembler assembler(NULL, 0);
-  LCodeGen generator(chunk, &assembler, info());
+  LCodeGen generator(chunk, &assembler, info);
 
   if (FLAG_eliminate_empty_blocks) {
     chunk->MarkEmptyBlocks();
   }
 
   if (generator.GenerateCode()) {
     if (FLAG_trace_codegen) {
       PrintF("Crankshaft Compiler - ");
     }
-    CodeGenerator::MakeCodePrologue(info());
+    CodeGenerator::MakeCodePrologue(info);
     Code::Flags flags =
         Code::ComputeFlags(Code::OPTIMIZED_FUNCTION, NOT_IN_LOOP);
     Handle<Code> code =
-        CodeGenerator::MakeCodeEpilogue(&assembler, flags, info());
+        CodeGenerator::MakeCodeEpilogue(&assembler, flags, info);
     generator.FinishCode(code);
-    CodeGenerator::PrintCode(code, info());
+    CodeGenerator::PrintCode(code, info);
     return code;
   }
   return Handle<Code>::null();
 }
 
 
 HBasicBlock* HGraph::CreateBasicBlock() {
   HBasicBlock* result = new HBasicBlock(this);
   blocks_.Add(result);
   return result;
@@ skipping 570 matching lines @@
       HGoto::cast(instr)->set_include_stack_check(false);
       return;
     }
     instr = instr->next();
   }
 }
 
 
 class HGlobalValueNumberer BASE_EMBEDDED {
  public:
-  explicit HGlobalValueNumberer(HGraph* graph)
+  explicit HGlobalValueNumberer(HGraph* graph, CompilationInfo* info)
       : graph_(graph),
+        info_(info),
         block_side_effects_(graph_->blocks()->length()),
         loop_side_effects_(graph_->blocks()->length()) {
     ASSERT(Heap::allow_allocation(false));
     block_side_effects_.AddBlock(0, graph_->blocks()->length());
     loop_side_effects_.AddBlock(0, graph_->blocks()->length());
   }
   ~HGlobalValueNumberer() {
     ASSERT(!Heap::allow_allocation(true));
   }
 
   void Analyze();
 
  private:
   void AnalyzeBlock(HBasicBlock* block, HValueMap* map);
   void ComputeBlockSideEffects();
   void LoopInvariantCodeMotion();
   void ProcessLoopBlock(HBasicBlock* block,
                         HBasicBlock* before_loop,
                         int loop_kills);
+  bool AllowCodeMotion();
   bool ShouldMove(HInstruction* instr, HBasicBlock* loop_header);
 
+  HGraph* graph() { return graph_; }
+  CompilationInfo* info() { return info_; }
+
   HGraph* graph_;
+  CompilationInfo* info_;
 
   // A map of block IDs to their side effects.
   ZoneList<int> block_side_effects_;
 
   // A map of loop header block IDs to their loop's side effects.
   ZoneList<int> loop_side_effects_;
 };
 
 
 void HGlobalValueNumberer::Analyze() {
@@ skipping 80 matching lines @@
         // Move the instruction out of the loop.
         instr->Unlink();
         instr->InsertBefore(pre_header->end());
       }
     }
     instr = next;
   }
 }
 
 
+bool HGlobalValueNumberer::AllowCodeMotion() {
+  return info()->shared_info()->opt_count() + 1 < Compiler::kDefaultMaxOptCount;
+}
+
+
 bool HGlobalValueNumberer::ShouldMove(HInstruction* instr,
                                       HBasicBlock* loop_header) {
   // If we've disabled code motion, don't move any instructions.
-  if (!graph_->AllowCodeMotion()) return false;
+  if (!AllowCodeMotion()) return false;
 
   // If --aggressive-loop-invariant-motion, move everything except change
   // instructions.
   if (FLAG_aggressive_loop_invariant_motion && !instr->IsChange()) {
     return true;
   }
 
   // Otherwise only move instructions that postdominate the loop header
   // (i.e. are always executed inside the loop). This is to avoid
   // unnecessary deoptimizations assuming the loop is executed at least
@@ skipping 524 matching lines @@
           ASSERT(visited.IsEmpty());
           PropagateMinusZeroChecks(change->value(), &visited);
           visited.Clear();
         }
       }
     }
   }
 }
 
 
+// Implementation of utility class to encapsulate the translation state for
+// a (possibly inlined) function.
+FunctionState::FunctionState(HGraphBuilder* owner,
+                             CompilationInfo* info,
+                             TypeFeedbackOracle* oracle)
+    : owner_(owner),
+      compilation_info_(info),
+      oracle_(oracle),
+      call_context_(NULL),
+      function_return_(NULL),
+      test_context_(NULL),
+      outer_(owner->function_state()) {
+  if (outer_ != NULL) {
+    // State for an inline function.
+    if (owner->ast_context()->IsTest()) {
+      HBasicBlock* if_true = owner->graph()->CreateBasicBlock();
+      HBasicBlock* if_false = owner->graph()->CreateBasicBlock();
+      if_true->MarkAsInlineReturnTarget();
+      if_false->MarkAsInlineReturnTarget();
+      // The AstContext constructor pushed on the context stack.  This newed
+      // instance is the reason that AstContext can't be BASE_EMBEDDED.
+      test_context_ = new TestContext(owner, if_true, if_false);
+    } else {
+      function_return_ = owner->graph()->CreateBasicBlock();
+      function_return()->MarkAsInlineReturnTarget();
+    }
+    // Set this after possibly allocating a new TestContext above.
+    call_context_ = owner->ast_context();
+  }
+
+  // Push on the state stack.
+  owner->set_function_state(this);
+}
+
+
+FunctionState::~FunctionState() {
+  delete test_context_;
+  owner_->set_function_state(outer_);
+}
+
+
 // Implementation of utility classes to represent an expression's context in
 // the AST.
 AstContext::AstContext(HGraphBuilder* owner, Expression::Context kind)
     : owner_(owner), kind_(kind), outer_(owner->ast_context()) {
   owner->set_ast_context(this);  // Push.
 #ifdef DEBUG
   original_length_ = owner->environment()->length();
 #endif
 }
 
@@ skipping 150 matching lines @@
 
  private:
   HGraphBuilder* builder_;
   HSubgraph* old_subgraph_;
   HSubgraph* subgraph_;
 };
 
 
 void HGraphBuilder::Bailout(const char* reason) {
   if (FLAG_trace_bailout) {
-    SmartPointer<char> debug_name = graph()->debug_name()->ToCString();
-    PrintF("Bailout in HGraphBuilder: @\"%s\": %s\n", *debug_name, reason);
+    SmartPointer<char> name(info()->shared_info()->DebugName()->ToCString());
+    PrintF("Bailout in HGraphBuilder: @\"%s\": %s\n", *name, reason);
   }
   SetStackOverflow();
 }
 
 
 void HGraphBuilder::VisitForEffect(Expression* expr) {
   EffectContext for_effect(this);
   Visit(expr);
 }
 
@@ skipping 26 matching lines @@
 }
 
 
 void HGraphBuilder::VisitExpressions(ZoneList<Expression*>* exprs) {
   for (int i = 0; i < exprs->length(); ++i) {
     VISIT_FOR_VALUE(exprs->at(i));
   }
 }
 
 
-HGraph* HGraphBuilder::CreateGraph(CompilationInfo* info) {
+HGraph* HGraphBuilder::CreateGraph() {
   ASSERT(subgraph() == NULL);
-  graph_ = new HGraph(info);
+  graph_ = new HGraph(info());
 
   {
     HPhase phase("Block building");
     graph()->Initialize(CreateBasicBlock(graph()->start_environment()));
     current_subgraph_ = graph();
 
-    Scope* scope = info->scope();
+    Scope* scope = info()->scope();
     if (scope->HasIllegalRedeclaration()) {
       Bailout("function with illegal redeclaration");
       return NULL;
     }
     SetupScope(scope);
     VisitDeclarations(scope->declarations());
     AddInstruction(new HStackCheck());
 
     // Add an edge to the body entry.  This is warty: the graph's start
     // environment will be used by the Lithium translation as the initial
     // environment on graph entry, but it has now been mutated by the
     // Hydrogen translation of the instructions in the start block.  This
     // environment uses values which have not been defined yet.  These
     // Hydrogen instructions will then be replayed by the Lithium
     // translation, so they cannot have an environment effect.  The edge to
     // the body's entry block (along with some special logic for the start
     // block in HInstruction::InsertAfter) seals the start block from
     // getting unwanted instructions inserted.
     //
     // TODO(kmillikin): Fix this.  Stop mutating the initial environment.
     // Make the Hydrogen instructions in the initial block into Hydrogen
     // values (but not instructions), present in the initial environment and
     // not replayed by the Lithium translation.
     HEnvironment* initial_env = environment()->CopyWithoutHistory();
     HBasicBlock* body_entry = CreateBasicBlock(initial_env);
     current_block()->Goto(body_entry);
-    body_entry->SetJoinId(info->function()->id());
+    body_entry->SetJoinId(info()->function()->id());
     set_current_block(body_entry);
-    VisitStatements(info->function()->body());
+    VisitStatements(info()->function()->body());
     if (HasStackOverflow()) return NULL;
 
     if (current_block() != NULL) {
       HReturn* instr = new HReturn(graph()->GetConstantUndefined());
       current_block()->FinishExit(instr);
       set_current_block(NULL);
     }
   }
 
   graph()->OrderBlocks();
@@ skipping 17 matching lines @@
   graph()->InsertRepresentationChanges();
   graph()->ComputeMinusZeroChecks();
 
   // Eliminate redundant stack checks on backwards branches.
   HStackCheckEliminator sce(graph());
   sce.Process();
 
   // Perform common subexpression elimination and loop-invariant code motion.
   if (FLAG_use_gvn) {
     HPhase phase("Global value numbering", graph());
-    HGlobalValueNumberer gvn(graph());
+    HGlobalValueNumberer gvn(graph(), info());
     gvn.Analyze();
   }
 
   return graph();
 }
 
 
 void HGraphBuilder::AddToSubgraph(HSubgraph* graph, Statement* stmt) {
   SubgraphScope scope(this, graph);
   Visit(stmt);
@@ skipping 260 matching lines @@
       HValue* return_value = NULL;
       if (context->IsEffect()) {
         VISIT_FOR_EFFECT(stmt->expression());
         return_value = graph()->GetConstantUndefined();
       } else {
         ASSERT(context->IsValue());
         VISIT_FOR_VALUE(stmt->expression());
         return_value = environment()->Pop();
       }
       current_block()->AddLeaveInlined(return_value,
-                                       function_return_);
+                                       function_return());
       set_current_block(NULL);
     }
   }
 }
 
 
 void HGraphBuilder::VisitWithEnterStatement(WithEnterStatement* stmt) {
   BAILOUT("WithEnterStatement");
 }
 
@@ skipping 163 matching lines @@
     last_false_block->Finish(new HGoto(single_exit_block));
   }
 
   if (single_exit_block->HasPredecessor()) {
     set_current_block(single_exit_block);
   } else {
     set_current_block(NULL);
   }
 }
 
-bool HGraph::HasOsrEntryAt(IterationStatement* statement) {
+bool HGraphBuilder::HasOsrEntryAt(IterationStatement* statement) {
   return statement->OsrEntryId() == info()->osr_ast_id();
 }
 
 
 void HGraphBuilder::PreProcessOsrEntry(IterationStatement* statement) {
-  if (!graph()->HasOsrEntryAt(statement)) return;
+  if (!HasOsrEntryAt(statement)) return;
 
   HBasicBlock* non_osr_entry = graph()->CreateBasicBlock();
   HBasicBlock* osr_entry = graph()->CreateBasicBlock();
   HValue* true_value = graph()->GetConstantTrue();
   HTest* test = new HTest(true_value, non_osr_entry, osr_entry);
   current_block()->Finish(test);
 
   HBasicBlock* loop_predecessor = graph()->CreateBasicBlock();
   non_osr_entry->Goto(loop_predecessor);
 
@@ skipping 146 matching lines @@
 }
 
 
 void HGraphBuilder::VisitDebuggerStatement(DebuggerStatement* stmt) {
   BAILOUT("DebuggerStatement");
 }
 
 
 void HGraphBuilder::VisitFunctionLiteral(FunctionLiteral* expr) {
   Handle<SharedFunctionInfo> shared_info =
-      Compiler::BuildFunctionInfo(expr, graph_->info()->script());
+      Compiler::BuildFunctionInfo(expr, info()->script());
   CHECK_BAILOUT;
   HFunctionLiteral* instr =
       new HFunctionLiteral(shared_info, expr->pretenure());
   ast_context()->ReturnInstruction(instr, expr->id());
 }
 
 
 void HGraphBuilder::VisitSharedFunctionInfoLiteral(
     SharedFunctionInfoLiteral* expr) {
   BAILOUT("SharedFunctionInfoLiteral");
@@ skipping 21 matching lines @@
   ast_context()->ReturnValue(Pop());
 }
 
 
 void HGraphBuilder::LookupGlobalPropertyCell(Variable* var,
                                              LookupResult* lookup,
                                              bool is_store) {
   if (var->is_this()) {
     BAILOUT("global this reference");
   }
-  if (!graph()->info()->has_global_object()) {
+  if (!info()->has_global_object()) {
     BAILOUT("no global object to optimize VariableProxy");
   }
-  Handle<GlobalObject> global(graph()->info()->global_object());
+  Handle<GlobalObject> global(info()->global_object());
   global->Lookup(*var->name(), lookup);
   if (!lookup->IsProperty()) {
     BAILOUT("global variable cell not yet introduced");
   }
   if (lookup->type() != NORMAL) {
     BAILOUT("global variable has accessors");
   }
   if (is_store && lookup->IsReadOnly()) {
     BAILOUT("read-only global variable");
   }
   if (lookup->holder() != *global) {
     BAILOUT("global property on prototype of global object");
   }
 }
 
 
 HValue* HGraphBuilder::BuildContextChainWalk(Variable* var) {
   ASSERT(var->IsContextSlot());
   HInstruction* context = new HContext;
   AddInstruction(context);
-  int length = graph()->info()->scope()->ContextChainLength(var->scope());
+  int length = info()->scope()->ContextChainLength(var->scope());
   while (length-- > 0) {
     context = new HOuterContext(context);
     AddInstruction(context);
   }
   return context;
 }
 
 
 void HGraphBuilder::VisitVariableProxy(VariableProxy* expr) {
   Variable* variable = expr->AsVariable();
@@ skipping 10 matching lines @@
     }
     HValue* context = BuildContextChainWalk(variable);
     int index = variable->AsSlot()->index();
     HLoadContextSlot* instr = new HLoadContextSlot(context, index);
     ast_context()->ReturnInstruction(instr, expr->id());
   } else if (variable->is_global()) {
     LookupResult lookup;
     LookupGlobalPropertyCell(variable, &lookup, false);
     CHECK_BAILOUT;
 
-    Handle<GlobalObject> global(graph()->info()->global_object());
+    Handle<GlobalObject> global(info()->global_object());
     // TODO(3039103): Handle global property load through an IC call when access
     // checks are enabled.
     if (global->IsAccessCheckNeeded()) {
       BAILOUT("global object requires access check");
     }
     Handle<JSGlobalPropertyCell> cell(global->GetPropertyCell(&lookup));
     bool check_hole = !lookup.IsDontDelete() || lookup.IsReadOnly();
     HLoadGlobal* instr = new HLoadGlobal(cell, check_hole);
     ast_context()->ReturnInstruction(instr, expr->id());
   } else {
@@ skipping 249 matching lines @@
                              true)  // Needs smi and map check.
       : BuildStoreNamedGeneric(object, name, value);
 }
 
 
 void HGraphBuilder::HandlePolymorphicStoreNamedField(Assignment* expr,
                                                      HValue* object,
                                                      HValue* value,
                                                      ZoneMapList* types,
                                                      Handle<String> name) {
+  // 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;
     if (ComputeStoredField(map, name, &lookup)) {
-      ++count;
-      if (join == NULL) {
+      if (count == 0) {
         AddInstruction(new HCheckNonSmi(object));  // Only needed once.
         join = graph()->CreateBasicBlock();
       }
+      ++count;
       HBasicBlock* if_true = graph()->CreateBasicBlock();
       HBasicBlock* if_false = graph()->CreateBasicBlock();
       HCompareMap* compare = new HCompareMap(object, map, if_true, if_false);
       current_block()->Finish(compare);
 
       set_current_block(if_true);
       HInstruction* instr =
           BuildStoreNamedField(object, name, value, map, &lookup, false);
       instr->set_position(expr->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);
     }
   }
 
-  // Finish up.  We need a generic IC if there were types we couldn't
-  // resolve statically or if we want to handle maps we've never seen.
-  if (count < types->length() || !FLAG_deoptimize_uncommon_cases) {
+  // 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) {

[fschneider, 2011/03/07 11:29:47]

Remove extra space.

+    current_block()->FinishExit(new HDeoptimize);
+  } else {
     HInstruction* instr = BuildStoreNamedGeneric(object, name, value);
     instr->set_position(expr->position());
     AddInstruction(instr);
 
-    if (join == NULL) {
+    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->HasSideEffects()) {

[fschneider, 2011/03/07 11:29:47]

HasSideEffects() is always true for HStoreNamedGeneric.

[Kevin Millikin (Chromium), 2011/03/07 11:51:52]

But this code shouldn't rely on assuming the type returned by the
BuildStoreNamedGeneric helper, or assume a property of that instruction.

Eventually I'll get rid of HGraphBuilder::AddSimulate and have AddInstruction or
else the constructor responsible for capturing the environment.  Until then and
since things are changing, it seems nicer to assume as little as possible.

         if (ast_context()->IsEffect()) {
           AddSimulate(expr->id());
         } else {
           Push(value);
           AddSimulate(expr->id());
           Drop(1);
         }
       }
       ast_context()->ReturnValue(value);
-    } else {
-      if (!ast_context()->IsEffect()) Push(value);
-      current_block()->Goto(join);
-      join->SetJoinId(expr->id());
-      set_current_block(join);
-      if (!ast_context()->IsEffect()) ast_context()->ReturnValue(Pop());
-    }
-
-  } else {
-    current_block()->FinishExit(new HDeoptimize);
-    set_current_block(join);
-    if (join != NULL) {
-      join->SetJoinId(expr->id());
-      if (!ast_context()->IsEffect()) ast_context()->ReturnValue(Pop());
+      return;
     }
   }
+
+  ASSERT(join != NULL);
+  join->SetJoinId(expr->id());
+  set_current_block(join);
+  if (!ast_context()->IsEffect()) ast_context()->ReturnValue(Pop());
 }
 
 
 void HGraphBuilder::HandlePropertyAssignment(Assignment* expr) {
   Property* prop = expr->target()->AsProperty();
   ASSERT(prop != NULL);
   expr->RecordTypeFeedback(oracle());
   VISIT_FOR_VALUE(prop->obj());
 
   HValue* value = NULL;
@@ skipping 60 matching lines @@
 // owning expression instead of position and ast_id separately.
 void HGraphBuilder::HandleGlobalVariableAssignment(Variable* var,
                                                    HValue* value,
                                                    int position,
                                                    int ast_id) {
   LookupResult lookup;
   LookupGlobalPropertyCell(var, &lookup, true);
   CHECK_BAILOUT;
 
   bool check_hole = !lookup.IsDontDelete() || lookup.IsReadOnly();
-  Handle<GlobalObject> global(graph()->info()->global_object());
+  Handle<GlobalObject> global(info()->global_object());
   Handle<JSGlobalPropertyCell> cell(global->GetPropertyCell(&lookup));
   HInstruction* instr = new HStoreGlobal(value, cell, check_hole);
   instr->set_position(position);
   AddInstruction(instr);
   if (instr->HasSideEffects()) AddSimulate(ast_id);
 }
 
 
 void HGraphBuilder::HandleCompoundAssignment(Assignment* expr) {
   Expression* target = expr->target();
@@ skipping 177 matching lines @@
   AddSimulate(expr->id());
   current_block()->FinishExit(new HAbnormalExit);
   set_current_block(NULL);
 }
 
 
 void HGraphBuilder::HandlePolymorphicLoadNamedField(Property* expr,
                                                     HValue* object,
                                                     ZoneMapList* types,
                                                     Handle<String> name) {
-  int number_of_types = Min(types->length(), kMaxLoadPolymorphism);
-  ZoneMapList maps(number_of_types);
-  ZoneList<HSubgraph*> subgraphs(number_of_types);
-  bool needs_generic = (types->length() > kMaxLoadPolymorphism);
-
-  // Build subgraphs for each of the specific maps.
-  //
-  // 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.
-  for (int i = 0; i < number_of_types; ++i) {
+  // 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 < kMaxLoadPolymorphism; ++i) {
     Handle<Map> map = types->at(i);
     LookupResult lookup;
     map->LookupInDescriptors(NULL, *name, &lookup);
     if (lookup.IsProperty() && lookup.type() == FIELD) {
-      HSubgraph* subgraph = CreateBranchSubgraph(environment());
-      SubgraphScope scope(this, subgraph);
+      if (count == 0) {
+        AddInstruction(new HCheckNonSmi(object));  // Only needed once.
+        join = graph()->CreateBasicBlock();
+      }
+      ++count;
+      HBasicBlock* if_true = graph()->CreateBasicBlock();
+      HBasicBlock* if_false = graph()->CreateBasicBlock();
+      HCompareMap* compare = new HCompareMap(object, map, if_true, if_false);
+      current_block()->Finish(compare);
+
+      set_current_block(if_true);
       HLoadNamedField* instr =
           BuildLoadNamedField(object, expr, map, &lookup, false);
       instr->set_position(expr->position());
-      instr->ClearFlag(HValue::kUseGVN);  // Don't do GVN on polymorphic loads.
-      PushAndAdd(instr);
-      maps.Add(map);
-      subgraphs.Add(subgraph);
+      instr->ClearFlag(HValue::kUseGVN);
+      AddInstruction(instr);
+      if (!ast_context()->IsEffect()) Push(instr);
+      current_block()->Goto(join);
+
+      set_current_block(if_false);
+     }

[fschneider, 2011/03/07 11:29:47]

Remove extra space.

[Kevin Millikin (Chromium), 2011/03/07 11:51:52]

Thanks.

+  }
+
+  // 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()->FinishExit(new HDeoptimize);
+  } else {
+    HInstruction* instr = BuildLoadNamedGeneric(object, expr);
+    instr->set_position(expr->position());
+
+    if (join != NULL) {
+      AddInstruction(instr);
+      if (!ast_context()->IsEffect()) Push(instr);
+      current_block()->Goto(join);
     } else {
-      needs_generic = true;
+      ast_context()->ReturnInstruction(instr, expr->id());
+      return;
     }
   }
 
-  // If none of the properties were named fields we generate a
-  // generic load.
-  if (maps.length() == 0) {
-    HInstruction* instr = BuildLoadNamedGeneric(object, expr);
-    instr->set_position(expr->position());
-    ast_context()->ReturnInstruction(instr, expr->id());
-  } else {
-    // Build subgraph for generic load through IC.
-    HSubgraph* default_graph = CreateBranchSubgraph(environment());
-    { SubgraphScope scope(this, default_graph);
-      if (!needs_generic && FLAG_deoptimize_uncommon_cases) {
-        default_graph->exit_block()->FinishExit(new HDeoptimize());
-        default_graph->set_exit_block(NULL);
-      } else {
-        HInstruction* instr = BuildLoadNamedGeneric(object, expr);
-        instr->set_position(expr->position());
-        PushAndAdd(instr);
-      }
-    }
-
-    HBasicBlock* new_exit_block =
-        BuildTypeSwitch(object, &maps, &subgraphs, default_graph, expr->id());
-    set_current_block(new_exit_block);
-    // In an effect context, we did not materialized the value in the
-    // predecessor environments so there's no need to handle it here.
-    if (current_block() != NULL && !ast_context()->IsEffect()) {
-      ast_context()->ReturnValue(Pop());
-    }
-  }
+  ASSERT(join != NULL);
+  join->SetJoinId(expr->id());
+  set_current_block(join);
+  if (!ast_context()->IsEffect()) ast_context()->ReturnValue(Pop());
 }
 
 
 HLoadNamedField* HGraphBuilder::BuildLoadNamedField(HValue* object,
                                                     Property* expr,
                                                     Handle<Map> type,
                                                     LookupResult* lookup,
                                                     bool smi_and_map_check) {
   if (smi_and_map_check) {
     AddInstruction(new HCheckNonSmi(object));
@@ skipping 347 matching lines @@
     set_current_block(new_exit_block);
     // In an effect context, we did not materialized the value in the
     // predecessor environments so there's no need to handle it here.
     if (new_exit_block != NULL && !ast_context()->IsEffect()) {
       ast_context()->ReturnValue(Pop());
     }
   }
 }
 
 
-void HGraphBuilder::TraceInline(Handle<JSFunction> target, bool result) {
-  SmartPointer<char> callee = target->shared()->DebugName()->ToCString();
-  SmartPointer<char> caller =
-      graph()->info()->function()->debug_name()->ToCString();
-  if (result) {
-    PrintF("Inlined %s called from %s.\n", *callee, *caller);
-  } else {
-    PrintF("Do not inline %s called from %s.\n", *callee, *caller);
+void HGraphBuilder::TraceInline(Handle<JSFunction> target, const char* reason) {
+  if (FLAG_trace_inlining) {
+    SmartPointer<char> callee = target->shared()->DebugName()->ToCString();
+    SmartPointer<char> caller =
+        info()->function()->debug_name()->ToCString();
+    if (reason == NULL) {
+      PrintF("Inlined %s called from %s.\n", *callee, *caller);
+    } else {
+      PrintF("Did not inline %s called from %s (%s).\n",
+             *callee, *caller, reason);
+    }
   }
 }
 
 
 bool HGraphBuilder::TryInline(Call* expr) {
   if (!FLAG_use_inlining) return false;
 
   // Precondition: call is monomorphic and we have found a target with the
   // appropriate arity.
   Handle<JSFunction> target = expr->target();
 
   // Do a quick check on source code length to avoid parsing large
   // inlining candidates.
   if (FLAG_limit_inlining && target->shared()->SourceSize() > kMaxSourceSize) {
-    if (FLAG_trace_inlining) TraceInline(target, false);
+    TraceInline(target, "target text too big");
     return false;
   }
 
   // Target must be inlineable.
-  if (!target->IsInlineable()) return false;
+  if (!target->IsInlineable()) {
+    TraceInline(target, "target not inlineable");
+    return false;
+  }
 
   // No context change required.
-  CompilationInfo* outer_info = graph()->info();
+  CompilationInfo* outer_info = info();
   if (target->context() != outer_info->closure()->context() ||
       outer_info->scope()->contains_with() ||
       outer_info->scope()->num_heap_slots() > 0) {
+    TraceInline(target, "target requires context change");
     return false;
   }
 
   // Don't inline deeper than two calls.
   HEnvironment* env = environment();
-  if (env->outer() != NULL && env->outer()->outer() != NULL) return false;
+  if (env->outer() != NULL && env->outer()->outer() != NULL) {
+    TraceInline(target, "inline depth limit reached");
+    return false;
+  }
 
   // Don't inline recursive functions.
-  if (target->shared() == outer_info->closure()->shared()) return false;
+  if (target->shared() == outer_info->closure()->shared()) {
+    TraceInline(target, "target is recursive");
+    return false;
+  }
 
   // We don't want to add more than a certain number of nodes from inlining.
   if (FLAG_limit_inlining && inlined_count_ > kMaxInlinedNodes) {
-    if (FLAG_trace_inlining) TraceInline(target, false);
+    TraceInline(target, "cumulative AST node limit reached");
     return false;
   }
 
   int count_before = AstNode::Count();
 
   // Parse and allocate variables.
-  CompilationInfo inner_info(target);
-  if (!ParserApi::Parse(&inner_info) ||
-      !Scope::Analyze(&inner_info)) {
+  CompilationInfo target_info(target);
+  if (!ParserApi::Parse(&target_info) ||
+      !Scope::Analyze(&target_info)) {
     if (Top::has_pending_exception()) {
+      // Parse or scope error, never optimize this function.
       SetStackOverflow();
-      // Stop trying to optimize and inline this function.
       target->shared()->set_optimization_disabled(true);
     }
+    TraceInline(target, "parse failure");
     return false;
   }
-  if (inner_info.scope()->num_heap_slots() > 0) return false;
-  FunctionLiteral* function = inner_info.function();
+
+  if (target_info.scope()->num_heap_slots() > 0) {
+    TraceInline(target, "target has context-allocated variables");
+    return false;
+  }
+  FunctionLiteral* function = target_info.function();
 
   // Count the number of AST nodes added by inlining this call.
   int nodes_added = AstNode::Count() - count_before;
   if (FLAG_limit_inlining && nodes_added > kMaxInlinedSize) {
-    if (FLAG_trace_inlining) TraceInline(target, false);
+    TraceInline(target, "target AST is too large");
     return false;
   }
 
   // Check if we can handle all declarations in the inlined functions.
-  VisitDeclarations(inner_info.scope()->declarations());
+  VisitDeclarations(target_info.scope()->declarations());
   if (HasStackOverflow()) {
+    TraceInline(target, "target has non-trivial declaration");
     ClearStackOverflow();
     return false;
   }
 
   // Don't inline functions that uses the arguments object or that
   // have a mismatching number of parameters.
-  Handle<SharedFunctionInfo> shared(target->shared());
+  Handle<SharedFunctionInfo> target_shared(target->shared());
   int arity = expr->arguments()->length();
   if (function->scope()->arguments() != NULL ||
-      arity != shared->formal_parameter_count()) {
+      arity != target_shared->formal_parameter_count()) {
+    TraceInline(target, "target requires special argument handling");
     return false;
   }
 
   // All statements in the body must be inlineable.
   for (int i = 0, count = function->body()->length(); i < count; ++i) {
-    if (!function->body()->at(i)->IsInlineable()) return false;
+    if (!function->body()->at(i)->IsInlineable()) {
+      TraceInline(target, "target contains unsupported syntax");
+      return false;
+    }
   }
 
   // Generate the deoptimization data for the unoptimized version of
   // the target function if we don't already have it.
-  if (!shared->has_deoptimization_support()) {
+  if (!target_shared->has_deoptimization_support()) {
     // Note that we compile here using the same AST that we will use for
     // generating the optimized inline code.
-    inner_info.EnableDeoptimizationSupport();
-    if (!FullCodeGenerator::MakeCode(&inner_info)) return false;
-    shared->EnableDeoptimizationSupport(*inner_info.code());
-    Compiler::RecordFunctionCompilation(
-        Logger::FUNCTION_TAG, &inner_info, shared);
+    target_info.EnableDeoptimizationSupport();
+    if (!FullCodeGenerator::MakeCode(&target_info)) {
+      TraceInline(target, "could not generate deoptimization info");
+      return false;
+    }
+    target_shared->EnableDeoptimizationSupport(*target_info.code());
+    Compiler::RecordFunctionCompilation(Logger::FUNCTION_TAG,
+                                        &target_info,
+                                        target_shared);
   }
 
+  // ----------------------------------------------------------------
   // Save the pending call context and type feedback oracle. Set up new ones
   // for the inlined function.
-  ASSERT(shared->has_deoptimization_support());
-  AstContext* saved_call_context = call_context();
-  HBasicBlock* saved_function_return = function_return();
-  TypeFeedbackOracle* saved_oracle = oracle();
-  // On-stack replacement cannot target inlined functions.  Since we don't
-  // use a separate CompilationInfo structure for the inlined function, we
-  // save and restore the AST ID in the original compilation info.
-  int saved_osr_ast_id = graph()->info()->osr_ast_id();
-
-  TestContext* test_context = NULL;
-  if (ast_context()->IsTest()) {
-    // Inlined body is treated as if it occurs in an 'inlined' call context
-    // with true and false blocks that will forward to the real ones.
-    HBasicBlock* if_true = graph()->CreateBasicBlock();
-    HBasicBlock* if_false = graph()->CreateBasicBlock();
-    if_true->MarkAsInlineReturnTarget();
-    if_false->MarkAsInlineReturnTarget();
-    // AstContext constructor pushes on the context stack.
-    test_context = new TestContext(this, if_true, if_false);
-    function_return_ = NULL;
-  } else {
-    // Inlined body is treated as if it occurs in the original call context.
-    function_return_ = graph()->CreateBasicBlock();
-    function_return_->MarkAsInlineReturnTarget();
-  }
-  call_context_ = ast_context();
-  TypeFeedbackOracle new_oracle(
-      Handle<Code>(shared->code()),
+  ASSERT(target_shared->has_deoptimization_support());
+  TypeFeedbackOracle target_oracle(
+      Handle<Code>(target_shared->code()),
       Handle<Context>(target->context()->global_context()));
-  oracle_ = &new_oracle;
-  graph()->info()->SetOsrAstId(AstNode::kNoNumber);
+  FunctionState target_state(this, &target_info, &target_oracle);
 
   HSubgraph* body = CreateInlinedSubgraph(env, target, function);
   body->exit_block()->AddInstruction(new HEnterInlined(target, function));
   AddToSubgraph(body, function->body());
   if (HasStackOverflow()) {
     // Bail out if the inline function did, as we cannot residualize a call
     // instead.
-    delete test_context;
-    call_context_ = saved_call_context;
-    function_return_ = saved_function_return;
-    oracle_ = saved_oracle;
-    graph()->info()->SetOsrAstId(saved_osr_ast_id);
+    TraceInline(target, "inline graph construction failed");
     return false;
   }
 
   // Update inlined nodes count.
   inlined_count_ += nodes_added;
 
-  if (FLAG_trace_inlining) TraceInline(target, true);
+  TraceInline(target, NULL);
 
   if (body->exit_block() != NULL) {
     // Add a return of undefined if control can fall off the body.  In a
     // test context, undefined is false.
     HValue* return_value = graph()->GetConstantUndefined();
-    if (test_context == NULL) {
-      ASSERT(function_return_ != NULL);
-      body->exit_block()->AddLeaveInlined(return_value, function_return_);
+    if (inlined_test_context() == NULL) {
+      ASSERT(function_return() != NULL);
+      body->exit_block()->AddLeaveInlined(return_value, function_return());
     } else {
       // The graph builder assumes control can reach both branches of a
       // test, so we materialize the undefined value and test it rather than
       // simply jumping to the false target.
       //
       // TODO(3168478): refactor to avoid this.
       HBasicBlock* empty_true = graph()->CreateBasicBlock();
       HBasicBlock* empty_false = graph()->CreateBasicBlock();
       HTest* test = new HTest(return_value, empty_true, empty_false);
       body->exit_block()->Finish(test);
 
       HValue* const no_return_value = NULL;
-      empty_true->AddLeaveInlined(no_return_value, test_context->if_true());
-      empty_false->AddLeaveInlined(no_return_value, test_context->if_false());
+      empty_true->AddLeaveInlined(no_return_value,
+                                  inlined_test_context()->if_true());
+      empty_false->AddLeaveInlined(no_return_value,
+                                   inlined_test_context()->if_false());
     }
     body->set_exit_block(NULL);
   }
 
   // Record the environment at the inlined function call.
   AddSimulate(expr->ReturnId());
 
   // Jump to the function entry (without re-recording the environment).
   current_block()->Finish(new HGoto(body->entry_block()));
 
   // Fix up the function exits.
-  if (test_context != NULL) {
-    HBasicBlock* if_true = test_context->if_true();
-    HBasicBlock* if_false = test_context->if_false();
+  if (inlined_test_context() != NULL) {
+    HBasicBlock* if_true = inlined_test_context()->if_true();
+    HBasicBlock* if_false = inlined_test_context()->if_false();
     if_true->SetJoinId(expr->id());
     if_false->SetJoinId(expr->id());
-    ASSERT(ast_context() == test_context);
-    delete test_context;  // Destructor pops from expression context stack.
+    ASSERT(ast_context() == inlined_test_context());
+    // Pop the return test context from the expression context stack.
+    ClearInlinedTestContext();
 
     // Forward to the real test context.
     HValue* const no_return_value = NULL;
     HBasicBlock* true_target = TestContext::cast(ast_context())->if_true();
     if (true_target->IsInlineReturnTarget()) {
       if_true->AddLeaveInlined(no_return_value, true_target);
     } else {
       if_true->Goto(true_target);
     }
 
     HBasicBlock* false_target = TestContext::cast(ast_context())->if_false();
     if (false_target->IsInlineReturnTarget()) {
       if_false->AddLeaveInlined(no_return_value, false_target);
     } else {
       if_false->Goto(false_target);
     }
 
     // TODO(kmillikin): Come up with a better way to handle this. It is too
     // subtle. NULL here indicates that the enclosing context has no control
     // flow to handle.
     set_current_block(NULL);
 
   } else {
-    function_return_->SetJoinId(expr->id());
-    set_current_block(function_return_);
+    function_return()->SetJoinId(expr->id());
+    set_current_block(function_return());
   }
 
-  call_context_ = saved_call_context;
-  function_return_ = saved_function_return;
-  oracle_ = saved_oracle;
-  graph()->info()->SetOsrAstId(saved_osr_ast_id);
-
   return true;
 }
 
 
 void HBasicBlock::AddLeaveInlined(HValue* return_value, HBasicBlock* target) {
   ASSERT(target->IsInlineReturnTarget());
   AddInstruction(new HLeaveInlined);
   HEnvironment* outer = last_environment()->outer();
   if (return_value != NULL) outer->Push(return_value);
   UpdateEnvironment(outer);
@@ skipping 87 matching lines @@
   }
   return false;
 }
 
 
 bool HGraphBuilder::TryCallApply(Call* expr) {
   Expression* callee = expr->expression();
   Property* prop = callee->AsProperty();
   ASSERT(prop != NULL);
 
-  if (graph()->info()->scope()->arguments() == NULL) return false;
+  if (info()->scope()->arguments() == NULL) return false;
 
   Handle<String> name = prop->key()->AsLiteral()->AsPropertyName();
   if (!name->IsEqualTo(CStrVector("apply"))) return false;
 
   ZoneList<Expression*>* args = expr->arguments();
   if (args->length() != 2) return false;
 
   VariableProxy* arg_two = args->at(1)->AsVariableProxy();
   if (arg_two == NULL || !arg_two->var()->IsStackAllocated()) return false;
   HValue* arg_two_value = environment()->Lookup(arg_two->var());
@@ skipping 135 matching lines @@
 
     if (!global_call) {
       ++argument_count;
       VISIT_FOR_VALUE(expr->expression());
     }
 
     if (global_call) {
       // If there is a global property cell for the name at compile time and
       // access check is not enabled we assume that the function will not change
       // and generate optimized code for calling the function.
-      CompilationInfo* info = graph()->info();
-      bool known_global_function = info->has_global_object() &&
-          !info->global_object()->IsAccessCheckNeeded() &&
-          expr->ComputeGlobalTarget(Handle<GlobalObject>(info->global_object()),
+      bool known_global_function = info()->has_global_object() &&
+          !info()->global_object()->IsAccessCheckNeeded() &&
+          expr->ComputeGlobalTarget(Handle<GlobalObject>(info()->global_object()),
                                     var->name());
       if (known_global_function) {
         // Push the global object instead of the global receiver because
         // code generated by the full code generator expects it.
         HContext* context = new HContext;
         HGlobalObject* global_object = new HGlobalObject(context);
         AddInstruction(context);
         PushAndAdd(global_object);
         VisitExpressions(expr->arguments());
         CHECK_BAILOUT;
@@ skipping 609 matching lines @@
     return;
   }
 
   VISIT_FOR_VALUE(expr->left());
   VISIT_FOR_VALUE(expr->right());
 
   HValue* right = Pop();
   HValue* left = Pop();
   Token::Value op = expr->op();
 
-  TypeInfo info = oracle()->CompareType(expr);
+  TypeInfo type_info = oracle()->CompareType(expr);
   HInstruction* instr = NULL;
   if (op == Token::INSTANCEOF) {
     // Check to see if the rhs of the instanceof is a global function not
     // residing in new space. If it is we assume that the function will stay the
     // same.
     Handle<JSFunction> target = Handle<JSFunction>::null();
     Variable* var = expr->right()->AsVariableProxy()->AsVariable();
     bool global_function = (var != NULL) && var->is_global() && !var->is_this();
-    CompilationInfo* info = graph()->info();
     if (global_function &&
-        info->has_global_object() &&
-        !info->global_object()->IsAccessCheckNeeded()) {
+        info()->has_global_object() &&
+        !info()->global_object()->IsAccessCheckNeeded()) {
       Handle<String> name = var->name();
-      Handle<GlobalObject> global(info->global_object());
+      Handle<GlobalObject> global(info()->global_object());
       LookupResult lookup;
       global->Lookup(*name, &lookup);
       if (lookup.IsProperty() &&
           lookup.type() == NORMAL &&
           lookup.GetValue()->IsJSFunction()) {
         Handle<JSFunction> candidate(JSFunction::cast(lookup.GetValue()));
         // If the function is in new space we assume it's more likely to
         // change and thus prefer the general IC code.
         if (!Heap::InNewSpace(*candidate)) {
           target = candidate;
         }
       }
     }
 
     // If the target is not null we have found a known global function that is
     // assumed to stay the same for this instanceof.
     if (target.is_null()) {
       HContext* context = new HContext;
       AddInstruction(context);
       instr = new HInstanceOf(context, left, right);
     } else {
       AddInstruction(new HCheckFunction(right, target));
       instr = new HInstanceOfKnownGlobal(left, target);
     }
   } else if (op == Token::IN) {
     BAILOUT("Unsupported comparison: in");
-  } else if (info.IsNonPrimitive()) {
+  } else if (type_info.IsNonPrimitive()) {
     switch (op) {
       case Token::EQ:
       case Token::EQ_STRICT: {
         AddInstruction(new HCheckNonSmi(left));
         AddInstruction(HCheckInstanceType::NewIsJSObjectOrJSFunction(left));
         AddInstruction(new HCheckNonSmi(right));
         AddInstruction(HCheckInstanceType::NewIsJSObjectOrJSFunction(right));
         instr = new HCompareJSObjectEq(left, right);
         break;
       }
       default:
         BAILOUT("Unsupported non-primitive compare");
         break;
     }
   } else {
     HCompare* compare = new HCompare(left, right, op);
-    Representation r = ToRepresentation(info);
+    Representation r = ToRepresentation(type_info);
     compare->SetInputRepresentation(r);
     instr = compare;
   }
   instr->set_position(expr->position());
   ast_context()->ReturnInstruction(instr, expr->id());
 }
 
 
 void HGraphBuilder::VisitCompareToNull(CompareToNull* expr) {
   VISIT_FOR_VALUE(expr->expression());
@@ skipping 892 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify();
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal