Recognize and optimize a.runtimeType == b.runtimeType pattern.

runtime/vm/precompiler.cc

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/precompiler.h"
 
 #include "vm/aot_optimizer.h"
 #include "vm/assembler.h"
 #include "vm/ast_printer.h"
 #include "vm/branch_optimizer.h"
@@ skipping 134 matching lines @@
 
  private:
   Zone* zone_;
   CompileType result_type_;
   FieldTypeMap* field_map_;
 };
 
 
 class PrecompileParsedFunctionHelper : public ValueObject {
  public:
-  PrecompileParsedFunctionHelper(ParsedFunction* parsed_function,
+  PrecompileParsedFunctionHelper(Precompiler* precompiler,
+                                 ParsedFunction* parsed_function,
                                  bool optimized)
-      : parsed_function_(parsed_function),
+      : precompiler_(precompiler),
+        parsed_function_(parsed_function),
         optimized_(optimized),
         thread_(Thread::Current()) {
   }
 
   bool Compile(CompilationPipeline* pipeline);
 
  private:
   ParsedFunction* parsed_function() const { return parsed_function_; }
   bool optimized() const { return optimized_; }
   Thread* thread() const { return thread_; }
   Isolate* isolate() const { return thread_->isolate(); }
 
   void FinalizeCompilation(Assembler* assembler,
                            FlowGraphCompiler* graph_compiler,
                            FlowGraph* flow_graph);
 
+  Precompiler* precompiler_;
   ParsedFunction* parsed_function_;
   const bool optimized_;
   Thread* const thread_;
 
   DISALLOW_COPY_AND_ASSIGN(PrecompileParsedFunctionHelper);
 };
 
 
 static void Jump(const Error& error) {
   Thread::Current()->long_jump_base()->Jump(1, error);
@@ skipping 123 matching lines @@
         GrowableObjectArray::Handle(GrowableObjectArray::New())),
     sent_selectors_(),
     enqueued_functions_(),
     fields_to_retain_(),
     functions_to_retain_(),
     classes_to_retain_(),
     typeargs_to_retain_(),
     types_to_retain_(),
     consts_to_retain_(),
     field_type_map_(),
-    error_(Error::Handle()) {
+    error_(Error::Handle()),
+    get_runtime_type_is_unique_(false) {
 }
 
 
 void Precompiler::DoCompileAll(
     Dart_QualifiedFunctionName embedder_entry_points[]) {
   ASSERT(I->compilation_allowed());
 
   {
     StackZone stack_zone(T);
     zone_ = stack_zone.GetZone();
@@ skipping 148 matching lines @@
 
   HANDLESCOPE(T);
   StaticInitializerVisitor visitor(Z);
   VisitClasses(&visitor);
 }
 
 
 void Precompiler::PrecompileConstructors() {
   class ConstructorVisitor : public FunctionVisitor {
    public:
-    explicit ConstructorVisitor(Zone* zone, FieldTypeMap* map)
-        : zone_(zone), field_type_map_(map) {
-      ASSERT(map != NULL);
+    explicit ConstructorVisitor(Precompiler* precompiler, Zone* zone)
+        : precompiler_(precompiler), zone_(zone) {
     }
     void Visit(const Function& function) {
       if (!function.IsGenerativeConstructor()) return;
       if (function.HasCode()) {
         // Const constructors may have been visited before. Recompile them here
         // to collect type information for final fields for them as well.
         function.ClearCode();
       }
       if (FLAG_trace_precompiler) {
         THR_Print("Precompiling constructor %s\n", function.ToCString());
       }
-      CompileFunction(Thread::Current(),
+      CompileFunction(precompiler_,
+                      Thread::Current(),
                       zone_,
-                      function,
-                      field_type_map_);
+                      function);
     }
+
    private:
+    Precompiler* precompiler_;
     Zone* zone_;
-    FieldTypeMap* field_type_map_;
   };
 
   HANDLESCOPE(T);
-  ConstructorVisitor visitor(zone_, &field_type_map_);
+  ConstructorVisitor visitor(this, zone_);
   VisitFunctions(&visitor);
 
   FieldTypeMap::Iterator it(field_type_map_.GetIterator());
   for (FieldTypePair* current = it.Next();
        current != NULL;
        current = it.Next()) {
     const intptr_t cid = current->cid_;
     current->field_->set_guarded_cid(cid);
     current->field_->set_is_nullable(cid == kNullCid || cid == kDynamicCid);
     if (FLAG_trace_precompiler) {
@@ skipping 267 matching lines @@
       THR_Print("Precompiling %" Pd " %s (%s, %s)\n",
                 function_count_,
                 function.ToLibNamePrefixedQualifiedCString(),
                 function.token_pos().ToCString(),
                 Function::KindToCString(function.kind()));
     }
 
     ASSERT(!function.is_abstract());
     ASSERT(!function.IsRedirectingFactory());
 
-    error_ = CompileFunction(thread_, zone_, function);
+    error_ = CompileFunction(this, thread_, zone_, function);
     if (!error_.IsNull()) {
       Jump(error_);
     }
     // Used in the JIT to save type-feedback across compilations.
     function.ClearICDataArray();
   } else {
     if (FLAG_trace_precompiler) {
       // This function was compiled from somewhere other than Precompiler,
       // such as const constructors compiled by the parser.
       THR_Print("Already has code: %s (%s, %s)\n",
@@ skipping 317 matching lines @@
 RawFunction* Precompiler::CompileStaticInitializer(const Field& field,
                                                    bool compute_type) {
   ASSERT(field.is_static());
   Thread* thread = Thread::Current();
   StackZone zone(thread);
 
   ParsedFunction* parsed_function = Parser::ParseStaticFieldInitializer(field);
 
   parsed_function->AllocateVariables();
   DartPrecompilationPipeline pipeline(zone.GetZone());
-  PrecompileParsedFunctionHelper helper(parsed_function,
+  PrecompileParsedFunctionHelper helper(/* precompiler = */ NULL,
+                                        parsed_function,
                                         /* optimized = */ true);
   bool success = helper.Compile(&pipeline);
   ASSERT(success);
 
   if (compute_type && field.is_final()) {
     intptr_t result_cid = pipeline.result_type().ToCid();
     if (result_cid != kDynamicCid) {
       if (FLAG_trace_precompiler && FLAG_support_il_printer) {
         THR_Print("Setting guarded_cid of %s to %s\n", field.ToCString(),
                   pipeline.result_type().ToCString());
@@ skipping 80 matching lines @@
     // here.
     ParsedFunction* parsed_function = new ParsedFunction(thread, func);
     parsed_function->SetNodeSequence(fragment);
     fragment->scope()->AddVariable(parsed_function->EnsureExpressionTemp());
     fragment->scope()->AddVariable(
         parsed_function->current_context_var());
     parsed_function->AllocateVariables();
 
     // Non-optimized code generator.
     DartPrecompilationPipeline pipeline(Thread::Current()->zone());
-    PrecompileParsedFunctionHelper helper(parsed_function,
+    PrecompileParsedFunctionHelper helper(/* precompiler = */ NULL,
+                                          parsed_function,
                                           /* optimized = */ false);
     helper.Compile(&pipeline);
     Code::Handle(func.unoptimized_code()).set_var_descriptors(
         Object::empty_var_descriptors());
 
     const Object& result = PassiveObject::Handle(
         DartEntry::InvokeFunction(func, Object::empty_array()));
     return result.raw();
   } else {
     Thread* const thread = Thread::Current();
@@ skipping 258 matching lines @@
     ASSERT(!farray.IsNull());
     if (farray.Length() == 1) {
       function ^= farray.At(0);
       cls = function.Owner();
       if (!CHA::IsImplemented(cls) && !CHA::HasSubclasses(cls)) {
         functions_set.Insert(function);
       }
     }
   }
 
+  farray ^= table.GetOrNull(Symbols::GetRuntimeType());
+
+  get_runtime_type_is_unique_ = !farray.IsNull() && (farray.Length() == 1);

[Florian Schneider, 2016/09/29 18:03:29]

Use CHA? Also can be used in JIT then.

[Vyacheslav Egorov (Google), 2016/09/30 09:56:28]

CHA does not track subclasses of Object - because everything is a subclass of
Object. So for any method of Object it just says it's overridden. That's why I
had to hand roll my own way to detect this.  

+
   if (FLAG_print_unique_targets) {
     UniqueFunctionsSet::Iterator unique_iter(&functions_set);
     while (unique_iter.MoveNext()) {
       intptr_t curr_key = unique_iter.Current();
       function ^= functions_set.GetKey(curr_key);
       THR_Print("* %s\n", function.ToQualifiedCString());
     }
     THR_Print("%" Pd " of %" Pd " dynamic selectors are unique\n",
         functions_set.NumOccupied(), table.NumOccupied());
   }
@@ skipping 1289 matching lines @@
         // We do not add the token position now because we don't know the
         // position of the inlined call until later. A side effect of this
         // is that the length of |inline_id_to_function| is always larger
         // than the length of |inline_id_to_token_pos| by one.
         // Top scope function has no caller (-1). We do this because we expect
         // all token positions to be at an inlined call.
         // Top scope function has no caller (-1).
         caller_inline_id.Add(-1);
         CSTAT_TIMER_SCOPE(thread(), graphoptimizer_timer);
 
-        AotOptimizer optimizer(flow_graph,
+        AotOptimizer optimizer(precompiler_,
+                               flow_graph,
                                use_speculative_inlining,
                                &inlining_black_list);
         optimizer.PopulateWithICData();
 
         optimizer.ApplyClassIds();
         DEBUG_ASSERT(flow_graph->VerifyUseLists());
 
         FlowGraphTypePropagator::Propagate(flow_graph);
         DEBUG_ASSERT(flow_graph->VerifyUseLists());
 
@@ skipping 21 matching lines @@
 
           // Use propagated class-ids to create more inlining opportunities.
           optimizer.ApplyClassIds();
           DEBUG_ASSERT(flow_graph->VerifyUseLists());
 
           FlowGraphInliner inliner(flow_graph,
                                    &inline_id_to_function,
                                    &inline_id_to_token_pos,
                                    &caller_inline_id,
                                    use_speculative_inlining,
-                                   &inlining_black_list);
+                                   &inlining_black_list,
+                                   precompiler_);
           inliner.Inline();
           // Use lists are maintained and validated by the inliner.
           DEBUG_ASSERT(flow_graph->VerifyUseLists());
         }
 
         // Propagate types and eliminate more type tests.
         FlowGraphTypePropagator::Propagate(flow_graph);
         DEBUG_ASSERT(flow_graph->VerifyUseLists());
 
         {
@@ skipping 358 matching lines @@
       }
       is_compiled = false;
     }
     // Reset global isolate state.
     thread()->set_deopt_id(prev_deopt_id);
   }
   return is_compiled;
 }
 
 
-static RawError* PrecompileFunctionHelper(CompilationPipeline* pipeline,
+static RawError* PrecompileFunctionHelper(Precompiler* precompiler,
+                                          CompilationPipeline* pipeline,
                                           const Function& function,
                                           bool optimized) {
   // Check that we optimize, except if the function is not optimizable.
   ASSERT(FLAG_precompiled_mode);
   ASSERT(!function.IsOptimizable() || optimized);
   ASSERT(!function.HasCode());
   LongJumpScope jump;
   if (setjmp(*jump.Set()) == 0) {
     Thread* const thread = Thread::Current();
     StackZone stack_zone(thread);
@@ skipping 21 matching lines @@
     {
       HANDLESCOPE(thread);
       const int64_t num_tokens_before = STAT_VALUE(thread, num_tokens_consumed);
       pipeline->ParseFunction(parsed_function);
       const int64_t num_tokens_after = STAT_VALUE(thread, num_tokens_consumed);
       INC_STAT(thread,
                num_func_tokens_compiled,
                num_tokens_after - num_tokens_before);
     }
 
-    PrecompileParsedFunctionHelper helper(parsed_function, optimized);
+    PrecompileParsedFunctionHelper helper(
+        precompiler, parsed_function, optimized);
     const bool success = helper.Compile(pipeline);
     if (!success) {
       // Encountered error.
       Error& error = Error::Handle();
       // We got an error during compilation.
       error = thread->sticky_error();
       thread->clear_sticky_error();
       ASSERT(error.IsLanguageError() &&
              LanguageError::Cast(error).kind() != Report::kBailout);
       return error.raw();
@@ skipping 27 matching lines @@
     // Precompilation may encounter compile-time errors.
     // Do not attempt to optimize functions that can cause errors.
     function.set_is_optimizable(false);
     return error.raw();
   }
   UNREACHABLE();
   return Error::null();
 }
 
 
-RawError* Precompiler::CompileFunction(Thread* thread,
+RawError* Precompiler::CompileFunction(Precompiler* precompiler,
+                                       Thread* thread,
                                        Zone* zone,
-                                       const Function& function,
-                                       FieldTypeMap* field_type_map) {
+                                       const Function& function) {
   VMTagScope tagScope(thread, VMTag::kCompileUnoptimizedTagId);
   TIMELINE_FUNCTION_COMPILATION_DURATION(thread, "CompileFunction", function);
 
   ASSERT(FLAG_precompiled_mode);
   const bool optimized = function.IsOptimizable();  // False for natives.
-  DartPrecompilationPipeline pipeline(zone, field_type_map);
-  return PrecompileFunctionHelper(&pipeline, function, optimized);
+  DartPrecompilationPipeline pipeline(zone,
+      (precompiler != NULL) ? precompiler->field_type_map() : NULL);
+  return PrecompileFunctionHelper(precompiler, &pipeline, function, optimized);
 }
 
 #endif  // DART_PRECOMPILER
 
 }  // namespace dart