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

runtime/vm/flow_graph_inliner.cc

Index: runtime/vm/flow_graph_inliner.cc
diff --git a/runtime/vm/flow_graph_inliner.cc b/runtime/vm/flow_graph_inliner.cc
index b42bba53d3ccab8bd7dc7569574db7ba23ee2b94..037d20a4cd385b863e3760c2a5e1c6427d3d66f4 100644
--- a/runtime/vm/flow_graph_inliner.cc
+++ b/runtime/vm/flow_graph_inliner.cc
@@ -829,7 +829,8 @@ class CallSiteInliner : public ValueObject {
           // Deopt-ids overlap between caller and callee.
           if (FLAG_precompiled_mode) {
 #ifdef DART_PRECOMPILER
-            AotOptimizer optimizer(callee_graph,
+            AotOptimizer optimizer(inliner_->precompiler_,
+                                   callee_graph,
                                    inliner_->use_speculative_inlining_,
                                    inliner_->inlining_black_list_);
             optimizer.PopulateWithICData();
@@ -1878,14 +1879,16 @@ FlowGraphInliner::FlowGraphInliner(
     GrowableArray<TokenPosition>* inline_id_to_token_pos,
     GrowableArray<intptr_t>* caller_inline_id,
     bool use_speculative_inlining,
-    GrowableArray<intptr_t>* inlining_black_list)
+    GrowableArray<intptr_t>* inlining_black_list,
+    Precompiler* precompiler)
     : flow_graph_(flow_graph),
       inline_id_to_function_(inline_id_to_function),
       inline_id_to_token_pos_(inline_id_to_token_pos),
       caller_inline_id_(caller_inline_id),
       trace_inlining_(ShouldTraceInlining(flow_graph)),
       use_speculative_inlining_(use_speculative_inlining),
-      inlining_black_list_(inlining_black_list) {
+      inlining_black_list_(inlining_black_list),
+      precompiler_(precompiler) {
   ASSERT(!use_speculative_inlining || (inlining_black_list != NULL));
 }
 
@@ -3758,6 +3761,36 @@ bool FlowGraphInliner::TryInlineRecognizedMethod(FlowGraph* flow_graph,
       return false;
     }
 
+    case MethodRecognizer::kObjectRuntimeType: {
+      Type& type = Type::Handle(Z);
+      if (RawObject::IsStringClassId(receiver_cid)) {
+        type = Type::StringType();
+      } else if (receiver_cid == kDoubleCid) {
+        type = Type::Double();
+      } else if (RawObject::IsIntegerClassId(receiver_cid)) {
+        type = Type::IntType();
+      } else if (receiver_cid != kClosureCid) {
+        const Class& cls = Class::Handle(Z,
+            flow_graph->isolate()->class_table()->At(receiver_cid));
+        if (!cls.IsGeneric()) {
+          type = cls.CanonicalType();
+        }
+      }
+
+      if (!type.IsNull()) {
+          *entry = new(Z) TargetEntryInstr(flow_graph->allocate_block_id(),
+                                           call->GetBlock()->try_index());
+          (*entry)->InheritDeoptTarget(Z, call);
+          *last = new(Z) ConstantInstr(type);
+          flow_graph->AppendTo(*entry, *last,
+                               call->deopt_id() != Thread::kNoDeoptId ?

[Florian Schneider, 2016/10/06 18:03:19]

Can call ever have Thread::kNoDeoptId?

[Vyacheslav Egorov (Google), 2016/10/24 20:23:03]

That's an interesting question. In JIT it should not be possible. In AOT I
suspect that we can be much more liberal with deopt ids. 

 The code above does the same check so I will leave it for now and we will
investigate later.

+                               call->env() : NULL,
+                               FlowGraph::kValue);
+          return true;
+      }
+      return false;
+    }
+
     case MethodRecognizer::kOneByteStringSetAt: {
       // This is an internal method, no need to check argument types nor
       // range.