AOT: Add a separate switchable call state for unlinked calls.

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 2095 matching lines @@
   // replace the ICCallThroughFunction stub with ICCallThroughCode.
 
   class SwitchICCallsVisitor : public FunctionVisitor {
    public:
     explicit SwitchICCallsVisitor(Zone* zone) :
         zone_(zone),
         code_(Code::Handle(zone)),
         pool_(ObjectPool::Handle(zone)),
         entry_(Object::Handle(zone)),
         ic_(ICData::Handle(zone)),
-        target_code_(Code::Handle(zone)) {
+        target_name_(String::Handle(zone)),
+        args_descriptor_(Array::Handle(zone)),
+        unlinked_(UnlinkedCall::Handle(zone)),
+        target_code_(Code::Handle(zone)),
+        canonical_unlinked_calls_() {
     }
 
     void Visit(const Function& function) {
       if (!function.HasCode()) {
         return;
       }
 
       code_ = function.CurrentCode();
       pool_ = code_.object_pool();
       for (intptr_t i = 0; i < pool_.Length(); i++) {
         if (pool_.InfoAt(i) != ObjectPool::kTaggedObject) continue;
         entry_ = pool_.ObjectAt(i);
         if (entry_.IsICData()) {
           // The only IC calls generated by precompilation are for switchable
           // calls.
           ic_ ^= entry_.raw();
           ic_.ResetSwitchable(zone_);
+
+          unlinked_ = UnlinkedCall::New();
+          target_name_ = ic_.target_name();
+          unlinked_.set_target_name(target_name_);
+          args_descriptor_ = ic_.arguments_descriptor();
+          unlinked_.set_args_descriptor(args_descriptor_);
+          unlinked_ = DedupUnlinkedCall(unlinked_);
+          pool_.SetObjectAt(i, unlinked_);
         } else if (entry_.raw() ==
                    StubCode::ICCallThroughFunction_entry()->code()) {
-          target_code_ = StubCode::ICCallThroughCode_entry()->code();
+          target_code_ = StubCode::UnlinkedCall_entry()->code();
           pool_.SetObjectAt(i, target_code_);
         }
       }
     }
 
+    RawUnlinkedCall* DedupUnlinkedCall(const UnlinkedCall& unlinked) {
+      const UnlinkedCall* canonical_unlinked =
+          canonical_unlinked_calls_.LookupValue(&unlinked);
+      if (canonical_unlinked == NULL) {
+        canonical_unlinked_calls_.Insert(
+            &UnlinkedCall::ZoneHandle(zone_, unlinked.raw()));
+        return unlinked.raw();
+      } else {
+        return canonical_unlinked->raw();
+      }
+    }
+
    private:
     Zone* zone_;
     Code& code_;
     ObjectPool& pool_;
     Object& entry_;
     ICData& ic_;
+    String& target_name_;
+    Array& args_descriptor_;
+    UnlinkedCall& unlinked_;
     Code& target_code_;
+    UnlinkedCallSet canonical_unlinked_calls_;
   };
 
   ASSERT(!I->compilation_allowed());
   SwitchICCallsVisitor visitor(Z);
   VisitFunctions(&visitor);
 #endif
 }
 
 
 void Precompiler::ShareMegamorphicBuckets() {
@@ skipping 1156 matching lines @@
 
   ASSERT(FLAG_precompiled_mode);
   const bool optimized = function.IsOptimizable();  // False for natives.
   DartPrecompilationPipeline pipeline(zone, field_type_map);
   return PrecompileFunctionHelper(&pipeline, function, optimized);
 }
 
 #endif  // DART_PRECOMPILER
 
 }  // namespace dart