VM: Explicitly load function and context before calling a closure.

runtime/vm/flow_graph_compiler.cc

 // Copyright (c) 2013, 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/globals.h"  // Needed here to get TARGET_ARCH_XXX.
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/cha.h"
 #include "vm/dart_entry.h"
@@ skipping 453 matching lines @@
   ASSERT(Code::kSCallTableOffsetEntry == 0);
   static_calls_target_table_.Add(
       Smi::Handle(Smi::New(assembler()->CodeSize())));
   ASSERT(Code::kSCallTableFunctionEntry == 1);
   static_calls_target_table_.Add(func);
   ASSERT(Code::kSCallTableCodeEntry == 2);
   static_calls_target_table_.Add(Code::Handle());
 }
 
 
+// Add a lazy deoptimization environment at a call. input_count specifies
+// a number of input operands that will be removed from the environment to
+// match the stack frame layout after the call: Pushed args are present,
+// input operands are consumed before the call.
 void FlowGraphCompiler::AddDeoptIndexAtCall(intptr_t deopt_id,
-                                            intptr_t token_pos) {
+                                            intptr_t token_pos,
+                                            intptr_t input_count) {
   ASSERT(is_optimizing());
+  Environment* env = pending_deoptimization_env_;
+  if (input_count > 0) {
+    env = env->DeepCopy(env->Length() - input_count);
+  }
   CompilerDeoptInfo* info =
       new CompilerDeoptInfo(deopt_id,
                             ICData::kDeoptAtCall,
-                            pending_deoptimization_env_);
+                            env);
   info->set_pc_offset(assembler()->CodeSize());
   deopt_infos_.Add(info);
 }
 
 
 // This function must be in sync with FlowGraphCompiler::SaveLiveRegisters
 // and FlowGraphCompiler::SlowPathEnvironmentFor.
 void FlowGraphCompiler::RecordSafepoint(LocationSummary* locs) {
   if (is_optimizing()) {
     RegisterSet* registers = locs->live_registers();
@@ skipping 804 matching lines @@
 
   for (int i = 0; i < len; i++) {
     sorted->Add(CidTarget(ic_data.GetReceiverClassIdAt(i),
                           &Function::ZoneHandle(ic_data.GetTargetAt(i)),
                           ic_data.GetCountAt(i)));
   }
   sorted->Sort(HighestCountFirst);
 }
 
 }  // namespace dart