Reland r25551: Allow inlining of closures with a context change.

runtime/vm/flow_graph_inliner.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/flow_graph_inliner.h"
 
 #include "vm/compiler.h"
 #include "vm/flags.h"
 #include "vm/flow_graph.h"
 #include "vm/flow_graph_builder.h"
@@ skipping 650 matching lines @@
       return false;
     }
   }
 
  private:
   void InlineCall(InlinedCallData* call_data) {
     TimerScope timer(FLAG_compiler_stats,
                      &CompilerStats::graphinliner_subst_timer,
                      Isolate::Current());
 
+    // For closure calls: Store context value.
+    FlowGraph* callee_graph = call_data->callee_graph;
+    TargetEntryInstr* callee_entry =
+        callee_graph->graph_entry()->normal_entry();
+    ClosureCallInstr* closure_call = call_data->call->AsClosureCall();
+    if (closure_call != NULL) {
+      // TODO(fschneider): Avoid setting the context, if not needed.
+      Definition* closure =
+          closure_call->PushArgumentAt(0)->value()->definition();
+      LoadFieldInstr* context =
+          new LoadFieldInstr(new Value(closure),
+                             Closure::context_offset(),
+                             Type::ZoneHandle());
+      context->set_ssa_temp_index(caller_graph()->alloc_ssa_temp_index());
+      context->InsertAfter(callee_entry);
+      StoreContextInstr* set_context =
+          new StoreContextInstr(new Value(context));
+      set_context->InsertAfter(context);
+    }
+
     // Plug result in the caller graph.
-    FlowGraph* callee_graph = call_data->callee_graph;
     InlineExitCollector* exit_collector = call_data->exit_collector;
     exit_collector->PrepareGraphs(callee_graph);
-    exit_collector->ReplaceCall(callee_graph->graph_entry()->normal_entry());
+    exit_collector->ReplaceCall(callee_entry);
 
     // Replace each stub with the actual argument or the caller's constant.
     // Nulls denote optional parameters for which no actual was given.
     GrowableArray<Value*>* arguments = call_data->arguments;
     for (intptr_t i = 0; i < arguments->length(); ++i) {
       Definition* stub = (*call_data->parameter_stubs)[i];
       Value* actual = (*arguments)[i];
       if (actual != NULL) stub->ReplaceUsesWith(actual->definition());
     }
 
@@ skipping 696 matching lines @@
         OS::Print("After Inlining of %s\n", flow_graph_->
                   parsed_function().function().ToFullyQualifiedCString());
         FlowGraphPrinter printer(*flow_graph_);
         printer.PrintBlocks();
       }
     }
   }
 }
 
 }  // namespace dart