Cleanup: Don't allocate a frame iterator in the IC miss handler when it's not needed.

runtime/vm/code_generator.cc

 // Copyright (c) 2012, 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/code_generator.h"
 
 #include "vm/assembler_macros.h"
 #include "vm/ast.h"
 #include "vm/bigint_operations.h"
 #include "vm/code_patcher.h"
@@ skipping 875 matching lines @@
     // closure calls.
     if (FLAG_trace_ic) {
       OS::Print("InlineCacheMissHandler NULL code for receiver: %s\n",
           receiver.ToCString());
     }
     return Function::null();
   }
   const Function& target_function =
       Function::Handle(target_code.function());
   ASSERT(!target_function.IsNull());
-  DartFrameIterator iterator;
-  StackFrame* caller_frame = iterator.NextFrame();
-  ASSERT(caller_frame != NULL);
   if (args.length() == 1) {
     ic_data.AddReceiverCheck(Class::Handle(args[0]->clazz()).id(),
                              target_function);
   } else {
     GrowableArray<intptr_t> class_ids(args.length());
     ASSERT(ic_data.num_args_tested() == args.length());
     for (intptr_t i = 0; i < args.length(); i++) {
       class_ids.Add(Class::Handle(args[i]->clazz()).id());
     }
     ic_data.AddCheck(class_ids, target_function);
   }
-  if (FLAG_trace_ic_miss_in_optimized) {
-    const Code& caller = Code::Handle(Code::LookupCode(caller_frame->pc()));
-    if (caller.is_optimized()) {
-      OS::Print("IC miss in optimized code; call %s -> %s\n",
-          Function::Handle(caller.function()).ToCString(),
+  if (FLAG_trace_ic_miss_in_optimized || FLAG_trace_ic) {
+    DartFrameIterator iterator;
+    StackFrame* caller_frame = iterator.NextFrame();
+    ASSERT(caller_frame != NULL);
+    if (FLAG_trace_ic_miss_in_optimized) {
+      const Code& caller = Code::Handle(Code::LookupCode(caller_frame->pc()));
+      if (caller.is_optimized()) {
+        OS::Print("IC miss in optimized code; call %s -> %s\n",
+            Function::Handle(caller.function()).ToCString(),
+            target_function.ToCString());
+      }
+    }
+    if (FLAG_trace_ic) {
+      OS::Print("InlineCacheMissHandler %d call at %#"Px"' "
+                "adding <%s> id:%"Pd" -> <%s>\n",
+          args.length(),
+          caller_frame->pc(),
+          Class::Handle(receiver.clazz()).ToCString(),
+          Class::Handle(receiver.clazz()).id(),
           target_function.ToCString());
     }
   }
-  if (FLAG_trace_ic) {
-    OS::Print("InlineCacheMissHandler %d call at %#"Px"' "
-              "adding <%s> id:%"Pd" -> <%s>\n",
-        args.length(),
-        caller_frame->pc(),
-        Class::Handle(receiver.clazz()).ToCString(),
-        Class::Handle(receiver.clazz()).id(),
-        target_function.ToCString());
-  }
   return target_function.raw();
 }
 
 
 // Handles inline cache misses by updating the IC data array of the call
 // site.
 //   Arg0: Receiver object.
 //   Arg1: IC data object.
 //   Arg2: Arguments descriptor array.
 //   Returns: target function with compiled code or null.
@@ skipping 860 matching lines @@
     return;
   }
   HeapTrace* heap_trace = Isolate::Current()->heap()->trace();
   heap_trace->TraceStoreIntoObject(RawObject::ToAddr(object),
                                    field_addr,
                                    RawObject::ToAddr(value));
 }
 END_LEAF_RUNTIME_ENTRY
 
 }  // namespace dart