VM: Remove unused IsClosureCall bit from IC data.

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/bit_vector.h"
 #include "vm/cha.h"
@@ skipping 854 matching lines @@
     intptr_t deopt_id,
     intptr_t token_pos,
     intptr_t argument_count,
     LocationSummary* locs,
     const ICData& ic_data) {
   ASSERT(!ic_data.IsNull());
   ASSERT(FLAG_propagate_ic_data || (ic_data.NumberOfUsedChecks() == 0));
   uword label_address = 0;
   StubCode* stub_code = isolate()->stub_code();
   if (is_optimizing() && (ic_data.NumberOfUsedChecks() == 0)) {
-    if (ic_data.IsClosureCall()) {

[Florian Schneider, 2014/09/08 16:17:17]

This code has effectively become unreachable, because the IC miss handler always
enters a target (normal method, or a closure dispatcher method) into the IC data
the first time around.

So ic_data.NumberOfUsedChecks() is never zero for closure calls if they have
been executed before optimizing.

If they have not been executed before optimizing, IsClosureCall is naturally
false.

-      // This IC call may be closure call only.
-      label_address = stub_code->ClosureCallInlineCacheEntryPoint();
-      ExternalLabel target_label(label_address);
-      EmitInstanceCall(&target_label,
-                       ICData::ZoneHandle(ic_data.AsUnaryClassChecks()),
-                       argument_count, deopt_id, token_pos, locs);
-      return;
-    }
     // Emit IC call that will count and thus may need reoptimization at
     // function entry.
     ASSERT(!is_optimizing()
            || may_reoptimize()
            || flow_graph().IsCompiledForOsr());
     switch (ic_data.NumArgsTested()) {
       case 1:
         label_address = stub_code->OneArgOptimizedCheckInlineCacheEntryPoint();
         break;
       case 2:
@@ skipping 570 matching lines @@
     threshold = FLAG_optimization_counter_scale * basic_blocks +
         FLAG_min_optimization_counter_threshold;
     if (threshold > FLAG_optimization_counter_threshold) {
       threshold = FLAG_optimization_counter_threshold;
     }
   }
   return threshold;
 }
 
 }  // namespace dart