[turbofan] Frame elision for code stubs

src/compiler/code-stub-assembler.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/code-stub-assembler.h"
 
 #include <ostream>
 
 #include "src/code-factory.h"
 #include "src/compiler/graph.h"
@@ skipping 635 matching lines @@
   Variable var_result(this, MachineRepresentation::kTagged);
   Bind(&if_valueisint32);
   {
     if (raw_assembler_->machine()->Is64()) {
       Node* result = SmiTag(ChangeInt32ToInt64(value32));
       var_result.Bind(result);
       Goto(&if_join);
     } else {
       Node* pair = Int32AddWithOverflow(value32, value32);
       Node* overflow = Projection(1, pair);
-      Label if_overflow(this, Label::kDeferred), if_notoverflow(this),
-          if_join(this);
+      Label if_overflow(this, Label::kDeferred), if_notoverflow(this);

[Benedikt Meurer, 2016/03/30 04:00:25]

Meh C++ should warn about this, really. But this should be in a separate CL.

       Branch(overflow, &if_overflow, &if_notoverflow);
       Bind(&if_overflow);
       Goto(&if_valueisheapnumber);
       Bind(&if_notoverflow);
       {
         Node* result = Projection(0, pair);
         var_result.Bind(result);
-        Goto(&if_join);
+        Goto(&if_valueisheapnumber);

[Benedikt Meurer, 2016/03/30 04:00:25]

This change looks completely unrelated and wrong to me. This way you'd even box
values in the Smi range into a HeapNumber. Why did you change this?

       }
     }
   }
   Bind(&if_valueisheapnumber);
   {
     Node* result = AllocateHeapNumberWithValue(value);
     var_result.Bind(result);
     Goto(&if_join);
   }
   Bind(&if_join);
@@ skipping 540 matching lines @@
       }
     }
   }
 
   bound_ = true;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8