Add dynamic stack frame alignment to optimized functions with untagged doubles on the stack.

src/objects.h

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 6560 matching lines @@
   static const int kKindOffset = kToNumberOffset + kPointerSize;
   static const int kSize = kKindOffset + kPointerSize;
 
   static const byte kFalse = 0;
   static const byte kTrue = 1;
   static const byte kNotBooleanMask = ~1;
   static const byte kTheHole = 2;
   static const byte kNull = 3;
   static const byte kArgumentMarker = 4;
   static const byte kUndefined = 5;
-  static const byte kOther = 6;
+  static const byte kFrameAlignmentMarker = 6;

[Kevin Millikin (Chromium), 2011/09/23 09:38:49]

You never use this constant that I can see.  Can you just reuse kOther?  I'm not
sure it's critical to have as many tags as oddballs.

[William Hesse, 2011/09/23 12:50:11]

Done.

+  static const byte kOther = 7;
+
+  // The ToNumber value of a hidden oddball is a negative smi.
+  static const int kLeastHiddenOddballNumber = -5;
 
   typedef FixedBodyDescriptor<kToStringOffset,
                               kToNumberOffset + kPointerSize,
                               kSize> BodyDescriptor;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(Oddball);
 };
 
 
@@ skipping 811 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_