Store both major and minor key on code stubs.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 8084474a9be9351c83df10d187d7dbabfd6c1aec..5aa3e58136c5f867c3b38a24e60cc6e70c1708d4 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -5460,13 +5460,13 @@ class Code: public HeapObject {
   // [raw_type_feedback_info]: This field stores various things, depending on
   // the kind of the code object.
   //   FUNCTION           => type feedback information.
-  //   STUB               => various things, e.g. a SMI
+  //   STUB and ICs       => major/minor key as Smi.
   DECL_ACCESSORS(raw_type_feedback_info, Object)
   inline Object* type_feedback_info();
   inline void set_type_feedback_info(
       Object* value, WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
-  inline int stub_info();
-  inline void set_stub_info(int info);
+  inline uint32_t stub_key();
+  inline void set_stub_key(uint32_t key);
 
   // [next_code_link]: Link for lists of optimized or deoptimized code.
   // Note that storage for this field is overlapped with typefeedback_info.
@@ -5530,14 +5530,11 @@ class Code: public HeapObject {
            ic_state() == MONOMORPHIC;
   }
 
+  inline bool IsCodeStubOrIC();
+
   inline void set_raw_kind_specific_flags1(int value);
   inline void set_raw_kind_specific_flags2(int value);
 
-  // [major_key]: For kind STUB or BINARY_OP_IC, the major key.
-  inline int major_key();
-  inline void set_major_key(int value);
-  inline bool has_major_key();
-
   // For kind STUB or ICs, tells whether or not a code object was generated by
   // the optimizing compiler (but it may not be an optimized function).
   bool is_crankshafted();
@@ -5808,6 +5805,7 @@ class Code: public HeapObject {
   static const int kHandlerTableOffset = kRelocationInfoOffset + kPointerSize;
   static const int kDeoptimizationDataOffset =
       kHandlerTableOffset + kPointerSize;
+  // For FUNCTION kind, we store the type feedback info here.
   static const int kTypeFeedbackInfoOffset =
       kDeoptimizationDataOffset + kPointerSize;
   static const int kNextCodeLinkOffset = kTypeFeedbackInfoOffset + kPointerSize;
@@ -5890,22 +5888,16 @@ class Code: public HeapObject {
       kIsCrankshaftedBit, 1> {};  // NOLINT
 
   // KindSpecificFlags2 layout (STUB and OPTIMIZED_FUNCTION)
-  static const int kStubMajorKeyFirstBit = kIsCrankshaftedBit + 1;
-  static const int kSafepointTableOffsetFirstBit =
-      kStubMajorKeyFirstBit + kStubMajorKeyBits;
+  static const int kSafepointTableOffsetFirstBit = kIsCrankshaftedBit + 1;
   static const int kSafepointTableOffsetBitCount = 24;

[Jakob Kummerow, 2014/07/21 12:23:19]

nit: let's add a comment that bits 25-31 (zero-indexed) are currently unused
(just to make it obvious that this is intentional).

 
-  STATIC_ASSERT(kStubMajorKeyFirstBit + kStubMajorKeyBits <= 32);
   STATIC_ASSERT(kSafepointTableOffsetFirstBit +
                 kSafepointTableOffsetBitCount <= 32);
-  STATIC_ASSERT(1 + kStubMajorKeyBits +
-                kSafepointTableOffsetBitCount <= 32);
+  STATIC_ASSERT(1 + kSafepointTableOffsetBitCount <= 32);
 
   class SafepointTableOffsetField: public BitField<int,
       kSafepointTableOffsetFirstBit,
       kSafepointTableOffsetBitCount> {};  // NOLINT
-  class StubMajorKeyField: public BitField<int,
-      kStubMajorKeyFirstBit, kStubMajorKeyBits> {};  // NOLINT
 
   // KindSpecificFlags2 layout (FUNCTION)
   class BackEdgeTableOffsetField: public BitField<int,