[Interpreter] Collect type feedback for subtract operation and pass it to turbofan.

src/ic/ic-state.h

Index: src/ic/ic-state.h
diff --git a/src/ic/ic-state.h b/src/ic/ic-state.h
index b12b17d3e20b2eb3a04cecbc27189ceed5a1ffb3..ab2458fa46cc39cfc91e6a1ec7f1778553086a16 100644
--- a/src/ic/ic-state.h
+++ b/src/ic/ic-state.h
@@ -253,6 +253,15 @@ class StoreICState final BASE_EMBEDDED {
   const ExtraICState state_;
 };
 
+// TODO(mythria): Move this to a different header that is accessible from
+// code-stub and bytecode-graph-builder.

[Benedikt Meurer, 2016/08/08 04:56:14]

I'd rather use a very simple enum to encode the lattice, i.e. similar to what
hydrogen-types.h did. Something along the lines of:

class BinaryOperationFeedback {
 public:
  enum {
    kNone = 0x00,
    kSignedSmall = 0x01,
    kNumber = 0x3,
    kAny = 0x7
  };
};

Or some enum class even.

That way it's easier to just use the enum names in the code and you still
preserve the simple ORing for combining. 

[mythria, 2016/08/08 07:17:36]

Thanks for the detailed comment Benedikt. Done.

+class BinaryOpTypeFeedback {
+ public:
+  class SmiType : public BitField8<int, 0, 1> {};
+  class NumberType : public BitField8<int, SmiType::kNext, 1> {};
+  class AnyType : public BitField8<int, NumberType::kNext, 1> {};
+};

[mythria, 2016/08/08 04:33:56]

I am not sure where is the right place to add this. This is not exactly
ic-state, so this is not the right place I think.

[Benedikt Meurer, 2016/08/08 04:56:13]

Please move it to globals.h for now.

[mythria, 2016/08/08 07:17:36]

Done.

+
 }  // namespace internal
 }  // namespace v8