1 // Copyright 2014 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #ifndef HYDROGEN_TYPES_H_
6 #define HYDROGEN_TYPES_H_
7 
8 #include <climits>
9 
10 #include "src/base/macros.h"
11 
12 namespace v8 {
13 namespace internal {
14 
15 // Forward declarations.
16 template <typename T> class Handle;
17 class Object;
18 class OStream;
19 
20 #define HTYPE_LIST(V)                                 \
21   V(Any, 0x0)              /* 0000 0000 0000 0000 */  \
22   V(Tagged, 0x1)           /* 0000 0000 0000 0001 */  \
23   V(TaggedPrimitive, 0x5)  /* 0000 0000 0000 0101 */  \
24   V(TaggedNumber, 0xd)     /* 0000 0000 0000 1101 */  \
25   V(Smi, 0x1d)             /* 0000 0000 0001 1101 */  \
26   V(HeapObject, 0x21)      /* 0000 0000 0010 0001 */  \
27   V(HeapPrimitive, 0x25)   /* 0000 0000 0010 0101 */  \
28   V(Null, 0x27)            /* 0000 0000 0010 0111 */  \
29   V(HeapNumber, 0x2d)      /* 0000 0000 0010 1101 */  \
30   V(String, 0x65)          /* 0000 0000 0110 0101 */  \
31   V(Boolean, 0xa5)         /* 0000 0000 1010 0101 */  \
32   V(Undefined, 0x125)      /* 0000 0001 0010 0101 */  \
33   V(JSObject, 0x221)       /* 0000 0010 0010 0001 */  \
34   V(JSArray, 0x621)        /* 0000 0110 0010 0001 */  \
35   V(None, 0x7ff)           /* 0000 0111 1111 1111 */
36 
37 class HType FINAL {
38  public:
39   #define DECLARE_CONSTRUCTOR(Name, mask) \
40     static HType Name() WARN_UNUSED_RESULT { return HType(k##Name); }
HTYPE_LIST(DECLARE_CONSTRUCTOR)41   HTYPE_LIST(DECLARE_CONSTRUCTOR)
42   #undef DECLARE_CONSTRUCTOR
43 
44   // Return the weakest (least precise) common type.
45   HType Combine(HType other) const WARN_UNUSED_RESULT {
46     return HType(static_cast<Kind>(kind_ & other.kind_));
47   }
48 
Equals(HType other)49   bool Equals(HType other) const WARN_UNUSED_RESULT {
50     return kind_ == other.kind_;
51   }
52 
IsSubtypeOf(HType other)53   bool IsSubtypeOf(HType other) const WARN_UNUSED_RESULT {
54     return Combine(other).Equals(other);
55   }
56 
57   #define DECLARE_IS_TYPE(Name, mask)               \
58     bool Is##Name() const WARN_UNUSED_RESULT {   \
59       return IsSubtypeOf(HType::Name());            \
60     }
61   HTYPE_LIST(DECLARE_IS_TYPE)
62   #undef DECLARE_IS_TYPE
63 
64   template <class T>
65   static HType FromType(typename T::TypeHandle type) WARN_UNUSED_RESULT;
66   static HType FromValue(Handle<Object> value) WARN_UNUSED_RESULT;
67 
68   friend OStream& operator<<(OStream& os, const HType& t);
69 
70  private:
71   enum Kind {
72     #define DECLARE_TYPE(Name, mask) k##Name = mask,
73     HTYPE_LIST(DECLARE_TYPE)
74     #undef DECLARE_TYPE
75     LAST_KIND = kNone
76   };
77 
78   // Make sure type fits in int16.
79   STATIC_ASSERT(LAST_KIND < (1 << (CHAR_BIT * sizeof(int16_t))));
80 
HType(Kind kind)81   explicit HType(Kind kind) : kind_(kind) { }
82 
83   int16_t kind_;
84 };
85 
86 
87 OStream& operator<<(OStream& os, const HType& t);
88 } }  // namespace v8::internal
89 
90 #endif  // HYDROGEN_TYPES_H_
91