Revert "[turbofan] Cleanup: Type only has a semantic dimension."

src/compiler/types.h

Index: src/compiler/types.h
diff --git a/src/compiler/types.h b/src/compiler/types.h
index 2ebbe1886c74f3afaa14766c93dbce1f162d596f..9a795a29ffda183f8600d5817be7f4673aa09446 100644
--- a/src/compiler/types.h
+++ b/src/compiler/types.h
@@ -22,7 +22,13 @@ namespace compiler {
 // can express class types (a.k.a. specific maps) and singleton types (i.e.,
 // concrete constants).
 //
-// The following equations and inequations hold:
+// Types consist of two dimensions: semantic (value range) and representation.
+// Both are related through subtyping.
+//
+//
+// SEMANTIC DIMENSION
+//
+// The following equations and inequations hold for the semantic axis:
 //
 //   None <= T
 //   T <= Any
@@ -34,6 +40,7 @@ namespace compiler {
 //   InternalizedString < String
 //
 //   Receiver = Object \/ Proxy
+//   RegExp < Object
 //   OtherUndetectable < Object
 //   DetectableReceiver = Receiver - OtherUndetectable
 //
@@ -96,13 +103,18 @@ namespace compiler {
 
 // clang-format off
 
+#define MASK_BITSET_TYPE_LIST(V) \
+  V(Semantic,       0xfffffffeu)
+
+#define SEMANTIC(k)       ((k) & BitsetType::kSemantic)
+
 #define INTERNAL_BITSET_TYPE_LIST(V)                                      \
   V(OtherUnsigned31, 1u << 1)  \
   V(OtherUnsigned32, 1u << 2)  \
   V(OtherSigned32,   1u << 3)  \
   V(OtherNumber,     1u << 4)  \
 
-#define PROPER_BITSET_TYPE_LIST(V) \
+#define SEMANTIC_BITSET_TYPE_LIST(V) \
   V(None,                0u)        \
   V(Negative31,          1u << 5)   \
   V(Null,                1u << 6)   \
@@ -181,9 +193,12 @@ namespace compiler {
  * occur as part of PlainNumber.
  */
 
+#define PROPER_BITSET_TYPE_LIST(V) SEMANTIC_BITSET_TYPE_LIST(V)
+
 #define BITSET_TYPE_LIST(V)    \
+  MASK_BITSET_TYPE_LIST(V)     \
   INTERNAL_BITSET_TYPE_LIST(V) \
-  PROPER_BITSET_TYPE_LIST(V)
+  SEMANTIC_BITSET_TYPE_LIST(V)
 
 class Type;
 
@@ -208,7 +223,11 @@ class BitsetType {
     return static_cast<bitset>(reinterpret_cast<uintptr_t>(this) ^ 1u);
   }
 
-  static bool IsInhabited(bitset bits) { return bits != kNone; }
+  static bool IsInhabited(bitset bits) { return SemanticIsInhabited(bits); }
+
+  static bool SemanticIsInhabited(bitset bits) {
+    return SEMANTIC(bits) != kNone;
+  }
 
   static bool Is(bitset bits1, bitset bits2) {
     return (bits1 | bits2) == bits2;
@@ -351,7 +370,7 @@ class RangeType : public TypeBase {
   static Type* New(Limits lim, Zone* zone) {
     DCHECK(IsInteger(lim.min) && IsInteger(lim.max));
     DCHECK(lim.min <= lim.max);
-    BitsetType::bitset bits = BitsetType::Lub(lim.min, lim.max);
+    BitsetType::bitset bits = SEMANTIC(BitsetType::Lub(lim.min, lim.max));
 
     return AsType(new (zone->New(sizeof(RangeType))) RangeType(bits, lim));
   }
@@ -506,6 +525,9 @@ class Type {
   }
   static Type* For(i::Handle<i::Map> map) { return For(*map); }
 
+  // Extraction of components.
+  static Type* Semantic(Type* t, Zone* zone);
+
   // Predicates.
   bool IsInhabited() { return BitsetType::IsInhabited(this->BitsetLub()); }
 
@@ -604,10 +626,14 @@ class Type {
   }
   UnionType* AsUnion() { return UnionType::cast(this); }
 
+  // Auxiliary functions.
+  bool SemanticMaybe(Type* that);
+
   bitset BitsetGlb() { return BitsetType::Glb(this); }
   bitset BitsetLub() { return BitsetType::Lub(this); }
 
   bool SlowIs(Type* that);
+  bool SemanticIs(Type* that);
 
   static bool Overlap(RangeType* lhs, RangeType* rhs);
   static bool Contains(RangeType* lhs, RangeType* rhs);