[turbofan] Introduce a dedicated ConvertTaggedHoleToUndefined operator.

src/types.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <iomanip>
 
 #include "src/types.h"
 
 #include "src/handles-inl.h"
 #include "src/ostreams.h"
@@ skipping 129 matching lines @@
     int bitset = type->AsUnion()->Get(0)->BitsetLub();
     for (int i = 0, n = type->AsUnion()->Length(); i < n; ++i) {
       // Other elements only contribute their semantic part.
       bitset |= SEMANTIC(type->AsUnion()->Get(i)->BitsetLub());
     }
     return bitset;
   }
   if (type->IsClass()) return type->AsClass()->Lub();
   if (type->IsConstant()) return type->AsConstant()->Lub();
   if (type->IsRange()) return type->AsRange()->Lub();
-  if (type->IsContext()) return kInternal & kTaggedPointer;
+  if (type->IsContext()) return kOtherInternal & kTaggedPointer;
   if (type->IsArray()) return kOtherObject;
   if (type->IsFunction()) return kFunction;
-  if (type->IsTuple()) return kInternal;
+  if (type->IsTuple()) return kOtherInternal;
   UNREACHABLE();
   return kNone;
 }
 
 Type::bitset BitsetType::Lub(i::Map* map) {
   DisallowHeapAllocation no_allocation;
   switch (map->instance_type()) {
     case STRING_TYPE:
     case ONE_BYTE_STRING_TYPE:
     case CONS_STRING_TYPE:
@@ skipping 16 matching lines @@
     case SHORT_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE:
     case SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE:
       return kInternalizedString;
     case SYMBOL_TYPE:
       return kSymbol;
     case ODDBALL_TYPE: {
       Heap* heap = map->GetHeap();
       if (map == heap->undefined_map()) return kUndefined;
       if (map == heap->null_map()) return kNull;
       if (map == heap->boolean_map()) return kBoolean;
-      DCHECK(map == heap->the_hole_map() ||
-             map == heap->uninitialized_map() ||
+      if (map == heap->the_hole_map()) return kHole;
+      DCHECK(map == heap->uninitialized_map() ||
              map == heap->no_interceptor_result_sentinel_map() ||
              map == heap->termination_exception_map() ||
              map == heap->arguments_marker_map() ||
              map == heap->optimized_out_map() ||
              map == heap->stale_register_map());
-      return kInternal & kTaggedPointer;
+      return kOtherInternal & kTaggedPointer;
     }
     case HEAP_NUMBER_TYPE:
       return kNumber & kTaggedPointer;
     case SIMD128_VALUE_TYPE:
       return kSimd;
     case JS_OBJECT_TYPE:
     case JS_ARGUMENTS_TYPE:
     case JS_ERROR_TYPE:
     case JS_GLOBAL_OBJECT_TYPE:
     case JS_GLOBAL_PROXY_TYPE:
@@ skipping 35 matching lines @@
     case ACCESSOR_PAIR_TYPE:
     case FIXED_ARRAY_TYPE:
     case FIXED_DOUBLE_ARRAY_TYPE:
     case BYTE_ARRAY_TYPE:
     case BYTECODE_ARRAY_TYPE:
     case TRANSITION_ARRAY_TYPE:
     case FOREIGN_TYPE:
     case SCRIPT_TYPE:
     case CODE_TYPE:
     case PROPERTY_CELL_TYPE:
-      return kInternal & kTaggedPointer;
+      return kOtherInternal & kTaggedPointer;
 
     // Remaining instance types are unsupported for now. If any of them do
-    // require bit set types, they should get kInternal & kTaggedPointer.
+    // require bit set types, they should get kOtherInternal & kTaggedPointer.
     case MUTABLE_HEAP_NUMBER_TYPE:
     case FREE_SPACE_TYPE:
 #define FIXED_TYPED_ARRAY_CASE(Type, type, TYPE, ctype, size) \
   case FIXED_##TYPE##_ARRAY_TYPE:
 
       TYPED_ARRAYS(FIXED_TYPED_ARRAY_CASE)
 #undef FIXED_TYPED_ARRAY_CASE
     case FILLER_TYPE:
     case ACCESS_CHECK_INFO_TYPE:
     case INTERCEPTOR_INFO_TYPE:
@@ skipping 1003 matching lines @@
 #undef CONSTRUCT_SIMD_TYPE
 
 // -----------------------------------------------------------------------------
 // Instantiations.
 
 template class Type::Iterator<i::Map>;
 template class Type::Iterator<i::Object>;
 
 }  // namespace internal
 }  // namespace v8