Generalize virtually dispatched scavenger to virtually dispatched specialized visitors.

src/objects-visiting.cc

+// Copyright 2009 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "v8.h"
+
+#include "ic-inl.h"
+#include "objects-visiting.h"
+
+namespace v8 {
+namespace internal {
+
+
+static inline bool IsShortcutCandidate(int type) {
+  return ((type & kShortcutTypeMask) == kShortcutTypeTag);
+}
+
+
+StaticVisitorBase::VisitorId StaticVisitorBase::GetVisitorId(
+    int instance_type,
+    int instance_size) {
+  if (instance_type < FIRST_NONSTRING_TYPE) {
+    switch (instance_type & kStringRepresentationMask) {
+      case kSeqStringTag:
+        if ((instance_type & kStringEncodingMask) == kAsciiStringTag) {
+          return kVisitSeqAsciiString;
+        } else {
+          return kVisitSeqTwoByteString;
+        }
+
+      case kConsStringTag:
+        if (IsShortcutCandidate(instance_type)) {
+          return kVisitShortcutCandidate;
+        } else {
+          return kVisitConsString;
+        }
+
+      case kExternalStringTag:
+        return GetVisitorIdForSize(kVisitDataObject,
+                                   kVisitDataObjectGeneric,
+                                   ExternalString::kSize);
+    }
+    UNREACHABLE();
+  }
+
+  switch (instance_type) {
+    case BYTE_ARRAY_TYPE:
+      return kVisitByteArray;
+
+    case FIXED_ARRAY_TYPE:
+      return kVisitFixedArray;
+
+    case ODDBALL_TYPE:
+      return kVisitOddball;
+
+    case MAP_TYPE:
+      return kVisitMap;
+
+    case CODE_TYPE:
+      return kVisitCode;
+
+    case JS_GLOBAL_PROPERTY_CELL_TYPE:
+      return kVisitPropertyCell;
+
+    case SHARED_FUNCTION_INFO_TYPE:
+      return kVisitSharedFunctionInfo;
+
+    case PROXY_TYPE:
+      return GetVisitorIdForSize(kVisitDataObject,
+                                 kVisitDataObjectGeneric,
+                                 Proxy::kSize);
+
+    case FILLER_TYPE:
+      return kVisitDataObjectGeneric;
+
+    case JS_OBJECT_TYPE:
+    case JS_CONTEXT_EXTENSION_OBJECT_TYPE:
+    case JS_VALUE_TYPE:
+    case JS_ARRAY_TYPE:
+    case JS_REGEXP_TYPE:
+    case JS_FUNCTION_TYPE:
+    case JS_GLOBAL_PROXY_TYPE:
+    case JS_GLOBAL_OBJECT_TYPE:
+    case JS_BUILTINS_OBJECT_TYPE:
+      return GetVisitorIdForSize(kVisitJSObject,
+                                 kVisitJSObjectGeneric,
+                                 instance_size);
+
+    case HEAP_NUMBER_TYPE:
+    case PIXEL_ARRAY_TYPE:
+    case EXTERNAL_BYTE_ARRAY_TYPE:
+    case EXTERNAL_UNSIGNED_BYTE_ARRAY_TYPE:
+    case EXTERNAL_SHORT_ARRAY_TYPE:
+    case EXTERNAL_UNSIGNED_SHORT_ARRAY_TYPE:
+    case EXTERNAL_INT_ARRAY_TYPE:
+    case EXTERNAL_UNSIGNED_INT_ARRAY_TYPE:
+    case EXTERNAL_FLOAT_ARRAY_TYPE:
+      return GetVisitorIdForSize(kVisitDataObject,
+                                 kVisitDataObjectGeneric,
+                                 instance_size);
+
+#define MAKE_STRUCT_CASE(NAME, Name, name) \
+        case NAME##_TYPE:
+      STRUCT_LIST(MAKE_STRUCT_CASE)
+#undef MAKE_STRUCT_CASE
+          return GetVisitorIdForSize(kVisitStruct,
+                                     kVisitStructGeneric,
+                                     instance_size);
+
+    default:
+      UNREACHABLE();
+      return kVisitorIdCount;
+  }
+}
+
+} }  // namespace v8::internal