Move Oddball/String to %Typearray%.prototype.fill fast path

src/elements.cc

 // Copyright 2012 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 "src/elements.h"
 
 #include "src/arguments.h"
 #include "src/conversions.h"
 #include "src/factory.h"
 #include "src/isolate-inl.h"
@@ skipping 2845 matching lines @@
     *nof_items = count;
     return Just(true);
   }
 
   static Object* FillImpl(Isolate* isolate, Handle<JSObject> receiver,
                           Handle<Object> obj_value, uint32_t start,
                           uint32_t end) {
     Handle<JSTypedArray> array = Handle<JSTypedArray>::cast(receiver);
     DCHECK(!array->WasNeutered());
 
-    if (!obj_value->IsNumber()) {
-      return FillNumberSlowPath(isolate, array, obj_value, start, end);
-    }
-
-    ctype value = 0;
+    ctype value;
     if (obj_value->IsSmi()) {
       value = BackingStore::from_int(Smi::cast(*obj_value)->value());
     } else {
-      DCHECK(obj_value->IsHeapNumber());
-      value = BackingStore::from_double(HeapNumber::cast(*obj_value)->value());
+      Handle<HeapObject> heap_obj_value = Handle<HeapObject>::cast(obj_value);
+      if (heap_obj_value->IsHeapNumber()) {
+        value = BackingStore::from_double(
+            HeapNumber::cast(*heap_obj_value)->value());
+      } else if (heap_obj_value->IsUndefined(isolate)) {
+        value =
+            BackingStore::from_double(std::numeric_limits<double>::quiet_NaN());

[Camillo Bruni, 2017/03/23 10:56:43]

I just realized that we do already have a number cache on the oddball objects
(True, false, undefined).
So you can do, the following (and reuse some more code):

    if (input->IsOddball()) {
      value =  BackingStore::from_double(
                 Oddball::ToNumber(Handle<Oddball>::cast(input)->Number());
    } else if (input->IsString()) {
      value = BackingStore::from_double(
                 String::ToNumber(Handle<String>::cast(input))->Number());
    }

[rongjie, 2017/03/23 12:39:14]

Done.

+      } else if (heap_obj_value->IsNull(isolate)) {
+        value = static_cast<ctype>(+0.0);
+      } else if (heap_obj_value->IsBoolean()) {
+        value = static_cast<ctype>(heap_obj_value->IsTrue(isolate));
+      } else {
+        return FillNumberSlowPath(isolate, array, obj_value, start, end);
+      }
     }
 
     // Ensure indexes are within array bounds
     DCHECK_LE(0, start);
     DCHECK_LE(start, end);
     DCHECK_LE(end, array->length_value());
 
     DisallowHeapAllocation no_gc;
     BackingStore* elements = BackingStore::cast(receiver->elements());
     ctype* data = static_cast<ctype*>(elements->DataPtr());
@@ skipping 1090 matching lines @@
     insertion_index += len;
   }
 
   DCHECK_EQ(insertion_index, result_len);
   return result_array;
 }
 
 ElementsAccessor** ElementsAccessor::elements_accessors_ = NULL;
 }  // namespace internal
 }  // namespace v8