Revision: 12840
Author: [email protected]
Date: Fri Nov 2 03:24:56 2012
Log: Ensure reducing the length of an array doesn't make it go holey.
Also only transition and/or change anything to the backing store if we are
actually going to delete anything.
BUG=
Review URL: https://chromiumcodereview.appspot.com/11358011
http://code.google.com/p/v8/source/detail?r=12840
Added:
/branches/bleeding_edge/test/mjsunit/elements-length-no-holey.js
/branches/bleeding_edge/test/mjsunit/regress/regress-delete-empty-double.js
Modified:
/branches/bleeding_edge/src/elements.cc
=======================================
--- /dev/null
+++ /branches/bleeding_edge/test/mjsunit/elements-length-no-holey.js Fri
Nov 2 03:24:56 2012
@@ -0,0 +1,33 @@
+// Copyright 2012 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.
+
+// Flags: --allow-natives-syntax
+
+a = [1,2,3];
+a.length = 1;
+assertFalse(%HasFastHoleyElements(a));
+assertTrue(%HasFastSmiElements(a));
=======================================
--- /dev/null
+++
/branches/bleeding_edge/test/mjsunit/regress/regress-delete-empty-double.js
Fri Nov 2 03:24:56 2012
@@ -0,0 +1,40 @@
+// Copyright 2012 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.
+
+// Flags: --allow-natives-syntax
+
+a = [1.1,2.2,3.3];
+a.length = 1;
+delete a[1];
+
+assertTrue(%HasFastDoubleElements(a));
+assertFalse(%HasFastHoleyElements(a));
+
+delete a[0];
+
+assertTrue(%HasFastDoubleElements(a));
+assertTrue(%HasFastHoleyElements(a));
=======================================
--- /branches/bleeding_edge/src/elements.cc Thu Oct 25 04:52:37 2012
+++ /branches/bleeding_edge/src/elements.cc Fri Nov 2 03:24:56 2012
@@ -770,11 +770,11 @@
uint32_t length) {
uint32_t old_capacity = backing_store->length();
Object* old_length = array->length();
- bool same_size = old_length->IsSmi() &&
- static_cast<uint32_t>(Smi::cast(old_length)->value()) == length;
+ bool same_or_smaller_size = old_length->IsSmi() &&
+ static_cast<uint32_t>(Smi::cast(old_length)->value()) >= length;
ElementsKind kind = array->GetElementsKind();
- if (!same_size && IsFastElementsKind(kind) &&
+ if (!same_or_smaller_size && IsFastElementsKind(kind) &&
!IsFastHoleyElementsKind(kind)) {
kind = GetHoleyElementsKind(kind);
MaybeObject* maybe_obj = array->TransitionElementsKind(kind);
@@ -829,32 +829,39 @@
ASSERT(obj->HasFastSmiOrObjectElements() ||
obj->HasFastDoubleElements() ||
obj->HasFastArgumentsElements());
+ Heap* heap = obj->GetHeap();
+ Object* elements = obj->elements();
+ if (elements == heap->empty_fixed_array()) {
+ return heap->true_value();
+ }
typename KindTraits::BackingStore* backing_store =
- KindTraits::BackingStore::cast(obj->elements());
- Heap* heap = obj->GetHeap();
- if (backing_store->map() == heap->non_strict_arguments_elements_map())
{
+ KindTraits::BackingStore::cast(elements);
+ bool is_non_strict_arguments_elements_map =
+ backing_store->map() == heap->non_strict_arguments_elements_map();
+ if (is_non_strict_arguments_elements_map) {
backing_store =
KindTraits::BackingStore::cast(
FixedArray::cast(backing_store)->get(1));
- } else {
- ElementsKind kind = KindTraits::Kind;
- if (IsFastPackedElementsKind(kind)) {
- MaybeObject* transitioned =
- obj->TransitionElementsKind(GetHoleyElementsKind(kind));
- if (transitioned->IsFailure()) return transitioned;
- }
- if (IsFastSmiOrObjectElementsKind(KindTraits::Kind)) {
- Object* writable;
- MaybeObject* maybe = obj->EnsureWritableFastElements();
- if (!maybe->ToObject(&writable)) return maybe;
- backing_store = KindTraits::BackingStore::cast(writable);
- }
}
uint32_t length = static_cast<uint32_t>(
obj->IsJSArray()
? Smi::cast(JSArray::cast(obj)->length())->value()
: backing_store->length());
if (key < length) {
+ if (!is_non_strict_arguments_elements_map) {
+ ElementsKind kind = KindTraits::Kind;
+ if (IsFastPackedElementsKind(kind)) {
+ MaybeObject* transitioned =
+ obj->TransitionElementsKind(GetHoleyElementsKind(kind));
+ if (transitioned->IsFailure()) return transitioned;
+ }
+ if (IsFastSmiOrObjectElementsKind(KindTraits::Kind)) {
+ Object* writable;
+ MaybeObject* maybe = obj->EnsureWritableFastElements();
+ if (!maybe->ToObject(&writable)) return maybe;
+ backing_store = KindTraits::BackingStore::cast(writable);
+ }
+ }
backing_store->set_the_hole(key);
// If an old space backing store is larger than a certain size and
// has too few used values, normalize it.
--
v8-dev mailing list
[email protected]
http://groups.google.com/group/v8-dev
