Faster moving FixedArray elements around.

Review URL: http://codereview.chromium.org/660245

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3987 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/array.js

@@ -1149,6 +1149,8 @@ function SetupArray() {
     ArrayReduce: 1,
     ArrayReduceRight: 1
   });
+
+  %FinishArrayPrototypeSetup($Array.prototype);
 }
 
 

src/heap-inl.h

@@ -187,6 +187,18 @@ void Heap::RecordWrite(Address address, int offset) {
 }
 
 
+void Heap::RecordWrites(Address address, int start, int len) {
+  if (new_space_.Contains(address)) return;
+  ASSERT(!new_space_.FromSpaceContains(address));
+  for (int offset = start;
+       offset < start + len * kPointerSize;
+       offset += kPointerSize) {
+    SLOW_ASSERT(Contains(address + offset));
+    Page::SetRSet(address, offset);
+  }
+}
+
+
 OldSpace* Heap::TargetSpace(HeapObject* object) {
   InstanceType type = object->map()->instance_type();
   AllocationSpace space = TargetSpaceId(type);

src/heap.h

@@ -771,6 +771,9 @@ class Heap : public AllStatic {
   // Write barrier support for address[offset] = o.
   static inline void RecordWrite(Address address, int offset);
 
+  // Write barrier support for address[start : start + len[ = o.
+  static inline void RecordWrites(Address address, int start, int len);
+
   // Given an address occupied by a live code object, return that object.
   static Object* FindCodeObject(Address a);
 

src/objects-inl.h

@@ -1397,6 +1397,11 @@ void FixedArray::set_the_hole(int index) {
 }
 
 
+Object** FixedArray::data_start() {
+  return HeapObject::RawField(this, kHeaderSize);
+}
+
+
 bool DescriptorArray::IsEmpty() {
   ASSERT(this == Heap::empty_descriptor_array() ||
          this->length() > 2);

src/objects.h

@@ -1626,6 +1626,9 @@ class FixedArray: public Array {
   inline void set_null(int index);
   inline void set_the_hole(int index);
 
+  // Gives access to raw memory which stores the array's data.
+  inline Object** data_start();
+
   // Copy operations.
   inline Object* Copy();
   Object* CopySize(int new_length);

src/runtime.cc

@@ -1230,6 +1230,17 @@ static Object* Runtime_RegExpExec(Arguments args) {
 }
 
 
+static Object* Runtime_FinishArrayPrototypeSetup(Arguments args) {
+  HandleScope scope;
+  ASSERT(args.length() == 1);
+  CONVERT_ARG_CHECKED(JSArray, prototype, 0);
+  // This is necessary to enable fast checks for absence of elements
+  // on Array.prototype and below.
+  prototype->set_elements(Heap::empty_fixed_array());
+  return Smi::FromInt(0);
+}
+
+
 static Object* Runtime_MaterializeRegExpLiteral(Arguments args) {
   HandleScope scope;
   ASSERT(args.length() == 4);

src/runtime.h

@@ -60,6 +60,7 @@ namespace internal {
   F(GetArgumentsProperty, 1, 1) \
   F(ToFastProperties, 1, 1) \
   F(ToSlowProperties, 1, 1) \
+  F(FinishArrayPrototypeSetup, 1, 1) \
   \
   F(IsInPrototypeChain, 2, 1) \
   F(SetHiddenPrototype, 2, 1) \

test/mjsunit/array-elements-from-array-prototype-chain.js

+// Copyright 2010 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.
+
+////////////////////////////////////////////////////////////////////////
+// Tests below verify that elements set on Array.prototype's proto propagate
+// for various Array.prototype functions (like unshift, shift, etc.)
+// If add any new tests here, consider adding them to all other files:
+//   array-elements-from-array-prototype.js
+//   array-elements-from-array-prototype-chain.js
+//   array-elements-from-object-prototype.js
+// those ideally should be identical modulo host of elements and
+// the way elements introduced.
+//
+// Note: they are put into a separate file as we need maximally clean
+// VM setup---some optimizations might be already turned off in
+// 'dirty' VM.
+////////////////////////////////////////////////////////////////////////
+
+var at3 = '@3'
+var at7 = '@7'
+
+Array.prototype.__proto__ = {3: at3};
+Array.prototype.__proto__.__proto__ = {7: at7};
+
+var a = new Array(13)
+
+assertEquals(at3, a[3])
+assertFalse(a.hasOwnProperty(3))
+
+assertEquals(at7, a[7])
+assertFalse(a.hasOwnProperty(7))
+
+assertEquals(undefined, a.shift(), 'hole should be returned as undefined')
+// Side-effects: Array.prototype[3] percolates into a[2] and Array.prototype[7[
+// into a[6], still visible at the corresponding indices.
+
+assertEquals(at3, a[2])
+assertTrue(a.hasOwnProperty(2))
+assertEquals(at3, a[3])
+assertFalse(a.hasOwnProperty(3))
+
+assertEquals(at7, a[6])
+assertTrue(a.hasOwnProperty(6))
+assertEquals(at7, a[7])
+assertFalse(a.hasOwnProperty(7))
+
+a.unshift('foo', 'bar')
+// Side-effects: Array.prototype[3] now percolates into a[5] and Array.prototype[7]
+// into a[9].
+
+assertEquals(at3, a[3])
+assertFalse(a.hasOwnProperty(3))
+assertEquals(at3, a[4])
+assertTrue(a.hasOwnProperty(4))
+assertEquals(at3, a[5])
+assertTrue(a.hasOwnProperty(5))
+
+assertEquals(undefined, a[6])
+assertFalse(a.hasOwnProperty(6))
+
+assertEquals(at7, a[7])
+assertFalse(a.hasOwnProperty(7))
+assertEquals(at7, a[8])
+assertTrue(a.hasOwnProperty(8))
+assertEquals(at7, a[9])
+assertTrue(a.hasOwnProperty(9))
+
+var sliced = a.slice(3, 10)
+// Slice must keep intact a and reify holes at indices 0--2 and 4--6.
+
+assertEquals(at3, a[3])
+assertFalse(a.hasOwnProperty(3))
+assertEquals(at3, a[4])
+assertTrue(a.hasOwnProperty(4))
+assertEquals(at3, a[5])
+assertTrue(a.hasOwnProperty(5))
+
+assertEquals(undefined, a[6])
+assertFalse(a.hasOwnProperty(6))
+
+assertEquals(at7, a[7])
+assertFalse(a.hasOwnProperty(7))
+assertEquals(at7, a[8])
+assertTrue(a.hasOwnProperty(8))
+assertEquals(at7, a[9])
+assertTrue(a.hasOwnProperty(9))
+
+assertEquals(at3, sliced[0])
+assertTrue(sliced.hasOwnProperty(0))
+assertEquals(at3, sliced[1])
+assertTrue(sliced.hasOwnProperty(1))
+assertEquals(at3, sliced[2])
+assertTrue(sliced.hasOwnProperty(2))
+
+// Note: sliced[3] comes directly from Array.prototype[3]
+assertEquals(at3, sliced[3]);
+assertFalse(sliced.hasOwnProperty(3))
+
+assertEquals(at7, sliced[4])
+assertTrue(sliced.hasOwnProperty(4))
+assertEquals(at7, sliced[5])
+assertTrue(sliced.hasOwnProperty(5))
+assertEquals(at7, sliced[6])
+assertTrue(sliced.hasOwnProperty(6))
+
+
+// Splice is too complicated the operation, start afresh.
+
+// Shrking array.
+var a0 = [0, 1, , , 4, 5, , , , 9]
+var result = a0.splice(4, 1)
+// Side-effects: everything before 4 is kept intact:
+
+assertEquals(0, a0[0])
+assertTrue(a0.hasOwnProperty(0))
+assertEquals(1, a0[1])
+assertTrue(a0.hasOwnProperty(1))
+assertEquals(undefined, a0[2])
+assertFalse(a0.hasOwnProperty(2))
+assertEquals(at3, a0[3])
+assertFalse(a0.hasOwnProperty(3))
+
+// 4 and above shifted left by one reifying at7 into a0[6] and keeping
+// a hole at a0[7]
+
+assertEquals(5, a0[4])
+assertTrue(a0.hasOwnProperty(4))
+assertEquals(undefined, a0[5])
+assertFalse(a0.hasOwnProperty(5))
+assertEquals(at7, a0[6])
+assertTrue(a0.hasOwnProperty(6))
+assertEquals(at7, a0[7])
+assertFalse(a0.hasOwnProperty(7))
+assertEquals(9, a0[8])
+assertTrue(a0.hasOwnProperty(8))
+
+// Growing array.
+var a1 = [0, 1, , , 4, 5, , , , 9]
+var result = a1.splice(4, 0, undefined)
+// Side-effects: everything before 4 is kept intact:
+
+assertEquals(0, a1[0])
+assertTrue(a1.hasOwnProperty(0))
+assertEquals(1, a1[1])
+assertTrue(a1.hasOwnProperty(1))
+assertEquals(undefined, a1[2])
+assertFalse(a1.hasOwnProperty(2))
+assertEquals(at3, a1[3])
+assertFalse(a1.hasOwnProperty(3))
+
+// Now owned undefined resides at 4 and rest is shifted right by one
+// reifying at7 into a0[8] and keeping a hole at a0[7].
+
+assertEquals(undefined, a1[4])
+assertTrue(a1.hasOwnProperty(4))
+assertEquals(4, a1[5])
+assertTrue(a1.hasOwnProperty(5))
+assertEquals(5, a1[6])
+assertTrue(a1.hasOwnProperty(6))
+assertEquals(at7, a1[7])
+assertFalse(a1.hasOwnProperty(7))
+assertEquals(at7, a1[8])
+assertTrue(a1.hasOwnProperty(8))
+assertEquals(undefined, a1[9])
+assertFalse(a1.hasOwnProperty(9))
+assertEquals(9, a1[10])
+assertTrue(a1.hasOwnProperty(10))

test/mjsunit/array-elements-from-array-prototype.js

+// Copyright 2010 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.
+
+////////////////////////////////////////////////////////////////////////
+// Tests below verify that elements set on Array.prototype propagate
+// for various Array.prototype functions (like unshift, shift, etc.)
+// If add any new tests here, consider adding them to all other files:
+//   array-elements-from-array-prototype.js
+//   array-elements-from-array-prototype-chain.js
+//   array-elements-from-object-prototype.js
+// those ideally should be identical modulo host of elements and
+// the way elements introduced.
+//
+// Note: they are put into a separate file as we need maximally clean
+// VM setup---some optimizations might be already turned off in
+// 'dirty' VM.
+////////////////////////////////////////////////////////////////////////
+
+var at3 = '@3'
+var at7 = '@7'
+
+Array.prototype[3] = at3
+Array.prototype[7] = at7
+
+var a = new Array(13)
+
+assertEquals(at3, a[3])
+assertFalse(a.hasOwnProperty(3))
+
+assertEquals(at7, a[7])
+assertFalse(a.hasOwnProperty(7))
+
+assertEquals(undefined, a.shift(), 'hole should be returned as undefined')
+// Side-effects: Array.prototype[3] percolates into a[2] and Array.prototype[7[
+// into a[6], still visible at the corresponding indices.
+
+assertEquals(at3, a[2])
+assertTrue(a.hasOwnProperty(2))
+assertEquals(at3, a[3])
+assertFalse(a.hasOwnProperty(3))
+
+assertEquals(at7, a[6])
+assertTrue(a.hasOwnProperty(6))
+assertEquals(at7, a[7])
+assertFalse(a.hasOwnProperty(7))
+
+a.unshift('foo', 'bar')
+// Side-effects: Array.prototype[3] now percolates into a[5] and Array.prototype[7]
+// into a[9].
+
+assertEquals(at3, a[3])
+assertFalse(a.hasOwnProperty(3))
+assertEquals(at3, a[4])
+assertTrue(a.hasOwnProperty(4))
+assertEquals(at3, a[5])
+assertTrue(a.hasOwnProperty(5))
+
+assertEquals(undefined, a[6])
+assertFalse(a.hasOwnProperty(6))
+
+assertEquals(at7, a[7])
+assertFalse(a.hasOwnProperty(7))
+assertEquals(at7, a[8])
+assertTrue(a.hasOwnProperty(8))
+assertEquals(at7, a[9])
+assertTrue(a.hasOwnProperty(9))
+
+var sliced = a.slice(3, 10)
+// Slice must keep intact a and reify holes at indices 0--2 and 4--6.
+
+assertEquals(at3, a[3])
+assertFalse(a.hasOwnProperty(3))
+assertEquals(at3, a[4])
+assertTrue(a.hasOwnProperty(4))
+assertEquals(at3, a[5])
+assertTrue(a.hasOwnProperty(5))
+
+assertEquals(undefined, a[6])
+assertFalse(a.hasOwnProperty(6))
+
+assertEquals(at7, a[7])
+assertFalse(a.hasOwnProperty(7))
+assertEquals(at7, a[8])
+assertTrue(a.hasOwnProperty(8))
+assertEquals(at7, a[9])
+assertTrue(a.hasOwnProperty(9))
+
+assertEquals(at3, sliced[0])
+assertTrue(sliced.hasOwnProperty(0))
+assertEquals(at3, sliced[1])
+assertTrue(sliced.hasOwnProperty(1))
+assertEquals(at3, sliced[2])
+assertTrue(sliced.hasOwnProperty(2))
+
+// Note: sliced[3] comes directly from Array.prototype[3]
+assertEquals(at3, sliced[3]);
+assertFalse(sliced.hasOwnProperty(3))
+
+assertEquals(at7, sliced[4])
+assertTrue(sliced.hasOwnProperty(4))
+assertEquals(at7, sliced[5])
+assertTrue(sliced.hasOwnProperty(5))
+assertEquals(at7, sliced[6])
+assertTrue(sliced.hasOwnProperty(6))
+
+
+// Splice is too complicated the operation, start afresh.
+
+// Shrking array.
+var a0 = [0, 1, , , 4, 5, , , , 9]
+var result = a0.splice(4, 1)
+// Side-effects: everything before 4 is kept intact:
+
+assertEquals(0, a0[0])
+assertTrue(a0.hasOwnProperty(0))
+assertEquals(1, a0[1])
+assertTrue(a0.hasOwnProperty(1))
+assertEquals(undefined, a0[2])
+assertFalse(a0.hasOwnProperty(2))
+assertEquals(at3, a0[3])
+assertFalse(a0.hasOwnProperty(3))
+
+// 4 and above shifted left by one reifying at7 into a0[6] and keeping
+// a hole at a0[7]
+
+assertEquals(5, a0[4])
+assertTrue(a0.hasOwnProperty(4))
+assertEquals(undefined, a0[5])
+assertFalse(a0.hasOwnProperty(5))
+assertEquals(at7, a0[6])
+assertTrue(a0.hasOwnProperty(6))
+assertEquals(at7, a0[7])
+assertFalse(a0.hasOwnProperty(7))
+assertEquals(9, a0[8])
+assertTrue(a0.hasOwnProperty(8))
+
+// Growing array.
+var a1 = [0, 1, , , 4, 5, , , , 9]
+var result = a1.splice(4, 0, undefined)
+// Side-effects: everything before 4 is kept intact:
+
+assertEquals(0, a1[0])
+assertTrue(a1.hasOwnProperty(0))
+assertEquals(1, a1[1])
+assertTrue(a1.hasOwnProperty(1))
+assertEquals(undefined, a1[2])
+assertFalse(a1.hasOwnProperty(2))
+assertEquals(at3, a1[3])
+assertFalse(a1.hasOwnProperty(3))
+
+// Now owned undefined resides at 4 and rest is shifted right by one
+// reifying at7 into a0[8] and keeping a hole at a0[7].
+
+assertEquals(undefined, a1[4])
+assertTrue(a1.hasOwnProperty(4))
+assertEquals(4, a1[5])
+assertTrue(a1.hasOwnProperty(5))
+assertEquals(5, a1[6])
+assertTrue(a1.hasOwnProperty(6))
+assertEquals(at7, a1[7])
+assertFalse(a1.hasOwnProperty(7))
+assertEquals(at7, a1[8])
+assertTrue(a1.hasOwnProperty(8))
+assertEquals(undefined, a1[9])
+assertFalse(a1.hasOwnProperty(9))
+assertEquals(9, a1[10])
+assertTrue(a1.hasOwnProperty(10))

test/mjsunit/array-elements-from-object-prototype.js

+// Copyright 2010 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.
+
+////////////////////////////////////////////////////////////////////////
+// Tests below verify that elements set on Object.prototype propagate
+// for various Array.prototype functions (like unshift, shift, etc.)
+// If add any new tests here, consider adding them to all other files:
+//   array-elements-from-array-prototype.js
+//   array-elements-from-array-prototype-chain.js
+//   array-elements-from-object-prototype.js
+// those ideally should be identical modulo host of elements and
+// the way elements introduced.
+//
+// Note: they are put into a separate file as we need maximally clean
+// VM setup---some optimizations might be already turned off in
+// 'dirty' VM.
+////////////////////////////////////////////////////////////////////////
+
+var at3 = '@3'
+var at7 = '@7'
+
+Object.prototype[3] = at3
+Object.prototype[7] = at7
+
+var a = new Array(13)
+
+assertEquals(at3, a[3])
+assertFalse(a.hasOwnProperty(3))
+
+assertEquals(at7, a[7])
+assertFalse(a.hasOwnProperty(7))
+
+assertEquals(undefined, a.shift(), 'hole should be returned as undefined')
+// Side-effects: Array.prototype[3] percolates into a[2] and Array.prototype[7[
+// into a[6], still visible at the corresponding indices.
+
+assertEquals(at3, a[2])
+assertTrue(a.hasOwnProperty(2))
+assertEquals(at3, a[3])
+assertFalse(a.hasOwnProperty(3))
+
+assertEquals(at7, a[6])
+assertTrue(a.hasOwnProperty(6))
+assertEquals(at7, a[7])
+assertFalse(a.hasOwnProperty(7))
+
+a.unshift('foo', 'bar')
+// Side-effects: Array.prototype[3] now percolates into a[5] and Array.prototype[7]
+// into a[9].
+
+assertEquals(at3, a[3])
+assertFalse(a.hasOwnProperty(3))
+assertEquals(at3, a[4])
+assertTrue(a.hasOwnProperty(4))
+assertEquals(at3, a[5])
+assertTrue(a.hasOwnProperty(5))
+
+assertEquals(undefined, a[6])
+assertFalse(a.hasOwnProperty(6))
+
+assertEquals(at7, a[7])
+assertFalse(a.hasOwnProperty(7))
+assertEquals(at7, a[8])
+assertTrue(a.hasOwnProperty(8))
+assertEquals(at7, a[9])
+assertTrue(a.hasOwnProperty(9))
+
+var sliced = a.slice(3, 10)
+// Slice must keep intact a and reify holes at indices 0--2 and 4--6.
+
+assertEquals(at3, a[3])
+assertFalse(a.hasOwnProperty(3))
+assertEquals(at3, a[4])
+assertTrue(a.hasOwnProperty(4))
+assertEquals(at3, a[5])
+assertTrue(a.hasOwnProperty(5))
+
+assertEquals(undefined, a[6])
+assertFalse(a.hasOwnProperty(6))
+
+assertEquals(at7, a[7])
+assertFalse(a.hasOwnProperty(7))
+assertEquals(at7, a[8])
+assertTrue(a.hasOwnProperty(8))
+assertEquals(at7, a[9])
+assertTrue(a.hasOwnProperty(9))
+
+assertEquals(at3, sliced[0])
+assertTrue(sliced.hasOwnProperty(0))
+assertEquals(at3, sliced[1])
+assertTrue(sliced.hasOwnProperty(1))
+assertEquals(at3, sliced[2])
+assertTrue(sliced.hasOwnProperty(2))
+
+// Note: sliced[3] comes directly from Array.prototype[3]
+assertEquals(at3, sliced[3]);
+assertFalse(sliced.hasOwnProperty(3))
+
+assertEquals(at7, sliced[4])
+assertTrue(sliced.hasOwnProperty(4))
+assertEquals(at7, sliced[5])
+assertTrue(sliced.hasOwnProperty(5))
+assertEquals(at7, sliced[6])
+assertTrue(sliced.hasOwnProperty(6))
+
+
+// Splice is too complicated the operation, start afresh.
+
+// Shrking array.
+var a0 = [0, 1, , , 4, 5, , , , 9]
+var result = a0.splice(4, 1)
+// Side-effects: everything before 4 is kept intact:
+
+assertEquals(0, a0[0])
+assertTrue(a0.hasOwnProperty(0))
+assertEquals(1, a0[1])
+assertTrue(a0.hasOwnProperty(1))
+assertEquals(undefined, a0[2])
+assertFalse(a0.hasOwnProperty(2))
+assertEquals(at3, a0[3])
+assertFalse(a0.hasOwnProperty(3))
+
+// 4 and above shifted left by one reifying at7 into a0[6] and keeping
+// a hole at a0[7]
+
+assertEquals(5, a0[4])
+assertTrue(a0.hasOwnProperty(4))
+assertEquals(undefined, a0[5])
+assertFalse(a0.hasOwnProperty(5))
+assertEquals(at7, a0[6])
+assertTrue(a0.hasOwnProperty(6))
+assertEquals(at7, a0[7])
+assertFalse(a0.hasOwnProperty(7))
+assertEquals(9, a0[8])
+assertTrue(a0.hasOwnProperty(8))
+
+// Growing array.
+var a1 = [0, 1, , , 4, 5, , , , 9]
+var result = a1.splice(4, 0, undefined)
+// Side-effects: everything before 4 is kept intact:
+
+assertEquals(0, a1[0])
+assertTrue(a1.hasOwnProperty(0))
+assertEquals(1, a1[1])
+assertTrue(a1.hasOwnProperty(1))
+assertEquals(undefined, a1[2])
+assertFalse(a1.hasOwnProperty(2))
+assertEquals(at3, a1[3])
+assertFalse(a1.hasOwnProperty(3))
+
+// Now owned undefined resides at 4 and rest is shifted right by one
+// reifying at7 into a0[8] and keeping a hole at a0[7].
+
+assertEquals(undefined, a1[4])
+assertTrue(a1.hasOwnProperty(4))
+assertEquals(4, a1[5])
+assertTrue(a1.hasOwnProperty(5))
+assertEquals(5, a1[6])
+assertTrue(a1.hasOwnProperty(6))
+assertEquals(at7, a1[7])
+assertFalse(a1.hasOwnProperty(7))
+assertEquals(at7, a1[8])
+assertTrue(a1.hasOwnProperty(8))
+assertEquals(undefined, a1[9])
+assertFalse(a1.hasOwnProperty(9))
+assertEquals(9, a1[10])
+assertTrue(a1.hasOwnProperty(10))

test/mjsunit/array-splice.js

@@ -287,3 +287,13 @@
     assertEquals(bigNum + 7, array.length);
   }
 })();
+
+(function() {
+  for (var i = 0; i < 7; i++) {
+    var a = [7, 8, 9];
+    a.splice(0, 0, 1, 2, 3, 4, 5, 6);
+    assertEquals([1, 2, 3, 4, 5, 6, 7, 8, 9], a);
+    assertFalse(a.hasOwnProperty(10));
+    assertEquals(undefined, a[10]);
+  }
+})();

test/mjsunit/array-unshift.js

@@ -130,3 +130,11 @@
     assertEquals(bigNum + 7, new Array(bigNum).unshift(1, 2, 3, 4, 5, 6, 7));
   }
 })();
+
+(function() {
+  for (var i = 0; i < 7; i++) {
+    var a = [6, 7, 8, 9];
+    a.unshift(1, 2, 3, 4, 5);
+    assertEquals([1, 2, 3, 4, 5, 6, 7, 8, 9], a);
+  }
+})();

test/mjsunit/fuzz-natives.js

@@ -147,7 +147,10 @@ var knownProblems = {
   "DeclareGlobals": true,
 
   "PromoteScheduledException": true,
-  "DeleteHandleScopeExtensions": true
+  "DeleteHandleScopeExtensions": true,
+
+  // That can only be invoked on Array.prototype.
+  "FinishArrayPrototypeSetup": true
 };
 
 var currentlyUncallable = {

test/mjsunit/undeletable-functions.js

@@ -39,6 +39,13 @@ array = [
   "every", "map", "indexOf", "lastIndexOf", "reduce", "reduceRight"];
 CheckJSCSemantics(Array.prototype, array, "Array prototype");
 
+var old_Array_prototype = Array.prototype;
+var new_Array_prototype = {};
+for (var i = 0; i < 7; i++) {
+  Array.prototype = new_Array_prototype;
+  assertEquals(old_Array_prototype, Array.prototype);
+}
+
 array = [
   "toString", "toDateString", "toTimeString", "toLocaleString",
   "toLocaleDateString", "toLocaleTimeString", "valueOf", "getTime",
@@ -79,6 +86,13 @@ array = [
   "__lookupGetter__", "__defineSetter__", "__lookupSetter__"];
 CheckEcmaSemantics(Object.prototype, array, "Object prototype");
 
+var old_Object_prototype = Object.prototype;
+var new_Object_prototype = {};
+for (var i = 0; i < 7; i++) {
+  Object.prototype = new_Object_prototype;
+  assertEquals(old_Object_prototype, Object.prototype);
+}
+
 array = [
   "toString", "valueOf", "toJSON"];
 CheckEcmaSemantics(Boolean.prototype, array, "Boolean prototype");