Elements kind conversion in generated code (ia32).

test/mjsunit/elements-kind.js

+// Copyright 2011 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 --smi-only-arrays --expose-gc
+
+// Test element kind of objects.
+// Since --smi-only-arrays affects builtins, its default setting at compile
+// time sticks if built with snapshot.  If --smi-only-arrays is deactivated
+// by default, only a no-snapshot build actually has smi-only arrays enabled
+// in this test case.  Depending on whether smi-only arrays are actually
+// enabled, this test takes the appropriate code path to check smi-only arrays.
+
+
+support_smi_only_arrays = %HasFastSmiOnlyElements([]);
+
+if (support_smi_only_arrays) {
+  print("Tests include smi-only arrays.");
+} else {
+  print("Tests do NOT include smi-only arrays.");
+}
+
+var elements_kind = {
+  fast_smi_only            :  'fast smi only elements',
+  fast                     :  'fast elements',
+  fast_double              :  'fast double elements',
+  dictionary               :  'dictionary elements',
+  external_byte            :  'external byte elements',
+  external_unsigned_byte   :  'external unsigned byte elements',
+  external_short           :  'external short elements',
+  external_unsigned_short  :  'external unsigned short elements',
+  external_int             :  'external int elements',
+  external_unsigned_int    :  'external unsigned int elements',
+  external_float           :  'external float elements',
+  external_double          :  'external double elements',
+  external_pixel           :  'external pixel elements'
+}
+
+function getKind(obj) {
+  if (%HasFastSmiOnlyElements(obj)) return elements_kind.fast_smi_only;
+  if (%HasFastElements(obj)) return elements_kind.fast;
+  if (%HasFastDoubleElements(obj)) return elements_kind.fast_double;
+  if (%HasDictionaryElements(obj)) return elements_kind.dictionary;
+  // Every external kind is also an external array.
+  assertTrue(%HasExternalArrayElements(obj));
+  if (%HasExternalByteElements(obj)) {
+    return elements_kind.external_byte;
+  }
+  if (%HasExternalUnsignedByteElements(obj)) {
+    return elements_kind.external_unsigned_byte;
+  }
+  if (%HasExternalShortElements(obj)) {
+    return elements_kind.external_short;
+  }
+  if (%HasExternalUnsignedShortElements(obj)) {
+    return elements_kind.external_unsigned_short;
+  }
+  if (%HasExternalIntElements(obj)) {
+    return elements_kind.external_int;
+  }
+  if (%HasExternalUnsignedIntElements(obj)) {
+    return elements_kind.external_unsigned_int;
+  }
+  if (%HasExternalFloatElements(obj)) {
+    return elements_kind.external_float;
+  }
+  if (%HasExternalDoubleElements(obj)) {
+    return elements_kind.external_double;
+  }
+  if (%HasExternalPixelElements(obj)) {
+    return elements_kind.external_pixel;
+  }
+}
+
+function assertKind(expected, obj, name_opt) {
+  if (!support_smi_only_arrays &&
+      expected == elements_kind.fast_smi_only) {
+    expected = elements_kind.fast;
+  }
+  assertEquals(expected, getKind(obj), name_opt);

[Jakob Kummerow, 2011/10/13 09:15:59]

Nice! I like this refactoring.

+}
+
+var me = {};
+assertKind(elements_kind.fast, me);
+me.dance = 0xD15C0;
+me.drink = 0xC0C0A;
+assertKind(elements_kind.fast, me);
+
+var too = [1,2,3];
+assertKind(elements_kind.fast_smi_only, too);
+too.dance = 0xD15C0;
+too.drink = 0xC0C0A;
+assertKind(elements_kind.fast_smi_only, too);
+
+// Make sure the element kind transitions from smionly when a non-smi is stored.
+var you = new Array();
+assertKind(elements_kind.fast_smi_only, you);
+for (var i = 0; i < 1337; i++) {
+  var val = i;
+  if (i == 1336) {
+    assertKind(elements_kind.fast_smi_only, you);
+    val = new Object();
+  }
+  you[i] = val;
+}
+assertKind(elements_kind.fast, you);
+
+assertKind(elements_kind.dictionary, new Array(0xDECAF));
+
+var fast_double_array = new Array(0xDECAF);
+for (var i = 0; i < 0xDECAF; i++) fast_double_array[i] = i / 2;
+assertKind(elements_kind.fast_double, fast_double_array);
+
+assertKind(elements_kind.external_byte,           new Int8Array(9001));
+assertKind(elements_kind.external_unsigned_byte,  new Uint8Array(007));
+assertKind(elements_kind.external_short,          new Int16Array(666));
+assertKind(elements_kind.external_unsigned_short, new Uint16Array(42));
+assertKind(elements_kind.external_int,            new Int32Array(0xF));
+assertKind(elements_kind.external_unsigned_int,   new Uint32Array(23));
+assertKind(elements_kind.external_float,          new Float32Array(7));
+assertKind(elements_kind.external_double,         new Float64Array(0));
+assertKind(elements_kind.external_pixel,          new PixelArray(512));
+
+// Crankshaft support for smi-only array elements.
+function monomorphic(array) {
+  for (var i = 0; i < 3; i++) {
+    array[i] = i + 10;
+  }
+  assertKind(elements_kind.fast_smi_only, array);
+  for (var i = 0; i < 3; i++) {
+    var a = array[i];
+    assertEquals(i + 10, a);
+  }
+}
+var smi_only = [1, 2, 3];
+for (var i = 0; i < 3; i++) monomorphic(smi_only);
+%OptimizeFunctionOnNextCall(monomorphic);
+monomorphic(smi_only);
+function polymorphic(array, expected_kind) {
+  array[1] = 42;
+  assertKind(expected_kind, array);
+  var a = array[1];
+  assertEquals(42, a);
+}
+var smis = [1, 2, 3];
+var strings = [0, 0, 0]; strings[0] = "one";
+var doubles = [0, 0, 0]; doubles[0] = 1.5;
+assertKind(support_smi_only_arrays
+               ? elements_kind.fast_double
+               : elements_kind.fast,
+           doubles);
+for (var i = 0; i < 3; i++) {
+  polymorphic(smis, elements_kind.fast_smi_only);
+}
+for (var i = 0; i < 3; i++) {
+  polymorphic(strings, elements_kind.fast);
+}
+for (var i = 0; i < 3; i++) {
+  polymorphic(doubles,  i == 0
+                            ? elements_kind.fast_double
+                            : elements_kind.fast);
+}
+//%OptimizeFunctionOnNextCall(polymorphic);

[Jakob Kummerow, 2011/10/13 09:15:59]

Please add a comment stating why this section is disabled. On a side note, I'd
prefer /*...*/, but leave that up to you.

+//polymorphic(smis, elements_kind.fast_smi_only);
+//polymorphic(strings, elements_kind.fast);
+//polymorphic(doubles, elements_kind.fast);
+//
+//// Crankshaft support for smi-only elements in dynamic array literals.
+//function get(foo) { return foo; }  // Used to generate dynamic values.
+//
+//function crankshaft_test() {
+//  var a = [get(1), get(2), get(3)];
+//  assertKind(elements_kind.fast_smi_only, a);
+//  var b = [get(1), get(2), get("three")];
+//  assertKind(elements_kind.fast, b);
+//  var c = [get(1), get(2), get(3.5)];
+//  // The full code generator doesn't support conversion to fast_double
+//  // yet. Crankshaft does, but only with --smi-only-arrays support.
+//  if ((%GetOptimizationStatus(crankshaft_test) & 1) &&
+//      support_smi_only_arrays) {
+//    assertKind(elements_kind.fast_double, c);
+//  } else {
+//    assertKind(elements_kind.fast, c);
+//  }
+//}
+//for (var i = 0; i < 3; i++) {
+//  crankshaft_test();
+//}
+//%OptimizeFunctionOnNextCall(crankshaft_test);
+//crankshaft_test();
+
+// Elements_kind transitions for arrays.
+
+// A map can have three different elements_kind transitions: SMI->DOUBLE,
+// DOUBLE->OBJECT, and SMI->OBJECT. No matter in which order these three are
+// created, they must always end up with the same FAST map.
+
+// This test is meaningless without FAST_SMI_ONLY_ELEMENTS.
+if (support_smi_only_arrays) {
+  // Preparation: create one pair of identical objects for each case.
+  var a = [1, 2, 3];
+  var b = [1, 2, 3];
+  assertTrue(%HaveSameMap(a, b));
+  assertKind(elements_kind.fast_smi_only, a);
+  var c = [1, 2, 3];
+  c["case2"] = true;
+  var d = [1, 2, 3];
+  d["case2"] = true;
+  assertTrue(%HaveSameMap(c, d));
+  assertFalse(%HaveSameMap(a, c));
+  assertKind(elements_kind.fast_smi_only, c);
+  var e = [1, 2, 3];
+  e["case3"] = true;
+  var f = [1, 2, 3];
+  f["case3"] = true;
+  assertTrue(%HaveSameMap(e, f));
+  assertFalse(%HaveSameMap(a, e));
+  assertFalse(%HaveSameMap(c, e));
+  assertKind(elements_kind.fast_smi_only, e);
+  // Case 1: SMI->DOUBLE, DOUBLE->OBJECT, SMI->OBJECT.
+  a[0] = 1.5;
+  assertKind(elements_kind.fast_double, a);
+  a[0] = "foo";
+  assertKind(elements_kind.fast, a);
+  b[0] = "bar";
+  assertTrue(%HaveSameMap(a, b));
+  // Case 2: SMI->DOUBLE, SMI->OBJECT, DOUBLE->OBJECT.
+  c[0] = 1.5;
+  assertKind(elements_kind.fast_double, c);
+  assertFalse(%HaveSameMap(c, d));
+  d[0] = "foo";
+  assertKind(elements_kind.fast, d);
+  assertFalse(%HaveSameMap(c, d));
+  c[0] = "bar";
+  assertTrue(%HaveSameMap(c, d));
+  // Case 3: SMI->OBJECT, SMI->DOUBLE, DOUBLE->OBJECT.
+  e[0] = "foo";
+  assertKind(elements_kind.fast, e);
+  assertFalse(%HaveSameMap(e, f));
+  f[0] = 1.5;
+  assertKind(elements_kind.fast_double, f);
+  assertFalse(%HaveSameMap(e, f));
+  f[0] = "bar";
+  assertKind(elements_kind.fast, f);
+  assertTrue(%HaveSameMap(e, f));
+}
+
+// Throw away type information in the ICs for next stress run.
+gc();