Additional work to get array literal allocation tracking working, even with --always-opt

test/mjsunit/allocation-site-info.js

+// 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 --smi-only-arrays --expose-gc
+// Flags: --track-allocation-sites
+
+// 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 = %HasFastSmiElements(new Array(1,2,3,4,5,6,7,8));
+
+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 (%HasFastSmiElements(obj)) return elements_kind.fast_smi_only;
+  if (%HasFastObjectElements(obj)) return elements_kind.fast;
+  if (%HasFastDoubleElements(obj)) return elements_kind.fast_double;
+  if (%HasDictionaryElements(obj)) return elements_kind.dictionary;
+}
+
+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);
+}
+
+if (support_smi_only_arrays) {
+    function fastliteralcase(value) {
+        var literal = [1, 2, 3];
+        literal[0] = value;
+        return literal;
+    }
+
+    // Case: [1,2,3] as allocation site
+    obj = fastliteralcase(1);
+    assertKind(elements_kind.fast_smi_only, obj);
+    obj = fastliteralcase(1.5);
+    assertKind(elements_kind.fast_double, obj);
+    obj = fastliteralcase(2);
+    assertKind(elements_kind.fast_double, obj);
+
+    // Verify that we will not pretransition the double->fast path.
+    obj = fastliteralcase("elliot");
+    assertKind(elements_kind.fast, obj);
+
+    // This fails until we turn off optimistic transitions to the
+    // most general elements kind seen on keyed stores. It's a goal
+    // to turn it off, but for now we need it.
+    // obj = fastliteralcase(3);
+    // assertKind(elements_kind.fast_double, obj);
+
+    function fastliteralcase_smifast(value) {
+        var literal = [1, 2, 3, 4];
+        literal[0] = value;
+        return literal;
+    }
+
+    obj = fastliteralcase_smifast(1);
+    assertKind(elements_kind.fast_smi_only, obj);
+    obj = fastliteralcase_smifast("carter");
+    assertKind(elements_kind.fast, obj);
+    obj = fastliteralcase_smifast(2);
+    assertKind(elements_kind.fast, obj);
+}