Optimize Crankshaft array literal initialization from boilerplate.

test/mjsunit/array-literal-transitions.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
@@ skipping 104 matching lines @@
     assertEquals(large,
                  [0, 1, 2, 3, 4, 5, 2.5, 2.5, 2.5, 2.5, 2.5, 2.5,
                   new Object(), new Object(), new Object(), new Object()]);
   }
 
   for (var i = 0; i < 3; i++) {
     test_large_literal();
   }
   %OptimizeFunctionOnNextCall(test_large_literal);
   test_large_literal();
+
+  function deopt_array(use_literal) {
+    if (use_literal) {
+      return [.5, 3, 4];
+    }  else {
+      return new Array();
+    }
+  }
+
+  deopt_array(false);
+  deopt_array(false);
+  deopt_array(false);
+  %OptimizeFunctionOnNextCall(deopt_array);
+  var array = deopt_array(false);
+  assertTrue(2 != %GetOptimizationStatus(deopt_array));
+  deopt_array(true);
+  assertTrue(1 != %GetOptimizationStatus(deopt_array));
+  array = deopt_array(false);
+  assertTrue(1 != %GetOptimizationStatus(deopt_array));
+
+  // Check that unexpected changes in the objects stored into the boilerplate
+  // also force a deopt.
+  function deopt_array_literal_all_smis(a) {
+    return [0, 1, a];
+  }
+
+  deopt_array_literal_all_smis(2);
+  deopt_array_literal_all_smis(3);
+  deopt_array_literal_all_smis(4);
+  array = deopt_array_literal_all_smis(4);
+  assertEquals(0, array[0]);
+  assertEquals(1, array[1]);
+  assertEquals(4, array[2]);
+  %OptimizeFunctionOnNextCall(deopt_array_literal_all_smis);
+  array = deopt_array_literal_all_smis(5);
+  array = deopt_array_literal_all_smis(6);
+  assertTrue(2 != %GetOptimizationStatus(deopt_array_literal_all_smis));
+  assertEquals(0, array[0]);
+  assertEquals(1, array[1]);
+  assertEquals(6, array[2]);
+
+  array = deopt_array_literal_all_smis(.5);
+  assertTrue(1 != %GetOptimizationStatus(deopt_array_literal_all_smis));
+  assertEquals(0, array[0]);
+  assertEquals(1, array[1]);
+  assertEquals(.5, array[2]);
+
+  function deopt_array_literal_all_doubles(a) {
+    return [0.5, 1, a];
+  }
+
+  deopt_array_literal_all_doubles(.5);
+  deopt_array_literal_all_doubles(.5);
+  deopt_array_literal_all_doubles(.5);
+  array = deopt_array_literal_all_doubles(0.5);
+  assertEquals(0.5, array[0]);
+  assertEquals(1, array[1]);
+  assertEquals(0.5, array[2]);
+  %OptimizeFunctionOnNextCall(deopt_array_literal_all_doubles);
+  array = deopt_array_literal_all_doubles(5);
+  array = deopt_array_literal_all_doubles(6);
+  assertTrue(2 != %GetOptimizationStatus(deopt_array_literal_all_doubles));
+  assertEquals(0.5, array[0]);
+  assertEquals(1, array[1]);
+  assertEquals(6, array[2]);
+
+  var foo = new Object();
+  array = deopt_array_literal_all_doubles(foo);;

[Jakob Kummerow, 2011/11/30 14:04:51]

nit: duplicate semicolon

[danno, 2011/12/01 14:41:11]

Done.

+  assertTrue(1 != %GetOptimizationStatus(deopt_array_literal_all_doubles));
+  assertEquals(0.5, array[0]);
+  assertEquals(1, array[1]);
+  assertEquals(foo, array[2]);
 }