Reland 8636: Implement setting the length property for FixedDoubleArrays.

test/mjsunit/unbox-double-arrays.js

Index: test/mjsunit/unbox-double-arrays.js
diff --git a/test/mjsunit/unbox-double-arrays.js b/test/mjsunit/unbox-double-arrays.js
index 312955bde94df50688c6b84e76a3bd666c9d0888..11498389b38835bdae56485c3c2b042292ac4e45 100644
--- a/test/mjsunit/unbox-double-arrays.js
+++ b/test/mjsunit/unbox-double-arrays.js
@@ -28,8 +28,8 @@
 // Test dictionary -> double elements -> dictionary elements round trip
 
 // Flags: --allow-natives-syntax --unbox-double-arrays --expose-gc
-var large_array_size = 500000;
-var approx_dict_to_elements_threshold = 69000;
+var large_array_size = 100000;
+var approx_dict_to_elements_threshold = 75000;
 
 var name = 0;
 
@@ -42,14 +42,21 @@ function expected_array_value(i) {
 }
 
 function force_to_fast_double_array(a) {
+  a[large_array_size - 2] = 1;
   for (var i= 0; i < approx_dict_to_elements_threshold; ++i ) {
     a[i] = expected_array_value(i);
   }
   assertTrue(%HasFastDoubleElements(a));
 }
 
+function make_object_like_array(size) {
+  obj = new Object();
+  obj.length = size;
+  return obj;
+}
+
 function testOneArrayType(allocator) {
-  var large_array = new allocator(500000);
+  var large_array = new allocator(large_array_size);
   force_to_fast_double_array(large_array);
   var six = 6;
 
@@ -319,35 +326,94 @@ function testOneArrayType(allocator) {
 
   // Make sure that we haven't converted from fast double.
   assertTrue(%HasFastDoubleElements(large_array));
-  // Cause the array to grow beyond it's JSArray length. This will double the
-  // size of the capacity and force the array into "slow" dictionary case.
-  large_array[large_array_size+1] = 50;
-  assertTrue(%HasDictionaryElements(large_array));
-  assertEquals(50, large_array[large_array_size+1]);
-  assertEquals(large_array_size+2, large_array.length);
-  assertEquals(Infinity, large_array[5]);
-  assertEquals(undefined, large_array[large_array_size-1]);
-  assertEquals(undefined, large_array[-1]);
-  assertEquals(large_array_size+2, large_array.length);
-
-  // Test dictionary -> double elements -> fast elements.
-  var large_array2 = new allocator(large_array_size);
-  force_to_fast_double_array(large_array2);
-  delete large_array2[5];
-
-  // Convert back to fast elements and make sure the contents of the array are
-  // unchanged.
-  large_array2[25] = new Object();
-  assertTrue(%HasFastElements(large_array2));
-  for (var i= 0; i < approx_dict_to_elements_threshold; i += 500 ) {
-    if (i != 25 && i != 5) {
-      assertEquals(expected_array_value(i), large_array2[i]);
-    }
-  }
-  assertEquals(undefined, large_array2[5])
-      assertEquals(undefined, large_array2[large_array_size-1])
-      assertEquals(undefined, large_array2[-1])
-      assertEquals(large_array_size, large_array2.length);
 }
 
+testOneArrayType(make_object_like_array);
 testOneArrayType(Array);
+
+var large_array = new Array(large_array_size);
+force_to_fast_double_array(large_array);
+assertTrue(%HasFastDoubleElements(large_array));
+
+// Cause the array to grow beyond it's JSArray length. This will double the
+// size of the capacity and force the array into "slow" dictionary case.
+large_array[5] = Infinity;
+large_array[large_array_size+10001] = 50;
+assertTrue(%HasDictionaryElements(large_array));
+assertEquals(50, large_array[large_array_size+10001]);
+assertEquals(large_array_size+10002, large_array.length);
+assertEquals(Infinity, large_array[5]);
+assertEquals(undefined, large_array[large_array_size-1]);
+assertEquals(undefined, large_array[-1]);
+assertEquals(large_array_size+10002, large_array.length);
+
+// Test dictionary -> double elements -> fast elements.
+var large_array2 = new Array(large_array_size);
+force_to_fast_double_array(large_array2);
+delete large_array2[5];
+
+// Convert back to fast elements and make sure the contents of the array are
+// unchanged.
+large_array2[25] = new Object();
+assertTrue(%HasFastElements(large_array2));
+for (var i= 0; i < approx_dict_to_elements_threshold; i += 500 ) {
+  if (i != 25 && i != 5) {
+    assertEquals(expected_array_value(i), large_array2[i]);
+  }
+}
+assertEquals(undefined, large_array2[5]);
+assertEquals(undefined, large_array2[large_array_size-1]);
+assertEquals(undefined, large_array2[-1]);
+assertEquals(large_array_size, large_array2.length);
+
+// Make sure it's possible to change the array's length and that array is still
+// intact after the resize.
+var large_array3 = new Array(large_array_size);
+force_to_fast_double_array(large_array3);
+large_array3.length = 60000;
+assertEquals(60000, large_array3.length);
+assertEquals(undefined, large_array3[60000]);
+assertTrue(%HasFastDoubleElements(large_array3));
+assertEquals(expected_array_value(5), large_array3[5]);
+assertEquals(expected_array_value(6), large_array3[6]);
+assertEquals(expected_array_value(7), large_array3[7]);
+assertEquals(expected_array_value(large_array3.length-1),
+             large_array3[large_array3.length-1]);
+assertEquals(undefined, large_array3[large_array_size-1]);
+assertEquals(undefined, large_array3[-1]);
+gc();
+
+for (var i= 0; i < large_array3.length; i += 501 ) {
+  assertEquals(expected_array_value(i), large_array3[i]);
+}
+
+large_array3.length = 25;
+assertEquals(25, large_array3.length);
+assertTrue(%HasFastDoubleElements(large_array3));
+assertEquals(undefined, large_array3[25]);
+assertEquals(expected_array_value(5), large_array3[5]);
+assertEquals(expected_array_value(6), large_array3[6]);
+assertEquals(expected_array_value(7), large_array3[7]);
+assertEquals(expected_array_value(large_array3.length-1),
+             large_array3[large_array3.length-1]);
+assertEquals(undefined, large_array3[large_array_size-1]);
+assertEquals(undefined, large_array3[-1]);
+gc();
+
+for (var i= 0; i < large_array3.length; ++i) {
+  assertEquals(expected_array_value(i), large_array3[i]);
+}
+
+large_array3.length = 100;
+assertEquals(100, large_array3.length);
+large_array3[95] = 95;
+assertTrue(%HasFastDoubleElements(large_array3));
+assertEquals(undefined, large_array3[100]);
+assertEquals(95, large_array3[95]);
+assertEquals(expected_array_value(5), large_array3[5]);
+assertEquals(expected_array_value(6), large_array3[6]);
+assertEquals(expected_array_value(7), large_array3[7]);
+assertEquals(undefined, large_array3[large_array3.length-1]);
+assertEquals(undefined, large_array3[large_array_size-1]);
+assertEquals(undefined, large_array3[-1]);
+gc();