Adapt Danno's Track Allocation Info idea to fast literals. When allocating a literal array,

test/mjsunit/array-natives-elements.js

Index: test/mjsunit/array-natives-elements.js
diff --git a/test/mjsunit/array-natives-elements.js b/test/mjsunit/array-natives-elements.js
index 96a8cb5d1984fd6a54089b103fb90190befd7fa1..f5911d3864e1a9c3a169b2c8468a418fc2fda722 100644
--- a/test/mjsunit/array-natives-elements.js
+++ b/test/mjsunit/array-natives-elements.js
@@ -57,17 +57,27 @@ function array_natives_test() {
 
   // Push
   var a0 = [1, 2, 3];
-  assertTrue(%HasFastSmiElements(a0));
-  a0.push(4);
-  assertTrue(%HasFastSmiElements(a0));
-  a0.push(1.3);
-  assertTrue(%HasFastDoubleElements(a0));
-  a0.push(1.5);
-  assertTrue(%HasFastDoubleElements(a0));
-  a0.push({});
-  assertTrue(%HasFastObjectElements(a0));
-  a0.push({});
-  assertTrue(%HasFastObjectElements(a0));
+  if (%HasFastSmiElements(a0)) {
+    assertTrue(%HasFastSmiElements(a0));
+    a0.push(4);
+    assertTrue(%HasFastSmiElements(a0));
+    a0.push(1.3);
+    assertTrue(%HasFastDoubleElements(a0));
+    a0.push(1.5);
+    assertTrue(%HasFastDoubleElements(a0));
+    a0.push({});
+    assertTrue(%HasFastObjectElements(a0));
+    a0.push({});
+    assertTrue(%HasFastObjectElements(a0));
+  } else {
+    assertTrue(%HasFastObjectElements(a0));
+    a0.push(4);
+    a0.push(1.3);
+    a0.push(1.5);
+    a0.push({});
+    a0.push({});
+    assertTrue(%HasFastObjectElements(a0));
+  }
   assertEquals([1,2,3,4,1.3,1.5,{},{}], a0);
 
   // Concat
@@ -304,4 +314,4 @@ if (support_smi_only_arrays) {
   }
   %OptimizeFunctionOnNextCall(array_natives_test);
   array_natives_test();
-}
+}

[danno, 2013/01/04 08:50:55]

unintended whitespace change?

[mvstanton, 2013/01/04 12:07:52]

Done.