On Ia32 optimistically assume that results from int32 and uint32 array loads fit into Smi. Only if …

tests/standalone/int_array_deopt.dart

+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+//
+// Dart deoptimization of Uint32Array and Int32Array loads.
+
+import 'dart:scalarlist';
+
+loadI32(a) => a[0] + 1;
+loadUi32(a) => a[0] + 1;
+
+main() {
+  var i32 = new Int32List(10);
+  var ui32 = new Uint32List(10);
+  i32[0] = ui32[0] = 8;
+  // Optimize loadI32 and LoadUi32 for Smi result of indexed load.
+  for (int i = 0; i < 2000; i++) {
+    Expect.equals(9, loadI32(i32));
+    Expect.equals(9, loadUi32(ui32));
+  }
+  // On ia32, deoptimize when attempting to load a value that exceeds
+  // Smi range.
+  i32[0] = ui32[0] = 2147483647;
+  Expect.equals(2147483648, loadI32(i32));
+  Expect.equals(2147483648, loadUi32(ui32));
+  // Reoptimize again, but this time assume mixed Smi/Mint results
+  i32[0] = ui32[0] = 10;
+  for (int i = 0; i < 2000; i++) {
+    Expect.equals(11, loadI32(i32));
+    Expect.equals(11, loadUi32(ui32));
+  }
+}