Add signMask getter to Float32x4

tests/lib/typed_data/uint32x4_sign_mask_test.dart

Index: tests/lib/typed_data/uint32x4_sign_mask_test.dart
diff --git a/tests/lib/typed_data/uint32x4_sign_mask_test.dart b/tests/lib/typed_data/uint32x4_sign_mask_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..052d0bf287c0fb073828783e1f6e9decd6c49cd5
--- /dev/null
+++ b/tests/lib/typed_data/uint32x4_sign_mask_test.dart
@@ -0,0 +1,62 @@
+// 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.
+// VMOptions=--optimization-counter-threshold=10
+
+// Library tag to be able to run in html test framework.
+library uint32x4_sign_mask;
+
+import 'dart:typed_data';
+import 'package:expect/expect.dart';
+
+void testImmediates() {
+  var f = new Uint32x4(1, 2, 3, 4);
+  var m = f.signMask;
+  Expect.equals(0x0, m);
+  f = new Uint32x4(-1, -2, -3, -4);
+  m = f.signMask;
+  Expect.equals(0xf, m);
+  f = new Uint32x4.bool(true, false, false, false);
+  m = f.signMask;
+  Expect.equals(0x1, m);
+  f = new Uint32x4.bool(false, true, false, false);
+  m = f.signMask;
+  Expect.equals(0x2, m);
+  f = new Uint32x4.bool(false, false, true, false);
+  m = f.signMask;
+  Expect.equals(0x4, m);
+  f = new Uint32x4.bool(false, false, false, true);
+  m = f.signMask;
+  Expect.equals(0x8, m);
+}
+
+void testZero() {
+  var f = new Uint32x4(0, 0, 0, 0);
+  var m = f.signMask;
+  Expect.equals(0x0, m);
+  f = new Uint32x4(-0, -0, -0, -0);
+  m = f.signMask;
+  Expect.equals(0x0, m);
+}
+
+void testLogic() {
+  var a = new Uint32x4(0x80000000, 0x80000000, 0x80000000, 0x80000000);
+  var b = new Uint32x4(0x70000000, 0x70000000, 0x70000000, 0x70000000);
+  var c = new Uint32x4(0xf0000000, 0xf0000000, 0xf0000000, 0xf0000000);
+  var m1 = (a & c).signMask;
+  Expect.equals(0xf, m1);
+  var m2 = (a & b).signMask;
+  Expect.equals(0x0, m2);
+  var m3 = (b ^ a).signMask;
+  Expect.equals(0xf, m3);
+  var m4 = (b | c).signMask;
+  Expect.equals(0xf, m4);
+}
+
+main() {
+  for (int i = 0; i < 2000; i++) {
+    testImmediates();
+    testZero();
+    testLogic();
+  }
+}