Faster 64-bit right-shift for the ia32 compiler.

tests/language/bit_operations_test.dart

 // Copyright (c) 2011, 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 test for testing bitwise operations.
 
 class BitOperationsTest {
   static testMain() {
     for (int i = 0; i < 4; i++) {
       testOne();
     }
@@ skipping 36 matching lines @@
     Expect.equals(15, 0xF00000000 >> 32);
     Expect.equals(1030792151040, 16492674416655 >> 4);
 
     Expect.equals(0xF0000000000000000F0, 0xF0000000000000000F << 4);
     Expect.equals(0xF00000000, 15 << 32);
 
     TestNegativeValueShifts();
     TestPositiveValueShifts();
     TestNoMaskingOfShiftCount();
     TestNegativeCountShifts();
-    for (int i = 0; i < 1000; i++) {
-      TestCornerCasesLeftShifts();
+    for (int i = 0; i < 10000; i++) {
+      TestCornerCasesRightShifts();
+      TestRightShift64Bit();
     }
   }
 
-  static void TestCornerCasesLeftShifts() {
+  static void TestCornerCasesRightShifts() {
     var v32 = 0xFF000000;
     var v64 = 0xFF00000000000000;
     Expect.equals(0x3, v32 >> 0x1E);
     Expect.equals(0x1, v32 >> 0x1F);
     Expect.equals(0x0, v32 >> 0x20);
     Expect.equals(0x3, v64 >> 0x3E);
     Expect.equals(0x1, v64 >> 0x3F);
     Expect.equals(0x0, v64 >> 0x40);
   }
 
+  static void TestRightShift64Bit() {
+    var t = 0x1ffffffff;
+    Expect.equals(0xffffffff, t >> 1);
+  }
+
   static void TestNegativeCountShifts() {
     bool throwOnLeft(a, b) {
       try {
         var x = a << b;
         return false;
       } catch (e) {
         return true;
       }
     }
 
@@ skipping 49 matching lines @@
     }
   }
 
   static int ShiftLeft(int a, int b) { return a << b; }
   static int ShiftRight(int a, int b) { return a >> b; }
 }
 
 main() {
   BitOperationsTest.testMain();
 }