Even more tests of ToInt32 conversion (from Lasse).

test/mjsunit/toint32.js

 // Copyright 2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 95 matching lines @@
 assertEquals(20480, toInt32(base + 21223));
 assertEquals(20480, toInt32(base + 22340));
 assertEquals(24576, toInt32(base + 23457));
 assertEquals(24576, toInt32(base + 24574));
 assertEquals(24576, toInt32(base + 25691));
 assertEquals(28672, toInt32(base + 26808));
 assertEquals(28672, toInt32(base + 27925));
 assertEquals(28672, toInt32(base + 29042));
 assertEquals(28672, toInt32(base + 30159));
 assertEquals(32768, toInt32(base + 31276));
+
+// bignum is (2^53 - 1) * 2^31 - highest number with bit 31 set.
+var bignum = Math.pow(2, 84) - Math.pow(2, 31);
+assertEquals(-Math.pow(2,31), toInt32(bignum));
+assertEquals(-Math.pow(2,31), toInt32(-bignum));
+assertEquals(0, toInt32(2 * bignum));
+assertEquals(0, toInt32(-(2 * bignum)));
+assertEquals(0, toInt32(bignum - Math.pow(2,31)));
+assertEquals(0, toInt32(-(bignum - Math.pow(2,31))));
+
+// max_fraction is largest number below 1.
+var max_fraction = (1 - Math.pow(2,-53));
+assertEquals(0, toInt32(max_fraction));
+assertEquals(0, toInt32(-max_fraction));