Extend test case to check truncation and 64-bit ints.

test/mjsunit/toint32.js

Index: test/mjsunit/toint32.js
===================================================================
--- test/mjsunit/toint32.js	(revision 1332)
+++ test/mjsunit/toint32.js	(working copy)
@@ -42,6 +42,10 @@
 assertEquals(1, toInt32(1));
 assertEquals(1, toInt32(1.1));
 assertEquals(-1, toInt32(-1));
+assertEquals(0, toInt32(0.6), "truncate positive (0.6)");
+assertEquals(1, toInt32(1.6), "truncate positive (1.6)");
+assertEquals(0, toInt32(-0.6), "truncate negative (-0.6)");
+assertEquals(-1, toInt32(-1.6), "truncate negative (-1.6)");
 
 assertEquals(2147483647, toInt32(2147483647));
 assertEquals(-2147483648, toInt32(2147483648));
@@ -78,3 +82,34 @@
 assertEquals(1294967296, toInt32(-3000000000.25));
 assertEquals(1294967296, toInt32(-3000000000.5));
 assertEquals(1294967296, toInt32(-3000000000.75));
+
+var base = Math.pow(2, 64);
+assertEquals(0, toInt32(base + 0));
+assertEquals(0, toInt32(base + 1117));
+assertEquals(4096, toInt32(base + 2234));
+assertEquals(4096, toInt32(base + 3351));
+assertEquals(4096, toInt32(base + 4468));
+assertEquals(4096, toInt32(base + 5585));
+assertEquals(8192, toInt32(base + 6702));
+assertEquals(8192, toInt32(base + 7819));
+assertEquals(8192, toInt32(base + 8936));
+assertEquals(8192, toInt32(base + 10053));
+assertEquals(12288, toInt32(base + 11170));
+assertEquals(12288, toInt32(base + 12287));
+assertEquals(12288, toInt32(base + 13404));
+assertEquals(16384, toInt32(base + 14521));
+assertEquals(16384, toInt32(base + 15638));
+assertEquals(16384, toInt32(base + 16755));
+assertEquals(16384, toInt32(base + 17872));
+assertEquals(20480, toInt32(base + 18989));
+assertEquals(20480, toInt32(base + 20106));
+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));