fdlibm: reduce accuracy slightly in favor of performance.

test/mjsunit/sin-cos.js

 // Copyright 2011 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 207 matching lines @@
 assertEquals(0.41421356237309503, Math.tan(Math.PI / 8));
 
 // Tests for Math.sin.
 assertEquals(0.479425538604203, Math.sin(0.5));
 assertEquals(-0.479425538604203, Math.sin(-0.5));
 assertEquals(1, Math.sin(Math.PI/2));
 assertEquals(-1, Math.sin(-Math.PI/2));
 assertEquals(1.2246467991473532e-16, Math.sin(Math.PI));
 assertEquals(-7.047032979958965e-14, Math.sin(2200*Math.PI));
 assertEquals(-0.7071067811865477, Math.sin(7/4 * Math.PI));
-assertEquals(0.7071067811865474, Math.sin(9/4 * Math.PI));
+// assertEquals(0.7071067811865474, Math.sin(9/4 * Math.PI));
 assertEquals(0.7071067811865483, Math.sin(11/4 * Math.PI));
-assertEquals(-0.7071067811865479, Math.sin(13/4 * Math.PI));
+// assertEquals(-0.7071067811865479, Math.sin(13/4 * Math.PI));
 assertEquals(-3.2103381051568376e-11, Math.sin(1048576/4 * Math.PI));
 
 // Tests for Math.cos.
 assertEquals(1, Math.cos(two_28));
 assertEquals(0.9689124217106447, Math.cos(0.25));
 assertEquals(0.8775825618903728, Math.cos(0.5));
 assertEquals(0.7073882691671998, Math.cos(0.785));
 assertEquals(6.123233995736766e-17, Math.cos(Math.PI/2));
 assertEquals(0.7071067811865474, Math.cos(7/4 * Math.PI));
 assertEquals(0.7071067811865477, Math.cos(9/4 * Math.PI));
 assertEquals(-0.7071067811865467, Math.cos(11/4 * Math.PI));
-assertEquals(-0.7071067811865471, Math.cos(13/4 * Math.PI));
+// assertEquals(-0.7071067811865471, Math.cos(13/4 * Math.PI));
 assertEquals(0.9367521275331447, Math.cos(1000000));
 assertEquals(-3.435757038074824e-12, Math.cos(1048575/2 * Math.PI));
 
 // Tests for Math.tan.
 assertEquals(two_28, Math.tan(two_28));
 assertEquals(1.633123935319537e16, Math.tan(Math.PI/2));
 assertEquals(0.5463024898437905, Math.tan(0.5));
 assertEquals(0.8211418015898941, Math.tan(11/16));
-assertEquals(2.0000000000000027, Math.tan(1.107148717794091));
+// assertEquals(2.0000000000000027, Math.tan(1.107148717794091));
 assertEquals(-1.0000000000000004, Math.tan(7/4*Math.PI));
 assertEquals(0.9999999999999994, Math.tan(9/4*Math.PI));
 assertEquals(-6.420676210313675e-11, Math.tan(1048576/2*Math.PI));
 assertEquals(2.910566692924059e11, Math.tan(1048575/2*Math.PI));