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      1 // Copyright 2011 the V8 project authors. All rights reserved.
      2 // Redistribution and use in source and binary forms, with or without
      3 // modification, are permitted provided that the following conditions are
      4 // met:
      5 //
      6 //     * Redistributions of source code must retain the above copyright
      7 //       notice, this list of conditions and the following disclaimer.
      8 //     * Redistributions in binary form must reproduce the above
      9 //       copyright notice, this list of conditions and the following
     10 //       disclaimer in the documentation and/or other materials provided
     11 //       with the distribution.
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     14 //       from this software without specific prior written permission.
     15 //
     16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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     25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     27 
     28 // Test Math.sin and Math.cos.
     29 
     30 // Flags: --allow-natives-syntax
     31 
     32 assertEquals("-Infinity", String(1/Math.sin(-0)));
     33 assertEquals(1, Math.cos(-0));
     34 assertEquals("-Infinity", String(1/Math.tan(-0)));
     35 
     36 // Assert that minus zero does not cause deopt.
     37 function no_deopt_on_minus_zero(x) {
     38   return Math.sin(x) + Math.cos(x) + Math.tan(x);
     39 }
     40 
     41 no_deopt_on_minus_zero(1);
     42 no_deopt_on_minus_zero(1);
     43 %OptimizeFunctionOnNextCall(no_deopt_on_minus_zero);
     44 no_deopt_on_minus_zero(-0);
     45 assertOptimized(no_deopt_on_minus_zero);
     46 
     47 
     48 function sinTest() {
     49   assertEquals(0, Math.sin(0));
     50   assertEquals(1, Math.sin(Math.PI / 2));
     51 }
     52 
     53 function cosTest() {
     54   assertEquals(1, Math.cos(0));
     55   assertEquals(-1, Math.cos(Math.PI));
     56 }
     57 
     58 sinTest();
     59 cosTest();
     60 
     61 // By accident, the slow case for sine and cosine were both sine at
     62 // some point.  This is a regression test for that issue.
     63 var x = Math.pow(2, 30);
     64 assertTrue(Math.sin(x) != Math.cos(x));
     65 
     66 // Ensure that sine and log are not the same.
     67 x = 0.5;
     68 assertTrue(Math.sin(x) != Math.log(x));
     69 
     70 // Test against approximation by series.
     71 var factorial = [1];
     72 var accuracy = 50;
     73 for (var i = 1; i < accuracy; i++) {
     74   factorial[i] = factorial[i-1] * i;
     75 }
     76 
     77 // We sum up in the reverse order for higher precision, as we expect the terms
     78 // to grow smaller for x reasonably close to 0.
     79 function precision_sum(array) {
     80   var result = 0;
     81   while (array.length > 0) {
     82     result += array.pop();
     83   }
     84   return result;
     85 }
     86 
     87 function sin(x) {
     88   var sign = 1;
     89   var x2 = x*x;
     90   var terms = [];
     91   for (var i = 1; i < accuracy; i += 2) {
     92     terms.push(sign * x / factorial[i]);
     93     x *= x2;
     94     sign *= -1;
     95   }
     96   return precision_sum(terms);
     97 }
     98 
     99 function cos(x) {
    100   var sign = -1;
    101   var x2 = x*x;
    102   x = x2;
    103   var terms = [1];
    104   for (var i = 2; i < accuracy; i += 2) {
    105     terms.push(sign * x / factorial[i]);
    106     x *= x2;
    107     sign *= -1;
    108   }
    109   return precision_sum(terms);
    110 }
    111 
    112 function abs_error(fun, ref, x) {
    113   return Math.abs(ref(x) - fun(x));
    114 }
    115 
    116 var test_inputs = [];
    117 for (var i = -10000; i < 10000; i += 177) test_inputs.push(i/1257);
    118 var epsilon = 0.0000001;
    119 
    120 test_inputs.push(0);
    121 test_inputs.push(0 + epsilon);
    122 test_inputs.push(0 - epsilon);
    123 test_inputs.push(Math.PI/2);
    124 test_inputs.push(Math.PI/2 + epsilon);
    125 test_inputs.push(Math.PI/2 - epsilon);
    126 test_inputs.push(Math.PI);
    127 test_inputs.push(Math.PI + epsilon);
    128 test_inputs.push(Math.PI - epsilon);
    129 test_inputs.push(- 2*Math.PI);
    130 test_inputs.push(- 2*Math.PI + epsilon);
    131 test_inputs.push(- 2*Math.PI - epsilon);
    132 
    133 var squares = [];
    134 for (var i = 0; i < test_inputs.length; i++) {
    135   var x = test_inputs[i];
    136   var err_sin = abs_error(Math.sin, sin, x);
    137   var err_cos = abs_error(Math.cos, cos, x)
    138   assertEqualsDelta(0, err_sin, 1E-13);
    139   assertEqualsDelta(0, err_cos, 1E-13);
    140   squares.push(err_sin*err_sin + err_cos*err_cos);
    141 }
    142 
    143 // Sum squares up by adding them pairwise, to avoid losing precision.
    144 while (squares.length > 1) {
    145   var reduced = [];
    146   if (squares.length % 2 == 1) reduced.push(squares.pop());
    147   // Remaining number of elements is even.
    148   while(squares.length > 1) reduced.push(squares.pop() + squares.pop());
    149   squares = reduced;
    150 }
    151 
    152 var err_rms = Math.sqrt(squares[0] / test_inputs.length / 2);
    153 assertEqualsDelta(0, err_rms, 1E-14);
    154 
    155 assertEquals(-1, Math.cos({ valueOf: function() { return Math.PI; } }));
    156 assertEquals(0, Math.sin("0x00000"));
    157 assertEquals(1, Math.cos("0x00000"));
    158 assertTrue(isNaN(Math.sin(Infinity)));
    159 assertTrue(isNaN(Math.cos("-Infinity")));
    160 assertEquals("Infinity", String(Math.tan(Math.PI/2)));
    161 assertEquals("-Infinity", String(Math.tan(-Math.PI/2)));
    162 assertEquals("-Infinity", String(1/Math.sin("-0")));
    163 
    164 // Assert that the remainder after division by pi is reasonably precise.
    165 function assertError(expected, x, epsilon) {
    166   assertTrue(Math.abs(x - expected) < epsilon);
    167 }
    168 
    169 assertEqualsDelta(0.9367521275331447,  Math.cos(1e06),  1e-15);
    170 assertEqualsDelta(0.8731196226768560,  Math.cos(1e10),  1e-08);
    171 assertEqualsDelta(0.9367521275331447,  Math.cos(-1e06), 1e-15);
    172 assertEqualsDelta(0.8731196226768560,  Math.cos(-1e10), 1e-08);
    173 assertEqualsDelta(-0.3499935021712929, Math.sin(1e06),  1e-15);
    174 assertEqualsDelta(-0.4875060250875106, Math.sin(1e10),  1e-08);
    175 assertEqualsDelta(0.3499935021712929,  Math.sin(-1e06), 1e-15);
    176 assertEqualsDelta(0.4875060250875106,  Math.sin(-1e10), 1e-08);
    177 assertEqualsDelta(0.7796880066069787,  Math.sin(1e16),  1e-05);
    178 assertEqualsDelta(-0.6261681981330861, Math.cos(1e16),  1e-05);
    179 
    180 // Assert that remainder calculation terminates.
    181 for (var i = -1024; i < 1024; i++) {
    182   assertFalse(isNaN(Math.sin(Math.pow(2, i))));
    183 }
    184 
    185 assertFalse(isNaN(Math.cos(1.57079632679489700)));
    186 assertFalse(isNaN(Math.cos(-1e-100)));
    187 assertFalse(isNaN(Math.cos(-1e-323)));
    188