Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 1 | // Copyright 2009 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. |
| 12 | // * Neither the name of Google Inc. nor the names of its |
| 13 | // contributors may be used to endorse or promote products derived |
| 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 |
| 18 | // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 19 | // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 20 | // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 21 | // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 22 | // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 23 | // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 24 | // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 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 fast div and mod. |
| 29 | |
| 30 | function divmod(div_func, mod_func, x, y) { |
| 31 | var div_answer = (div_func)(x); |
| 32 | assertEquals(x / y, div_answer, x + "/" + y); |
| 33 | var mod_answer = (mod_func)(x); |
| 34 | assertEquals(x % y, mod_answer, x + "%" + y); |
| 35 | var minus_div_answer = (div_func)(-x); |
| 36 | assertEquals(-x / y, minus_div_answer, "-" + x + "/" + y); |
| 37 | var minus_mod_answer = (mod_func)(-x); |
| 38 | assertEquals(-x % y, minus_mod_answer, "-" + x + "%" + y); |
| 39 | } |
| 40 | |
| 41 | |
| 42 | function run_tests_for(divisor) { |
| 43 | print("(function(left) { return left / " + divisor + "; })"); |
| 44 | var div_func = this.eval("(function(left) { return left / " + divisor + "; })"); |
| 45 | var mod_func = this.eval("(function(left) { return left % " + divisor + "; })"); |
| 46 | var exp; |
| 47 | // Strange number test. |
| 48 | divmod(div_func, mod_func, 0, divisor); |
| 49 | divmod(div_func, mod_func, 1 / 0, divisor); |
| 50 | // Floating point number test. |
| 51 | for (exp = -1024; exp <= 1024; exp += 8) { |
| 52 | divmod(div_func, mod_func, Math.pow(2, exp), divisor); |
| 53 | divmod(div_func, mod_func, 0.9999999 * Math.pow(2, exp), divisor); |
| 54 | divmod(div_func, mod_func, 1.0000001 * Math.pow(2, exp), divisor); |
| 55 | } |
| 56 | // Integer number test. |
| 57 | for (exp = 0; exp <= 32; exp++) { |
| 58 | divmod(div_func, mod_func, 1 << exp, divisor); |
| 59 | divmod(div_func, mod_func, (1 << exp) + 1, divisor); |
| 60 | divmod(div_func, mod_func, (1 << exp) - 1, divisor); |
| 61 | } |
| 62 | divmod(div_func, mod_func, Math.floor(0x1fffffff / 3), divisor); |
| 63 | divmod(div_func, mod_func, Math.floor(-0x20000000 / 3), divisor); |
| 64 | } |
| 65 | |
| 66 | |
| 67 | var divisors = [ |
| 68 | 0, |
| 69 | 1, |
| 70 | 2, |
| 71 | 3, |
| 72 | 4, |
| 73 | 5, |
| 74 | 6, |
| 75 | 7, |
| 76 | 8, |
| 77 | 9, |
| 78 | 10, |
| 79 | 0x1000000, |
| 80 | 0x40000000, |
| 81 | 12, |
| 82 | 60, |
| 83 | 100, |
| 84 | 1000 * 60 * 60 * 24]; |
| 85 | |
| 86 | for (var i = 0; i < divisors.length; i++) { |
| 87 | run_tests_for(divisors[i]); |
| 88 | } |
Steve Block | 3ce2e20 | 2009-11-05 08:53:23 +0000 | [diff] [blame^] | 89 | |
| 90 | // Test extreme corner cases of modulo. |
| 91 | |
| 92 | // Computes the modulo by slow but lossless operations. |
| 93 | function compute_mod(dividend, divisor) { |
| 94 | // Return NaN if either operand is NaN, if divisor is 0 or |
| 95 | // dividend is an infinity. Return dividend if divisor is an infinity. |
| 96 | if (isNaN(dividend) || isNaN(divisor) || divisor == 0) { return NaN; } |
| 97 | var sign = 1; |
| 98 | if (dividend < 0) { dividend = -dividend; sign = -1; } |
| 99 | if (dividend == Infinity) { return NaN; } |
| 100 | if (divisor < 0) { divisor = -divisor; } |
| 101 | if (divisor == Infinity) { return sign * dividend; } |
| 102 | function rec_mod(a, b) { |
| 103 | // Subtracts maximal possible multiplum of b from a. |
| 104 | if (a >= b) { |
| 105 | a = rec_mod(a, 2 * b); |
| 106 | if (a >= b) { a -= b; } |
| 107 | } |
| 108 | return a; |
| 109 | } |
| 110 | return sign * rec_mod(dividend, divisor); |
| 111 | } |
| 112 | |
| 113 | (function () { |
| 114 | var large_non_smi = 1234567891234.12245; |
| 115 | var small_non_smi = 43.2367243; |
| 116 | var repeating_decimal = 0.3; |
| 117 | var finite_decimal = 0.5; |
| 118 | var smi = 43; |
| 119 | var power_of_two = 64; |
| 120 | var min_normal = Number.MIN_VALUE * Math.pow(2, 52); |
| 121 | var max_denormal = Number.MIN_VALUE * (Math.pow(2, 52) - 1); |
| 122 | |
| 123 | // All combinations of NaN, Infinity, normal, denormal and zero. |
| 124 | var example_numbers = [ |
| 125 | NaN, |
| 126 | 0, |
| 127 | Number.MIN_VALUE, |
| 128 | 3 * Number.MIN_VALUE, |
| 129 | max_denormal, |
| 130 | min_normal, |
| 131 | repeating_decimal, |
| 132 | finite_decimal, |
| 133 | smi, |
| 134 | power_of_two, |
| 135 | small_non_smi, |
| 136 | large_non_smi, |
| 137 | Number.MAX_VALUE, |
| 138 | Infinity |
| 139 | ]; |
| 140 | |
| 141 | function doTest(a, b) { |
| 142 | var exp = compute_mod(a, b); |
| 143 | var act = a % b; |
| 144 | assertEquals(exp, act, a + " % " + b); |
| 145 | } |
| 146 | |
| 147 | for (var i = 0; i < example_numbers.length; i++) { |
| 148 | for (var j = 0; j < example_numbers.length; j++) { |
| 149 | var a = example_numbers[i]; |
| 150 | var b = example_numbers[j]; |
| 151 | doTest(a,b); |
| 152 | doTest(-a,b); |
| 153 | doTest(a,-b); |
| 154 | doTest(-a,-b); |
| 155 | } |
| 156 | } |
| 157 | })() |