v8/test/mjsunit/div-mod.js
2010-03-23 15:18:00 +00:00

193 lines
6.0 KiB
JavaScript

// Copyright 2009 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
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// Test fast div and mod.
function divmod(div_func, mod_func, x, y) {
var div_answer = (div_func)(x);
assertEquals(x / y, div_answer, x + "/" + y);
var mod_answer = (mod_func)(x);
assertEquals(x % y, mod_answer, x + "%" + y);
var minus_div_answer = (div_func)(-x);
assertEquals(-x / y, minus_div_answer, "-" + x + "/" + y);
var minus_mod_answer = (mod_func)(-x);
assertEquals(-x % y, minus_mod_answer, "-" + x + "%" + y);
}
function run_tests_for(divisor) {
print("(function(left) { return left / " + divisor + "; })");
var div_func = this.eval("(function(left) { return left / " + divisor + "; })");
var mod_func = this.eval("(function(left) { return left % " + divisor + "; })");
var exp;
// Strange number test.
divmod(div_func, mod_func, 0, divisor);
divmod(div_func, mod_func, 1 / 0, divisor);
// Floating point number test.
for (exp = -1024; exp <= 1024; exp += 8) {
divmod(div_func, mod_func, Math.pow(2, exp), divisor);
divmod(div_func, mod_func, 0.9999999 * Math.pow(2, exp), divisor);
divmod(div_func, mod_func, 1.0000001 * Math.pow(2, exp), divisor);
}
// Integer number test.
for (exp = 0; exp <= 32; exp++) {
divmod(div_func, mod_func, 1 << exp, divisor);
divmod(div_func, mod_func, (1 << exp) + 1, divisor);
divmod(div_func, mod_func, (1 << exp) - 1, divisor);
}
divmod(div_func, mod_func, Math.floor(0x1fffffff / 3), divisor);
divmod(div_func, mod_func, Math.floor(-0x20000000 / 3), divisor);
}
var divisors = [
0,
1,
2,
3,
4,
5,
6,
7,
8,
9,
10,
0x1000000,
0x40000000,
12,
60,
100,
1000 * 60 * 60 * 24];
for (var i = 0; i < divisors.length; i++) {
run_tests_for(divisors[i]);
}
// Test extreme corner cases of modulo.
// Computes the modulo by slow but lossless operations.
function compute_mod(dividend, divisor) {
// Return NaN if either operand is NaN, if divisor is 0 or
// dividend is an infinity. Return dividend if divisor is an infinity.
if (isNaN(dividend) || isNaN(divisor) || divisor == 0) { return NaN; }
var sign = 1;
if (dividend < 0) { dividend = -dividend; sign = -1; }
if (dividend == Infinity) { return NaN; }
if (divisor < 0) { divisor = -divisor; }
if (divisor == Infinity) { return sign * dividend; }
function rec_mod(a, b) {
// Subtracts maximal possible multiplum of b from a.
if (a >= b) {
a = rec_mod(a, 2 * b);
if (a >= b) { a -= b; }
}
return a;
}
return sign * rec_mod(dividend, divisor);
}
(function () {
var large_non_smi = 1234567891234.12245;
var small_non_smi = 43.2367243;
var repeating_decimal = 0.3;
var finite_decimal = 0.5;
var smi = 43;
var power_of_two = 64;
var min_normal = Number.MIN_VALUE * Math.pow(2, 52);
var max_denormal = Number.MIN_VALUE * (Math.pow(2, 52) - 1);
// All combinations of NaN, Infinity, normal, denormal and zero.
var example_numbers = [
NaN,
0,
Number.MIN_VALUE,
3 * Number.MIN_VALUE,
max_denormal,
min_normal,
repeating_decimal,
finite_decimal,
smi,
power_of_two,
small_non_smi,
large_non_smi,
Number.MAX_VALUE,
Infinity
];
function doTest(a, b) {
var exp = compute_mod(a, b);
var act = a % b;
assertEquals(exp, act, a + " % " + b);
}
for (var i = 0; i < example_numbers.length; i++) {
for (var j = 0; j < example_numbers.length; j++) {
var a = example_numbers[i];
var b = example_numbers[j];
doTest(a,b);
doTest(-a,b);
doTest(a,-b);
doTest(-a,-b);
}
}
})();
(function () {
// Edge cases
var zero = 0;
var minsmi32 = -0x40000000;
var minsmi64 = -0x80000000;
var somenum = 3532;
assertEquals(-0, zero / -1, "0 / -1");
assertEquals(1, minsmi32 / -0x40000000, "minsmi/minsmi-32");
assertEquals(1, minsmi64 / -0x80000000, "minsmi/minsmi-64");
assertEquals(somenum, somenum % -0x40000000, "%minsmi-32");
assertEquals(somenum, somenum % -0x80000000, "%minsmi-64");
})();
// Side-effect-free expressions containing bit operations use
// an optimized compiler with int32 values. Ensure that modulus
// produces negative zeros correctly.
function negative_zero_modulus_test() {
var x = 4;
var y = -4;
x = x + x - x;
y = y + y - y;
var z = (y | y | y | y) % x;
assertEquals(-1 / 0, 1 / z);
z = (x | x | x | x) % x;
assertEquals(1 / 0, 1 / z);
z = (y | y | y | y) % y;
assertEquals(-1 / 0, 1 / z);
z = (x | x | x | x) % y;
assertEquals(1 / 0, 1 / z);
}
negative_zero_modulus_test();