test/mjsunit/div-mod.js

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// 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]);
}