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// Copyright 2006-2008 the V8 project authors. All rights reserved.
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// 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.


// Keep reference to original values of some global properties.  This
// has the added benefit that the code in this file is isolated from
// changes to these properties.
const $Infinity = global.Infinity;
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const $floor = MathFloor;
const $random = MathRandom;
const $abs = MathAbs;
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// Instance class name can only be set on functions. That is the only
// purpose for MathConstructor.
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function MathConstructor() {}
%FunctionSetInstanceClassName(MathConstructor, 'Math');
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const $Math = new MathConstructor();
$Math.__proto__ = global.Object.prototype;
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%SetProperty(global, "Math", $Math, DONT_ENUM);
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// ECMA 262 - 15.8.2.1
function MathAbs(x) {
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  if (%_IsSmi(x)) return x >= 0 ? x : -x;
  if (!IS_NUMBER(x)) x = ToNumber(x);
  return %Math_abs(x);
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}
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// ECMA 262 - 15.8.2.2
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function MathAcos(x) {
  if (!IS_NUMBER(x)) x = ToNumber(x);
  return %Math_acos(x);
}
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// ECMA 262 - 15.8.2.3
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function MathAsin(x) {
  if (!IS_NUMBER(x)) x = ToNumber(x);
  return %Math_asin(x);
}
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// ECMA 262 - 15.8.2.4
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function MathAtan(x) {
  if (!IS_NUMBER(x)) x = ToNumber(x);
  return %Math_atan(x);
}
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// ECMA 262 - 15.8.2.5
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// The naming of y and x matches the spec, as does the order in which
// ToNumber (valueOf) is called.
function MathAtan2(y, x) {
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  if (!IS_NUMBER(y)) y = ToNumber(y);
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  if (!IS_NUMBER(x)) x = ToNumber(x);
  return %Math_atan2(y, x);
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}
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// ECMA 262 - 15.8.2.6
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function MathCeil(x) {
  if (!IS_NUMBER(x)) x = ToNumber(x);
  return %Math_ceil(x);
}
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// ECMA 262 - 15.8.2.7
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function MathCos(x) {
  if (!IS_NUMBER(x)) x = ToNumber(x);
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  return %_Math_cos(x);
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}
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// ECMA 262 - 15.8.2.8
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function MathExp(x) {
  if (!IS_NUMBER(x)) x = ToNumber(x);
  return %Math_exp(x);
}
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// ECMA 262 - 15.8.2.9
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function MathFloor(x) {
  if (!IS_NUMBER(x)) x = ToNumber(x);
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  // It's more common to call this with a positive number that's out
  // of range than negative numbers; check the upper bound first.
  if (x <= 0x7FFFFFFF && x > 0) {
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    // Numbers in the range [0, 2^31) can be floored by converting
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    // them to an unsigned 32-bit value using the shift operator.
    // We avoid doing so for -0, because the result of Math.floor(-0)
    // has to be -0, which wouldn't be the case with the shift.
    return x << 0;
  } else {
    return %Math_floor(x);
  }
}
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// ECMA 262 - 15.8.2.10
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function MathLog(x) {
  if (!IS_NUMBER(x)) x = ToNumber(x);
  return %Math_log(x);
}
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// ECMA 262 - 15.8.2.11
function MathMax(arg1, arg2) {  // length == 2
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  var r = -$Infinity;
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  var length = %_ArgumentsLength();
  for (var i = 0; i < length; i++) {
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    var n = ToNumber(%_Arguments(i));
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    if (NUMBER_IS_NAN(n)) return n;
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    // Make sure +0 is considered greater than -0.
    if (n > r || (r === 0 && n === 0 && !%_IsSmi(r))) r = n;
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  }
  return r;
}

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// ECMA 262 - 15.8.2.12
function MathMin(arg1, arg2) {  // length == 2
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  var r = $Infinity;
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  var length = %_ArgumentsLength();
  for (var i = 0; i < length; i++) {
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    var n = ToNumber(%_Arguments(i));
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    if (NUMBER_IS_NAN(n)) return n;
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    // Make sure -0 is considered less than +0.
    if (n < r || (r === 0 && n === 0 && !%_IsSmi(n))) r = n;
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  }
  return r;
}

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// ECMA 262 - 15.8.2.13
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function MathPow(x, y) {
  if (!IS_NUMBER(x)) x = ToNumber(x);
  if (!IS_NUMBER(y)) y = ToNumber(y);
  return %Math_pow(x, y);
}
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// ECMA 262 - 15.8.2.14
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function MathRandom() {
  return %_RandomPositiveSmi() / 0x40000000;
}
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// ECMA 262 - 15.8.2.15
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function MathRound(x) {
  if (!IS_NUMBER(x)) x = ToNumber(x);
  return %Math_round(x);
}
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// ECMA 262 - 15.8.2.16
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function MathSin(x) {
  if (!IS_NUMBER(x)) x = ToNumber(x);
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  return %_Math_sin(x);
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}
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// ECMA 262 - 15.8.2.17
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function MathSqrt(x) {
  if (!IS_NUMBER(x)) x = ToNumber(x);
  return %Math_sqrt(x);
}
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// ECMA 262 - 15.8.2.18
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function MathTan(x) {
  if (!IS_NUMBER(x)) x = ToNumber(x);
  return %Math_tan(x);
}
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// -------------------------------------------------------------------

function SetupMath() {
  // Setup math constants.
  // ECMA-262, section 15.8.1.1.
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  %SetProperty($Math,
               "E",
               2.7182818284590452354,
               DONT_ENUM |  DONT_DELETE | READ_ONLY);
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  // ECMA-262, section 15.8.1.2.
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  %SetProperty($Math,
               "LN10",
               2.302585092994046,
               DONT_ENUM |  DONT_DELETE | READ_ONLY);
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  // ECMA-262, section 15.8.1.3.
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  %SetProperty($Math,
               "LN2",
               0.6931471805599453,
               DONT_ENUM |  DONT_DELETE | READ_ONLY);
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  // ECMA-262, section 15.8.1.4.
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  %SetProperty($Math,
               "LOG2E",
               1.4426950408889634,
               DONT_ENUM |  DONT_DELETE | READ_ONLY);
  %SetProperty($Math,
               "LOG10E",
               0.43429448190325176,
               DONT_ENUM |  DONT_DELETE | READ_ONLY);
  %SetProperty($Math,
               "PI",
               3.1415926535897932,
               DONT_ENUM |  DONT_DELETE | READ_ONLY);
  %SetProperty($Math,
               "SQRT1_2",
               0.7071067811865476,
               DONT_ENUM |  DONT_DELETE | READ_ONLY);
  %SetProperty($Math,
               "SQRT2",
               1.4142135623730951,
               DONT_ENUM |  DONT_DELETE | READ_ONLY);
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  // Setup non-enumerable functions of the Math object and
  // set their names.
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  InstallFunctionsOnHiddenPrototype($Math, DONT_ENUM, $Array(
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    "random", MathRandom,
    "abs", MathAbs,
    "acos", MathAcos,
    "asin", MathAsin,
    "atan", MathAtan,
    "ceil", MathCeil,
    "cos", MathCos,
    "exp", MathExp,
    "floor", MathFloor,
    "log", MathLog,
    "round", MathRound,
    "sin", MathSin,
    "sqrt", MathSqrt,
    "tan", MathTan,
    "atan2", MathAtan2,
    "pow", MathPow,
    "max", MathMax,
    "min", MathMin
  ));
};


SetupMath();