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// Copyright 2013 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.
'use strict';
// ES6 draft 09-27-13, section 20.2.2.28.
function MathSign(x) {
x = TO_NUMBER_INLINE(x);
if (x > 0) return 1;
if (x < 0) return -1;
if (x === 0) return x;
return NAN;
}
// ES6 draft 09-27-13, section 20.2.2.34.
function MathTrunc(x) {
x = TO_NUMBER_INLINE(x);
if (x > 0) return MathFloor(x);
if (x < 0) return MathCeil(x);
if (x === 0) return x;
return NAN;
}
// ES6 draft 09-27-13, section 20.2.2.30.
function MathSinh(x) {
if (!IS_NUMBER(x)) x = NonNumberToNumber(x);
// Idempotent for NaN, +/-0 and +/-Infinity.
if (x === 0 || !NUMBER_IS_FINITE(x)) return x;
return (MathExp(x) - MathExp(-x)) / 2;
}
// ES6 draft 09-27-13, section 20.2.2.12.
function MathCosh(x) {
if (!IS_NUMBER(x)) x = NonNumberToNumber(x);
// Idempotent for NaN and +/-Infinity.
if (!NUMBER_IS_FINITE(x)) return x;
return (MathExp(x) + MathExp(-x)) / 2;
}
// ES6 draft 09-27-13, section 20.2.2.33.
function MathTanh(x) {
if (!IS_NUMBER(x)) x = NonNumberToNumber(x);
// Idempotent for +/-0.
if (x === 0) return x;
// Returns +/-1 for +/-Infinity.
if (!NUMBER_IS_FINITE(x)) return MathSign(x);
var exp1 = MathExp(x);
var exp2 = MathExp(-x);
return (exp1 - exp2) / (exp1 + exp2);
}
// ES6 draft 09-27-13, section 20.2.2.5.
function MathAsinh(x) {
if (!IS_NUMBER(x)) x = NonNumberToNumber(x);
// Idempotent for NaN, +/-0 and +/-Infinity.
if (x === 0 || !NUMBER_IS_FINITE(x)) return x;
if (x > 0) return MathLog(x + MathSqrt(x * x + 1));
// This is to prevent numerical errors caused by large negative x.
return -MathLog(-x + MathSqrt(x * x + 1));
}
// ES6 draft 09-27-13, section 20.2.2.3.
function MathAcosh(x) {
if (!IS_NUMBER(x)) x = NonNumberToNumber(x);
if (x < 1) return NAN;
// Idempotent for NaN and +Infinity.
if (!NUMBER_IS_FINITE(x)) return x;
return MathLog(x + MathSqrt(x + 1) * MathSqrt(x - 1));
}
// ES6 draft 09-27-13, section 20.2.2.7.
function MathAtanh(x) {
if (!IS_NUMBER(x)) x = NonNumberToNumber(x);
// Idempotent for +/-0.
if (x === 0) return x;
// Returns NaN for NaN and +/- Infinity.
if (!NUMBER_IS_FINITE(x)) return NAN;
return 0.5 * MathLog((1 + x) / (1 - x));
}
//ES6 draft 09-27-13, section 20.2.2.21.
function MathLog10(x) {
return MathLog(x) * 0.434294481903251828; // log10(x) = log(x)/log(10).
}
//ES6 draft 09-27-13, section 20.2.2.22.
function MathLog2(x) {
return MathLog(x) * 1.442695040888963407; // log2(x) = log(x)/log(2).
}
//ES6 draft 09-27-13, section 20.2.2.17.
function MathHypot(x, y) { // Function length is 2.
// We may want to introduce fast paths for two arguments and when
// normalization to avoid overflow is not necessary. For now, we
// simply assume the general case.
var length = %_ArgumentsLength();
var args = new InternalArray(length);
var max = 0;
for (var i = 0; i < length; i++) {
var n = %_Arguments(i);
if (!IS_NUMBER(n)) n = NonNumberToNumber(n);
if (n === INFINITY || n === -INFINITY) return INFINITY;
n = MathAbs(n);
if (n > max) max = n;
args[i] = n;
}
// Kahan summation to avoid rounding errors.
// Normalize the numbers to the largest one to avoid overflow.
if (max === 0) max = 1;
var sum = 0;
var compensation = 0;
for (var i = 0; i < length; i++) {
var n = args[i] / max;
var summand = n * n - compensation;
var preliminary = sum + summand;
compensation = (preliminary - sum) - summand;
sum = preliminary;
}
return MathSqrt(sum) * max;
}
function ExtendMath() {
%CheckIsBootstrapping();
// Set up the non-enumerable functions on the Math object.
InstallFunctions($Math, DONT_ENUM, $Array(
"sign", MathSign,
"trunc", MathTrunc,
"sinh", MathSinh,
"cosh", MathCosh,
"tanh", MathTanh,
"asinh", MathAsinh,
"acosh", MathAcosh,
"atanh", MathAtanh,
"log10", MathLog10,
"log2", MathLog2,
"hypot", MathHypot
));
}
ExtendMath();
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