v8/src/math.js

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// Copyright 2012 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.
// 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.
var $floor = MathFloor;
var $abs = MathAbs;
// Instance class name can only be set on functions. That is the only
// purpose for MathConstructor.
function MathConstructor() {}
%FunctionSetInstanceClassName(MathConstructor, 'Math');
var $Math = new MathConstructor();
$Math.__proto__ = $Object.prototype;
%SetProperty(global, "Math", $Math, DONT_ENUM);
// ECMA 262 - 15.8.2.1
function MathAbs(x) {
if (%_IsSmi(x)) return x >= 0 ? x : -x;
if (!IS_NUMBER(x)) x = NonNumberToNumber(x);
if (x === 0) return 0; // To handle -0.
return x > 0 ? x : -x;
}
// ECMA 262 - 15.8.2.2
function MathAcos(x) {
if (!IS_NUMBER(x)) x = NonNumberToNumber(x);
return %Math_acos(x);
}
// ECMA 262 - 15.8.2.3
function MathAsin(x) {
if (!IS_NUMBER(x)) x = NonNumberToNumber(x);
return %Math_asin(x);
}
// ECMA 262 - 15.8.2.4
function MathAtan(x) {
if (!IS_NUMBER(x)) x = NonNumberToNumber(x);
return %Math_atan(x);
}
// ECMA 262 - 15.8.2.5
// The naming of y and x matches the spec, as does the order in which
// ToNumber (valueOf) is called.
function MathAtan2(y, x) {
if (!IS_NUMBER(y)) y = NonNumberToNumber(y);
if (!IS_NUMBER(x)) x = NonNumberToNumber(x);
return %Math_atan2(y, x);
}
// ECMA 262 - 15.8.2.6
function MathCeil(x) {
if (!IS_NUMBER(x)) x = NonNumberToNumber(x);
return %Math_ceil(x);
}
// ECMA 262 - 15.8.2.7
function MathCos(x) {
if (!IS_NUMBER(x)) x = NonNumberToNumber(x);
return %_MathCos(x);
}
// ECMA 262 - 15.8.2.8
function MathExp(x) {
if (!IS_NUMBER(x)) x = NonNumberToNumber(x);
return %Math_exp(x);
}
// ECMA 262 - 15.8.2.9
function MathFloor(x) {
if (!IS_NUMBER(x)) x = NonNumberToNumber(x);
// 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 < 0x80000000 && x > 0) {
// Numbers in the range [0, 2^31) can be floored by converting
// 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 TO_UINT32(x);
} else {
return %Math_floor(x);
}
}
// ECMA 262 - 15.8.2.10
function MathLog(x) {
if (!IS_NUMBER(x)) x = NonNumberToNumber(x);
return %_MathLog(x);
}
// ECMA 262 - 15.8.2.11
function MathMax(arg1, arg2) { // length == 2
var length = %_ArgumentsLength();
if (length == 2) {
if (!IS_NUMBER(arg1)) arg1 = NonNumberToNumber(arg1);
if (!IS_NUMBER(arg2)) arg2 = NonNumberToNumber(arg2);
if (arg2 > arg1) return arg2;
if (arg1 > arg2) return arg1;
if (arg1 == arg2) {
// Make sure -0 is considered less than +0. -0 is never a Smi, +0 can be
// a Smi or a heap number.
return (arg1 == 0 && !%_IsSmi(arg1) && 1 / arg1 < 0) ? arg2 : arg1;
}
// All comparisons failed, one of the arguments must be NaN.
return 0/0; // Compiler constant-folds this to NaN.
}
if (length == 0) {
return -1/0; // Compiler constant-folds this to -Infinity.
}
var r = arg1;
if (!IS_NUMBER(r)) r = NonNumberToNumber(r);
if (NUMBER_IS_NAN(r)) return r;
for (var i = 1; i < length; i++) {
var n = %_Arguments(i);
if (!IS_NUMBER(n)) n = NonNumberToNumber(n);
if (NUMBER_IS_NAN(n)) return n;
// Make sure +0 is considered greater than -0. -0 is never a Smi, +0 can be
// a Smi or heap number.
if (n > r || (r == 0 && n == 0 && !%_IsSmi(r) && 1 / r < 0)) r = n;
}
return r;
}
// ECMA 262 - 15.8.2.12
function MathMin(arg1, arg2) { // length == 2
var length = %_ArgumentsLength();
if (length == 2) {
if (!IS_NUMBER(arg1)) arg1 = NonNumberToNumber(arg1);
if (!IS_NUMBER(arg2)) arg2 = NonNumberToNumber(arg2);
if (arg2 > arg1) return arg1;
if (arg1 > arg2) return arg2;
if (arg1 == arg2) {
// Make sure -0 is considered less than +0. -0 is never a Smi, +0 can be
// a Smi or a heap number.
return (arg1 == 0 && !%_IsSmi(arg1) && 1 / arg1 < 0) ? arg1 : arg2;
}
// All comparisons failed, one of the arguments must be NaN.
return 0/0; // Compiler constant-folds this to NaN.
}
if (length == 0) {
return 1/0; // Compiler constant-folds this to Infinity.
}
var r = arg1;
if (!IS_NUMBER(r)) r = NonNumberToNumber(r);
if (NUMBER_IS_NAN(r)) return r;
for (var i = 1; i < length; i++) {
var n = %_Arguments(i);
if (!IS_NUMBER(n)) n = NonNumberToNumber(n);
if (NUMBER_IS_NAN(n)) return n;
// Make sure -0 is considered less than +0. -0 is never a Smi, +0 can be a
// Smi or a heap number.
if (n < r || (r == 0 && n == 0 && !%_IsSmi(n) && 1 / n < 0)) r = n;
}
return r;
}
// ECMA 262 - 15.8.2.13
function MathPow(x, y) {
if (!IS_NUMBER(x)) x = NonNumberToNumber(x);
if (!IS_NUMBER(y)) y = NonNumberToNumber(y);
return %_MathPow(x, y);
}
// ECMA 262 - 15.8.2.14
function MathRandom() {
return %_RandomHeapNumber();
}
// ECMA 262 - 15.8.2.15
function MathRound(x) {
if (!IS_NUMBER(x)) x = NonNumberToNumber(x);
return %RoundNumber(x);
}
// ECMA 262 - 15.8.2.16
function MathSin(x) {
if (!IS_NUMBER(x)) x = NonNumberToNumber(x);
return %_MathSin(x);
}
// ECMA 262 - 15.8.2.17
function MathSqrt(x) {
if (!IS_NUMBER(x)) x = NonNumberToNumber(x);
return %_MathSqrt(x);
}
// ECMA 262 - 15.8.2.18
function MathTan(x) {
if (!IS_NUMBER(x)) x = NonNumberToNumber(x);
return %_MathTan(x);
}
// -------------------------------------------------------------------
function SetUpMath() {
%CheckIsBootstrapping();
// Set up math constants.
// ECMA-262, section 15.8.1.1.
%OptimizeObjectForAddingMultipleProperties($Math, 8);
%SetProperty($Math,
"E",
2.7182818284590452354,
DONT_ENUM | DONT_DELETE | READ_ONLY);
// ECMA-262, section 15.8.1.2.
%SetProperty($Math,
"LN10",
2.302585092994046,
DONT_ENUM | DONT_DELETE | READ_ONLY);
// ECMA-262, section 15.8.1.3.
%SetProperty($Math,
"LN2",
0.6931471805599453,
DONT_ENUM | DONT_DELETE | READ_ONLY);
// ECMA-262, section 15.8.1.4.
%SetProperty($Math,
"LOG2E",
1.4426950408889634,
DONT_ENUM | DONT_DELETE | READ_ONLY);
%SetProperty($Math,
"LOG10E",
0.4342944819032518,
DONT_ENUM | DONT_DELETE | READ_ONLY);
%SetProperty($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);
%ToFastProperties($Math);
// Set up non-enumerable functions of the Math object and
// set their names.
InstallFunctions($Math, DONT_ENUM, $Array(
"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();