Mozilla/mozilla/js/tamarin/core/MathUtils.h
gerv%gerv.net 0a3a70857a Bug 236613: fix formatting of MPL/LGPL/GPL tri-license.
git-svn-id: svn://10.0.0.236/trunk@220064 18797224-902f-48f8-a5cc-f745e15eee43
2007-02-13 18:05:02 +00:00

226 lines
8.2 KiB
C++

/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is [Open Source Virtual Machine.].
*
* The Initial Developer of the Original Code is
* Adobe System Incorporated.
* Portions created by the Initial Developer are Copyright (C) 1993-2006
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Adobe AS3 Team
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#ifndef __avmplus_MathUtils__
#define __avmplus_MathUtils__
#include "BigInteger.h"
namespace avmplus
{
#undef min
#undef max
/**
* Data structure for state of fast random number generator.
*/
struct TRandomFast
{
/* Random result and seed for next random result. */
uint32 uValue;
/* XOR mask for generating the next random value. */
uint32 uXorMask;
/* This is the number of values which will be generated in the
/ sequence given the initial value of n. */
uint32 uSequenceLength;
};
//
// Random number generator
//
typedef struct TRandomFast *pTRandomFast;
/**
* The pure random number generator returns random numbers between zero
* and this number. This value is useful to know for scaling random
* numbers to a desired range.
*/
#define kRandomPureMax 0x7FFFFFFFL
/**
* The MathUtils class is a utility class which supports many
* common mathematical operations, particularly those defined in
* ECMAScript's Math class.
*/
class MathUtils
{
public:
static double abs(double value);
static double acos(double value);
static double asin(double value);
static double atan(double value);
static double atan2(double y, double x);
static double ceil(double value);
static double cos(double value);
static bool equals(double x, double y);
static double exp(double value);
static double floor(double value);
static uint64 frexp(double x, int *eptr);
static double infinity();
static int isInfinite(double value);
#ifdef UNIX
static bool isNaN(double value);
#else
static bool isNaN(double value) { return value != value; }
#endif
static bool isNegZero(double x);
static bool isHexNumber(const wchar *ptr);
static double log(double value);
static double max(double x, double y) { return (x > y) ? x : y; }
static double min(double x, double y) { return (x < y) ? x : y; }
static double mod(double x, double y);
static double nan();
static int nextPowerOfTwo(int n);
static double parseInt(const wchar *s, int len, int radix=10, bool strict=true);
static double pow(double x, double y);
static double powInternal(double x, double y);
static void initRandom(TRandomFast *seed);
static double random(TRandomFast *seed);
static double round(double value);
static double sin(double value);
static double sqrt(double value);
static double tan(double value);
static double toInt(double value);
#ifdef WIN32
// This routine will return 0x80000000 if the double value overflows
// and integer and is not between -2^31 and 2^31-1.
static int32 real2int(double value);
#else
static int32 real2int(double val) { return (int32) val; }
#endif
static bool convertIntegerToString(sintptr value,
wchar *buffer,
int& len,
int radix=10,
bool treatAsUnsigned=false);
static Stringp convertDoubleToStringRadix(AvmCore *core,
double value,
int radix);
enum {
DTOSTR_NORMAL,
DTOSTR_FIXED,
DTOSTR_PRECISION,
DTOSTR_EXPONENTIAL
};
static void convertDoubleToString(double value,
wchar *buffer,
int &len,
int mode = DTOSTR_NORMAL,
int precision = 15);
static bool convertStringToDouble(const wchar *s,
int len,
double *value,
bool strict=false);
static double convertStringToNumber(const wchar* ptr, int strlen);
static int nextDigit(double *value);
private:
static double powerOfTen(int exponent, double value);
static wchar *handleSign(const wchar *s, bool& negative);
static wchar *skipSpaces(const wchar *s);
static int parseIntDigit(wchar ch);
static int roundInt(double x);
static void RandomFastInit(pTRandomFast pRandomFast);
static sint32 RandomPureHasher(sint32 iSeed);
static sint32 GenerateRandomNumber(pTRandomFast pRandomFast);
static sint32 Random(sint32 range, pTRandomFast pRandomFast);
};
/* D2A class implemention, used for converting double values to */
/* strings accurately. */
// This algorithm for printing floating point numbers is based on the paper
// "Printing floating-point numbers quickly and accurately" by Robert G Burger
// and R. Kent Dybvig http://www.cs.indiana.edu/~burger/FP-Printing-PLDI96.pdf
// See that paper for details.
//
// The algorithm generates the shortest, correctly rounded output string that
// converts to the same number when read back in. This implementation assumes
// IEEE unbiased rounding, that the input is a 64 bit (base 2) floating point
// number composed of a sign bit, a hidden bit (valued 1) and 52 explict bits of
// mantissa data, and an 11 bit exponent (in base 2). It also assumes the output
// desired is base 10.
class D2A {
public:
D2A(double value, int mode, int minPrecision=0);
~D2A();
int nextDigit();
int expBase10() { return base10Exp; }
double value; // double value for quick work when e and mantissa are small;
int e;
uint64 mantissa; // on input, value = mantissa*2^e; Only last 53 bits are used
int mantissaPrec; // how many bits of precision are actually used in the mantissa;
int base10Exp; // the (derived) base 10 exponent of value.
bool finished; // set to true when we've output all relevant digits.
bool bFastEstimateOk; // if minPrecision < 16, use double, rather than BigInteger math
private:
int minPrecision; // precision requested
bool lowOk; // for IEEE unbiased rounding, this is true when mantissa is even. When true, use >= in mMinus test instead of >
bool highOk; // ditto, but for mPlus test.
// if !bFastEstimateOk, use these
BigInteger r; // on initialization, input double <value> = r / s. After each nextDigit() call, r = r % s
BigInteger s;
BigInteger mPlus; // when (r+mPlus) > s, we have generated all relevant digits. Just return 0 for remaining nextDigit requests
BigInteger mMinus; // when (r < mMins), we have generated all relevant digits. Just return 0 form remaining nextDigit requests
// if bFastEstimateOk, use these
double dr; // same as above, but integer value stored in double
double ds;
double dMPlus;
double dMMinus;
int scale(); // Estimate base 10 exponent of number, scale r,s,mPlus,mMinus appropriately.
// Returns result of fixup_ExponentEstimate(est).
int fixup_ExponentEstimate(int expEst); // Used by scale to adjust for possible off-by-one error
// in the base 10 exponent estimate. Returns exact base10 exponent of number.
};
}
#endif /* __avmplus__MathUtils__ */