pjs/js/src/jsnum.h

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C

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* ***** 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 Mozilla Communicator client code, released
* March 31, 1998.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of 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 jsnum_h___
#define jsnum_h___
/*
* JS number (IEEE double) interface.
*
* JS numbers are optimistically stored in the top 31 bits of 32-bit integers,
* but floating point literals, results that overflow 31 bits, and division and
* modulus operands and results require a 64-bit IEEE double. These are GC'ed
* and pointed to by 32-bit jsvals on the stack and in object properties.
*/
JS_BEGIN_EXTERN_C
/*
* Stefan Hanske <sh990154@mail.uni-greifswald.de> reports:
* ARM is a little endian architecture but 64 bit double words are stored
* differently: the 32 bit words are in little endian byte order, the two words
* are stored in big endian`s way.
*/
#if defined(__arm) || defined(__arm32__) || defined(__arm26__) || defined(__arm__)
#define CPU_IS_ARM
#endif
typedef union jsdpun {
struct {
#if defined(IS_LITTLE_ENDIAN) && !defined(CPU_IS_ARM)
uint32 lo, hi;
#else
uint32 hi, lo;
#endif
} s;
jsdouble d;
} jsdpun;
#if (__GNUC__ == 2 && __GNUC_MINOR__ > 95) || __GNUC__ > 2
/*
* This version of the macros is safe for the alias optimizations that gcc
* does, but uses gcc-specific extensions.
*/
#define JSDOUBLE_HI32(x) (__extension__ ({ jsdpun u; u.d = (x); u.s.hi; }))
#define JSDOUBLE_LO32(x) (__extension__ ({ jsdpun u; u.d = (x); u.s.lo; }))
#define JSDOUBLE_SET_HI32(x, y) \
(__extension__ ({ jsdpun u; u.d = (x); u.s.hi = (y); (x) = u.d; }))
#define JSDOUBLE_SET_LO32(x, y) \
(__extension__ ({ jsdpun u; u.d = (x); u.s.lo = (y); (x) = u.d; }))
#else /* not or old GNUC */
/*
* We don't know of any non-gcc compilers that perform alias optimization,
* so this code should work.
*/
#if defined(IS_LITTLE_ENDIAN) && !defined(CPU_IS_ARM)
#define JSDOUBLE_HI32(x) (((uint32 *)&(x))[1])
#define JSDOUBLE_LO32(x) (((uint32 *)&(x))[0])
#else
#define JSDOUBLE_HI32(x) (((uint32 *)&(x))[0])
#define JSDOUBLE_LO32(x) (((uint32 *)&(x))[1])
#endif
#define JSDOUBLE_SET_HI32(x, y) (JSDOUBLE_HI32(x)=(y))
#define JSDOUBLE_SET_LO32(x, y) (JSDOUBLE_LO32(x)=(y))
#endif /* not or old GNUC */
#define JSDOUBLE_HI32_SIGNBIT 0x80000000
#define JSDOUBLE_HI32_EXPMASK 0x7ff00000
#define JSDOUBLE_HI32_MANTMASK 0x000fffff
#define JSDOUBLE_IS_NaN(x) \
((JSDOUBLE_HI32(x) & JSDOUBLE_HI32_EXPMASK) == JSDOUBLE_HI32_EXPMASK && \
(JSDOUBLE_LO32(x) || (JSDOUBLE_HI32(x) & JSDOUBLE_HI32_MANTMASK)))
#define JSDOUBLE_IS_INFINITE(x) \
((JSDOUBLE_HI32(x) & ~JSDOUBLE_HI32_SIGNBIT) == JSDOUBLE_HI32_EXPMASK && \
!JSDOUBLE_LO32(x))
#define JSDOUBLE_IS_FINITE(x) \
((JSDOUBLE_HI32(x) & JSDOUBLE_HI32_EXPMASK) != JSDOUBLE_HI32_EXPMASK)
#define JSDOUBLE_IS_NEGZERO(d) (JSDOUBLE_HI32(d) == JSDOUBLE_HI32_SIGNBIT && \
JSDOUBLE_LO32(d) == 0)
/*
* JSDOUBLE_IS_INT first checks that d is neither NaN nor infinite, to avoid
* raising SIGFPE on platforms such as Alpha Linux, then (only if the cast is
* safe) leaves i as (jsint)d. This also avoid anomalous NaN floating point
* comparisons under MSVC.
*/
#define JSDOUBLE_IS_INT(d, i) (JSDOUBLE_IS_FINITE(d) \
&& !JSDOUBLE_IS_NEGZERO(d) \
&& ((d) == (i = (jsint)(d))))
#if defined(XP_WIN)
#define JSDOUBLE_COMPARE(LVAL, OP, RVAL, IFNAN) \
((JSDOUBLE_IS_NaN(LVAL) || JSDOUBLE_IS_NaN(RVAL)) \
? (IFNAN) \
: (LVAL) OP (RVAL))
#else
#define JSDOUBLE_COMPARE(LVAL, OP, RVAL, IFNAN) ((LVAL) OP (RVAL))
#endif
/* Initialize number constants and runtime state for the first context. */
extern JSBool
js_InitRuntimeNumberState(JSContext *cx);
extern void
js_FinishRuntimeNumberState(JSContext *cx);
/* Initialize the Number class, returning its prototype object. */
extern JSClass js_NumberClass;
extern JSObject *
js_InitNumberClass(JSContext *cx, JSObject *obj);
/*
* String constants for global function names, used in jsapi.c and jsnum.c.
*/
extern const char js_Infinity_str[];
extern const char js_NaN_str[];
extern const char js_isNaN_str[];
extern const char js_isFinite_str[];
extern const char js_parseFloat_str[];
extern const char js_parseInt_str[];
/* GC-allocate a new JS number. */
extern jsdouble *
js_NewDouble(JSContext *cx, jsdouble d, uintN gcflag);
extern void
js_FinalizeDouble(JSContext *cx, jsdouble *dp);
extern JSBool
js_NewDoubleValue(JSContext *cx, jsdouble d, jsval *rval);
extern JSBool
js_NewNumberValue(JSContext *cx, jsdouble d, jsval *rval);
/* Construct a Number instance that wraps around d. */
extern JSObject *
js_NumberToObject(JSContext *cx, jsdouble d);
/* Convert a number to a GC'ed string. */
extern JSString *
js_NumberToString(JSContext *cx, jsdouble d);
/*
* Convert a value to a number, returning false after reporting any error,
* otherwise returning true with *dp set.
*/
extern JSBool
js_ValueToNumber(JSContext *cx, jsval v, jsdouble *dp);
/*
* Convert a value or a double to an int32, according to the ECMA rules
* for ToInt32.
*/
extern JSBool
js_ValueToECMAInt32(JSContext *cx, jsval v, int32 *ip);
extern JSBool
js_DoubleToECMAInt32(JSContext *cx, jsdouble d, int32 *ip);
/*
* Convert a value or a double to a uint32, according to the ECMA rules
* for ToUint32.
*/
extern JSBool
js_ValueToECMAUint32(JSContext *cx, jsval v, uint32 *ip);
extern JSBool
js_DoubleToECMAUint32(JSContext *cx, jsdouble d, uint32 *ip);
/*
* Convert a value to a number, then to an int32 if it fits by rounding to
* nearest; but failing with an error report if the double is out of range
* or unordered.
*/
extern JSBool
js_ValueToInt32(JSContext *cx, jsval v, int32 *ip);
/*
* Convert a value to a number, then to a uint16 according to the ECMA rules
* for ToUint16.
*/
extern JSBool
js_ValueToUint16(JSContext *cx, jsval v, uint16 *ip);
/*
* Convert a jsdouble to an integral number, stored in a jsdouble.
* If d is NaN, return 0. If d is an infinity, return it without conversion.
*/
extern jsdouble
js_DoubleToInteger(jsdouble d);
/*
* Similar to strtod except that it replaces overflows with infinities of the
* correct sign, and underflows with zeros of the correct sign. Guaranteed to
* return the closest double number to the given input in dp.
*
* Also allows inputs of the form [+|-]Infinity, which produce an infinity of
* the appropriate sign. The case of the "Infinity" string must match exactly.
* If the string does not contain a number, set *ep to s and return 0.0 in dp.
* Return false if out of memory.
*/
extern JSBool
js_strtod(JSContext *cx, const jschar *s, const jschar **ep, jsdouble *dp);
/*
* Similar to strtol except that it handles integers of arbitrary size.
* Guaranteed to return the closest double number to the given input when radix
* is 10 or a power of 2. Callers may see round-off errors for very large
* numbers of a different radix than 10 or a power of 2.
*
* If the string does not contain a number, set *ep to s and return 0.0 in dp.
* Return false if out of memory.
*/
extern JSBool
js_strtointeger(JSContext *cx, const jschar *s, const jschar **ep, jsint radix, jsdouble *dp);
JS_END_EXTERN_C
#endif /* jsnum_h___ */