[wxWidgets.git] / src / common / extended.c

#include "wx/setup.h"
#include <math.h>

#if wxUSE_APPLE_IEEE

/*
 * C O N V E R T   T O	 I E E E   E X T E N D E D
 */

/* Copyright (C) 1988-1991 Apple Computer, Inc.
 * All rights reserved.
 *
 * Machine-independent I/O routines for IEEE floating-point numbers.
 *
 * NaN's and infinities are converted to HUGE_VAL or HUGE, which
 * happens to be infinity on IEEE machines.	 Unfortunately, it is
 * impossible to preserve NaN's in a machine-independent way.
 * Infinities are, however, preserved on IEEE machines.
 *
 * These routines have been tested on the following machines:
 *    Apple Macintosh, MPW 3.1 C compiler
 *    Apple Macintosh, THINK C compiler
 *    Silicon Graphics IRIS, MIPS compiler
 *    Cray X/MP and Y/MP
 *    Digital Equipment VAX
 *
 *
 * Implemented by Malcolm Slaney and Ken Turkowski.
 *
 * Malcolm Slaney contributions during 1988-1990 include big- and little-
 * endian file I/O, conversion to and from Motorola's extended 80-bit
 * floating-point format, and conversions to and from IEEE single-
 * precision floating-point format.
 *
 * In 1991, Ken Turkowski implemented the conversions to and from
 * IEEE double-precision format, added more precision to the extended
 * conversions, and accommodated conversions involving +/- infinity,
 * NaN's, and denormalized numbers.
 */

#ifndef HUGE_VAL
#define HUGE_VAL HUGE
#endif /*HUGE_VAL*/

#define FloatToUnsigned(f) ((unsigned long) (((long) (f - 2147483648.0)) + 2147483647L) + 1)

void ConvertToIeeeExtended(double num, unsigned char *bytes)
{
	int				sign;
	int				expon;
	double			fMant, fsMant;
	unsigned long	hiMant, loMant;

	if (num < 0) {
		sign = 0x8000;
		num *= -1;
	} else {
		sign = 0;
	}

	if (num == 0) {
		expon = 0; hiMant = 0; loMant = 0;
	}
	else {
		fMant = frexp(num, &expon);
		if ((expon > 16384) || !(fMant < 1)) {	  /* Infinity or NaN */
			expon = sign|0x7FFF; hiMant = 0; loMant = 0; /* infinity */
		}
		else {	  /* Finite */
			expon += 16382;
			if (expon < 0) {	/* denormalized */
				fMant = ldexp(fMant, expon);
				expon = 0;
			}
			expon |= sign;
			fMant = ldexp(fMant, 32);
			fsMant = floor(fMant);
			hiMant = FloatToUnsigned(fsMant);
			fMant = ldexp(fMant - fsMant, 32);
			fsMant = floor(fMant);
			loMant = FloatToUnsigned(fsMant);
		}
	}

	bytes[0] = expon >> 8;
	bytes[1] = expon;
	bytes[2] = (unsigned char) hiMant >> 24;
	bytes[3] = (unsigned char) hiMant >> 16;
	bytes[4] = (unsigned char) hiMant >> 8;
	bytes[5] = (unsigned char) hiMant;
	bytes[6] = (unsigned char) loMant >> 24;
	bytes[7] = (unsigned char) loMant >> 16;
	bytes[8] = (unsigned char) loMant >> 8;
	bytes[9] = (unsigned char) loMant;
}

/*
 * C O N V E R T   F R O M	 I E E E   E X T E N D E D
 */

/*
 * Copyright (C) 1988-1991 Apple Computer, Inc.
 * All rights reserved.
 *
 * Machine-independent I/O routines for IEEE floating-point numbers.
 *
 * NaN's and infinities are converted to HUGE_VAL or HUGE, which
 * happens to be infinity on IEEE machines.	 Unfortunately, it is
 * impossible to preserve NaN's in a machine-independent way.
 * Infinities are, however, preserved on IEEE machines.
 *
 * These routines have been tested on the following machines:
 *	  Apple Macintosh, MPW 3.1 C compiler
 *	  Apple Macintosh, THINK C compiler
 *	  Silicon Graphics IRIS, MIPS compiler
 *	  Cray X/MP and Y/MP
 *	  Digital Equipment VAX
 *
 *
 * Implemented by Malcolm Slaney and Ken Turkowski.
 *
 * Malcolm Slaney contributions during 1988-1990 include big- and little-
 * endian file I/O, conversion to and from Motorola's extended 80-bit
 * floating-point format, and conversions to and from IEEE single-
 * precision floating-point format.
 *
 * In 1991, Ken Turkowski implemented the conversions to and from
 * IEEE double-precision format, added more precision to the extended
 * conversions, and accommodated conversions involving +/- infinity,
 * NaN's, and denormalized numbers.
 */

#ifndef HUGE_VAL
# define HUGE_VAL HUGE
#endif /*HUGE_VAL*/

# define UnsignedToFloat(u) (((double) ((long) (u - 2147483647L - 1))) + 2147483648.0)

/****************************************************************
 * Extended precision IEEE floating-point conversion routine.
 ****************************************************************/

double ConvertFromIeeeExtended(const unsigned char *bytes)
{
	double			f;
	int				expon;
	unsigned long	hiMant, loMant;

	expon = ((bytes[0] & 0x7F) << 8) | (bytes[1] & 0xFF);
	hiMant = ((unsigned long)(bytes[2] & 0xFF) << 24)
		| ((unsigned long) (bytes[3] & 0xFF) << 16)
		| ((unsigned long) (bytes[4] & 0xFF) << 8)
		| ((unsigned long) (bytes[5] & 0xFF));
	loMant = ((unsigned long) (bytes[6] & 0xFF) << 24)
		| ((unsigned long) (bytes[7] & 0xFF) << 16)
		| ((unsigned long) (bytes[8] & 0xFF) << 8)
		| ((unsigned long) (bytes[9] & 0xFF));

	if (expon == 0 && hiMant == 0 && loMant == 0) {
		f = 0;
	}
	else {
		if (expon == 0x7FFF) {	  /* Infinity or NaN */
			f = HUGE_VAL;
		}
		else {
			expon -= 16383;
			f  = ldexp(UnsignedToFloat(hiMant), expon-=31);
			f += ldexp(UnsignedToFloat(loMant), expon-=32);
		}
	}

	if (bytes[0] & 0x80)
		return -f;
	else
		return f;
}

#endif // wxUSE_APPLE_IEEE
Commit	Line	Data
cf447356 GL	1	#include "wx/setup.h"
	2	#include <math.h>
	3
126eb09b	4	#if wxUSE_APPLE_IEEE
cf447356 GL	5
	6	/*
	7	* C O N V E R T T O I E E E E X T E N D E D
	8	*/
	9
	10	/* Copyright (C) 1988-1991 Apple Computer, Inc.
	11	* All rights reserved.
	12	*
	13	* Machine-independent I/O routines for IEEE floating-point numbers.
	14	*
	15	* NaN's and infinities are converted to HUGE_VAL or HUGE, which
	16	* happens to be infinity on IEEE machines. Unfortunately, it is
	17	* impossible to preserve NaN's in a machine-independent way.
	18	* Infinities are, however, preserved on IEEE machines.
	19	*
	20	* These routines have been tested on the following machines:
	21	* Apple Macintosh, MPW 3.1 C compiler
	22	* Apple Macintosh, THINK C compiler
	23	* Silicon Graphics IRIS, MIPS compiler
	24	* Cray X/MP and Y/MP
	25	* Digital Equipment VAX
	26	*
	27	*
	28	* Implemented by Malcolm Slaney and Ken Turkowski.
	29	*
	30	* Malcolm Slaney contributions during 1988-1990 include big- and little-
	31	* endian file I/O, conversion to and from Motorola's extended 80-bit
	32	* floating-point format, and conversions to and from IEEE single-
	33	* precision floating-point format.
	34	*
	35	* In 1991, Ken Turkowski implemented the conversions to and from
	36	* IEEE double-precision format, added more precision to the extended
	37	* conversions, and accommodated conversions involving +/- infinity,
	38	* NaN's, and denormalized numbers.
	39	*/
	40
	41	#ifndef HUGE_VAL
	42	#define HUGE_VAL HUGE
	43	#endif /HUGE_VAL/
	44
	45	#define FloatToUnsigned(f) ((unsigned long) (((long) (f - 2147483648.0)) + 2147483647L) + 1)
	46
	47	void ConvertToIeeeExtended(double num, unsigned char *bytes)
	48	{
	49	int sign;
	50	int expon;
	51	double fMant, fsMant;
	52	unsigned long hiMant, loMant;
	53
	54	if (num < 0) {
	55	sign = 0x8000;
	56	num *= -1;
	57	} else {
	58	sign = 0;
	59	}
	60
	61	if (num == 0) {
	62	expon = 0; hiMant = 0; loMant = 0;
	63	}
	64	else {
	65	fMant = frexp(num, &expon);
	66	if ((expon > 16384) \|\| !(fMant < 1)) { /* Infinity or NaN */
	67	expon = sign\|0x7FFF; hiMant = 0; loMant = 0; /* infinity */
	68	}
69	else { /* Finite */
70	expon += 16382;
71	if (expon < 0) { /* denormalized */
72	fMant = ldexp(fMant, expon);
73	expon = 0;
74	}
75	expon \|= sign;
76	fMant = ldexp(fMant, 32);
77	fsMant = floor(fMant);
78	hiMant = FloatToUnsigned(fsMant);
79	fMant = ldexp(fMant - fsMant, 32);
80	fsMant = floor(fMant);
81	loMant = FloatToUnsigned(fsMant);
82	}
83	}
84
85	bytes[0] = expon >> 8;
86	bytes[1] = expon;
0c32066b JS	87	bytes[2] = (unsigned char) hiMant >> 24;
	88	bytes[3] = (unsigned char) hiMant >> 16;
	89	bytes[4] = (unsigned char) hiMant >> 8;
	90	bytes[5] = (unsigned char) hiMant;
	91	bytes[6] = (unsigned char) loMant >> 24;
	92	bytes[7] = (unsigned char) loMant >> 16;
	93	bytes[8] = (unsigned char) loMant >> 8;
	94	bytes[9] = (unsigned char) loMant;
cf447356 GL	95	}
	96
	97	/*
	98	* C O N V E R T F R O M I E E E E X T E N D E D
	99	*/
	100
	101	/*
	102	* Copyright (C) 1988-1991 Apple Computer, Inc.
	103	* All rights reserved.
	104	*
	105	* Machine-independent I/O routines for IEEE floating-point numbers.
	106	*
	107	* NaN's and infinities are converted to HUGE_VAL or HUGE, which
	108	* happens to be infinity on IEEE machines. Unfortunately, it is
	109	* impossible to preserve NaN's in a machine-independent way.
	110	* Infinities are, however, preserved on IEEE machines.
	111	*
	112	* These routines have been tested on the following machines:
	113	* Apple Macintosh, MPW 3.1 C compiler
	114	* Apple Macintosh, THINK C compiler
	115	* Silicon Graphics IRIS, MIPS compiler
	116	* Cray X/MP and Y/MP
	117	* Digital Equipment VAX
	118	*
	119	*
	120	* Implemented by Malcolm Slaney and Ken Turkowski.
	121	*
	122	* Malcolm Slaney contributions during 1988-1990 include big- and little-
	123	* endian file I/O, conversion to and from Motorola's extended 80-bit
	124	* floating-point format, and conversions to and from IEEE single-
	125	* precision floating-point format.
	126	*
	127	* In 1991, Ken Turkowski implemented the conversions to and from
	128	* IEEE double-precision format, added more precision to the extended
	129	* conversions, and accommodated conversions involving +/- infinity,
	130	* NaN's, and denormalized numbers.
	131	*/
	132
	133	#ifndef HUGE_VAL
	134	# define HUGE_VAL HUGE
	135	#endif /HUGE_VAL/
	136
	137	# define UnsignedToFloat(u) (((double) ((long) (u - 2147483647L - 1))) + 2147483648.0)
	138
	139	/****************************************************************
	140	* Extended precision IEEE floating-point conversion routine.
	141	****************************************************************/
	142
	143	double ConvertFromIeeeExtended(const unsigned char *bytes)
	144	{
	145	double f;
	146	int expon;
	147	unsigned long hiMant, loMant;
	148
	149	expon = ((bytes[0] & 0x7F) << 8) \| (bytes[1] & 0xFF);
	150	hiMant = ((unsigned long)(bytes[2] & 0xFF) << 24)
	151	\| ((unsigned long) (bytes[3] & 0xFF) << 16)
	152	\| ((unsigned long) (bytes[4] & 0xFF) << 8)
	153	\| ((unsigned long) (bytes[5] & 0xFF));
	154	loMant = ((unsigned long) (bytes[6] & 0xFF) << 24)
	155	\| ((unsigned long) (bytes[7] & 0xFF) << 16)
	156	\| ((unsigned long) (bytes[8] & 0xFF) << 8)
	157	\| ((unsigned long) (bytes[9] & 0xFF));
	158
159	if (expon == 0 && hiMant == 0 && loMant == 0) {
160	f = 0;
161	}
162	else {
163	if (expon == 0x7FFF) { /* Infinity or NaN */
164	f = HUGE_VAL;
165	}
166	else {
167	expon -= 16383;
168	f = ldexp(UnsignedToFloat(hiMant), expon-=31);
169	f += ldexp(UnsignedToFloat(loMant), expon-=32);
170	}
171	}
172
173	if (bytes[0] & 0x80)
174	return -f;
175	else
176	return f;
177	}
178
126eb09b	179	#endif // wxUSE_APPLE_IEEE