bcd.h   [plain text]

/*
 * Copyright (c) 2002 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/////////////////////////////////////////////////////////////////////////
// File: bcd.h
// void num2dec(const decform *f,double x,decimal *d);
// double dec2num(const decimal *d);
// void dec2str(const decform *f,const decimal *d,char *s);
// void str2dec(const char *s,short *ix,decimal *d,short *vp);
// Status: ALPHA
// Copyright Apple Computer, Inc. 1984, 1985, 1990, 1991, 1992, 1993
//
// Written by Kenton Hanson, 1991 - 1993
//
// Modification History:
//		22 Jun 92  KLH	Released to Danny Kubota for inclusion in the debugger
//						Needs tens tables hard coded and tens buffer removed.
//
//		10 Aug 92  KLH  Bug fixes for rounding logic and denormalization shifting.
//
//		25 Aug 92  KLH  Added tens table, and comments.
//
//		28 Jan 93  KLH  Added double notation.
//
//		13 May 93  KLH  long double part split out into file "dec2bin2L.c"
//
/////////////////////////////////////////////////////////////////////////
#define	FALSE		0
#define	TRUE		1

#define SIGDIGLEN      36              
#define      DECSTROUTLEN   80               /* max length for dec2str output */
#define      FLOATDECIMAL   ((char)(0))
#define      FIXEDDECIMAL   ((char)(1))

#define	FORDEBUGGER	FALSE	// is this a stanalone all c debugger version

#define	BIGARITH TRUE		// provides access to bigarithmetic 
							// necessary for conversions.c prgram

#define CACHESIZE 0			// size of tens cache, if zero no cache code generated
							// cache must be set to zero if FORDEBUGGER TRUE
					
#define GENERATEBIGTENS FALSE	// code necessary for generating big tens tables

#define USE68020 FALSE		// use 68020 assembly language routines
					// debugger shouldn't use assembly code if FORDEBUGGER TRUE

#define MAXDIGITS	36		// 21;	proposed = floor(log10(2^bits))+2

//typedef double double;
#define MAXTEN		22	// largest double exact power of ten

#define	SIGSIZE		8		// # of long words used in signficand of type big

#define SIGSIZE8 (SIGSIZE == 8)
#define FORDBGRORSIG8 (FORDEBUGGER || SIGSIZE8)

struct decimal {
	char 							sgn;						/* sign 0 for +, 1 for - */
	char 							unused;
	short 							exp;						/* decimal exponent */
	struct {
		unsigned char 					length;
		unsigned char 					text[SIGDIGLEN];		/* significant digits */
		unsigned char 					unused;
	} 								sig;
};
typedef struct decimal decimal;

struct decform {
	char 							style;						/*  FLOATDECIMAL or FIXEDDECIMAL */
	char 							unused;
	short 							digits;
};
typedef struct decform decform;


//#define SIGDIGLEN 128						/* significant decimal digits */


//struct decimal {
//	char sgn;								/*sign 0 for +, 1 for -*/
//	char unused;
//	short exp;								/*decimal exponent*/
//	struct{
//		unsigned char length;
//		char text[SIGDIGLEN];		/*significant digits */
//		char unused;
//		}sig;
//};

//typedef struct decimal decimal;


//struct decform {
//	char style; 							/*FLOATDECIMAL or FIXEDDECIMAL*/
//	char unused;
//	short digits;
//};

//typedef struct decform decform;


#define DECSTROUTLEN 80 					/* max length for dec2str output */

/* Decimal Formatting Styles */

//#define FLOATDECIMAL ((char)(0))
//#define FIXEDDECIMAL ((char)(1))


void num2dec(const decform *f,double x, decimal *d);
double dec2num(const decimal *d);
float dec2f ( const decimal *d );		//	float
short dec2s ( const decimal *d );		//	short
long dec2l ( const decimal *d );		//	long

void dec2str(const decform *f,const decimal *d,char *s);
void str2dec(const char *s,short *ix,decimal *d,short *vp);

#define	SIGSIZEM	SIGSIZE-1
#define	SIGSIZEP2	SIGSIZE+2
#define	SIGSIZE2	2*SIGSIZE
#define	SIGSIZE2M	SIGSIZE2-1
#define	SIGSIZE2M2	SIGSIZE2-2
#define	SIGSIZE4M	4*SIGSIZE-1

struct big {
	long exp;
	union {
	unsigned long lng [SIGSIZE];
	unsigned short shrt [2*SIGSIZE];
		} sig;
};

typedef struct big big;

void bigtenpower (const long n, big *y );
void axb2c ( big *a, big *b, big *c, int finishRounding );
void adivb2c ( big *a, big *b, big *c );
void biggetsig ( big *s, decimal *d );