doprnt.c

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#ifndef lint
static char *sccsid = "@(#)doprnt.c	4.2  (ULTRIX)        8/13/90";
#endif
/************************************************************************
 *                                                                      *
 *                      Copyright (c) 1988 by                           *
 *              Digital Equipment Corporation, Maynard, MA              *
 *                      All rights reserved.                            *
 *                                                                      *
 *   This software is furnished under a license and may be used and     *
 *   copied  only  in accordance with the terms of such license and     *
 *   with the  inclusion  of  the  above  copyright  notice.   This     *
 *   software  or  any  other copies thereof may not be provided or     *
 *   otherwise made available to any other person.  No title to and     *
 *   ownership of the software is hereby transferred.                   *
 *                                                                      *
 *   The information in this software is subject to change  without     *
 *   notice  and should not be construed as a commitment by Digital     *
 *   Equipment Corporation.                                             *
 *                                                                      *
 *   Digital assumes no responsibility for the use  or  reliability     *
 *   of its software on equipment which is not supplied by Digital.     *
 *                                                                      *
 ************************************************************************/
/* ------------------------------------------------------------------ */
/* | Copyright Unpublished, MIPS Computer Systems, Inc.  All Rights | */
/* | Reserved.  This software contains proprietary and confidential | */
/* | information of MIPS and its suppliers.  Use, disclosure or     | */
/* | reproduction is prohibited without the prior express written   | */
/* | consent of MIPS.                                               | */
/* ------------------------------------------------------------------ */
/*  doprnt.c 2.2 */

/*
 *	_doprnt: common code for printf, fprintf, sprintf
 *
 * Modification History
 * 002 - Bob Fontaine - Thu Jun 21 10:22:20 EDT 1990
 *	Changed name of _doprnt routine to csh_doprnt.  This allows
 *	the Cshell to work with library routines that use the stdio
 *	library printf functions.  Fixes QAR #4449.
 *
 * 001 - Gary A. Gaudet - Thu Dec 28 17:20:42 EST 1989
 *	Fixed MAX and MIN floating point numbers.
 *	Initialized variables.
 */

#include <ctype.h>
#include <varargs.h>
#include <math.h>	/* 001 - GAG */
#include <limits.h>	/* 001 - GAG */
#define NULL	0

/* #include "values.h"		*/
#ifndef BITSPERBYTE
/* These values work with any binary representation of integers
 * where the high-order bit contains the sign. */

/* a number used normally for size of a shift */
#if gcos
#define BITSPERBYTE	9
#else
#define BITSPERBYTE	8
#endif
#define BITS(type)	(BITSPERBYTE * (int)sizeof(type))

/* short, regular and long ints with only the high-order bit turned on */
#define HIBITS	((short)(1 << BITS(short) - 1))
#define HIBITI	(1 << BITS(int) - 1)
#define HIBITL	(1L << BITS(long) - 1)

/* largest short, regular and long int */
#define MAXSHORT	((short)~HIBITS)
#define MAXINT	(~HIBITI)
#define MAXLONG	(~HIBITL)

/* various values that describe the binary floating-point representation
 * _EXPBASE	- the exponent base
 * DMAXEXP 	- the maximum exponent of a double (as returned by frexp())
 * FMAXEXP 	- the maximum exponent of a float  (as returned by frexp())
 * DMINEXP 	- the minimum exponent of a double (as returned by frexp())
 * FMINEXP 	- the minimum exponent of a float  (as returned by frexp())
 * MAXDOUBLE	- the largest double
			((_EXPBASE ** DMAXEXP) * (1 - (_EXPBASE ** -DSIGNIF)))
 * MAXFLOAT	- the largest float
			((_EXPBASE ** FMAXEXP) * (1 - (_EXPBASE ** -FSIGNIF)))
 * MINDOUBLE	- the smallest double (_EXPBASE ** (DMINEXP - 1))
 * MINFLOAT	- the smallest float (_EXPBASE ** (FMINEXP - 1))
 * DSIGNIF	- the number of significant bits in a double
 * FSIGNIF	- the number of significant bits in a float
 * DMAXPOWTWO	- the largest power of two exactly representable as a double
 * FMAXPOWTWO	- the largest power of two exactly representable as a float
 * _IEEE	- 1 if IEEE standard representation is used
 * _DEXPLEN	- the number of bits for the exponent of a double
 * _FEXPLEN	- the number of bits for the exponent of a float
 * _HIDDENBIT	- 1 if high-significance bit of mantissa is implicit
 * LN_MAXDOUBLE	- the natural log of the largest double  -- log(MAXDOUBLE)
 * LN_MINDOUBLE	- the natural log of the smallest double -- log(MINDOUBLE)
 */
#if u3b || u3b5
#define MAXDOUBLE	1.79769313486231470e+308
#define MAXFLOAT	((float)3.40282346638528860e+38)
#define MINDOUBLE	4.94065645841246544e-324
#define MINFLOAT	((float)1.40129846432481707e-45)
#define	_IEEE		1
#define _DEXPLEN	11
#define _HIDDENBIT	1
#define DMINEXP	(-(DMAXEXP + DSIGNIF - _HIDDENBIT - 3))
#define FMINEXP	(-(FMAXEXP + FSIGNIF - _HIDDENBIT - 3))
#endif
#if pdp11 || vax || mips
#define MAXDOUBLE	DBL_MAX	/* 001 - GAG */
/* The following is kludged because the PDP-11 compilers botch the simple form.
   The kludge causes the constant to be computed at run-time on the PDP-11,
   even though it is still "folded" at compile-time on the VAX. */
#define MINDOUBLE	DBL_MIN		/* 001 - GAG */
#define MINFLOAT	-MAXFLOAT	/* 001 - GAG */
#define _IEEE		0
#define _DEXPLEN	8
#define _HIDDENBIT	1
#define DMINEXP	(-DMAXEXP)
#define FMINEXP	(-FMAXEXP)
#endif
#if gcos
#define MAXDOUBLE	1.7014118346046923171e+38
#define MAXFLOAT	((float)1.7014118219281863150e+38)
#define MINDOUBLE	2.9387358770557187699e-39
#define MINFLOAT	((float)MINDOUBLE)
#define _IEEE		0
#define _DEXPLEN	8
#define _HIDDENBIT	0
#define DMINEXP	(-(DMAXEXP + 1))
#define FMINEXP	(-(FMAXEXP + 1))
#endif
#if u370 || gould
#define MAXDOUBLE	0.7237005577332262e+76
#define MAXFLOAT	((float)0.7237005145e+76)
#define MINDOUBLE	5.3976053469342702e-79
#define MINFLOAT	((float)MINDOUBLE)
#define _IEEE		0
#define _DEXPLEN	8	/* DAG -- Gould said 7, but I think this is right */
#define _HIDDENBIT	0
#define DMINEXP	(-(DMAXEXP + 1))
#define FMINEXP	(-(FMAXEXP + 1))
#endif
#if u370 || gould
#define _LENBASE	4
#else
#define _LENBASE	1
#endif
#define _EXPBASE	(1 << _LENBASE)
#define _FEXPLEN	8
#define DSIGNIF	(BITS(double) - _DEXPLEN + _HIDDENBIT - 1)
#define FSIGNIF	(BITS(float)  - _FEXPLEN + _HIDDENBIT - 1)
#define DMAXPOWTWO	((double)(1L << BITS(long) - 2) * \
				(1L << DSIGNIF - BITS(long) + 1))
#define FMAXPOWTWO	((float)(1L << FSIGNIF - 1))
#define DMAXEXP	((1 << _DEXPLEN - 1) - 1 + _IEEE)
#define FMAXEXP	((1 << _FEXPLEN - 1) - 1 + _IEEE)
#define LN_MAXDOUBLE	(M_LN2 * DMAXEXP)
#define LN_MINDOUBLE	(M_LN2 * (DMINEXP - 1))
#define H_PREC	(DSIGNIF % 2 ? (1L << DSIGNIF/2) * M_SQRT2 : 1L << DSIGNIF/2)
#define X_EPS	(1.0/H_PREC)
#define X_PLOSS	((double)(long)(M_PI * H_PREC))
#define X_TLOSS	(M_PI * DMAXPOWTWO)
#define M_LN2	0.69314718055994530942
#define M_PI	3.14159265358979323846
#define M_SQRT2	1.41421356237309504880
#define MAXBEXP	DMAXEXP /* for backward compatibility */
#define MINBEXP	DMINEXP /* for backward compatibility */
#define MAXPOWTWO	DMAXPOWTWO /* for backward compatibility */
#endif

/* #include "print.h"		*/
/* Maximum number of digits in any integer representation */
#define MAXDIGS 11

/* Maximum total number of digits in E format */
#if u3b || u3b5
#define MAXECVT 17
#else
#define MAXECVT 18
#endif

/* Maximum number of digits after decimal point in F format */
#define MAXFCVT 60

/* Maximum significant figures in a floating-point number */
#define MAXFSIG MAXECVT

/* Maximum number of characters in an exponent */
#if u3b || u3b5
#define MAXESIZ 5
#else
#define MAXESIZ 4
#endif

/* Maximum (positive) exponent */
#if u3b || u3b5
#define MAXEXP 325	/* DAG -- bug fix (was 310) */
#else
#if gould
#define MAXEXP 80
#else
#define MAXEXP 40
#endif
#endif

/* Data type for flags */
typedef char bool;

/* Convert a digit character to the corresponding number */
#define tonumber(x) ((x)-'0')

/* Convert a number between 0 and 9 to the corresponding digit */
#define todigit(x) ((x)+'0')

/* Max and Min macros */
#define max(a,b) ((a) > (b)? (a): (b))
#define min(a,b) ((a) < (b)? (a): (b))

/*#include "nan.h"		*/
/* Handling of Not_a_Number's (only in IEEE floating-point standard) */

#define KILLFPE()	(void) kill(getpid(), 8)
#if u3b || u3b5
#define NaN(X)	(((union { double d; struct { unsigned :1, e:11; } s; } \
			*)&X)->s.e == 0x7ff)
#define KILLNaN(X)	if (NaN(X)) KILLFPE()
#else
#define Nan(X)	0
#define KILLNaN(X)
#endif

/*
 * Returns the number of
 * non-NULL bytes in string argument.
 */

static int
strlen(s)
register char *s;
{
	register char *s0 = s + 1;

	while (*s++ != '\0')
		;
	return (s - s0);
}


/*
 *	ecvt converts to decimal
 *	the number of digits is specified by ndigit
 *	decpt is set to the position of the decimal point
 *	sign is set to 0 for positive, 1 for negative
 *
 */
#define	NMAX	((DSIGNIF * 3 + 19)/10) /* restrict max precision */
#define	NDIG	80


#define PUT(p, n)     { register int nn; \
			if (n > 0) { \
				nn = 0; \
				do { \
					putchar((int)*(p+nn)); \
					nn++; \
				} while (nn != n); \
			} \
		      }

/* bit positions for flags used in doprnt */
#define LENGTH	1	/* l */
#define FPLUS	2	/* + */
#define FMINUS	4	/* - */
#define FBLANK	8	/* blank */
#define FSHARP	16	/* # */
#define PADZERO 32	/* padding zeroes requested via '0' */
#define DOTSEEN 64	/* dot appeared in format specification */
#define SUFFIX	128	/* a suffix is to appear in the output */
#define RZERO	256	/* there will be trailing zeros in output */
#define LZERO	512	/* there will be leading zeroes in output */

static int
_lowdigit(valptr)
long *valptr;
{	/* This function computes the decimal low-order digit of the number */
	/* pointed to by valptr, and returns this digit after dividing   */
	/* *valptr by ten.  This function is called ONLY to compute the */
	/* low-order digit of a long whose high-order bit is set. */

	int lowbit = *valptr & 1;
	long value = (*valptr >> 1) & ~HIBITL;

	*valptr = value / 5;
	return(value % 5 * 2 + lowbit + '0');
}

int
csh_doprnt(format, args)		/* 002 RNF */
register char	*format;
va_list args;
{

	/* This variable counts output characters. */
	int	count = 0;

	/* Starting and ending points for value to be printed */
	register char	*bp;
	char *p;

	/* Field width and precision */
	int	width, prec;

	/* Format code */
	register int	fcode;

	/* Number of padding zeroes required on the left and right */
	int	lzero = 0,	/* 001 - GAG */
		rzero = 0;	/* 001 - GAG */

	/* Flags - bit positions defined by LENGTH, FPLUS, FMINUS, FBLANK, */
	/* and FSHARP are set if corresponding character is in format */
	/* Bit position defined by PADZERO means extra space in the field */
	/* should be padded with leading zeroes rather than with blanks */
	register int	flagword;

	/* Values are developed in this buffer */
	char	buf[max(MAXDIGS, 1+max(MAXFCVT+MAXEXP, MAXECVT))];

	/* Pointer to sign, "0x", "0X", or empty */
	char	*prefix;

	/* Exponent or empty */
	char	*suffix = 0;	/* 001 - GAG */

	/* Length of prefix and of suffix */
	int	prefixlength = 0,	/* 001 - GAG */
		suffixlength = 0;	/* 001 - GAG */

	/* combined length of leading zeroes, trailing zeroes, and suffix */
	int 	otherlength;

	/* The value being converted, if integer */
	long	val;

	/* Pointer to a translate table for digits of whatever radix */
	char	*tab;

	/* Work variables */
	int	k, lradix, mradix;

	/*
	 *	The main loop -- this loop goes through one iteration
	 *	for each string of ordinary characters or format specification.
	 */
	for ( ; ; ) {
		register int n;

		while ((fcode = *format) != '\0' && fcode != '%') {
			putchar(fcode);
			format++;
		}
		if (fcode == '\0') {  /* end of format; return */
			return;
		}

		/*
		 *	% has been found.
		 *	The following switch is used to parse the format
		 *	specification and to perform the operation specified
		 *	by the format letter.  The program repeatedly goes
		 *	back to this switch until the format letter is
		 *	encountered.
		 */
		width = prefixlength = otherlength = flagword = 0;
		format++;

	charswitch:

		switch (fcode = *format++) {

		case '+':
			flagword |= FPLUS;
			goto charswitch;
		case '-':
			flagword |= FMINUS;
			goto charswitch;
		case ' ':
			flagword |= FBLANK;
			goto charswitch;
		case '#':
			flagword |= FSHARP;
			goto charswitch;