uclibc-ng/libc/stdio/_fpmaxtostr.c

/* Copyright (C) 2004       Manuel Novoa III    <mjn3@codepoet.org>
 *
 * GNU Library General Public License (LGPL) version 2 or later.
 *
 * Dedicated to Toni.  See uClibc/DEDICATION.mjn3 for details.
 */

#include "_stdio.h"
#include <printf.h>
#include <float.h>
#include <locale.h>
#include <bits/uClibc_fpmax.h>


typedef size_t (__fp_outfunc_t)(FILE *fp, intptr_t type, intptr_t len,
								intptr_t buf);


/* Copyright (C) 2000, 2001, 2003      Manuel Novoa III
 *
 * Function:
 *
 *     ssize_t _fpmaxtostr(FILE * fp, __fpmax_t x, struct printf_info *info,
 *                         __fp_outfunc_t fp_outfunc);
 *
 * This is derived from the old _dtostr, whic I wrote for uClibc to provide
 * floating point support for the printf functions.  It handles +/- infinity,
 * nan, and signed 0 assuming you have ieee arithmetic.  It also now handles
 * digit grouping (for the uClibc supported locales) and hexadecimal float
 * notation.  Finally, via the fp_outfunc parameter, it now supports wide
 * output.
 *
 * Notes:
 *
 * At most DECIMAL_DIG significant digits are kept.  Any trailing digits
 * are treated as 0 as they are really just the results of rounding noise
 * anyway.  If you want to do better, use an arbitary precision arithmetic
 * package.  ;-)
 *
 * It should also be fairly portable, as no assumptions are made about the
 * bit-layout of doubles.  Of course, that does make it less efficient than
 * it could be.
 *
 */

/*****************************************************************************/
/* Don't change anything that follows unless you know what you're doing.     */
/*****************************************************************************/
/* Fairly portable nan check.  Bitwise for i386 generated larger code.
 * If you have a better version, comment this out.
 */
#define isnan(x)             ((x) != (x))

/* Without seminumerical functions to examine the sign bit, this is
 * about the best we can do to test for '-0'.
 */
#define zeroisnegative(x)    ((1./(x)) < 0)

/*****************************************************************************/
/* Don't change anything that follows peroid!!!  ;-)                         */
/*****************************************************************************/
#ifdef __UCLIBC_HAS_HEXADECIMAL_FLOATS__
#if FLT_RADIX != 2
#error FLT_RADIX != 2 is not currently supported
#endif
#endif /* __UCLIBC_HAS_HEXADECIMAL_FLOATS__ */

#define NUM_HEX_DIGITS      ((FPMAX_MANT_DIG + 3)/ 4)

/* WARNING: Adjust _fp_out_wide() below if this changes! */
/* With 32 bit ints, we can get 9 decimal digits per block. */
#define DIGITS_PER_BLOCK     9
#define HEX_DIGITS_PER_BLOCK 8

/* Maximum number of subcases to output double is...
 *  0 - sign
 *  1 - padding and initial digit
 *  2 - digits left of the radix
 *  3 - 0s left of the radix        or   radix
 *  4 - radix                       or   digits right of the radix
 *  5 - 0s right of the radix
 *  6 - exponent
 *  7 - trailing space padding
 * although not all cases may occur.
 */
#define MAX_CALLS 8

/*****************************************************************************/

#define NUM_DIGIT_BLOCKS   ((DECIMAL_DIG+DIGITS_PER_BLOCK-1)/DIGITS_PER_BLOCK)
#define NUM_HEX_DIGIT_BLOCKS \
   ((NUM_HEX_DIGITS+HEX_DIGITS_PER_BLOCK-1)/HEX_DIGITS_PER_BLOCK)

/* WARNING: Adjust _fp_out_wide() below if this changes! */

/* extra space for '-', '.', 'e+###', and nul */
#define BUF_SIZE  ( 3 + NUM_DIGIT_BLOCKS * DIGITS_PER_BLOCK )

/*****************************************************************************/

static const char fmt[] = "inf\0INF\0nan\0NAN\0.\0,";

#define INF_OFFSET        0		/* must be 1st */
#define NAN_OFFSET        8		/* must be 2nd.. see hex sign handling */
#define DECPT_OFFSET     16
#define THOUSEP_OFFSET   18

#define EMPTY_STRING_OFFSET 3

/*****************************************************************************/
#if FPMAX_MAX_10_EXP < -FPMAX_MIN_10_EXP
#error scaling code can not handle FPMAX_MAX_10_EXP < -FPMAX_MIN_10_EXP
#endif

static const __fpmax_t exp10_table[] =
{
	1e1L, 1e2L, 1e4L, 1e8L, 1e16L, 1e32L,	/* floats */
#if FPMAX_MAX_10_EXP < 32
#error unsupported FPMAX_MAX_10_EXP (< 32).  ANSI/ISO C requires >= 37.
#endif
#if FPMAX_MAX_10_EXP >= 64
	1e64L,
#endif
#if FPMAX_MAX_10_EXP >= 128
	1e128L,
#endif
#if FPMAX_MAX_10_EXP >= 256
	1e256L,
#endif
#if FPMAX_MAX_10_EXP >= 512
	1e512L,
#endif
#if FPMAX_MAX_10_EXP >= 1024
	1e1024L,
#endif
#if FPMAX_MAX_10_EXP >= 2048
	1e2048L,
#endif
#if FPMAX_MAX_10_EXP >= 4096
	1e4096L
#endif
#if FPMAX_MAX_10_EXP >= 8192
#error unsupported FPMAX_MAX_10_EXP.  please increase table
#endif
};

#define EXP10_TABLE_SIZE     (sizeof(exp10_table)/sizeof(exp10_table[0]))
#define EXP10_TABLE_MAX      (1U<<(EXP10_TABLE_SIZE-1))

/*****************************************************************************/
#ifdef __UCLIBC_HAS_HEXADECIMAL_FLOATS__

#if FLT_RADIX != 2
#error FLT_RADIX != 2 is not currently supported
#endif

#if FPMAX_MAX_EXP < -FPMAX_MIN_EXP
#error scaling code can not handle FPMAX_MAX_EXP < -FPMAX_MIN_EXP
#endif

static const __fpmax_t exp16_table[] = {
	0x1.0p4L, 0x1.0p8L, 0x1.0p16L, 0x1.0p32L, 0x1.0p64L,
#if FPMAX_MAX_EXP >= 128
	0x1.0p128L,
#endif
#if FPMAX_MAX_EXP >= 256
	0x1.0p256L,
#endif
#if FPMAX_MAX_EXP >= 512
	0x1.0p512L,
#endif
#if FPMAX_MAX_EXP >= 1024
	0x1.0p1024L,
#endif
#if FPMAX_MAX_EXP >= 2048
	0x1.0p2048L,
#endif
#if FPMAX_MAX_EXP >= 4096
	0x1.0p4096L,
#endif
#if FPMAX_MAX_EXP >= 8192
	0x1.0p8192L,
#endif
#if FPMAX_MAX_EXP >= 16384
	0x1.0p16384L
#endif
#if FPMAX_MAX_EXP >= 32768
#error unsupported FPMAX_MAX_EXP.  please increase table
#endif
};

#define EXP16_TABLE_SIZE     (sizeof(exp16_table)/sizeof(exp16_table[0]))
#define EXP16_TABLE_MAX      (1U<<(EXP16_TABLE_SIZE-1))

#endif /* __UCLIBC_HAS_HEXADECIMAL_FLOATS__ */
/*****************************************************************************/

#define FPO_ZERO_PAD    (0x80 | '0')
#define FPO_STR_WIDTH   (0x80 | ' ');
#define FPO_STR_PREC    'p'

ssize_t _fpmaxtostr(FILE * fp, __fpmax_t x, struct printf_info *info,
					__fp_outfunc_t fp_outfunc) attribute_hidden;
ssize_t _fpmaxtostr(FILE * fp, __fpmax_t x, struct printf_info *info,
					__fp_outfunc_t fp_outfunc)
{
#ifdef __UCLIBC_HAS_HEXADECIMAL_FLOATS__
	__fpmax_t lower_bnd;
	__fpmax_t upper_bnd = 1e9;
#endif /* __UCLIBC_HAS_HEXADECIMAL_FLOATS__ */
#ifdef __UCLIBC_HAS_HEXADECIMAL_FLOATS__
	uint_fast32_t base = 10;
	const __fpmax_t *power_table;
	int dpb = DIGITS_PER_BLOCK;
	int ndb = NUM_DIGIT_BLOCKS;
	int nd = DECIMAL_DIG;
	int sufficient_precision = 0;
#endif /* __UCLIBC_HAS_HEXADECIMAL_FLOATS__ */
#ifdef __UCLIBC_HAS_GLIBC_DIGIT_GROUPING__
	int num_groups = 0;
	int initial_group;	   /* This does not need to be initialized. */
	int tslen;			   /* This does not need to be initialized. */
	int nblk2;			   /* This does not need to be initialized. */
	const char *ts;		   /* This does not need to be initialized. */
#endif /* __UCLIBC_HAS_GLIBC_DIGIT_GROUPING__ */
	int round, o_exp;
	int exp;
	int width, preci;
	int cnt;
	char *s;
	char *e;
	intptr_t pc_fwi[3*MAX_CALLS];
	intptr_t *ppc;
	intptr_t *ppc_last;
#ifdef __UCLIBC_MJN3_ONLY__
#warning TODO: The size of exp_buf[] should really be determined by the float constants.
#endif /* __UCLIBC_MJN3_ONLY__ */
	char exp_buf[16];
	char buf[BUF_SIZE];
	char sign_str[6];			/* Last 2 are for 1st digit + nul. */
	char o_mode;
	char mode;


	width = info->width;
	preci = info->prec;
	mode = info->spec;

	*exp_buf = 'e';
	if ((mode|0x20) == 'a') {
#ifdef __UCLIBC_HAS_HEXADECIMAL_FLOATS__
		*exp_buf = 'p';
		if (preci < 0) {
			preci = NUM_HEX_DIGITS;
			sufficient_precision = 1;
		}
#else
		mode += ('g' - 'a');
#endif
	}

	if (preci < 0) {
		preci = 6;
	}

	*sign_str = '\0';
	if (PRINT_INFO_FLAG_VAL(info,showsign)) {
		*sign_str = '+';
	} else if (PRINT_INFO_FLAG_VAL(info,space)) {
		*sign_str = ' ';
	}

	*(sign_str+1) = 0;
	pc_fwi[5] = INF_OFFSET;
	if (isnan(x)) {				/* First, check for nan. */
		pc_fwi[5] = NAN_OFFSET;
		goto INF_NAN;
	}

	if (x == 0) {				/* Handle 0 now to avoid false positive. */
#ifdef __UCLIBC_HAVE_SIGNED_ZERO__
		if (zeroisnegative(x)) { /* Handle 'signed' zero. */
			*sign_str = '-';
		}
#endif /* __UCLIBC_HAVE_SIGNED_ZERO__ */
		exp = -1;
		goto GENERATE_DIGITS;
	}

	if (x < 0) {				/* Convert negatives to positives. */
		*sign_str = '-';
		x = -x;
	}

	if (__FPMAX_ZERO_OR_INF_CHECK(x)) {	/* Inf since zero handled above. */
	INF_NAN:
		info->pad = ' ';
		ppc = pc_fwi + 6;
		pc_fwi[3] = FPO_STR_PREC;
		pc_fwi[4] = 3;
		if (mode < 'a') {
			pc_fwi[5] += 4;
		}
		pc_fwi[5] = (intptr_t)(fmt + pc_fwi[5]);
		goto EXIT_SPECIAL;
	}

	{
		int i, j;
#ifdef __UCLIBC_MJN3_ONLY__
#warning TODO: Clean up defines when hexadecimal float notation is unsupported.
#endif /* __UCLIBC_MJN3_ONLY__ */

#ifdef __UCLIBC_HAS_HEXADECIMAL_FLOATS__

		if ((mode|0x20) == 'a') {
			lower_bnd = 0x1.0p31L;
			upper_bnd = 0x1.0p32L;
			power_table = exp16_table;
			exp = HEX_DIGITS_PER_BLOCK - 1;
			i = EXP16_TABLE_SIZE;
			j = EXP16_TABLE_MAX;
			dpb = HEX_DIGITS_PER_BLOCK;
			ndb = NUM_HEX_DIGIT_BLOCKS;
			nd = NUM_HEX_DIGITS;
			base = 16;
		} else {
			lower_bnd = 1e8;
			/* 		upper_bnd = 1e9; */
			power_table = exp10_table;
			exp = DIGITS_PER_BLOCK - 1;
			i = EXP10_TABLE_SIZE;
			j = EXP10_TABLE_MAX;
			/* 		dpb = DIGITS_PER_BLOCK; */
			/* 		ndb = NUM_DIGIT_BLOCKS; */
			/* 		base = 10; */
		}



#else  /* __UCLIBC_HAS_HEXADECIMAL_FLOATS__ */

#define lower_bnd    1e8
#define upper_bnd    1e9
#define power_table  exp10_table
#define dpb          DIGITS_PER_BLOCK
#define base         10
#define ndb          NUM_DIGIT_BLOCKS
#define nd           DECIMAL_DIG

		exp = DIGITS_PER_BLOCK - 1;
		i = EXP10_TABLE_SIZE;
		j = EXP10_TABLE_MAX;

#endif /* __UCLIBC_HAS_HEXADECIMAL_FLOATS__ */

		{
			int exp_neg = 0;
			if (x < lower_bnd) { /* Do we need to scale up or down? */
				exp_neg = 1;
			}

			do {
				--i;
				if (exp_neg) {
					if (x * power_table[i] < upper_bnd) {
						x *= power_table[i];
						exp -= j;
					}
				} else {
					if (x / power_table[i] >= lower_bnd) {
						x /= power_table[i];
						exp += j;
					}
				}
				j >>= 1;
			} while (i);
		}
	}
	if (x >= upper_bnd) {		/* Handle bad rounding case. */
		x /= power_table[0];
		++exp;
	}
	assert(x < upper_bnd);

 GENERATE_DIGITS:
	{
		int i, j;
		s = buf + 2;			/* Leave space for '\0' and '0'. */
		i = 0;
		do {
			uint_fast32_t digit_block = (uint_fast32_t) x;
			assert(digit_block < upper_bnd);
#ifdef __UCLIBC_MJN3_ONLY__
#warning CONSIDER: Can rounding be a problem?
#endif /* __UCLIBC_MJN3_ONLY__ */
			x = (x - digit_block) * upper_bnd;
			s += dpb;
			j = 0;
			do {
				s[- ++j] = '0' + (digit_block % base);
				digit_block /= base;
			} while (j < dpb);
		} while (++i < ndb);
	}

	/*************************************************************************/

	if (mode < 'a') {
		*exp_buf -= ('a' - 'A'); /* e->E and p->P */
		mode += ('a' - 'A');
	}

	o_mode = mode;
	if ((mode == 'g') && (preci > 0)){
		--preci;
	}
	round = preci;

	if (mode == 'f') {
		round += exp;
		if (round < -1) {
			memset(buf, '0', DECIMAL_DIG); /* OK, since 'f' -> decimal case. */
		    exp = -1;
		    round = -1;
		}
	}

	s = buf;
	*s++ = 0;					/* Terminator for rounding and 0-triming. */
	*s = '0';					/* Space to round. */

	{
		int i;
		i = 0;
		e = s + nd + 1;
		if (round < nd) {
			e = s + round + 2;
			if (*e >= '0' + (base/2)) {	/* NOTE: We always round away from 0! */
				i = 1;
			}
		}

		do {			   /* Handle rounding and trim trailing 0s. */
			*--e += i;			/* Add the carry. */
		} while ((*e == '0') || (*e > '0' - 1 + base));
	}

#ifdef __UCLIBC_HAS_HEXADECIMAL_FLOATS__
	if ((mode|0x20) == 'a') {
		char *q;

		for (q = e ; *q ; --q) {
			if (*q > '9') {
				*q += (*exp_buf - ('p' - 'a') - '9' - 1);
			}
		}

		if (e > s) {
			exp *= 4;			/* Change from base 16 to base 2. */
		}
	}
#endif /* __UCLIBC_HAS_HEXADECIMAL_FLOATS__ */

	o_exp = exp;
	if (e <= s) {				/* We carried into an extra digit. */
		++o_exp;
		e = s;					/* Needed if all 0s. */
	} else {
		++s;
	}
	*++e = 0;					/* Terminating nul char. */

	if ((mode == 'g') && ((o_exp >= -4) && (o_exp <= round))) {
		mode = 'f';
		preci = round - o_exp;
	}

	exp = o_exp;
	if (mode != 'f') {
		o_exp = 0;
	}

	if (o_exp < 0) {			/* Exponent is < 0, so */
		*--s = '0';				/* fake the first 0 digit. */
	}

	pc_fwi[3] = FPO_ZERO_PAD;
	pc_fwi[4] = 1;
	pc_fwi[5] = (intptr_t)(sign_str + 4);
	sign_str[4] = *s++;
	sign_str[5] = 0;
	ppc = pc_fwi + 6;

	{
		int i = e - s;			/* Total digits is 'i'. */
		if (o_exp >= 0) {
#ifdef __UCLIBC_HAS_GLIBC_DIGIT_GROUPING__

			const char *p;

			if (PRINT_INFO_FLAG_VAL(info,group)
			 && *(p = __UCLIBC_CURLOCALE->grouping)
			) {
				int nblk1;

				nblk2 = nblk1 = *p;
				if (*++p) {
					nblk2 = *p;
					assert(!*++p);
				}

				if (o_exp >= nblk1) {
					num_groups = (o_exp - nblk1) / nblk2 + 1;
					initial_group = (o_exp - nblk1) % nblk2;

#ifdef __UCLIBC_HAS_WCHAR__
					if (PRINT_INFO_FLAG_VAL(info,wide)) {
						/* _fp_out_wide() will fix this up. */
						ts = fmt + THOUSEP_OFFSET;
						tslen = 1;
					} else {
#endif /* __UCLIBC_HAS_WCHAR__ */
						ts = __UCLIBC_CURLOCALE->thousands_sep;
						tslen = __UCLIBC_CURLOCALE->thousands_sep_len;
#ifdef __UCLIBC_HAS_WCHAR__
					}
#endif /* __UCLIBC_HAS_WCHAR__ */

					width -= num_groups * tslen;
				}
			}


#endif /* __UCLIBC_HAS_GLIBC_DIGIT_GROUPING__ */
			ppc[0] = FPO_STR_PREC;
			ppc[2] = (intptr_t)(s);
			if (o_exp >= i) {		/* all digit(s) left of decimal */
				ppc[1] = i;
				ppc += 3;
				o_exp -= i;
				i = 0;
				if (o_exp>0) {		/* have 0s left of decimal */
					ppc[0] = FPO_ZERO_PAD;
					ppc[1] = o_exp;
					ppc[2] = (intptr_t)(fmt + EMPTY_STRING_OFFSET);
					ppc += 3;
				}
			} else if (o_exp > 0) {	/* decimal between digits */
				ppc[1] = o_exp;
				ppc += 3;
				s += o_exp;
				i -= o_exp;
			}
			o_exp = -1;
		}

		if (PRINT_INFO_FLAG_VAL(info,alt)
			|| (i)
			|| ((o_mode != 'g')
#ifdef __UCLIBC_HAS_HEXADECIMAL_FLOATS__
				&& (o_mode != 'a')
#endif /* __UCLIBC_HAS_HEXADECIMAL_FLOATS__ */
				&& (preci > 0))
			) {
			ppc[0] = FPO_STR_PREC;
#ifdef __LOCALE_C_ONLY
			ppc[1] = 1;
			ppc[2] = (intptr_t)(fmt + DECPT_OFFSET);
#else  /* __LOCALE_C_ONLY */
#ifdef __UCLIBC_HAS_WCHAR__
			if (PRINT_INFO_FLAG_VAL(info,wide)) {
				/* _fp_out_wide() will fix this up. */
				ppc[1] = 1;
				ppc[2] = (intptr_t)(fmt + DECPT_OFFSET);
			} else {
#endif /* __UCLIBC_HAS_WCHAR__ */
				ppc[1] = __UCLIBC_CURLOCALE->decimal_point_len;
				ppc[2] = (intptr_t)(__UCLIBC_CURLOCALE->decimal_point);
#ifdef __UCLIBC_HAS_WCHAR__
			}
#endif /* __UCLIBC_HAS_WCHAR__ */
#endif /* __LOCALE_C_ONLY */
			ppc += 3;
		}

		if (++o_exp < 0) {			/* Have 0s right of decimal. */
			ppc[0] = FPO_ZERO_PAD;
			ppc[1] = -o_exp;
			ppc[2] = (intptr_t)(fmt + EMPTY_STRING_OFFSET);
			ppc += 3;
		}
		if (i) {					/* Have digit(s) right of decimal. */
			ppc[0] = FPO_STR_PREC;
			ppc[1] = i;
			ppc[2] = (intptr_t)(s);
			ppc += 3;
		}

		if (((o_mode != 'g') || PRINT_INFO_FLAG_VAL(info,alt))
#ifdef __UCLIBC_HAS_HEXADECIMAL_FLOATS__
			&& !sufficient_precision
#endif /* __UCLIBC_HAS_HEXADECIMAL_FLOATS__ */
			) {
			i -= o_exp;
			if (i < preci) {		/* Have 0s right of digits. */
				i = preci - i;
				ppc[0] = FPO_ZERO_PAD;
				ppc[1] = i;
				ppc[2] = (intptr_t)(fmt + EMPTY_STRING_OFFSET);
				ppc += 3;
			}
		}
	}

	/* Build exponent string. */
	if (mode != 'f') {
		char *p = exp_buf + sizeof(exp_buf);
		int j;
		char exp_char = *exp_buf;
		char exp_sign = '+';
#ifdef __UCLIBC_HAS_HEXADECIMAL_FLOATS__
		int min_exp_dig_plus_2 = ((o_mode != 'a') ? (2+2) : (2+1));
#else  /* __UCLIBC_HAS_HEXADECIMAL_FLOATS__ */
#define min_exp_dig_plus_2  (2+2)
#endif /* __UCLIBC_HAS_HEXADECIMAL_FLOATS__ */

		if (exp < 0) {
			exp_sign = '-';
			exp = -exp;
		}

		*--p = 0;			/* nul-terminate */
		j = 2;				/* Count exp_char and exp_sign. */
		do {
			*--p = '0' + (exp % 10);
			exp /= 10;
		} while ((++j < min_exp_dig_plus_2) || exp); /* char+sign+mindigits */
		*--p = exp_sign;
		*--p = exp_char;

		ppc[0] = FPO_STR_PREC;
		ppc[1] = j;
		ppc[2] = (intptr_t)(p);
		ppc += 3;
	}

 EXIT_SPECIAL:
	{
		int i;
		ppc_last = ppc;
		ppc = pc_fwi + 4;	 /* Need width fields starting with second. */
		do {
			width -= *ppc;
			ppc += 3;
		} while (ppc < ppc_last);

		ppc = pc_fwi;
		ppc[0] = FPO_STR_WIDTH;
		ppc[1] = i = ((*sign_str) != 0);
		ppc[2] = (intptr_t) sign_str;

#ifdef __UCLIBC_HAS_HEXADECIMAL_FLOATS__
		if (((mode|0x20) == 'a') && (pc_fwi[3] >= 16)) { /* Hex sign handling. */
			/* Hex and not inf or nan, so prefix with 0x. */
			char *h = sign_str + i;
			*h = '0';
			*++h = 'x' - 'p' + *exp_buf;
			*++h = 0;
			ppc[1] = (i += 2);
		}
#endif /* __UCLIBC_HAS_HEXADECIMAL_FLOATS__ */

		if ((width -= i) > 0) {
			if (PRINT_INFO_FLAG_VAL(info,left)) { /* Left-justified. */
				ppc_last[0] = FPO_STR_WIDTH;
				ppc_last[1] = width;
				ppc_last[2] = (intptr_t)(fmt + EMPTY_STRING_OFFSET);
				ppc_last += 3;
			} else if (info->pad == '0') { /* 0 padding */
				ppc[4] += width;	/* Pad second field. */
			} else {
				ppc[1] += width;	/* Pad first (sign) field. */
			}
		}

		cnt = 0;
	}

	do {
#ifdef __UCLIBC_HAS_GLIBC_DIGIT_GROUPING__

		if ((ppc == pc_fwi + 6) && num_groups) {
			const char *gp = (const char *) ppc[2];
			int len = ppc[1];
			int blk = initial_group;

			cnt += num_groups * tslen; /* Adjust count now for sep chars. */

/* 			__printf("\n"); */
			do {
				if (!blk) {		/* Initial group could be 0 digits long! */
					blk = nblk2;
				} else if (len >= blk) { /* Enough digits for a group. */
/* 					__printf("norm:  len=%d blk=%d  \"%.*s\"\n", len, blk, blk, gp); */
					if (fp_outfunc(fp, *ppc, blk, (intptr_t) gp) != blk) {
						return -1;
					}
					assert(gp);
					if (*gp) {
						gp += blk;
					}
					len -= blk;
				} else {		/* Transition to 0s. */
/* 					__printf("trans: len=%d blk=%d  \"%.*s\"\n", len, blk, len, gp); */
					if (len) {
/* 						__printf("len\n"); */
						if (fp_outfunc(fp, *ppc, len, (intptr_t) gp) != len) {
							return -1;
						}
						gp += len;
					}

					if (ppc[3] == FPO_ZERO_PAD) { /* Need to group 0s */
/* 						__printf("zeropad\n"); */
						cnt += ppc[1];
						ppc += 3;
						gp = (const char *) ppc[2];
						blk -= len;	/* blk > len, so blk still > 0. */
						len = ppc[1];
						continue; /* Don't decrement num_groups here. */
					} else {
						assert(num_groups == 0);
						break;
					}
				}

				if (num_groups <= 0) {
					break;
				}
				--num_groups;

				if (fp_outfunc(fp, FPO_STR_PREC, tslen, (intptr_t) ts) != tslen) {
					return -1;
				}
				blk = nblk2;

/* 				__printf("num_groups=%d   blk=%d\n", num_groups, blk); */

			} while (1);
		} else

#endif /* __UCLIBC_HAS_GLIBC_DIGIT_GROUPING__ */
		{						/* NOTE: Remember 'else' above! */
			if (fp_outfunc(fp, *ppc, ppc[1], ppc[2]) != ppc[1]) {
				return -1;
			}
		}

		cnt += ppc[1];
		ppc += 3;
	} while (ppc < ppc_last);

	return cnt;
}