1 /* Floating point output for `printf'.
2 Copyright (C) 1995, 1996 Free Software Foundation, Inc.
3 Written by Ulrich Drepper.
5 This file is part of the GNU C Library.
7 The GNU C Library is free software; you can redistribute it and/or
8 modify it under the terms of the GNU Library General Public License as
9 published by the Free Software Foundation; either version 2 of the
10 License, or (at your option) any later version.
12 The GNU C Library is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 Library General Public License for more details.
17 You should have received a copy of the GNU Library General Public
18 License along with the GNU C Library; see the file COPYING.LIB. If
19 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
20 Cambridge, MA 02139, USA. */
22 /* The gmp headers need some configuration frobs. */
33 #include <gmp-mparam.h>
34 #include "../stdlib/gmp.h"
35 #include "../stdlib/gmp-impl.h"
36 #include "../stdlib/longlong.h"
37 #include "../stdlib/fpioconst.h"
38 #include "../locale/localeinfo.h"
46 #define NDEBUG /* Undefine this for debugging assertions. */
49 /* This defines make it possible to use the same code for GNU C library and
50 the GNU I/O library. */
52 # define PUT(f, s, n) _IO_sputn (f, s, n)
53 # define PAD(f, c, n) _IO_padn (f, c, n)
54 /* We use this file GNU C library and GNU I/O library. So make
57 # define putc(c, f) _IO_putc_unlocked (c, f)
58 # define size_t _IO_size_t
59 # define FILE _IO_FILE
60 #else /* ! USE_IN_LIBIO */
61 # define PUT(f, s, n) fwrite (s, 1, n, f)
62 # define PAD(f, c, n) __printf_pad (f, c, n)
63 ssize_t __printf_pad
__P ((FILE *, char pad
, int n
)); /* In vfprintf.c. */
64 #endif /* USE_IN_LIBIO */
66 /* Macros for doing the actual output. */
71 register const int outc = (ch); \
72 if (putc (outc, fp) == EOF) \
77 #define PRINT(ptr, len) \
80 register size_t outlen = (len); \
83 if (PUT (fp, ptr, outlen) != outlen) \
90 while (outlen-- > 0) \
95 #define PADN(ch, len) \
98 if (PAD (fp, ch, len) != len) \
104 /* We use the GNU MP library to handle large numbers.
106 An MP variable occupies a varying number of entries in its array. We keep
107 track of this number for efficiency reasons. Otherwise we would always
108 have to process the whole array. */
109 #define MPN_VAR(name) mp_limb_t *name; mp_size_t name##size
111 #define MPN_ASSIGN(dst,src) \
112 memcpy (dst, src, (dst##size = src##size) * sizeof (mp_limb_t))
113 #define MPN_GE(u,v) \
114 (u##size > v##size || (u##size == v##size && __mpn_cmp (u, v, u##size) >= 0))
116 extern int __isinfl (long double), __isnanl (long double);
118 extern mp_size_t
__mpn_extract_double (mp_ptr res_ptr
, mp_size_t size
,
119 int *expt
, int *is_neg
,
121 extern mp_size_t
__mpn_extract_long_double (mp_ptr res_ptr
, mp_size_t size
,
122 int *expt
, int *is_neg
,
124 extern unsigned int __guess_grouping (unsigned int intdig_max
,
125 const char *grouping
, wchar_t sepchar
);
128 static char *group_number (char *buf
, char *bufend
, unsigned int intdig_no
,
129 const char *grouping
, wchar_t thousands_sep
);
133 __printf_fp (FILE *fp
,
134 const struct printf_info
*info
,
135 const void *const *args
)
137 /* The floating-point value to output. */
141 __long_double_t ldbl
;
145 /* Locale-dependent representation of decimal point. */
148 /* Locale-dependent thousands separator and grouping specification. */
149 wchar_t thousands_sep
;
150 const char *grouping
;
152 /* "NaN" or "Inf" for the special cases. */
153 const char *special
= NULL
;
155 /* We need just a few limbs for the input before shifting to the right
157 mp_limb_t fp_input
[(LDBL_MANT_DIG
+ BITS_PER_MP_LIMB
- 1) / BITS_PER_MP_LIMB
];
158 /* We need to shift the contents of fp_input by this amount of bits. */
161 /* The significant of the floting-point value in question */
163 /* and the exponent. */
165 /* Sign of the exponent. */
167 /* Sign of float number. */
170 /* Scaling factor. */
173 /* Temporary bignum value. */
176 /* Digit which is result of last hack_digit() call. */
179 /* The type of output format that will be used: 'e'/'E' or 'f'. */
182 /* Counter for number of written characters. */
185 /* General helper (carry limb). */
188 char hack_digit (void)
192 if (expsign
!= 0 && type
== 'f' && exponent
-- > 0)
194 else if (scalesize
== 0)
196 hi
= frac
[fracsize
- 1];
197 cy
= __mpn_mul_1 (frac
, frac
, fracsize
- 1, 10);
198 frac
[fracsize
- 1] = cy
;
202 if (fracsize
< scalesize
)
206 hi
= mpn_divmod (tmp
, frac
, fracsize
, scale
, scalesize
);
207 tmp
[fracsize
- scalesize
] = hi
;
210 fracsize
= scalesize
;
211 while (fracsize
!= 0 && frac
[fracsize
- 1] == 0)
215 /* We're not prepared for an mpn variable with zero
222 cy
= __mpn_mul_1 (frac
, frac
, fracsize
, 10);
224 frac
[fracsize
++] = cy
;
231 /* Figure out the decimal point character. */
232 if (info
->extra
== 0)
234 if (mbtowc (&decimal
, _NL_CURRENT (LC_NUMERIC
, DECIMAL_POINT
),
235 strlen (_NL_CURRENT (LC_NUMERIC
, DECIMAL_POINT
))) <= 0)
236 decimal
= (wchar_t) *_NL_CURRENT (LC_NUMERIC
, DECIMAL_POINT
);
240 if (mbtowc (&decimal
, _NL_CURRENT (LC_MONETARY
, MON_DECIMAL_POINT
),
241 strlen (_NL_CURRENT (LC_MONETARY
, MON_DECIMAL_POINT
))) <= 0)
242 decimal
= (wchar_t) *_NL_CURRENT (LC_MONETARY
, MON_DECIMAL_POINT
);
244 /* Give default value. */
245 if (decimal
== L
'\0')
251 if (info
->extra
== 0)
252 grouping
= _NL_CURRENT (LC_NUMERIC
, GROUPING
);
254 grouping
= _NL_CURRENT (LC_MONETARY
, MON_GROUPING
);
256 if (*grouping
<= 0 || *grouping
== CHAR_MAX
)
260 /* Figure out the thousands seperator character. */
261 if (info
->extra
== 0)
263 if (mbtowc (&thousands_sep
, _NL_CURRENT (LC_NUMERIC
,
265 strlen (_NL_CURRENT (LC_NUMERIC
, THOUSANDS_SEP
)))
267 thousands_sep
= (wchar_t) *_NL_CURRENT (LC_NUMERIC
,
272 if (mbtowc (&thousands_sep
, _NL_CURRENT (LC_MONETARY
,
274 strlen (_NL_CURRENT (LC_MONETARY
,
275 MON_THOUSANDS_SEP
))) <= 0)
276 thousands_sep
= (wchar_t) *_NL_CURRENT (LC_MONETARY
,
280 if (thousands_sep
== L
'\0')
287 /* Fetch the argument value. */
288 if (info
->is_long_double
&& sizeof (long double) > sizeof (double))
290 fpnum
.ldbl
= *(const long double *) args
[0];
292 /* Check for special values: not a number or infinity. */
293 if (__isnanl (fpnum
.ldbl
))
298 else if (__isinfl (fpnum
.ldbl
))
301 is_neg
= fpnum
.ldbl
< 0;
305 fracsize
= __mpn_extract_long_double (fp_input
,
307 sizeof (fp_input
[0])),
310 to_shift
= 1 + fracsize
* BITS_PER_MP_LIMB
- LDBL_MANT_DIG
;
315 fpnum
.dbl
= *(const double *) args
[0];
317 /* Check for special values: not a number or infinity. */
318 if (__isnan (fpnum
.dbl
))
323 else if (__isinf (fpnum
.dbl
))
326 is_neg
= fpnum
.dbl
< 0;
330 fracsize
= __mpn_extract_double (fp_input
,
332 / sizeof (fp_input
[0])),
333 &exponent
, &is_neg
, fpnum
.dbl
);
334 to_shift
= 1 + fracsize
* BITS_PER_MP_LIMB
- DBL_MANT_DIG
;
340 int width
= info
->prec
> info
->width
? info
->prec
: info
->width
;
342 if (is_neg
|| info
->showsign
|| info
->space
)
346 if (!info
->left
&& width
> 0)
351 else if (info
->showsign
)
353 else if (info
->space
)
358 if (info
->left
&& width
> 0)
365 /* We need three multiprecision variables. Now that we have the exponent
366 of the number we can allocate the needed memory. It would be more
367 efficient to use variables of the fixed maximum size but because this
368 would be really big it could lead to memory problems. */
370 mp_size_t bignum_size
= ((ABS (exponent
) + BITS_PER_MP_LIMB
- 1)
371 / BITS_PER_MP_LIMB
+ 4) * sizeof (mp_limb_t
);
372 frac
= (mp_limb_t
*) alloca (bignum_size
);
373 tmp
= (mp_limb_t
*) alloca (bignum_size
);
374 scale
= (mp_limb_t
*) alloca (bignum_size
);
377 /* We now have to distinguish between numbers with positive and negative
378 exponents because the method used for the one is not applicable/efficient
385 int explog
= LDBL_MAX_10_EXP_LOG
;
387 const struct mp_power
*tens
= &_fpioconst_pow10
[explog
+ 1];
390 if ((exponent
+ to_shift
) % BITS_PER_MP_LIMB
== 0)
392 MPN_COPY_DECR (frac
+ (exponent
+ to_shift
) / BITS_PER_MP_LIMB
,
394 fracsize
+= (exponent
+ to_shift
) / BITS_PER_MP_LIMB
;
398 cy
= __mpn_lshift (frac
+ (exponent
+ to_shift
) / BITS_PER_MP_LIMB
,
400 (exponent
+ to_shift
) % BITS_PER_MP_LIMB
);
401 fracsize
+= (exponent
+ to_shift
) / BITS_PER_MP_LIMB
;
403 frac
[fracsize
++] = cy
;
405 MPN_ZERO (frac
, (exponent
+ to_shift
) / BITS_PER_MP_LIMB
);
407 assert (tens
> &_fpioconst_pow10
[0]);
412 /* The number of the product of two binary numbers with n and m
413 bits respectively has m+n or m+n-1 bits. */
414 if (exponent
>= scaleexpo
+ tens
->p_expo
- 1)
417 MPN_ASSIGN (tmp
, tens
->array
);
420 cy
= __mpn_mul (tmp
, scale
, scalesize
,
421 &tens
->array
[_FPIO_CONST_OFFSET
],
422 tens
->arraysize
- _FPIO_CONST_OFFSET
);
423 tmpsize
= scalesize
+ tens
->arraysize
- _FPIO_CONST_OFFSET
;
428 if (MPN_GE (frac
, tmp
))
431 MPN_ASSIGN (scale
, tmp
);
432 count_leading_zeros (cnt
, scale
[scalesize
- 1]);
433 scaleexpo
= (scalesize
- 2) * BITS_PER_MP_LIMB
- cnt
- 1;
434 exp10
|= 1 << explog
;
439 while (tens
> &_fpioconst_pow10
[0]);
442 /* Optimize number representations. We want to represent the numbers
443 with the lowest number of bytes possible without losing any
444 bytes. Also the highest bit in the scaling factor has to be set
445 (this is a requirement of the MPN division routines). */
448 /* Determine minimum number of zero bits at the end of
450 for (i
= 0; scale
[i
] == 0 && frac
[i
] == 0; i
++)
453 /* Determine number of bits the scaling factor is misplaced. */
454 count_leading_zeros (cnt_h
, scale
[scalesize
- 1]);
458 /* The highest bit of the scaling factor is already set. So
459 we only have to remove the trailing empty limbs. */
462 MPN_COPY_INCR (scale
, scale
+ i
, scalesize
- i
);
464 MPN_COPY_INCR (frac
, frac
+ i
, fracsize
- i
);
472 count_trailing_zeros (cnt_l
, scale
[i
]);
476 count_trailing_zeros (cnt_l2
, frac
[i
]);
482 count_trailing_zeros (cnt_l
, frac
[i
]);
484 /* Now shift the numbers to their optimal position. */
485 if (i
== 0 && BITS_PER_MP_LIMB
- cnt_h
> cnt_l
)
487 /* We cannot save any memory. So just roll both numbers
488 so that the scaling factor has its highest bit set. */
490 (void) __mpn_lshift (scale
, scale
, scalesize
, cnt_h
);
491 cy
= __mpn_lshift (frac
, frac
, fracsize
, cnt_h
);
493 frac
[fracsize
++] = cy
;
495 else if (BITS_PER_MP_LIMB
- cnt_h
<= cnt_l
)
497 /* We can save memory by removing the trailing zero limbs
498 and by packing the non-zero limbs which gain another
501 (void) __mpn_rshift (scale
, scale
+ i
, scalesize
- i
,
502 BITS_PER_MP_LIMB
- cnt_h
);
504 (void) __mpn_rshift (frac
, frac
+ i
, fracsize
- i
,
505 BITS_PER_MP_LIMB
- cnt_h
);
506 fracsize
-= frac
[fracsize
- i
- 1] == 0 ? i
+ 1 : i
;
510 /* We can only save the memory of the limbs which are zero.
511 The non-zero parts occupy the same number of limbs. */
513 (void) __mpn_rshift (scale
, scale
+ (i
- 1),
515 BITS_PER_MP_LIMB
- cnt_h
);
517 (void) __mpn_rshift (frac
, frac
+ (i
- 1),
519 BITS_PER_MP_LIMB
- cnt_h
);
520 fracsize
-= frac
[fracsize
- (i
- 1) - 1] == 0 ? i
: i
- 1;
525 else if (exponent
< 0)
529 int explog
= LDBL_MAX_10_EXP_LOG
;
530 const struct mp_power
*tens
= &_fpioconst_pow10
[explog
+ 1];
531 mp_size_t used_limbs
= fracsize
- 1;
533 /* Now shift the input value to its right place. */
534 cy
= __mpn_lshift (frac
, fp_input
, fracsize
, to_shift
);
535 frac
[fracsize
++] = cy
;
536 assert (cy
== 1 || (frac
[fracsize
- 2] == 0 && frac
[0] == 0));
539 exponent
= -exponent
;
541 assert (tens
!= &_fpioconst_pow10
[0]);
546 if (exponent
>= tens
->m_expo
)
548 int i
, incr
, cnt_h
, cnt_l
;
551 /* The __mpn_mul function expects the first argument to be
552 bigger than the second. */
553 if (fracsize
< tens
->arraysize
- _FPIO_CONST_OFFSET
)
554 cy
= __mpn_mul (tmp
, &tens
->array
[_FPIO_CONST_OFFSET
],
555 tens
->arraysize
- _FPIO_CONST_OFFSET
,
558 cy
= __mpn_mul (tmp
, frac
, fracsize
,
559 &tens
->array
[_FPIO_CONST_OFFSET
],
560 tens
->arraysize
- _FPIO_CONST_OFFSET
);
561 tmpsize
= fracsize
+ tens
->arraysize
- _FPIO_CONST_OFFSET
;
565 count_leading_zeros (cnt_h
, tmp
[tmpsize
- 1]);
566 incr
= (tmpsize
- fracsize
) * BITS_PER_MP_LIMB
567 + BITS_PER_MP_LIMB
- 1 - cnt_h
;
569 assert (incr
<= tens
->p_expo
);
571 /* If we increased the exponent by exactly 3 we have to test
572 for overflow. This is done by comparing with 10 shifted
573 to the right position. */
574 if (incr
== exponent
+ 3)
575 if (cnt_h
<= BITS_PER_MP_LIMB
- 4)
579 = ((mp_limb_t
) 10) << (BITS_PER_MP_LIMB
- 4 - cnt_h
);
583 topval
[0] = ((mp_limb_t
) 10) << (BITS_PER_MP_LIMB
- 4);
585 (void) __mpn_lshift (topval
, topval
, 2,
586 BITS_PER_MP_LIMB
- cnt_h
);
589 /* We have to be careful when multiplying the last factor.
590 If the result is greater than 1.0 be have to test it
591 against 10.0. If it is greater or equal to 10.0 the
592 multiplication was not valid. This is because we cannot
593 determine the number of bits in the result in advance. */
594 if (incr
< exponent
+ 3
595 || (incr
== exponent
+ 3 &&
596 (tmp
[tmpsize
- 1] < topval
[1]
597 || (tmp
[tmpsize
- 1] == topval
[1]
598 && tmp
[tmpsize
- 2] < topval
[0]))))
600 /* The factor is right. Adapt binary and decimal
603 exp10
|= 1 << explog
;
605 /* If this factor yields a number greater or equal to
606 1.0, we must not shift the non-fractional digits down. */
610 /* Now we optimize the number representation. */
611 for (i
= 0; tmp
[i
] == 0; ++i
);
612 if (cnt_h
== BITS_PER_MP_LIMB
- 1)
614 MPN_COPY (frac
, tmp
+ i
, tmpsize
- i
);
615 fracsize
= tmpsize
- i
;
619 count_trailing_zeros (cnt_l
, tmp
[i
]);
621 /* Now shift the numbers to their optimal position. */
622 if (i
== 0 && BITS_PER_MP_LIMB
- 1 - cnt_h
> cnt_l
)
624 /* We cannot save any memory. Just roll the
625 number so that the leading digit is in a
628 cy
= __mpn_lshift (frac
, tmp
, tmpsize
, cnt_h
+ 1);
629 fracsize
= tmpsize
+ 1;
630 frac
[fracsize
- 1] = cy
;
632 else if (BITS_PER_MP_LIMB
- 1 - cnt_h
<= cnt_l
)
634 (void) __mpn_rshift (frac
, tmp
+ i
, tmpsize
- i
,
635 BITS_PER_MP_LIMB
- 1 - cnt_h
);
636 fracsize
= tmpsize
- i
;
640 /* We can only save the memory of the limbs which
641 are zero. The non-zero parts occupy the same
644 (void) __mpn_rshift (frac
, tmp
+ (i
- 1),
646 BITS_PER_MP_LIMB
- 1 - cnt_h
);
647 fracsize
= tmpsize
- (i
- 1);
650 used_limbs
= fracsize
- 1;
655 while (tens
!= &_fpioconst_pow10
[1] && exponent
> 0);
656 /* All factors but 10^-1 are tested now. */
661 cy
= __mpn_mul_1 (tmp
, frac
, fracsize
, 10);
663 assert (cy
== 0 || tmp
[tmpsize
- 1] < 20);
665 count_trailing_zeros (cnt_l
, tmp
[0]);
666 if (cnt_l
< MIN (4, exponent
))
668 cy
= __mpn_lshift (frac
, tmp
, tmpsize
,
669 BITS_PER_MP_LIMB
- MIN (4, exponent
));
671 frac
[tmpsize
++] = cy
;
674 (void) __mpn_rshift (frac
, tmp
, tmpsize
, MIN (4, exponent
));
677 assert (frac
[fracsize
- 1] < 10);
683 /* This is a special case. We don't need a factor because the
684 numbers are in the range of 0.0 <= fp < 8.0. We simply
685 shift it to the right place and divide it by 1.0 to get the
686 leading digit. (Of course this division is not really made.) */
687 assert (0 <= exponent
&& exponent
< 3 &&
688 exponent
+ to_shift
< BITS_PER_MP_LIMB
);
690 /* Now shift the input value to its right place. */
691 cy
= __mpn_lshift (frac
, fp_input
, fracsize
, (exponent
+ to_shift
));
692 frac
[fracsize
++] = cy
;
697 int width
= info
->width
;
698 char *buffer
, *startp
, *cp
;
701 int intdig_max
, intdig_no
= 0;
702 int fracdig_min
, fracdig_max
, fracdig_no
= 0;
706 if (tolower (info
->spec
) == 'e')
710 fracdig_min
= fracdig_max
= info
->prec
< 0 ? 6 : info
->prec
;
711 chars_needed
= 1 + 1 + fracdig_max
+ 1 + 1 + 4;
712 /* d . ddd e +- ddd */
713 dig_max
= INT_MAX
; /* Unlimited. */
714 significant
= 1; /* Does not matter here. */
716 else if (info
->spec
== 'f')
719 fracdig_min
= fracdig_max
= info
->prec
< 0 ? 6 : info
->prec
;
722 intdig_max
= exponent
+ 1;
723 /* This can be really big! */ /* XXX Maybe malloc if too big? */
724 chars_needed
= exponent
+ 1 + 1 + fracdig_max
;
729 chars_needed
= 1 + 1 + fracdig_max
;
731 dig_max
= INT_MAX
; /* Unlimited. */
732 significant
= 1; /* Does not matter here. */
736 dig_max
= info
->prec
< 0 ? 6 : (info
->prec
== 0 ? 1 : info
->prec
);
737 if ((expsign
== 0 && exponent
>= dig_max
)
738 || (expsign
!= 0 && exponent
> 4))
740 type
= isupper (info
->spec
) ? 'E' : 'e';
741 fracdig_max
= dig_max
- 1;
743 chars_needed
= 1 + 1 + fracdig_max
+ 1 + 1 + 4;
748 intdig_max
= expsign
== 0 ? exponent
+ 1 : 0;
749 fracdig_max
= dig_max
- intdig_max
;
750 /* We need space for the significant digits and perhaps for
751 leading zeros when < 1.0. Pessimistic guess: dig_max. */
752 chars_needed
= dig_max
+ dig_max
+ 1;
754 fracdig_min
= info
->alt
? fracdig_max
: 0;
755 significant
= 0; /* We count significant digits. */
759 /* Guess the number of groups we will make, and thus how
760 many spaces we need for separator characters. */
761 chars_needed
+= __guess_grouping (intdig_max
, grouping
, thousands_sep
);
763 /* Allocate buffer for output. We need two more because while rounding
764 it is possible that we need two more characters in front of all the
766 buffer
= alloca (2 + chars_needed
);
767 cp
= startp
= buffer
+ 2; /* Let room for rounding. */
769 /* Do the real work: put digits in allocated buffer. */
770 if (expsign
== 0 || type
!= 'f')
772 assert (expsign
== 0 || intdig_max
== 1);
773 while (intdig_no
< intdig_max
)
776 *cp
++ = hack_digit ();
781 || (fracdig_max
> 0 && (fracsize
> 1 || frac
[0] != 0)))
786 /* |fp| < 1.0 and the selected type is 'f', so put "0."
793 /* Generate the needed number of fractional digits. */
794 while (fracdig_no
< fracdig_min
795 || (fracdig_no
< fracdig_max
&& (fracsize
> 1 || frac
[0] != 0)))
801 else if (significant
== 0)
811 digit
= hack_digit ();
817 /* This is the critical case. */
818 if (fracsize
== 1 && frac
[0] == 0)
819 /* Rest of the number is zero -> round to even.
820 (IEEE 754-1985 4.1 says this is the default rounding.) */
821 if ((*(cp
- 1) & 1) == 0)
826 /* Process fractional digits. Terminate if not rounded or
827 radix character is reached. */
828 while (*--tp
!= decimal
&& *tp
== '9')
835 if (fracdig_no
== 0 || *tp
== decimal
)
837 /* Round the integer digits. */
838 if (*(tp
- 1) == decimal
)
841 while (--tp
>= startp
&& *tp
== '9')
848 /* It is more citical. All digits were 9's. */
853 exponent
+= expsign
== 0 ? 1 : -1;
855 else if (intdig_no
== dig_max
)
857 /* This is the case where for type %g the number fits
858 really in the range for %f output but after rounding
859 the number of digits is too big. */
863 if (info
->alt
|| fracdig_no
> 0)
865 /* Overwrite the old radix character. */
866 startp
[intdig_no
+ 2] = '0';
870 fracdig_no
+= intdig_no
;
872 fracdig_max
= intdig_max
- intdig_no
;
874 /* Now we must print the exponent. */
875 type
= isupper (info
->spec
) ? 'E' : 'e';
879 /* We can simply add another another digit before the
885 /* While rounding the number of digits can change.
886 If the number now exceeds the limits remove some
887 fractional digits. */
888 if (intdig_no
+ fracdig_no
> dig_max
)
890 cp
-= intdig_no
+ fracdig_no
- dig_max
;
891 fracdig_no
-= intdig_no
+ fracdig_no
- dig_max
;
898 /* Now remove unnecessary '0' at the end of the string. */
899 while (fracdig_no
> fracdig_min
&& *(cp
- 1) == '0')
904 /* If we eliminate all fractional digits we perhaps also can remove
905 the radix character. */
906 if (fracdig_no
== 0 && !info
->alt
&& *(cp
- 1) == decimal
)
910 /* Add in separator characters, overwriting the same buffer. */
911 cp
= group_number (startp
, cp
, intdig_no
, grouping
, thousands_sep
);
913 /* Write the exponent if it is needed. */
917 *cp
++ = expsign
? '-' : '+';
919 /* Find the magnitude of the exponent. */
921 while (expscale
<= exponent
)
925 /* Exponent always has at least two digits. */
931 *cp
++ = '0' + (exponent
/ expscale
);
932 exponent
%= expscale
;
934 while (expscale
> 10);
935 *cp
++ = '0' + exponent
;
938 /* Compute number of characters which must be filled with the padding
940 if (is_neg
|| info
->showsign
|| info
->space
)
942 width
-= cp
- startp
;
944 if (!info
->left
&& info
->pad
!= '0' && width
> 0)
945 PADN (info
->pad
, width
);
949 else if (info
->showsign
)
951 else if (info
->space
)
954 if (!info
->left
&& info
->pad
== '0' && width
> 0)
957 PRINT (startp
, cp
- startp
);
959 if (info
->left
&& width
> 0)
960 PADN (info
->pad
, width
);
965 /* Return the number of extra grouping characters that will be inserted
966 into a number with INTDIG_MAX integer digits. */
969 __guess_grouping (unsigned int intdig_max
, const char *grouping
,
974 /* We treat all negative values like CHAR_MAX. */
976 if (*grouping
== CHAR_MAX
|| *grouping
<= 0)
977 /* No grouping should be done. */
981 while (intdig_max
> (unsigned int) *grouping
)
984 intdig_max
-= *grouping
++;
986 if (*grouping
== CHAR_MAX
|| *grouping
< 0)
987 /* No more grouping should be done. */
989 else if (*grouping
== 0)
991 /* Same grouping repeats. */
992 groups
+= intdig_max
/ grouping
[-1];
1000 /* Group the INTDIG_NO integer digits of the number in [BUF,BUFEND).
1001 There is guaranteed enough space past BUFEND to extend it.
1002 Return the new end of buffer. */
1005 group_number (char *buf
, char *bufend
, unsigned int intdig_no
,
1006 const char *grouping
, wchar_t thousands_sep
)
1008 unsigned int groups
= __guess_grouping (intdig_no
, grouping
, thousands_sep
);
1014 /* Move the fractional part down. */
1015 memmove (buf
+ intdig_no
+ groups
, buf
+ intdig_no
,
1016 bufend
- (buf
+ intdig_no
));
1018 p
= buf
+ intdig_no
+ groups
- 1;
1021 unsigned int len
= *grouping
++;
1023 *p
-- = buf
[--intdig_no
];
1025 *p
-- = thousands_sep
;
1027 if (*grouping
== CHAR_MAX
|| *grouping
< 0)
1028 /* No more grouping should be done. */
1030 else if (*grouping
== 0)
1031 /* Same grouping repeats. */
1033 } while (intdig_no
> (unsigned int) *grouping
);
1035 /* Copy the remaining ungrouped digits. */
1037 *p
-- = buf
[--intdig_no
];
1040 return bufend
+ groups
;