1 /* Floating point output for `printf'.
2 Copyright (C) 1995, 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995.
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Library General Public License as
8 published by the Free Software Foundation; either version 2 of the
9 License, or (at your option) any later version.
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Library General Public License for more details.
16 You should have received a copy of the GNU Library General Public
17 License along with the GNU C Library; see the file COPYING.LIB. If not,
18 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
21 /* The gmp headers need some configuration frobs. */
32 #include <gmp-mparam.h>
33 #include <stdlib/gmp.h>
34 #include <stdlib/gmp-impl.h>
35 #include <stdlib/longlong.h>
36 #include <stdlib/fpioconst.h>
37 #include <locale/localeinfo.h>
47 # define NDEBUG /* Undefine this for debugging assertions. */
51 /* This defines make it possible to use the same code for GNU C library and
52 the GNU I/O library. */
54 # define PUT(f, s, n) _IO_sputn (f, s, n)
55 # define PAD(f, c, n) _IO_padn (f, c, n)
56 /* We use this file GNU C library and GNU I/O library. So make
59 # define putc(c, f) _IO_putc_unlocked (c, f)
60 # define size_t _IO_size_t
61 # define FILE _IO_FILE
62 #else /* ! USE_IN_LIBIO */
63 # define PUT(f, s, n) fwrite (s, 1, n, f)
64 # define PAD(f, c, n) __printf_pad (f, c, n)
65 ssize_t __printf_pad
__P ((FILE *, char pad
, int n
)); /* In vfprintf.c. */
66 #endif /* USE_IN_LIBIO */
68 /* Macros for doing the actual output. */
73 register const int outc = (ch); \
74 if (putc (outc, fp) == EOF) \
79 #define PRINT(ptr, len) \
82 register size_t outlen = (len); \
85 if (PUT (fp, ptr, outlen) != outlen) \
92 while (outlen-- > 0) \
97 #define PADN(ch, len) \
100 if (PAD (fp, ch, len) != len) \
106 /* We use the GNU MP library to handle large numbers.
108 An MP variable occupies a varying number of entries in its array. We keep
109 track of this number for efficiency reasons. Otherwise we would always
110 have to process the whole array. */
111 #define MPN_VAR(name) mp_limb_t *name; mp_size_t name##size
113 #define MPN_ASSIGN(dst,src) \
114 memcpy (dst, src, (dst##size = src##size) * sizeof (mp_limb_t))
115 #define MPN_GE(u,v) \
116 (u##size > v##size || (u##size == v##size && __mpn_cmp (u, v, u##size) >= 0))
118 extern int __isinfl (long double), __isnanl (long double);
120 extern mp_size_t
__mpn_extract_double (mp_ptr res_ptr
, mp_size_t size
,
121 int *expt
, int *is_neg
,
123 extern mp_size_t
__mpn_extract_long_double (mp_ptr res_ptr
, mp_size_t size
,
124 int *expt
, int *is_neg
,
126 extern unsigned int __guess_grouping (unsigned int intdig_max
,
127 const char *grouping
, wchar_t sepchar
);
130 static char *group_number (char *buf
, char *bufend
, unsigned int intdig_no
,
131 const char *grouping
, wchar_t thousands_sep
)
136 __printf_fp (FILE *fp
,
137 const struct printf_info
*info
,
138 const void *const *args
)
140 /* The floating-point value to output. */
144 __long_double_t ldbl
;
148 /* Locale-dependent representation of decimal point. */
151 /* Locale-dependent thousands separator and grouping specification. */
152 wchar_t thousands_sep
;
153 const char *grouping
;
155 /* "NaN" or "Inf" for the special cases. */
156 const char *special
= NULL
;
158 /* We need just a few limbs for the input before shifting to the right
160 mp_limb_t fp_input
[(LDBL_MANT_DIG
+ BITS_PER_MP_LIMB
- 1) / BITS_PER_MP_LIMB
];
161 /* We need to shift the contents of fp_input by this amount of bits. */
164 /* The fraction of the floting-point value in question */
166 /* and the exponent. */
168 /* Sign of the exponent. */
170 /* Sign of float number. */
173 /* Scaling factor. */
176 /* Temporary bignum value. */
179 /* Digit which is result of last hack_digit() call. */
182 /* The type of output format that will be used: 'e'/'E' or 'f'. */
185 /* Counter for number of written characters. */
188 /* General helper (carry limb). */
191 char hack_digit (void)
195 if (expsign
!= 0 && type
== 'f' && exponent
-- > 0)
197 else if (scalesize
== 0)
199 hi
= frac
[fracsize
- 1];
200 cy
= __mpn_mul_1 (frac
, frac
, fracsize
- 1, 10);
201 frac
[fracsize
- 1] = cy
;
205 if (fracsize
< scalesize
)
209 hi
= mpn_divmod (tmp
, frac
, fracsize
, scale
, scalesize
);
210 tmp
[fracsize
- scalesize
] = hi
;
213 fracsize
= scalesize
;
214 while (fracsize
!= 0 && frac
[fracsize
- 1] == 0)
218 /* We're not prepared for an mpn variable with zero
225 cy
= __mpn_mul_1 (frac
, frac
, fracsize
, 10);
227 frac
[fracsize
++] = cy
;
234 /* Figure out the decimal point character. */
235 if (info
->extra
== 0)
239 memset (&state
, '\0', sizeof (state
));
240 if (__mbrtowc (&decimal
, _NL_CURRENT (LC_NUMERIC
, DECIMAL_POINT
),
241 strlen (_NL_CURRENT (LC_NUMERIC
, DECIMAL_POINT
)),
243 decimal
= (wchar_t) *_NL_CURRENT (LC_NUMERIC
, DECIMAL_POINT
);
249 memset (&state
, '\0', sizeof (state
));
250 if (__mbrtowc (&decimal
, _NL_CURRENT (LC_MONETARY
, MON_DECIMAL_POINT
),
251 strlen (_NL_CURRENT (LC_MONETARY
, MON_DECIMAL_POINT
)),
253 decimal
= (wchar_t) *_NL_CURRENT (LC_MONETARY
, MON_DECIMAL_POINT
);
255 /* Give default value. */
256 if (decimal
== L
'\0')
262 if (info
->extra
== 0)
263 grouping
= _NL_CURRENT (LC_NUMERIC
, GROUPING
);
265 grouping
= _NL_CURRENT (LC_MONETARY
, MON_GROUPING
);
267 if (*grouping
<= 0 || *grouping
== CHAR_MAX
)
271 /* Figure out the thousands separator character. */
272 if (info
->extra
== 0)
276 memset (&state
, '\0', sizeof (state
));
277 if (__mbrtowc (&thousands_sep
, _NL_CURRENT (LC_NUMERIC
,
279 strlen (_NL_CURRENT (LC_NUMERIC
, THOUSANDS_SEP
)),
281 thousands_sep
= (wchar_t) *_NL_CURRENT (LC_NUMERIC
,
288 memset (&state
, '\0', sizeof (state
));
289 if (__mbrtowc (&thousands_sep
, _NL_CURRENT (LC_MONETARY
,
291 strlen (_NL_CURRENT (LC_MONETARY
,
294 thousands_sep
= (wchar_t) *_NL_CURRENT (LC_MONETARY
,
298 if (thousands_sep
== L
'\0')
305 /* Fetch the argument value. */
306 #ifndef __NO_LONG_DOUBLE_MATH
307 if (info
->is_long_double
&& sizeof (long double) > sizeof (double))
309 fpnum
.ldbl
= *(const long double *) args
[0];
311 /* Check for special values: not a number or infinity. */
312 if (__isnanl (fpnum
.ldbl
))
314 special
= isupper (info
->spec
) ? "NAN" : "nan";
317 else if (__isinfl (fpnum
.ldbl
))
319 special
= isupper (info
->spec
) ? "INF" : "inf";
320 is_neg
= fpnum
.ldbl
< 0;
324 fracsize
= __mpn_extract_long_double (fp_input
,
326 sizeof (fp_input
[0])),
329 to_shift
= 1 + fracsize
* BITS_PER_MP_LIMB
- LDBL_MANT_DIG
;
333 #endif /* no long double */
335 fpnum
.dbl
= *(const double *) args
[0];
337 /* Check for special values: not a number or infinity. */
338 if (__isnan (fpnum
.dbl
))
340 special
= isupper (info
->spec
) ? "NAN" : "nan";
343 else if (__isinf (fpnum
.dbl
))
345 special
= isupper (info
->spec
) ? "INF" : "inf";
346 is_neg
= fpnum
.dbl
< 0;
350 fracsize
= __mpn_extract_double (fp_input
,
352 / sizeof (fp_input
[0])),
353 &exponent
, &is_neg
, fpnum
.dbl
);
354 to_shift
= 1 + fracsize
* BITS_PER_MP_LIMB
- DBL_MANT_DIG
;
360 int width
= info
->width
;
362 if (is_neg
|| info
->showsign
|| info
->space
)
366 if (!info
->left
&& width
> 0)
371 else if (info
->showsign
)
373 else if (info
->space
)
378 if (info
->left
&& width
> 0)
385 /* We need three multiprecision variables. Now that we have the exponent
386 of the number we can allocate the needed memory. It would be more
387 efficient to use variables of the fixed maximum size but because this
388 would be really big it could lead to memory problems. */
390 mp_size_t bignum_size
= ((ABS (exponent
) + BITS_PER_MP_LIMB
- 1)
391 / BITS_PER_MP_LIMB
+ 4) * sizeof (mp_limb_t
);
392 frac
= (mp_limb_t
*) alloca (bignum_size
);
393 tmp
= (mp_limb_t
*) alloca (bignum_size
);
394 scale
= (mp_limb_t
*) alloca (bignum_size
);
397 /* We now have to distinguish between numbers with positive and negative
398 exponents because the method used for the one is not applicable/efficient
405 int explog
= LDBL_MAX_10_EXP_LOG
;
407 const struct mp_power
*tens
= &_fpioconst_pow10
[explog
+ 1];
410 if ((exponent
+ to_shift
) % BITS_PER_MP_LIMB
== 0)
412 MPN_COPY_DECR (frac
+ (exponent
+ to_shift
) / BITS_PER_MP_LIMB
,
414 fracsize
+= (exponent
+ to_shift
) / BITS_PER_MP_LIMB
;
418 cy
= __mpn_lshift (frac
+ (exponent
+ to_shift
) / BITS_PER_MP_LIMB
,
420 (exponent
+ to_shift
) % BITS_PER_MP_LIMB
);
421 fracsize
+= (exponent
+ to_shift
) / BITS_PER_MP_LIMB
;
423 frac
[fracsize
++] = cy
;
425 MPN_ZERO (frac
, (exponent
+ to_shift
) / BITS_PER_MP_LIMB
);
427 assert (tens
> &_fpioconst_pow10
[0]);
432 /* The number of the product of two binary numbers with n and m
433 bits respectively has m+n or m+n-1 bits. */
434 if (exponent
>= scaleexpo
+ tens
->p_expo
- 1)
437 MPN_ASSIGN (tmp
, tens
->array
);
440 cy
= __mpn_mul (tmp
, scale
, scalesize
,
441 &tens
->array
[_FPIO_CONST_OFFSET
],
442 tens
->arraysize
- _FPIO_CONST_OFFSET
);
443 tmpsize
= scalesize
+ tens
->arraysize
- _FPIO_CONST_OFFSET
;
448 if (MPN_GE (frac
, tmp
))
451 MPN_ASSIGN (scale
, tmp
);
452 count_leading_zeros (cnt
, scale
[scalesize
- 1]);
453 scaleexpo
= (scalesize
- 2) * BITS_PER_MP_LIMB
- cnt
- 1;
454 exp10
|= 1 << explog
;
459 while (tens
> &_fpioconst_pow10
[0]);
462 /* Optimize number representations. We want to represent the numbers
463 with the lowest number of bytes possible without losing any
464 bytes. Also the highest bit in the scaling factor has to be set
465 (this is a requirement of the MPN division routines). */
468 /* Determine minimum number of zero bits at the end of
470 for (i
= 0; scale
[i
] == 0 && frac
[i
] == 0; i
++)
473 /* Determine number of bits the scaling factor is misplaced. */
474 count_leading_zeros (cnt_h
, scale
[scalesize
- 1]);
478 /* The highest bit of the scaling factor is already set. So
479 we only have to remove the trailing empty limbs. */
482 MPN_COPY_INCR (scale
, scale
+ i
, scalesize
- i
);
484 MPN_COPY_INCR (frac
, frac
+ i
, fracsize
- i
);
492 count_trailing_zeros (cnt_l
, scale
[i
]);
496 count_trailing_zeros (cnt_l2
, frac
[i
]);
502 count_trailing_zeros (cnt_l
, frac
[i
]);
504 /* Now shift the numbers to their optimal position. */
505 if (i
== 0 && BITS_PER_MP_LIMB
- cnt_h
> cnt_l
)
507 /* We cannot save any memory. So just roll both numbers
508 so that the scaling factor has its highest bit set. */
510 (void) __mpn_lshift (scale
, scale
, scalesize
, cnt_h
);
511 cy
= __mpn_lshift (frac
, frac
, fracsize
, cnt_h
);
513 frac
[fracsize
++] = cy
;
515 else if (BITS_PER_MP_LIMB
- cnt_h
<= cnt_l
)
517 /* We can save memory by removing the trailing zero limbs
518 and by packing the non-zero limbs which gain another
521 (void) __mpn_rshift (scale
, scale
+ i
, scalesize
- i
,
522 BITS_PER_MP_LIMB
- cnt_h
);
524 (void) __mpn_rshift (frac
, frac
+ i
, fracsize
- i
,
525 BITS_PER_MP_LIMB
- cnt_h
);
526 fracsize
-= frac
[fracsize
- i
- 1] == 0 ? i
+ 1 : i
;
530 /* We can only save the memory of the limbs which are zero.
531 The non-zero parts occupy the same number of limbs. */
533 (void) __mpn_rshift (scale
, scale
+ (i
- 1),
535 BITS_PER_MP_LIMB
- cnt_h
);
537 (void) __mpn_rshift (frac
, frac
+ (i
- 1),
539 BITS_PER_MP_LIMB
- cnt_h
);
540 fracsize
-= frac
[fracsize
- (i
- 1) - 1] == 0 ? i
: i
- 1;
545 else if (exponent
< 0)
549 int explog
= LDBL_MAX_10_EXP_LOG
;
550 const struct mp_power
*tens
= &_fpioconst_pow10
[explog
+ 1];
551 mp_size_t used_limbs
= fracsize
- 1;
553 /* Now shift the input value to its right place. */
554 cy
= __mpn_lshift (frac
, fp_input
, fracsize
, to_shift
);
555 frac
[fracsize
++] = cy
;
556 assert (cy
== 1 || (frac
[fracsize
- 2] == 0 && frac
[0] == 0));
559 exponent
= -exponent
;
561 assert (tens
!= &_fpioconst_pow10
[0]);
566 if (exponent
>= tens
->m_expo
)
568 int i
, incr
, cnt_h
, cnt_l
;
571 /* The __mpn_mul function expects the first argument to be
572 bigger than the second. */
573 if (fracsize
< tens
->arraysize
- _FPIO_CONST_OFFSET
)
574 cy
= __mpn_mul (tmp
, &tens
->array
[_FPIO_CONST_OFFSET
],
575 tens
->arraysize
- _FPIO_CONST_OFFSET
,
578 cy
= __mpn_mul (tmp
, frac
, fracsize
,
579 &tens
->array
[_FPIO_CONST_OFFSET
],
580 tens
->arraysize
- _FPIO_CONST_OFFSET
);
581 tmpsize
= fracsize
+ tens
->arraysize
- _FPIO_CONST_OFFSET
;
585 count_leading_zeros (cnt_h
, tmp
[tmpsize
- 1]);
586 incr
= (tmpsize
- fracsize
) * BITS_PER_MP_LIMB
587 + BITS_PER_MP_LIMB
- 1 - cnt_h
;
589 assert (incr
<= tens
->p_expo
);
591 /* If we increased the exponent by exactly 3 we have to test
592 for overflow. This is done by comparing with 10 shifted
593 to the right position. */
594 if (incr
== exponent
+ 3)
596 if (cnt_h
<= BITS_PER_MP_LIMB
- 4)
600 = ((mp_limb_t
) 10) << (BITS_PER_MP_LIMB
- 4 - cnt_h
);
604 topval
[0] = ((mp_limb_t
) 10) << (BITS_PER_MP_LIMB
- 4);
606 (void) __mpn_lshift (topval
, topval
, 2,
607 BITS_PER_MP_LIMB
- cnt_h
);
611 /* We have to be careful when multiplying the last factor.
612 If the result is greater than 1.0 be have to test it
613 against 10.0. If it is greater or equal to 10.0 the
614 multiplication was not valid. This is because we cannot
615 determine the number of bits in the result in advance. */
616 if (incr
< exponent
+ 3
617 || (incr
== exponent
+ 3 &&
618 (tmp
[tmpsize
- 1] < topval
[1]
619 || (tmp
[tmpsize
- 1] == topval
[1]
620 && tmp
[tmpsize
- 2] < topval
[0]))))
622 /* The factor is right. Adapt binary and decimal
625 exp10
|= 1 << explog
;
627 /* If this factor yields a number greater or equal to
628 1.0, we must not shift the non-fractional digits down. */
632 /* Now we optimize the number representation. */
633 for (i
= 0; tmp
[i
] == 0; ++i
);
634 if (cnt_h
== BITS_PER_MP_LIMB
- 1)
636 MPN_COPY (frac
, tmp
+ i
, tmpsize
- i
);
637 fracsize
= tmpsize
- i
;
641 count_trailing_zeros (cnt_l
, tmp
[i
]);
643 /* Now shift the numbers to their optimal position. */
644 if (i
== 0 && BITS_PER_MP_LIMB
- 1 - cnt_h
> cnt_l
)
646 /* We cannot save any memory. Just roll the
647 number so that the leading digit is in a
650 cy
= __mpn_lshift (frac
, tmp
, tmpsize
, cnt_h
+ 1);
651 fracsize
= tmpsize
+ 1;
652 frac
[fracsize
- 1] = cy
;
654 else if (BITS_PER_MP_LIMB
- 1 - cnt_h
<= cnt_l
)
656 (void) __mpn_rshift (frac
, tmp
+ i
, tmpsize
- i
,
657 BITS_PER_MP_LIMB
- 1 - cnt_h
);
658 fracsize
= tmpsize
- i
;
662 /* We can only save the memory of the limbs which
663 are zero. The non-zero parts occupy the same
666 (void) __mpn_rshift (frac
, tmp
+ (i
- 1),
668 BITS_PER_MP_LIMB
- 1 - cnt_h
);
669 fracsize
= tmpsize
- (i
- 1);
672 used_limbs
= fracsize
- 1;
677 while (tens
!= &_fpioconst_pow10
[1] && exponent
> 0);
678 /* All factors but 10^-1 are tested now. */
683 cy
= __mpn_mul_1 (tmp
, frac
, fracsize
, 10);
685 assert (cy
== 0 || tmp
[tmpsize
- 1] < 20);
687 count_trailing_zeros (cnt_l
, tmp
[0]);
688 if (cnt_l
< MIN (4, exponent
))
690 cy
= __mpn_lshift (frac
, tmp
, tmpsize
,
691 BITS_PER_MP_LIMB
- MIN (4, exponent
));
693 frac
[tmpsize
++] = cy
;
696 (void) __mpn_rshift (frac
, tmp
, tmpsize
, MIN (4, exponent
));
699 assert (frac
[fracsize
- 1] < 10);
705 /* This is a special case. We don't need a factor because the
706 numbers are in the range of 0.0 <= fp < 8.0. We simply
707 shift it to the right place and divide it by 1.0 to get the
708 leading digit. (Of course this division is not really made.) */
709 assert (0 <= exponent
&& exponent
< 3 &&
710 exponent
+ to_shift
< BITS_PER_MP_LIMB
);
712 /* Now shift the input value to its right place. */
713 cy
= __mpn_lshift (frac
, fp_input
, fracsize
, (exponent
+ to_shift
));
714 frac
[fracsize
++] = cy
;
719 int width
= info
->width
;
720 char *buffer
, *startp
, *cp
;
723 int intdig_max
, intdig_no
= 0;
724 int fracdig_min
, fracdig_max
, fracdig_no
= 0;
728 if (_tolower (info
->spec
) == 'e')
732 fracdig_min
= fracdig_max
= info
->prec
< 0 ? 6 : info
->prec
;
733 chars_needed
= 1 + 1 + fracdig_max
+ 1 + 1 + 4;
734 /* d . ddd e +- ddd */
735 dig_max
= INT_MAX
; /* Unlimited. */
736 significant
= 1; /* Does not matter here. */
738 else if (info
->spec
== 'f')
741 fracdig_min
= fracdig_max
= info
->prec
< 0 ? 6 : info
->prec
;
744 intdig_max
= exponent
+ 1;
745 /* This can be really big! */ /* XXX Maybe malloc if too big? */
746 chars_needed
= exponent
+ 1 + 1 + fracdig_max
;
751 chars_needed
= 1 + 1 + fracdig_max
;
753 dig_max
= INT_MAX
; /* Unlimited. */
754 significant
= 1; /* Does not matter here. */
758 dig_max
= info
->prec
< 0 ? 6 : (info
->prec
== 0 ? 1 : info
->prec
);
759 if ((expsign
== 0 && exponent
>= dig_max
)
760 || (expsign
!= 0 && exponent
> 4))
762 type
= isupper (info
->spec
) ? 'E' : 'e';
763 fracdig_max
= dig_max
- 1;
765 chars_needed
= 1 + 1 + fracdig_max
+ 1 + 1 + 4;
770 intdig_max
= expsign
== 0 ? exponent
+ 1 : 0;
771 fracdig_max
= dig_max
- intdig_max
;
772 /* We need space for the significant digits and perhaps for
773 leading zeros when < 1.0. Pessimistic guess: dig_max. */
774 chars_needed
= dig_max
+ dig_max
+ 1;
776 fracdig_min
= info
->alt
? fracdig_max
: 0;
777 significant
= 0; /* We count significant digits. */
781 /* Guess the number of groups we will make, and thus how
782 many spaces we need for separator characters. */
783 chars_needed
+= __guess_grouping (intdig_max
, grouping
, thousands_sep
);
785 /* Allocate buffer for output. We need two more because while rounding
786 it is possible that we need two more characters in front of all the
788 buffer
= alloca (2 + chars_needed
);
789 cp
= startp
= buffer
+ 2; /* Let room for rounding. */
791 /* Do the real work: put digits in allocated buffer. */
792 if (expsign
== 0 || type
!= 'f')
794 assert (expsign
== 0 || intdig_max
== 1);
795 while (intdig_no
< intdig_max
)
798 *cp
++ = hack_digit ();
803 || (fracdig_max
> 0 && (fracsize
> 1 || frac
[0] != 0)))
808 /* |fp| < 1.0 and the selected type is 'f', so put "0."
815 /* Generate the needed number of fractional digits. */
816 while (fracdig_no
< fracdig_min
817 || (fracdig_no
< fracdig_max
&& (fracsize
> 1 || frac
[0] != 0)))
823 else if (significant
== 0)
833 digit
= hack_digit ();
838 if (digit
== '5' && (*(cp
- 1) & 1) == 0)
840 /* This is the critical case. */
841 if (fracsize
== 1 && frac
[0] == 0)
842 /* Rest of the number is zero -> round to even.
843 (IEEE 754-1985 4.1 says this is the default rounding.) */
845 else if (scalesize
== 0)
847 /* Here we have to see whether all limbs are zero since no
848 normalization happened. */
849 size_t lcnt
= fracsize
;
850 while (lcnt
>= 1 && frac
[lcnt
- 1] == 0)
853 /* Rest of the number is zero -> round to even.
854 (IEEE 754-1985 4.1 says this is the default rounding.) */
861 /* Process fractional digits. Terminate if not rounded or
862 radix character is reached. */
863 while (*--tp
!= decimal
&& *tp
== '9')
870 if (fracdig_no
== 0 || *tp
== decimal
)
872 /* Round the integer digits. */
873 if (*(tp
- 1) == decimal
)
876 while (--tp
>= startp
&& *tp
== '9')
883 /* It is more critical. All digits were 9's. */
888 exponent
+= expsign
== 0 ? 1 : -1;
890 else if (intdig_no
== dig_max
)
892 /* This is the case where for type %g the number fits
893 really in the range for %f output but after rounding
894 the number of digits is too big. */
898 if (info
->alt
|| fracdig_no
> 0)
900 /* Overwrite the old radix character. */
901 startp
[intdig_no
+ 2] = '0';
905 fracdig_no
+= intdig_no
;
907 fracdig_max
= intdig_max
- intdig_no
;
909 /* Now we must print the exponent. */
910 type
= isupper (info
->spec
) ? 'E' : 'e';
914 /* We can simply add another another digit before the
920 /* While rounding the number of digits can change.
921 If the number now exceeds the limits remove some
922 fractional digits. */
923 if (intdig_no
+ fracdig_no
> dig_max
)
925 cp
-= intdig_no
+ fracdig_no
- dig_max
;
926 fracdig_no
-= intdig_no
+ fracdig_no
- dig_max
;
933 /* Now remove unnecessary '0' at the end of the string. */
934 while (fracdig_no
> fracdig_min
&& *(cp
- 1) == '0')
939 /* If we eliminate all fractional digits we perhaps also can remove
940 the radix character. */
941 if (fracdig_no
== 0 && !info
->alt
&& *(cp
- 1) == decimal
)
945 /* Add in separator characters, overwriting the same buffer. */
946 cp
= group_number (startp
, cp
, intdig_no
, grouping
, thousands_sep
);
948 /* Write the exponent if it is needed. */
952 *cp
++ = expsign
? '-' : '+';
954 /* Find the magnitude of the exponent. */
956 while (expscale
<= exponent
)
960 /* Exponent always has at least two digits. */
966 *cp
++ = '0' + (exponent
/ expscale
);
967 exponent
%= expscale
;
969 while (expscale
> 10);
970 *cp
++ = '0' + exponent
;
973 /* Compute number of characters which must be filled with the padding
975 if (is_neg
|| info
->showsign
|| info
->space
)
977 width
-= cp
- startp
;
979 if (!info
->left
&& info
->pad
!= '0' && width
> 0)
980 PADN (info
->pad
, width
);
984 else if (info
->showsign
)
986 else if (info
->space
)
989 if (!info
->left
&& info
->pad
== '0' && width
> 0)
992 PRINT (startp
, cp
- startp
);
994 if (info
->left
&& width
> 0)
995 PADN (info
->pad
, width
);
1000 /* Return the number of extra grouping characters that will be inserted
1001 into a number with INTDIG_MAX integer digits. */
1004 __guess_grouping (unsigned int intdig_max
, const char *grouping
,
1007 unsigned int groups
;
1009 /* We treat all negative values like CHAR_MAX. */
1011 if (*grouping
== CHAR_MAX
|| *grouping
<= 0)
1012 /* No grouping should be done. */
1016 while (intdig_max
> (unsigned int) *grouping
)
1019 intdig_max
-= *grouping
++;
1021 if (*grouping
== CHAR_MAX
1026 /* No more grouping should be done. */
1028 else if (*grouping
== 0)
1030 /* Same grouping repeats. */
1031 groups
+= (intdig_max
- 1) / grouping
[-1];
1039 /* Group the INTDIG_NO integer digits of the number in [BUF,BUFEND).
1040 There is guaranteed enough space past BUFEND to extend it.
1041 Return the new end of buffer. */
1045 group_number (char *buf
, char *bufend
, unsigned int intdig_no
,
1046 const char *grouping
, wchar_t thousands_sep
)
1048 unsigned int groups
= __guess_grouping (intdig_no
, grouping
, thousands_sep
);
1054 /* Move the fractional part down. */
1055 memmove (buf
+ intdig_no
+ groups
, buf
+ intdig_no
,
1056 bufend
- (buf
+ intdig_no
));
1058 p
= buf
+ intdig_no
+ groups
- 1;
1061 unsigned int len
= *grouping
++;
1063 *p
-- = buf
[--intdig_no
];
1065 *p
-- = thousands_sep
;
1067 if (*grouping
== CHAR_MAX
1072 /* No more grouping should be done. */
1074 else if (*grouping
== 0)
1075 /* Same grouping repeats. */
1077 } while (intdig_no
> (unsigned int) *grouping
);
1079 /* Copy the remaining ungrouped digits. */
1081 *p
-- = buf
[--intdig_no
];
1084 return bufend
+ groups
;