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
*powers
= &_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 (powers
> &_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
+ powers
->p_expo
- 1)
438 tmpsize
= powers
->arraysize
;
439 memcpy (tmp
, &__tens
[powers
->arrayoff
],
440 tmpsize
* sizeof (mp_limb_t
));
444 cy
= __mpn_mul (tmp
, scale
, scalesize
,
445 &__tens
[powers
->arrayoff
446 + _FPIO_CONST_OFFSET
],
447 powers
->arraysize
- _FPIO_CONST_OFFSET
);
448 tmpsize
= scalesize
+ powers
->arraysize
- _FPIO_CONST_OFFSET
;
453 if (MPN_GE (frac
, tmp
))
456 MPN_ASSIGN (scale
, tmp
);
457 count_leading_zeros (cnt
, scale
[scalesize
- 1]);
458 scaleexpo
= (scalesize
- 2) * BITS_PER_MP_LIMB
- cnt
- 1;
459 exp10
|= 1 << explog
;
464 while (powers
> &_fpioconst_pow10
[0]);
467 /* Optimize number representations. We want to represent the numbers
468 with the lowest number of bytes possible without losing any
469 bytes. Also the highest bit in the scaling factor has to be set
470 (this is a requirement of the MPN division routines). */
473 /* Determine minimum number of zero bits at the end of
475 for (i
= 0; scale
[i
] == 0 && frac
[i
] == 0; i
++)
478 /* Determine number of bits the scaling factor is misplaced. */
479 count_leading_zeros (cnt_h
, scale
[scalesize
- 1]);
483 /* The highest bit of the scaling factor is already set. So
484 we only have to remove the trailing empty limbs. */
487 MPN_COPY_INCR (scale
, scale
+ i
, scalesize
- i
);
489 MPN_COPY_INCR (frac
, frac
+ i
, fracsize
- i
);
497 count_trailing_zeros (cnt_l
, scale
[i
]);
501 count_trailing_zeros (cnt_l2
, frac
[i
]);
507 count_trailing_zeros (cnt_l
, frac
[i
]);
509 /* Now shift the numbers to their optimal position. */
510 if (i
== 0 && BITS_PER_MP_LIMB
- cnt_h
> cnt_l
)
512 /* We cannot save any memory. So just roll both numbers
513 so that the scaling factor has its highest bit set. */
515 (void) __mpn_lshift (scale
, scale
, scalesize
, cnt_h
);
516 cy
= __mpn_lshift (frac
, frac
, fracsize
, cnt_h
);
518 frac
[fracsize
++] = cy
;
520 else if (BITS_PER_MP_LIMB
- cnt_h
<= cnt_l
)
522 /* We can save memory by removing the trailing zero limbs
523 and by packing the non-zero limbs which gain another
526 (void) __mpn_rshift (scale
, scale
+ i
, scalesize
- i
,
527 BITS_PER_MP_LIMB
- cnt_h
);
529 (void) __mpn_rshift (frac
, frac
+ i
, fracsize
- i
,
530 BITS_PER_MP_LIMB
- cnt_h
);
531 fracsize
-= frac
[fracsize
- i
- 1] == 0 ? i
+ 1 : i
;
535 /* We can only save the memory of the limbs which are zero.
536 The non-zero parts occupy the same number of limbs. */
538 (void) __mpn_rshift (scale
, scale
+ (i
- 1),
540 BITS_PER_MP_LIMB
- cnt_h
);
542 (void) __mpn_rshift (frac
, frac
+ (i
- 1),
544 BITS_PER_MP_LIMB
- cnt_h
);
545 fracsize
-= frac
[fracsize
- (i
- 1) - 1] == 0 ? i
: i
- 1;
550 else if (exponent
< 0)
554 int explog
= LDBL_MAX_10_EXP_LOG
;
555 const struct mp_power
*powers
= &_fpioconst_pow10
[explog
+ 1];
556 mp_size_t used_limbs
= fracsize
- 1;
558 /* Now shift the input value to its right place. */
559 cy
= __mpn_lshift (frac
, fp_input
, fracsize
, to_shift
);
560 frac
[fracsize
++] = cy
;
561 assert (cy
== 1 || (frac
[fracsize
- 2] == 0 && frac
[0] == 0));
564 exponent
= -exponent
;
566 assert (powers
!= &_fpioconst_pow10
[0]);
571 if (exponent
>= powers
->m_expo
)
573 int i
, incr
, cnt_h
, cnt_l
;
576 /* The __mpn_mul function expects the first argument to be
577 bigger than the second. */
578 if (fracsize
< powers
->arraysize
- _FPIO_CONST_OFFSET
)
579 cy
= __mpn_mul (tmp
, &__tens
[powers
->arrayoff
580 + _FPIO_CONST_OFFSET
],
581 powers
->arraysize
- _FPIO_CONST_OFFSET
,
584 cy
= __mpn_mul (tmp
, frac
, fracsize
,
585 &__tens
[powers
->arrayoff
+ _FPIO_CONST_OFFSET
],
586 powers
->arraysize
- _FPIO_CONST_OFFSET
);
587 tmpsize
= fracsize
+ powers
->arraysize
- _FPIO_CONST_OFFSET
;
591 count_leading_zeros (cnt_h
, tmp
[tmpsize
- 1]);
592 incr
= (tmpsize
- fracsize
) * BITS_PER_MP_LIMB
593 + BITS_PER_MP_LIMB
- 1 - cnt_h
;
595 assert (incr
<= powers
->p_expo
);
597 /* If we increased the exponent by exactly 3 we have to test
598 for overflow. This is done by comparing with 10 shifted
599 to the right position. */
600 if (incr
== exponent
+ 3)
602 if (cnt_h
<= BITS_PER_MP_LIMB
- 4)
606 = ((mp_limb_t
) 10) << (BITS_PER_MP_LIMB
- 4 - cnt_h
);
610 topval
[0] = ((mp_limb_t
) 10) << (BITS_PER_MP_LIMB
- 4);
612 (void) __mpn_lshift (topval
, topval
, 2,
613 BITS_PER_MP_LIMB
- cnt_h
);
617 /* We have to be careful when multiplying the last factor.
618 If the result is greater than 1.0 be have to test it
619 against 10.0. If it is greater or equal to 10.0 the
620 multiplication was not valid. This is because we cannot
621 determine the number of bits in the result in advance. */
622 if (incr
< exponent
+ 3
623 || (incr
== exponent
+ 3 &&
624 (tmp
[tmpsize
- 1] < topval
[1]
625 || (tmp
[tmpsize
- 1] == topval
[1]
626 && tmp
[tmpsize
- 2] < topval
[0]))))
628 /* The factor is right. Adapt binary and decimal
631 exp10
|= 1 << explog
;
633 /* If this factor yields a number greater or equal to
634 1.0, we must not shift the non-fractional digits down. */
638 /* Now we optimize the number representation. */
639 for (i
= 0; tmp
[i
] == 0; ++i
);
640 if (cnt_h
== BITS_PER_MP_LIMB
- 1)
642 MPN_COPY (frac
, tmp
+ i
, tmpsize
- i
);
643 fracsize
= tmpsize
- i
;
647 count_trailing_zeros (cnt_l
, tmp
[i
]);
649 /* Now shift the numbers to their optimal position. */
650 if (i
== 0 && BITS_PER_MP_LIMB
- 1 - cnt_h
> cnt_l
)
652 /* We cannot save any memory. Just roll the
653 number so that the leading digit is in a
656 cy
= __mpn_lshift (frac
, tmp
, tmpsize
, cnt_h
+ 1);
657 fracsize
= tmpsize
+ 1;
658 frac
[fracsize
- 1] = cy
;
660 else if (BITS_PER_MP_LIMB
- 1 - cnt_h
<= cnt_l
)
662 (void) __mpn_rshift (frac
, tmp
+ i
, tmpsize
- i
,
663 BITS_PER_MP_LIMB
- 1 - cnt_h
);
664 fracsize
= tmpsize
- i
;
668 /* We can only save the memory of the limbs which
669 are zero. The non-zero parts occupy the same
672 (void) __mpn_rshift (frac
, tmp
+ (i
- 1),
674 BITS_PER_MP_LIMB
- 1 - cnt_h
);
675 fracsize
= tmpsize
- (i
- 1);
678 used_limbs
= fracsize
- 1;
683 while (powers
!= &_fpioconst_pow10
[1] && exponent
> 0);
684 /* All factors but 10^-1 are tested now. */
689 cy
= __mpn_mul_1 (tmp
, frac
, fracsize
, 10);
691 assert (cy
== 0 || tmp
[tmpsize
- 1] < 20);
693 count_trailing_zeros (cnt_l
, tmp
[0]);
694 if (cnt_l
< MIN (4, exponent
))
696 cy
= __mpn_lshift (frac
, tmp
, tmpsize
,
697 BITS_PER_MP_LIMB
- MIN (4, exponent
));
699 frac
[tmpsize
++] = cy
;
702 (void) __mpn_rshift (frac
, tmp
, tmpsize
, MIN (4, exponent
));
705 assert (frac
[fracsize
- 1] < 10);
711 /* This is a special case. We don't need a factor because the
712 numbers are in the range of 0.0 <= fp < 8.0. We simply
713 shift it to the right place and divide it by 1.0 to get the
714 leading digit. (Of course this division is not really made.) */
715 assert (0 <= exponent
&& exponent
< 3 &&
716 exponent
+ to_shift
< BITS_PER_MP_LIMB
);
718 /* Now shift the input value to its right place. */
719 cy
= __mpn_lshift (frac
, fp_input
, fracsize
, (exponent
+ to_shift
));
720 frac
[fracsize
++] = cy
;
725 int width
= info
->width
;
726 char *buffer
, *startp
, *cp
;
729 int intdig_max
, intdig_no
= 0;
730 int fracdig_min
, fracdig_max
, fracdig_no
= 0;
734 if (_tolower (info
->spec
) == 'e')
738 fracdig_min
= fracdig_max
= info
->prec
< 0 ? 6 : info
->prec
;
739 chars_needed
= 1 + 1 + fracdig_max
+ 1 + 1 + 4;
740 /* d . ddd e +- ddd */
741 dig_max
= INT_MAX
; /* Unlimited. */
742 significant
= 1; /* Does not matter here. */
744 else if (info
->spec
== 'f')
747 fracdig_min
= fracdig_max
= info
->prec
< 0 ? 6 : info
->prec
;
750 intdig_max
= exponent
+ 1;
751 /* This can be really big! */ /* XXX Maybe malloc if too big? */
752 chars_needed
= exponent
+ 1 + 1 + fracdig_max
;
757 chars_needed
= 1 + 1 + fracdig_max
;
759 dig_max
= INT_MAX
; /* Unlimited. */
760 significant
= 1; /* Does not matter here. */
764 dig_max
= info
->prec
< 0 ? 6 : (info
->prec
== 0 ? 1 : info
->prec
);
765 if ((expsign
== 0 && exponent
>= dig_max
)
766 || (expsign
!= 0 && exponent
> 4))
768 type
= isupper (info
->spec
) ? 'E' : 'e';
769 fracdig_max
= dig_max
- 1;
771 chars_needed
= 1 + 1 + fracdig_max
+ 1 + 1 + 4;
776 intdig_max
= expsign
== 0 ? exponent
+ 1 : 0;
777 fracdig_max
= dig_max
- intdig_max
;
778 /* We need space for the significant digits and perhaps for
779 leading zeros when < 1.0. Pessimistic guess: dig_max. */
780 chars_needed
= dig_max
+ dig_max
+ 1;
782 fracdig_min
= info
->alt
? fracdig_max
: 0;
783 significant
= 0; /* We count significant digits. */
787 /* Guess the number of groups we will make, and thus how
788 many spaces we need for separator characters. */
789 chars_needed
+= __guess_grouping (intdig_max
, grouping
, thousands_sep
);
791 /* Allocate buffer for output. We need two more because while rounding
792 it is possible that we need two more characters in front of all the
794 buffer
= alloca (2 + chars_needed
);
795 cp
= startp
= buffer
+ 2; /* Let room for rounding. */
797 /* Do the real work: put digits in allocated buffer. */
798 if (expsign
== 0 || type
!= 'f')
800 assert (expsign
== 0 || intdig_max
== 1);
801 while (intdig_no
< intdig_max
)
804 *cp
++ = hack_digit ();
809 || (fracdig_max
> 0 && (fracsize
> 1 || frac
[0] != 0)))
814 /* |fp| < 1.0 and the selected type is 'f', so put "0."
821 /* Generate the needed number of fractional digits. */
822 while (fracdig_no
< fracdig_min
823 || (fracdig_no
< fracdig_max
&& (fracsize
> 1 || frac
[0] != 0)))
829 else if (significant
== 0)
839 digit
= hack_digit ();
844 if (digit
== '5' && (*(cp
- 1) & 1) == 0)
846 /* This is the critical case. */
847 if (fracsize
== 1 && frac
[0] == 0)
848 /* Rest of the number is zero -> round to even.
849 (IEEE 754-1985 4.1 says this is the default rounding.) */
851 else if (scalesize
== 0)
853 /* Here we have to see whether all limbs are zero since no
854 normalization happened. */
855 size_t lcnt
= fracsize
;
856 while (lcnt
>= 1 && frac
[lcnt
- 1] == 0)
859 /* Rest of the number is zero -> round to even.
860 (IEEE 754-1985 4.1 says this is the default rounding.) */
867 /* Process fractional digits. Terminate if not rounded or
868 radix character is reached. */
869 while (*--tp
!= decimal
&& *tp
== '9')
876 if (fracdig_no
== 0 || *tp
== decimal
)
878 /* Round the integer digits. */
879 if (*(tp
- 1) == decimal
)
882 while (--tp
>= startp
&& *tp
== '9')
889 /* It is more critical. All digits were 9's. */
894 exponent
+= expsign
== 0 ? 1 : -1;
896 else if (intdig_no
== dig_max
)
898 /* This is the case where for type %g the number fits
899 really in the range for %f output but after rounding
900 the number of digits is too big. */
904 if (info
->alt
|| fracdig_no
> 0)
906 /* Overwrite the old radix character. */
907 startp
[intdig_no
+ 2] = '0';
911 fracdig_no
+= intdig_no
;
913 fracdig_max
= intdig_max
- intdig_no
;
915 /* Now we must print the exponent. */
916 type
= isupper (info
->spec
) ? 'E' : 'e';
920 /* We can simply add another another digit before the
926 /* While rounding the number of digits can change.
927 If the number now exceeds the limits remove some
928 fractional digits. */
929 if (intdig_no
+ fracdig_no
> dig_max
)
931 cp
-= intdig_no
+ fracdig_no
- dig_max
;
932 fracdig_no
-= intdig_no
+ fracdig_no
- dig_max
;
939 /* Now remove unnecessary '0' at the end of the string. */
940 while (fracdig_no
> fracdig_min
&& *(cp
- 1) == '0')
945 /* If we eliminate all fractional digits we perhaps also can remove
946 the radix character. */
947 if (fracdig_no
== 0 && !info
->alt
&& *(cp
- 1) == decimal
)
951 /* Add in separator characters, overwriting the same buffer. */
952 cp
= group_number (startp
, cp
, intdig_no
, grouping
, thousands_sep
);
954 /* Write the exponent if it is needed. */
958 *cp
++ = expsign
? '-' : '+';
960 /* Find the magnitude of the exponent. */
962 while (expscale
<= exponent
)
966 /* Exponent always has at least two digits. */
972 *cp
++ = '0' + (exponent
/ expscale
);
973 exponent
%= expscale
;
975 while (expscale
> 10);
976 *cp
++ = '0' + exponent
;
979 /* Compute number of characters which must be filled with the padding
981 if (is_neg
|| info
->showsign
|| info
->space
)
983 width
-= cp
- startp
;
985 if (!info
->left
&& info
->pad
!= '0' && width
> 0)
986 PADN (info
->pad
, width
);
990 else if (info
->showsign
)
992 else if (info
->space
)
995 if (!info
->left
&& info
->pad
== '0' && width
> 0)
998 PRINT (startp
, cp
- startp
);
1000 if (info
->left
&& width
> 0)
1001 PADN (info
->pad
, width
);
1006 /* Return the number of extra grouping characters that will be inserted
1007 into a number with INTDIG_MAX integer digits. */
1010 __guess_grouping (unsigned int intdig_max
, const char *grouping
,
1013 unsigned int groups
;
1015 /* We treat all negative values like CHAR_MAX. */
1017 if (*grouping
== CHAR_MAX
|| *grouping
<= 0)
1018 /* No grouping should be done. */
1022 while (intdig_max
> (unsigned int) *grouping
)
1025 intdig_max
-= *grouping
++;
1027 if (*grouping
== CHAR_MAX
1032 /* No more grouping should be done. */
1034 else if (*grouping
== 0)
1036 /* Same grouping repeats. */
1037 groups
+= (intdig_max
- 1) / grouping
[-1];
1045 /* Group the INTDIG_NO integer digits of the number in [BUF,BUFEND).
1046 There is guaranteed enough space past BUFEND to extend it.
1047 Return the new end of buffer. */
1051 group_number (char *buf
, char *bufend
, unsigned int intdig_no
,
1052 const char *grouping
, wchar_t thousands_sep
)
1054 unsigned int groups
= __guess_grouping (intdig_no
, grouping
, thousands_sep
);
1060 /* Move the fractional part down. */
1061 memmove (buf
+ intdig_no
+ groups
, buf
+ intdig_no
,
1062 bufend
- (buf
+ intdig_no
));
1064 p
= buf
+ intdig_no
+ groups
- 1;
1067 unsigned int len
= *grouping
++;
1069 *p
-- = buf
[--intdig_no
];
1071 *p
-- = thousands_sep
;
1073 if (*grouping
== CHAR_MAX
1078 /* No more grouping should be done. */
1080 else if (*grouping
== 0)
1081 /* Same grouping repeats. */
1083 } while (intdig_no
> (unsigned int) *grouping
);
1085 /* Copy the remaining ungrouped digits. */
1087 *p
-- = buf
[--intdig_no
];
1090 return bufend
+ groups
;