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[glibc.git] / stdio-common / printf_fp.c
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1 /* Floating point output for `printf'.
2 Copyright (C) 1995-1999,2000,2001,2002,2003 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 Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the 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 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, write to the Free
18 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
19 02111-1307 USA. */
21 /* The gmp headers need some configuration frobs. */
22 #define HAVE_ALLOCA 1
24 #include <libioP.h>
25 #include <alloca.h>
26 #include <ctype.h>
27 #include <float.h>
28 #include <gmp-mparam.h>
29 #include <gmp.h>
30 #include <stdlib/gmp-impl.h>
31 #include <stdlib/longlong.h>
32 #include <stdlib/fpioconst.h>
33 #include <locale/localeinfo.h>
34 #include <limits.h>
35 #include <math.h>
36 #include <printf.h>
37 #include <string.h>
38 #include <unistd.h>
39 #include <stdlib.h>
40 #include <wchar.h>
42 #ifdef COMPILE_WPRINTF
43 # define CHAR_T wchar_t
44 #else
45 # define CHAR_T char
46 #endif
48 #include "_i18n_number.h"
50 #ifndef NDEBUG
51 # define NDEBUG /* Undefine this for debugging assertions. */
52 #endif
53 #include <assert.h>
55 /* This defines make it possible to use the same code for GNU C library and
56 the GNU I/O library. */
57 #define PUT(f, s, n) _IO_sputn (f, s, n)
58 #define PAD(f, c, n) (wide ? _IO_wpadn (f, c, n) : INTUSE(_IO_padn) (f, c, n))
59 /* We use this file GNU C library and GNU I/O library. So make
60 names equal. */
61 #undef putc
62 #define putc(c, f) (wide \
63 ? (int)_IO_putwc_unlocked (c, f) : _IO_putc_unlocked (c, f))
64 #define size_t _IO_size_t
65 #define FILE _IO_FILE
67 /* Macros for doing the actual output. */
69 #define outchar(ch) \
70 do \
71 { \
72 register const int outc = (ch); \
73 if (putc (outc, fp) == EOF) \
74 return -1; \
75 ++done; \
76 } while (0)
78 #define PRINT(ptr, wptr, len) \
79 do \
80 { \
81 register size_t outlen = (len); \
82 if (len > 20) \
83 { \
84 if (PUT (fp, wide ? (const char *) wptr : ptr, outlen) != outlen) \
85 return -1; \
86 ptr += outlen; \
87 done += outlen; \
88 } \
89 else \
90 { \
91 if (wide) \
92 while (outlen-- > 0) \
93 outchar (*wptr++); \
94 else \
95 while (outlen-- > 0) \
96 outchar (*ptr++); \
97 } \
98 } while (0)
100 #define PADN(ch, len) \
101 do \
103 if (PAD (fp, ch, len) != len) \
104 return -1; \
105 done += len; \
107 while (0)
109 /* We use the GNU MP library to handle large numbers.
111 An MP variable occupies a varying number of entries in its array. We keep
112 track of this number for efficiency reasons. Otherwise we would always
113 have to process the whole array. */
114 #define MPN_VAR(name) mp_limb_t *name; mp_size_t name##size
116 #define MPN_ASSIGN(dst,src) \
117 memcpy (dst, src, (dst##size = src##size) * sizeof (mp_limb_t))
118 #define MPN_GE(u,v) \
119 (u##size > v##size || (u##size == v##size && __mpn_cmp (u, v, u##size) >= 0))
121 extern int __isinfl_internal (long double) attribute_hidden;
122 extern int __isnanl_internal (long double) attribute_hidden;
124 extern mp_size_t __mpn_extract_double (mp_ptr res_ptr, mp_size_t size,
125 int *expt, int *is_neg,
126 double value);
127 extern mp_size_t __mpn_extract_long_double (mp_ptr res_ptr, mp_size_t size,
128 int *expt, int *is_neg,
129 long double value);
130 extern unsigned int __guess_grouping (unsigned int intdig_max,
131 const char *grouping);
134 static wchar_t *group_number (wchar_t *buf, wchar_t *bufend,
135 unsigned int intdig_no, const char *grouping,
136 wchar_t thousands_sep, int ngroups)
137 internal_function;
141 __printf_fp (FILE *fp,
142 const struct printf_info *info,
143 const void *const *args)
145 /* The floating-point value to output. */
146 union
148 double dbl;
149 __long_double_t ldbl;
151 fpnum;
153 /* Locale-dependent representation of decimal point. */
154 const char *decimal;
155 wchar_t decimalwc;
157 /* Locale-dependent thousands separator and grouping specification. */
158 const char *thousands_sep = NULL;
159 wchar_t thousands_sepwc = 0;
160 const char *grouping;
162 /* "NaN" or "Inf" for the special cases. */
163 const char *special = NULL;
164 const wchar_t *wspecial = NULL;
166 /* We need just a few limbs for the input before shifting to the right
167 position. */
168 mp_limb_t fp_input[(LDBL_MANT_DIG + BITS_PER_MP_LIMB - 1) / BITS_PER_MP_LIMB];
169 /* We need to shift the contents of fp_input by this amount of bits. */
170 int to_shift = 0;
172 /* The fraction of the floting-point value in question */
173 MPN_VAR(frac);
174 /* and the exponent. */
175 int exponent;
176 /* Sign of the exponent. */
177 int expsign = 0;
178 /* Sign of float number. */
179 int is_neg = 0;
181 /* Scaling factor. */
182 MPN_VAR(scale);
184 /* Temporary bignum value. */
185 MPN_VAR(tmp);
187 /* Digit which is result of last hack_digit() call. */
188 wchar_t digit;
190 /* The type of output format that will be used: 'e'/'E' or 'f'. */
191 int type;
193 /* Counter for number of written characters. */
194 int done = 0;
196 /* General helper (carry limb). */
197 mp_limb_t cy;
199 /* Nonzero if this is output on a wide character stream. */
200 int wide = info->wide;
202 auto wchar_t hack_digit (void);
204 wchar_t hack_digit (void)
206 mp_limb_t hi;
208 if (expsign != 0 && type == 'f' && exponent-- > 0)
209 hi = 0;
210 else if (scalesize == 0)
212 hi = frac[fracsize - 1];
213 frac[fracsize - 1] = __mpn_mul_1 (frac, frac, fracsize - 1, 10);
215 else
217 if (fracsize < scalesize)
218 hi = 0;
219 else
221 hi = mpn_divmod (tmp, frac, fracsize, scale, scalesize);
222 tmp[fracsize - scalesize] = hi;
223 hi = tmp[0];
225 fracsize = scalesize;
226 while (fracsize != 0 && frac[fracsize - 1] == 0)
227 --fracsize;
228 if (fracsize == 0)
230 /* We're not prepared for an mpn variable with zero
231 limbs. */
232 fracsize = 1;
233 return L'0' + hi;
237 mp_limb_t _cy = __mpn_mul_1 (frac, frac, fracsize, 10);
238 if (_cy != 0)
239 frac[fracsize++] = _cy;
242 return L'0' + hi;
246 /* Figure out the decimal point character. */
247 if (info->extra == 0)
249 decimal = _NL_CURRENT (LC_NUMERIC, DECIMAL_POINT);
250 decimalwc = _NL_CURRENT_WORD (LC_NUMERIC, _NL_NUMERIC_DECIMAL_POINT_WC);
252 else
254 decimal = _NL_CURRENT (LC_MONETARY, MON_DECIMAL_POINT);
255 if (*decimal == '\0')
256 decimal = _NL_CURRENT (LC_NUMERIC, DECIMAL_POINT);
257 decimalwc = _NL_CURRENT_WORD (LC_MONETARY,
258 _NL_MONETARY_DECIMAL_POINT_WC);
259 if (decimalwc == L'\0')
260 decimalwc = _NL_CURRENT_WORD (LC_NUMERIC,
261 _NL_NUMERIC_DECIMAL_POINT_WC);
263 /* The decimal point character must not be zero. */
264 assert (*decimal != '\0');
265 assert (decimalwc != L'\0');
267 if (info->group)
269 if (info->extra == 0)
270 grouping = _NL_CURRENT (LC_NUMERIC, GROUPING);
271 else
272 grouping = _NL_CURRENT (LC_MONETARY, MON_GROUPING);
274 if (*grouping <= 0 || *grouping == CHAR_MAX)
275 grouping = NULL;
276 else
278 /* Figure out the thousands separator character. */
279 if (wide)
281 if (info->extra == 0)
282 thousands_sepwc =
283 _NL_CURRENT_WORD (LC_NUMERIC, _NL_NUMERIC_THOUSANDS_SEP_WC);
284 else
285 thousands_sepwc =
286 _NL_CURRENT_WORD (LC_MONETARY,
287 _NL_MONETARY_THOUSANDS_SEP_WC);
289 else
291 if (info->extra == 0)
292 thousands_sep = _NL_CURRENT (LC_NUMERIC, THOUSANDS_SEP);
293 else
294 thousands_sep = _NL_CURRENT (LC_MONETARY, MON_THOUSANDS_SEP);
297 if ((wide && thousands_sepwc == L'\0')
298 || (! wide && *thousands_sep == '\0'))
299 grouping = NULL;
300 else if (thousands_sepwc == L'\0')
301 /* If we are printing multibyte characters and there is a
302 multibyte representation for the thousands separator,
303 we must ensure the wide character thousands separator
304 is available, even if it is fake. */
305 thousands_sepwc = 0xfffffffe;
308 else
309 grouping = NULL;
311 /* Fetch the argument value. */
312 #ifndef __NO_LONG_DOUBLE_MATH
313 if (info->is_long_double && sizeof (long double) > sizeof (double))
315 fpnum.ldbl = *(const long double *) args[0];
317 /* Check for special values: not a number or infinity. */
318 if (__isnanl (fpnum.ldbl))
320 if (isupper (info->spec))
322 special = "NAN";
323 wspecial = L"NAN";
325 else
327 special = "nan";
328 wspecial = L"nan";
330 is_neg = 0;
332 else if (__isinfl (fpnum.ldbl))
334 if (isupper (info->spec))
336 special = "INF";
337 wspecial = L"INF";
339 else
341 special = "inf";
342 wspecial = L"inf";
344 is_neg = fpnum.ldbl < 0;
346 else
348 fracsize = __mpn_extract_long_double (fp_input,
349 (sizeof (fp_input) /
350 sizeof (fp_input[0])),
351 &exponent, &is_neg,
352 fpnum.ldbl);
353 to_shift = 1 + fracsize * BITS_PER_MP_LIMB - LDBL_MANT_DIG;
356 else
357 #endif /* no long double */
359 fpnum.dbl = *(const double *) args[0];
361 /* Check for special values: not a number or infinity. */
362 if (__isnan (fpnum.dbl))
364 is_neg = 0;
365 if (isupper (info->spec))
367 special = "NAN";
368 wspecial = L"NAN";
370 else
372 special = "nan";
373 wspecial = L"nan";
376 else if (__isinf (fpnum.dbl))
378 is_neg = fpnum.dbl < 0;
379 if (isupper (info->spec))
381 special = "INF";
382 wspecial = L"INF";
384 else
386 special = "inf";
387 wspecial = L"inf";
390 else
392 fracsize = __mpn_extract_double (fp_input,
393 (sizeof (fp_input)
394 / sizeof (fp_input[0])),
395 &exponent, &is_neg, fpnum.dbl);
396 to_shift = 1 + fracsize * BITS_PER_MP_LIMB - DBL_MANT_DIG;
400 if (special)
402 int width = info->width;
404 if (is_neg || info->showsign || info->space)
405 --width;
406 width -= 3;
408 if (!info->left && width > 0)
409 PADN (' ', width);
411 if (is_neg)
412 outchar ('-');
413 else if (info->showsign)
414 outchar ('+');
415 else if (info->space)
416 outchar (' ');
418 PRINT (special, wspecial, 3);
420 if (info->left && width > 0)
421 PADN (' ', width);
423 return done;
427 /* We need three multiprecision variables. Now that we have the exponent
428 of the number we can allocate the needed memory. It would be more
429 efficient to use variables of the fixed maximum size but because this
430 would be really big it could lead to memory problems. */
432 mp_size_t bignum_size = ((ABS (exponent) + BITS_PER_MP_LIMB - 1)
433 / BITS_PER_MP_LIMB
434 + (LDBL_MANT_DIG / BITS_PER_MP_LIMB > 2 ? 8 : 4))
435 * sizeof (mp_limb_t);
436 frac = (mp_limb_t *) alloca (bignum_size);
437 tmp = (mp_limb_t *) alloca (bignum_size);
438 scale = (mp_limb_t *) alloca (bignum_size);
441 /* We now have to distinguish between numbers with positive and negative
442 exponents because the method used for the one is not applicable/efficient
443 for the other. */
444 scalesize = 0;
445 if (exponent > 2)
447 /* |FP| >= 8.0. */
448 int scaleexpo = 0;
449 int explog = LDBL_MAX_10_EXP_LOG;
450 int exp10 = 0;
451 const struct mp_power *powers = &_fpioconst_pow10[explog + 1];
452 int cnt_h, cnt_l, i;
454 if ((exponent + to_shift) % BITS_PER_MP_LIMB == 0)
456 MPN_COPY_DECR (frac + (exponent + to_shift) / BITS_PER_MP_LIMB,
457 fp_input, fracsize);
458 fracsize += (exponent + to_shift) / BITS_PER_MP_LIMB;
460 else
462 cy = __mpn_lshift (frac + (exponent + to_shift) / BITS_PER_MP_LIMB,
463 fp_input, fracsize,
464 (exponent + to_shift) % BITS_PER_MP_LIMB);
465 fracsize += (exponent + to_shift) / BITS_PER_MP_LIMB;
466 if (cy)
467 frac[fracsize++] = cy;
469 MPN_ZERO (frac, (exponent + to_shift) / BITS_PER_MP_LIMB);
471 assert (powers > &_fpioconst_pow10[0]);
474 --powers;
476 /* The number of the product of two binary numbers with n and m
477 bits respectively has m+n or m+n-1 bits. */
478 if (exponent >= scaleexpo + powers->p_expo - 1)
480 if (scalesize == 0)
482 #ifndef __NO_LONG_DOUBLE_MATH
483 if (LDBL_MANT_DIG > _FPIO_CONST_OFFSET * BITS_PER_MP_LIMB
484 && info->is_long_double)
486 #define _FPIO_CONST_SHIFT \
487 (((LDBL_MANT_DIG + BITS_PER_MP_LIMB - 1) / BITS_PER_MP_LIMB) \
488 - _FPIO_CONST_OFFSET)
489 /* 64bit const offset is not enough for
490 IEEE quad long double. */
491 tmpsize = powers->arraysize + _FPIO_CONST_SHIFT;
492 memcpy (tmp + _FPIO_CONST_SHIFT,
493 &__tens[powers->arrayoff],
494 tmpsize * sizeof (mp_limb_t));
495 MPN_ZERO (tmp, _FPIO_CONST_SHIFT);
496 /* Adjust exponent, as scaleexpo will be this much
497 bigger too. */
498 exponent += _FPIO_CONST_SHIFT * BITS_PER_MP_LIMB;
500 else
501 #endif
503 tmpsize = powers->arraysize;
504 memcpy (tmp, &__tens[powers->arrayoff],
505 tmpsize * sizeof (mp_limb_t));
508 else
510 cy = __mpn_mul (tmp, scale, scalesize,
511 &__tens[powers->arrayoff
512 + _FPIO_CONST_OFFSET],
513 powers->arraysize - _FPIO_CONST_OFFSET);
514 tmpsize = scalesize + powers->arraysize - _FPIO_CONST_OFFSET;
515 if (cy == 0)
516 --tmpsize;
519 if (MPN_GE (frac, tmp))
521 int cnt;
522 MPN_ASSIGN (scale, tmp);
523 count_leading_zeros (cnt, scale[scalesize - 1]);
524 scaleexpo = (scalesize - 2) * BITS_PER_MP_LIMB - cnt - 1;
525 exp10 |= 1 << explog;
528 --explog;
530 while (powers > &_fpioconst_pow10[0]);
531 exponent = exp10;
533 /* Optimize number representations. We want to represent the numbers
534 with the lowest number of bytes possible without losing any
535 bytes. Also the highest bit in the scaling factor has to be set
536 (this is a requirement of the MPN division routines). */
537 if (scalesize > 0)
539 /* Determine minimum number of zero bits at the end of
540 both numbers. */
541 for (i = 0; scale[i] == 0 && frac[i] == 0; i++)
544 /* Determine number of bits the scaling factor is misplaced. */
545 count_leading_zeros (cnt_h, scale[scalesize - 1]);
547 if (cnt_h == 0)
549 /* The highest bit of the scaling factor is already set. So
550 we only have to remove the trailing empty limbs. */
551 if (i > 0)
553 MPN_COPY_INCR (scale, scale + i, scalesize - i);
554 scalesize -= i;
555 MPN_COPY_INCR (frac, frac + i, fracsize - i);
556 fracsize -= i;
559 else
561 if (scale[i] != 0)
563 count_trailing_zeros (cnt_l, scale[i]);
564 if (frac[i] != 0)
566 int cnt_l2;
567 count_trailing_zeros (cnt_l2, frac[i]);
568 if (cnt_l2 < cnt_l)
569 cnt_l = cnt_l2;
572 else
573 count_trailing_zeros (cnt_l, frac[i]);
575 /* Now shift the numbers to their optimal position. */
576 if (i == 0 && BITS_PER_MP_LIMB - cnt_h > cnt_l)
578 /* We cannot save any memory. So just roll both numbers
579 so that the scaling factor has its highest bit set. */
581 (void) __mpn_lshift (scale, scale, scalesize, cnt_h);
582 cy = __mpn_lshift (frac, frac, fracsize, cnt_h);
583 if (cy != 0)
584 frac[fracsize++] = cy;
586 else if (BITS_PER_MP_LIMB - cnt_h <= cnt_l)
588 /* We can save memory by removing the trailing zero limbs
589 and by packing the non-zero limbs which gain another
590 free one. */
592 (void) __mpn_rshift (scale, scale + i, scalesize - i,
593 BITS_PER_MP_LIMB - cnt_h);
594 scalesize -= i + 1;
595 (void) __mpn_rshift (frac, frac + i, fracsize - i,
596 BITS_PER_MP_LIMB - cnt_h);
597 fracsize -= frac[fracsize - i - 1] == 0 ? i + 1 : i;
599 else
601 /* We can only save the memory of the limbs which are zero.
602 The non-zero parts occupy the same number of limbs. */
604 (void) __mpn_rshift (scale, scale + (i - 1),
605 scalesize - (i - 1),
606 BITS_PER_MP_LIMB - cnt_h);
607 scalesize -= i;
608 (void) __mpn_rshift (frac, frac + (i - 1),
609 fracsize - (i - 1),
610 BITS_PER_MP_LIMB - cnt_h);
611 fracsize -= frac[fracsize - (i - 1) - 1] == 0 ? i : i - 1;
616 else if (exponent < 0)
618 /* |FP| < 1.0. */
619 int exp10 = 0;
620 int explog = LDBL_MAX_10_EXP_LOG;
621 const struct mp_power *powers = &_fpioconst_pow10[explog + 1];
622 mp_size_t used_limbs = fracsize - 1;
624 /* Now shift the input value to its right place. */
625 cy = __mpn_lshift (frac, fp_input, fracsize, to_shift);
626 frac[fracsize++] = cy;
627 assert (cy == 1 || (frac[fracsize - 2] == 0 && frac[0] == 0));
629 expsign = 1;
630 exponent = -exponent;
632 assert (powers != &_fpioconst_pow10[0]);
635 --powers;
637 if (exponent >= powers->m_expo)
639 int i, incr, cnt_h, cnt_l;
640 mp_limb_t topval[2];
642 /* The __mpn_mul function expects the first argument to be
643 bigger than the second. */
644 if (fracsize < powers->arraysize - _FPIO_CONST_OFFSET)
645 cy = __mpn_mul (tmp, &__tens[powers->arrayoff
646 + _FPIO_CONST_OFFSET],
647 powers->arraysize - _FPIO_CONST_OFFSET,
648 frac, fracsize);
649 else
650 cy = __mpn_mul (tmp, frac, fracsize,
651 &__tens[powers->arrayoff + _FPIO_CONST_OFFSET],
652 powers->arraysize - _FPIO_CONST_OFFSET);
653 tmpsize = fracsize + powers->arraysize - _FPIO_CONST_OFFSET;
654 if (cy == 0)
655 --tmpsize;
657 count_leading_zeros (cnt_h, tmp[tmpsize - 1]);
658 incr = (tmpsize - fracsize) * BITS_PER_MP_LIMB
659 + BITS_PER_MP_LIMB - 1 - cnt_h;
661 assert (incr <= powers->p_expo);
663 /* If we increased the exponent by exactly 3 we have to test
664 for overflow. This is done by comparing with 10 shifted
665 to the right position. */
666 if (incr == exponent + 3)
668 if (cnt_h <= BITS_PER_MP_LIMB - 4)
670 topval[0] = 0;
671 topval[1]
672 = ((mp_limb_t) 10) << (BITS_PER_MP_LIMB - 4 - cnt_h);
674 else
676 topval[0] = ((mp_limb_t) 10) << (BITS_PER_MP_LIMB - 4);
677 topval[1] = 0;
678 (void) __mpn_lshift (topval, topval, 2,
679 BITS_PER_MP_LIMB - cnt_h);
683 /* We have to be careful when multiplying the last factor.
684 If the result is greater than 1.0 be have to test it
685 against 10.0. If it is greater or equal to 10.0 the
686 multiplication was not valid. This is because we cannot
687 determine the number of bits in the result in advance. */
688 if (incr < exponent + 3
689 || (incr == exponent + 3 &&
690 (tmp[tmpsize - 1] < topval[1]
691 || (tmp[tmpsize - 1] == topval[1]
692 && tmp[tmpsize - 2] < topval[0]))))
694 /* The factor is right. Adapt binary and decimal
695 exponents. */
696 exponent -= incr;
697 exp10 |= 1 << explog;
699 /* If this factor yields a number greater or equal to
700 1.0, we must not shift the non-fractional digits down. */
701 if (exponent < 0)
702 cnt_h += -exponent;
704 /* Now we optimize the number representation. */
705 for (i = 0; tmp[i] == 0; ++i);
706 if (cnt_h == BITS_PER_MP_LIMB - 1)
708 MPN_COPY (frac, tmp + i, tmpsize - i);
709 fracsize = tmpsize - i;
711 else
713 count_trailing_zeros (cnt_l, tmp[i]);
715 /* Now shift the numbers to their optimal position. */
716 if (i == 0 && BITS_PER_MP_LIMB - 1 - cnt_h > cnt_l)
718 /* We cannot save any memory. Just roll the
719 number so that the leading digit is in a
720 separate limb. */
722 cy = __mpn_lshift (frac, tmp, tmpsize, cnt_h + 1);
723 fracsize = tmpsize + 1;
724 frac[fracsize - 1] = cy;
726 else if (BITS_PER_MP_LIMB - 1 - cnt_h <= cnt_l)
728 (void) __mpn_rshift (frac, tmp + i, tmpsize - i,
729 BITS_PER_MP_LIMB - 1 - cnt_h);
730 fracsize = tmpsize - i;
732 else
734 /* We can only save the memory of the limbs which
735 are zero. The non-zero parts occupy the same
736 number of limbs. */
738 (void) __mpn_rshift (frac, tmp + (i - 1),
739 tmpsize - (i - 1),
740 BITS_PER_MP_LIMB - 1 - cnt_h);
741 fracsize = tmpsize - (i - 1);
744 used_limbs = fracsize - 1;
747 --explog;
749 while (powers != &_fpioconst_pow10[1] && exponent > 0);
750 /* All factors but 10^-1 are tested now. */
751 if (exponent > 0)
753 int cnt_l;
755 cy = __mpn_mul_1 (tmp, frac, fracsize, 10);
756 tmpsize = fracsize;
757 assert (cy == 0 || tmp[tmpsize - 1] < 20);
759 count_trailing_zeros (cnt_l, tmp[0]);
760 if (cnt_l < MIN (4, exponent))
762 cy = __mpn_lshift (frac, tmp, tmpsize,
763 BITS_PER_MP_LIMB - MIN (4, exponent));
764 if (cy != 0)
765 frac[tmpsize++] = cy;
767 else
768 (void) __mpn_rshift (frac, tmp, tmpsize, MIN (4, exponent));
769 fracsize = tmpsize;
770 exp10 |= 1;
771 assert (frac[fracsize - 1] < 10);
773 exponent = exp10;
775 else
777 /* This is a special case. We don't need a factor because the
778 numbers are in the range of 0.0 <= fp < 8.0. We simply
779 shift it to the right place and divide it by 1.0 to get the
780 leading digit. (Of course this division is not really made.) */
781 assert (0 <= exponent && exponent < 3 &&
782 exponent + to_shift < BITS_PER_MP_LIMB);
784 /* Now shift the input value to its right place. */
785 cy = __mpn_lshift (frac, fp_input, fracsize, (exponent + to_shift));
786 frac[fracsize++] = cy;
787 exponent = 0;
791 int width = info->width;
792 wchar_t *wbuffer, *wstartp, *wcp;
793 int buffer_malloced;
794 int chars_needed;
795 int expscale;
796 int intdig_max, intdig_no = 0;
797 int fracdig_min, fracdig_max, fracdig_no = 0;
798 int dig_max;
799 int significant;
800 int ngroups = 0;
802 if (_tolower (info->spec) == 'e')
804 type = info->spec;
805 intdig_max = 1;
806 fracdig_min = fracdig_max = info->prec < 0 ? 6 : info->prec;
807 chars_needed = 1 + 1 + fracdig_max + 1 + 1 + 4;
808 /* d . ddd e +- ddd */
809 dig_max = INT_MAX; /* Unlimited. */
810 significant = 1; /* Does not matter here. */
812 else if (_tolower (info->spec) == 'f')
814 type = 'f';
815 fracdig_min = fracdig_max = info->prec < 0 ? 6 : info->prec;
816 dig_max = INT_MAX; /* Unlimited. */
817 significant = 1; /* Does not matter here. */
818 if (expsign == 0)
820 intdig_max = exponent + 1;
821 /* This can be really big! */ /* XXX Maybe malloc if too big? */
822 chars_needed = exponent + 1 + 1 + fracdig_max;
824 else
826 intdig_max = 1;
827 chars_needed = 1 + 1 + fracdig_max;
830 else
832 dig_max = info->prec < 0 ? 6 : (info->prec == 0 ? 1 : info->prec);
833 if ((expsign == 0 && exponent >= dig_max)
834 || (expsign != 0 && exponent > 4))
836 if ('g' - 'G' == 'e' - 'E')
837 type = 'E' + (info->spec - 'G');
838 else
839 type = isupper (info->spec) ? 'E' : 'e';
840 fracdig_max = dig_max - 1;
841 intdig_max = 1;
842 chars_needed = 1 + 1 + fracdig_max + 1 + 1 + 4;
844 else
846 type = 'f';
847 intdig_max = expsign == 0 ? exponent + 1 : 0;
848 fracdig_max = dig_max - intdig_max;
849 /* We need space for the significant digits and perhaps
850 for leading zeros when < 1.0. The number of leading
851 zeros can be as many as would be required for
852 exponential notation with a negative two-digit
853 exponent, which is 4. */
854 chars_needed = dig_max + 1 + 4;
856 fracdig_min = info->alt ? fracdig_max : 0;
857 significant = 0; /* We count significant digits. */
860 if (grouping)
862 /* Guess the number of groups we will make, and thus how
863 many spaces we need for separator characters. */
864 ngroups = __guess_grouping (intdig_max, grouping);
865 chars_needed += ngroups;
868 /* Allocate buffer for output. We need two more because while rounding
869 it is possible that we need two more characters in front of all the
870 other output. If the amount of memory we have to allocate is too
871 large use `malloc' instead of `alloca'. */
872 buffer_malloced = ! __libc_use_alloca (chars_needed * 2 * sizeof (wchar_t));
873 if (buffer_malloced)
875 wbuffer = (wchar_t *) malloc ((2 + chars_needed) * sizeof (wchar_t));
876 if (wbuffer == NULL)
877 /* Signal an error to the caller. */
878 return -1;
880 else
881 wbuffer = (wchar_t *) alloca ((2 + chars_needed) * sizeof (wchar_t));
882 wcp = wstartp = wbuffer + 2; /* Let room for rounding. */
884 /* Do the real work: put digits in allocated buffer. */
885 if (expsign == 0 || type != 'f')
887 assert (expsign == 0 || intdig_max == 1);
888 while (intdig_no < intdig_max)
890 ++intdig_no;
891 *wcp++ = hack_digit ();
893 significant = 1;
894 if (info->alt
895 || fracdig_min > 0
896 || (fracdig_max > 0 && (fracsize > 1 || frac[0] != 0)))
897 *wcp++ = decimalwc;
899 else
901 /* |fp| < 1.0 and the selected type is 'f', so put "0."
902 in the buffer. */
903 *wcp++ = L'0';
904 --exponent;
905 *wcp++ = decimalwc;
908 /* Generate the needed number of fractional digits. */
909 while (fracdig_no < fracdig_min
910 || (fracdig_no < fracdig_max && (fracsize > 1 || frac[0] != 0)))
912 ++fracdig_no;
913 *wcp = hack_digit ();
914 if (*wcp++ != L'0')
915 significant = 1;
916 else if (significant == 0)
918 ++fracdig_max;
919 if (fracdig_min > 0)
920 ++fracdig_min;
924 /* Do rounding. */
925 digit = hack_digit ();
926 if (digit > L'4')
928 wchar_t *wtp = wcp;
930 if (digit == L'5'
931 && ((*(wcp - 1) != decimalwc && (*(wcp - 1) & 1) == 0)
932 || ((*(wcp - 1) == decimalwc && (*(wcp - 2) & 1) == 0))))
934 /* This is the critical case. */
935 if (fracsize == 1 && frac[0] == 0)
936 /* Rest of the number is zero -> round to even.
937 (IEEE 754-1985 4.1 says this is the default rounding.) */
938 goto do_expo;
939 else if (scalesize == 0)
941 /* Here we have to see whether all limbs are zero since no
942 normalization happened. */
943 size_t lcnt = fracsize;
944 while (lcnt >= 1 && frac[lcnt - 1] == 0)
945 --lcnt;
946 if (lcnt == 0)
947 /* Rest of the number is zero -> round to even.
948 (IEEE 754-1985 4.1 says this is the default rounding.) */
949 goto do_expo;
953 if (fracdig_no > 0)
955 /* Process fractional digits. Terminate if not rounded or
956 radix character is reached. */
957 while (*--wtp != decimalwc && *wtp == L'9')
958 *wtp = '0';
959 if (*wtp != decimalwc)
960 /* Round up. */
961 (*wtp)++;
964 if (fracdig_no == 0 || *wtp == decimalwc)
966 /* Round the integer digits. */
967 if (*(wtp - 1) == decimalwc)
968 --wtp;
970 while (--wtp >= wstartp && *wtp == L'9')
971 *wtp = L'0';
973 if (wtp >= wstartp)
974 /* Round up. */
975 (*wtp)++;
976 else
977 /* It is more critical. All digits were 9's. */
979 if (type != 'f')
981 *wstartp = '1';
982 exponent += expsign == 0 ? 1 : -1;
984 else if (intdig_no == dig_max)
986 /* This is the case where for type %g the number fits
987 really in the range for %f output but after rounding
988 the number of digits is too big. */
989 *--wstartp = decimalwc;
990 *--wstartp = L'1';
992 if (info->alt || fracdig_no > 0)
994 /* Overwrite the old radix character. */
995 wstartp[intdig_no + 2] = L'0';
996 ++fracdig_no;
999 fracdig_no += intdig_no;
1000 intdig_no = 1;
1001 fracdig_max = intdig_max - intdig_no;
1002 ++exponent;
1003 /* Now we must print the exponent. */
1004 type = isupper (info->spec) ? 'E' : 'e';
1006 else
1008 /* We can simply add another another digit before the
1009 radix. */
1010 *--wstartp = L'1';
1011 ++intdig_no;
1014 /* While rounding the number of digits can change.
1015 If the number now exceeds the limits remove some
1016 fractional digits. */
1017 if (intdig_no + fracdig_no > dig_max)
1019 wcp -= intdig_no + fracdig_no - dig_max;
1020 fracdig_no -= intdig_no + fracdig_no - dig_max;
1026 do_expo:
1027 /* Now remove unnecessary '0' at the end of the string. */
1028 while (fracdig_no > fracdig_min && *(wcp - 1) == L'0')
1030 --wcp;
1031 --fracdig_no;
1033 /* If we eliminate all fractional digits we perhaps also can remove
1034 the radix character. */
1035 if (fracdig_no == 0 && !info->alt && *(wcp - 1) == decimalwc)
1036 --wcp;
1038 if (grouping)
1039 /* Add in separator characters, overwriting the same buffer. */
1040 wcp = group_number (wstartp, wcp, intdig_no, grouping, thousands_sepwc,
1041 ngroups);
1043 /* Write the exponent if it is needed. */
1044 if (type != 'f')
1046 *wcp++ = (wchar_t) type;
1047 *wcp++ = expsign ? L'-' : L'+';
1049 /* Find the magnitude of the exponent. */
1050 expscale = 10;
1051 while (expscale <= exponent)
1052 expscale *= 10;
1054 if (exponent < 10)
1055 /* Exponent always has at least two digits. */
1056 *wcp++ = L'0';
1057 else
1060 expscale /= 10;
1061 *wcp++ = L'0' + (exponent / expscale);
1062 exponent %= expscale;
1064 while (expscale > 10);
1065 *wcp++ = L'0' + exponent;
1068 /* Compute number of characters which must be filled with the padding
1069 character. */
1070 if (is_neg || info->showsign || info->space)
1071 --width;
1072 width -= wcp - wstartp;
1074 if (!info->left && info->pad != '0' && width > 0)
1075 PADN (info->pad, width);
1077 if (is_neg)
1078 outchar ('-');
1079 else if (info->showsign)
1080 outchar ('+');
1081 else if (info->space)
1082 outchar (' ');
1084 if (!info->left && info->pad == '0' && width > 0)
1085 PADN ('0', width);
1088 char *buffer = NULL;
1089 char *cp = NULL;
1090 char *tmpptr;
1092 if (! wide)
1094 /* Create the single byte string. */
1095 size_t decimal_len;
1096 size_t thousands_sep_len;
1097 wchar_t *copywc;
1099 decimal_len = strlen (decimal);
1101 if (thousands_sep == NULL)
1102 thousands_sep_len = 0;
1103 else
1104 thousands_sep_len = strlen (thousands_sep);
1106 if (buffer_malloced)
1108 buffer = (char *) malloc (2 + chars_needed + decimal_len
1109 + ngroups * thousands_sep_len);
1110 if (buffer == NULL)
1111 /* Signal an error to the caller. */
1112 return -1;
1114 else
1115 buffer = (char *) alloca (2 + chars_needed + decimal_len
1116 + ngroups * thousands_sep_len);
1118 /* Now copy the wide character string. Since the character
1119 (except for the decimal point and thousands separator) must
1120 be coming from the ASCII range we can esily convert the
1121 string without mapping tables. */
1122 for (cp = buffer, copywc = wstartp; copywc < wcp; ++copywc)
1123 if (*copywc == decimalwc)
1124 cp = (char *) __mempcpy (cp, decimal, decimal_len);
1125 else if (*copywc == thousands_sepwc)
1126 cp = (char *) __mempcpy (cp, thousands_sep, thousands_sep_len);
1127 else
1128 *cp++ = (char) *copywc;
1131 tmpptr = buffer;
1132 if (__builtin_expect (info->i18n, 0))
1134 #ifdef COMPILE_WPRINTF
1135 wstartp = _i18n_number_rewrite (wstartp, wcp);
1136 #else
1137 tmpptr = _i18n_number_rewrite (tmpptr, cp);
1138 #endif
1141 PRINT (tmpptr, wstartp, wide ? wcp - wstartp : cp - tmpptr);
1143 /* Free the memory if necessary. */
1144 if (buffer_malloced)
1146 free (buffer);
1147 free (wbuffer);
1151 if (info->left && width > 0)
1152 PADN (info->pad, width);
1154 return done;
1156 libc_hidden_def (__printf_fp)
1158 /* Return the number of extra grouping characters that will be inserted
1159 into a number with INTDIG_MAX integer digits. */
1161 unsigned int
1162 __guess_grouping (unsigned int intdig_max, const char *grouping)
1164 unsigned int groups;
1166 /* We treat all negative values like CHAR_MAX. */
1168 if (*grouping == CHAR_MAX || *grouping <= 0)
1169 /* No grouping should be done. */
1170 return 0;
1172 groups = 0;
1173 while (intdig_max > (unsigned int) *grouping)
1175 ++groups;
1176 intdig_max -= *grouping++;
1178 if (*grouping == CHAR_MAX
1179 #if CHAR_MIN < 0
1180 || *grouping < 0
1181 #endif
1183 /* No more grouping should be done. */
1184 break;
1185 else if (*grouping == 0)
1187 /* Same grouping repeats. */
1188 groups += (intdig_max - 1) / grouping[-1];
1189 break;
1193 return groups;
1196 /* Group the INTDIG_NO integer digits of the number in [BUF,BUFEND).
1197 There is guaranteed enough space past BUFEND to extend it.
1198 Return the new end of buffer. */
1200 static wchar_t *
1201 internal_function
1202 group_number (wchar_t *buf, wchar_t *bufend, unsigned int intdig_no,
1203 const char *grouping, wchar_t thousands_sep, int ngroups)
1205 wchar_t *p;
1207 if (ngroups == 0)
1208 return bufend;
1210 /* Move the fractional part down. */
1211 __wmemmove (buf + intdig_no + ngroups, buf + intdig_no,
1212 bufend - (buf + intdig_no));
1214 p = buf + intdig_no + ngroups - 1;
1217 unsigned int len = *grouping++;
1219 *p-- = buf[--intdig_no];
1220 while (--len > 0);
1221 *p-- = thousands_sep;
1223 if (*grouping == CHAR_MAX
1224 #if CHAR_MIN < 0
1225 || *grouping < 0
1226 #endif
1228 /* No more grouping should be done. */
1229 break;
1230 else if (*grouping == 0)
1231 /* Same grouping repeats. */
1232 --grouping;
1233 } while (intdig_no > (unsigned int) *grouping);
1235 /* Copy the remaining ungrouped digits. */
1237 *p-- = buf[--intdig_no];
1238 while (p > buf);
1240 return bufend + ngroups;