| /* Floating point output for `printf'. |
| Copyright (C) 1995, 1996, 1997 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Library General Public License as |
| published by the Free Software Foundation; either version 2 of the |
| License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Library General Public License for more details. |
| |
| You should have received a copy of the GNU Library General Public |
| License along with the GNU C Library; see the file COPYING.LIB. If not, |
| write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
| Boston, MA 02111-1307, USA. */ |
| |
| /* The gmp headers need some configuration frobs. */ |
| #define HAVE_ALLOCA 1 |
| |
| #ifdef USE_IN_LIBIO |
| # include <libioP.h> |
| #else |
| # include <stdio.h> |
| #endif |
| #include <alloca.h> |
| #include <ctype.h> |
| #include <float.h> |
| #include <gmp-mparam.h> |
| #include "../stdlib/gmp.h" |
| #include "../stdlib/gmp-impl.h" |
| #include "../stdlib/longlong.h" |
| #include "../stdlib/fpioconst.h" |
| #include "../locale/localeinfo.h" |
| #include <limits.h> |
| #include <math.h> |
| #include <printf.h> |
| #include <string.h> |
| #include <unistd.h> |
| #include <stdlib.h> |
| |
| #define NDEBUG /* Undefine this for debugging assertions. */ |
| #include <assert.h> |
| |
| /* This defines make it possible to use the same code for GNU C library and |
| the GNU I/O library. */ |
| #ifdef USE_IN_LIBIO |
| # define PUT(f, s, n) _IO_sputn (f, s, n) |
| # define PAD(f, c, n) _IO_padn (f, c, n) |
| /* We use this file GNU C library and GNU I/O library. So make |
| names equal. */ |
| # undef putc |
| # define putc(c, f) _IO_putc_unlocked (c, f) |
| # define size_t _IO_size_t |
| # define FILE _IO_FILE |
| #else /* ! USE_IN_LIBIO */ |
| # define PUT(f, s, n) fwrite (s, 1, n, f) |
| # define PAD(f, c, n) __printf_pad (f, c, n) |
| ssize_t __printf_pad __P ((FILE *, char pad, int n)); /* In vfprintf.c. */ |
| #endif /* USE_IN_LIBIO */ |
| |
| /* Macros for doing the actual output. */ |
| |
| #define outchar(ch) \ |
| do \ |
| { \ |
| register const int outc = (ch); \ |
| if (putc (outc, fp) == EOF) \ |
| return -1; \ |
| ++done; \ |
| } while (0) |
| |
| #define PRINT(ptr, len) \ |
| do \ |
| { \ |
| register size_t outlen = (len); \ |
| if (len > 20) \ |
| { \ |
| if (PUT (fp, ptr, outlen) != outlen) \ |
| return -1; \ |
| ptr += outlen; \ |
| done += outlen; \ |
| } \ |
| else \ |
| { \ |
| while (outlen-- > 0) \ |
| outchar (*ptr++); \ |
| } \ |
| } while (0) |
| |
| #define PADN(ch, len) \ |
| do \ |
| { \ |
| if (PAD (fp, ch, len) != len) \ |
| return -1; \ |
| done += len; \ |
| } \ |
| while (0) |
| |
| /* We use the GNU MP library to handle large numbers. |
| |
| An MP variable occupies a varying number of entries in its array. We keep |
| track of this number for efficiency reasons. Otherwise we would always |
| have to process the whole array. */ |
| #define MPN_VAR(name) mp_limb_t *name; mp_size_t name##size |
| |
| #define MPN_ASSIGN(dst,src) \ |
| memcpy (dst, src, (dst##size = src##size) * sizeof (mp_limb_t)) |
| #define MPN_GE(u,v) \ |
| (u##size > v##size || (u##size == v##size && __mpn_cmp (u, v, u##size) >= 0)) |
| |
| extern int __isinfl (long double), __isnanl (long double); |
| |
| extern mp_size_t __mpn_extract_double (mp_ptr res_ptr, mp_size_t size, |
| int *expt, int *is_neg, |
| double value); |
| extern mp_size_t __mpn_extract_long_double (mp_ptr res_ptr, mp_size_t size, |
| int *expt, int *is_neg, |
| long double value); |
| extern unsigned int __guess_grouping (unsigned int intdig_max, |
| const char *grouping, wchar_t sepchar); |
| |
| |
| static char *group_number (char *buf, char *bufend, unsigned int intdig_no, |
| const char *grouping, wchar_t thousands_sep); |
| |
| |
| int |
| __printf_fp (FILE *fp, |
| const struct printf_info *info, |
| const void *const *args) |
| { |
| /* The floating-point value to output. */ |
| union |
| { |
| double dbl; |
| __long_double_t ldbl; |
| } |
| fpnum; |
| |
| /* Locale-dependent representation of decimal point. */ |
| wchar_t decimal; |
| |
| /* Locale-dependent thousands separator and grouping specification. */ |
| wchar_t thousands_sep; |
| const char *grouping; |
| |
| /* "NaN" or "Inf" for the special cases. */ |
| const char *special = NULL; |
| |
| /* We need just a few limbs for the input before shifting to the right |
| position. */ |
| mp_limb_t fp_input[(LDBL_MANT_DIG + BITS_PER_MP_LIMB - 1) / BITS_PER_MP_LIMB]; |
| /* We need to shift the contents of fp_input by this amount of bits. */ |
| int to_shift = 0; |
| |
| /* The fraction of the floting-point value in question */ |
| MPN_VAR(frac); |
| /* and the exponent. */ |
| int exponent; |
| /* Sign of the exponent. */ |
| int expsign = 0; |
| /* Sign of float number. */ |
| int is_neg = 0; |
| |
| /* Scaling factor. */ |
| MPN_VAR(scale); |
| |
| /* Temporary bignum value. */ |
| MPN_VAR(tmp); |
| |
| /* Digit which is result of last hack_digit() call. */ |
| int digit; |
| |
| /* The type of output format that will be used: 'e'/'E' or 'f'. */ |
| int type; |
| |
| /* Counter for number of written characters. */ |
| int done = 0; |
| |
| /* General helper (carry limb). */ |
| mp_limb_t cy; |
| |
| char hack_digit (void) |
| { |
| mp_limb_t hi; |
| |
| if (expsign != 0 && type == 'f' && exponent-- > 0) |
| hi = 0; |
| else if (scalesize == 0) |
| { |
| hi = frac[fracsize - 1]; |
| cy = __mpn_mul_1 (frac, frac, fracsize - 1, 10); |
| frac[fracsize - 1] = cy; |
| } |
| else |
| { |
| if (fracsize < scalesize) |
| hi = 0; |
| else |
| { |
| hi = mpn_divmod (tmp, frac, fracsize, scale, scalesize); |
| tmp[fracsize - scalesize] = hi; |
| hi = tmp[0]; |
| |
| fracsize = scalesize; |
| while (fracsize != 0 && frac[fracsize - 1] == 0) |
| --fracsize; |
| if (fracsize == 0) |
| { |
| /* We're not prepared for an mpn variable with zero |
| limbs. */ |
| fracsize = 1; |
| return '0' + hi; |
| } |
| } |
| |
| cy = __mpn_mul_1 (frac, frac, fracsize, 10); |
| if (cy != 0) |
| frac[fracsize++] = cy; |
| } |
| |
| return '0' + hi; |
| } |
| |
| |
| /* Figure out the decimal point character. */ |
| if (info->extra == 0) |
| { |
| if (mbtowc (&decimal, _NL_CURRENT (LC_NUMERIC, DECIMAL_POINT), |
| strlen (_NL_CURRENT (LC_NUMERIC, DECIMAL_POINT))) <= 0) |
| decimal = (wchar_t) *_NL_CURRENT (LC_NUMERIC, DECIMAL_POINT); |
| } |
| else |
| { |
| if (mbtowc (&decimal, _NL_CURRENT (LC_MONETARY, MON_DECIMAL_POINT), |
| strlen (_NL_CURRENT (LC_MONETARY, MON_DECIMAL_POINT))) <= 0) |
| decimal = (wchar_t) *_NL_CURRENT (LC_MONETARY, MON_DECIMAL_POINT); |
| } |
| /* Give default value. */ |
| if (decimal == L'\0') |
| decimal = L'.'; |
| |
| |
| if (info->group) |
| { |
| if (info->extra == 0) |
| grouping = _NL_CURRENT (LC_NUMERIC, GROUPING); |
| else |
| grouping = _NL_CURRENT (LC_MONETARY, MON_GROUPING); |
| |
| if (*grouping <= 0 || *grouping == CHAR_MAX) |
| grouping = NULL; |
| else |
| { |
| /* Figure out the thousands separator character. */ |
| if (info->extra == 0) |
| { |
| if (mbtowc (&thousands_sep, _NL_CURRENT (LC_NUMERIC, |
| THOUSANDS_SEP), |
| strlen (_NL_CURRENT (LC_NUMERIC, THOUSANDS_SEP))) |
| <= 0) |
| thousands_sep = (wchar_t) *_NL_CURRENT (LC_NUMERIC, |
| THOUSANDS_SEP); |
| } |
| else |
| { |
| if (mbtowc (&thousands_sep, _NL_CURRENT (LC_MONETARY, |
| MON_THOUSANDS_SEP), |
| strlen (_NL_CURRENT (LC_MONETARY, |
| MON_THOUSANDS_SEP))) <= 0) |
| thousands_sep = (wchar_t) *_NL_CURRENT (LC_MONETARY, |
| MON_THOUSANDS_SEP); |
| } |
| |
| if (thousands_sep == L'\0') |
| grouping = NULL; |
| } |
| } |
| else |
| grouping = NULL; |
| |
| /* Fetch the argument value. */ |
| if (info->is_long_double && sizeof (long double) > sizeof (double)) |
| { |
| fpnum.ldbl = *(const long double *) args[0]; |
| |
| /* Check for special values: not a number or infinity. */ |
| if (__isnanl (fpnum.ldbl)) |
| { |
| special = isupper (info->spec) ? "NAN" : "nan"; |
| is_neg = 0; |
| } |
| else if (__isinfl (fpnum.ldbl)) |
| { |
| special = isupper (info->spec) ? "INF" : "inf"; |
| is_neg = fpnum.ldbl < 0; |
| } |
| else |
| { |
| fracsize = __mpn_extract_long_double (fp_input, |
| (sizeof (fp_input) / |
| sizeof (fp_input[0])), |
| &exponent, &is_neg, |
| fpnum.ldbl); |
| to_shift = 1 + fracsize * BITS_PER_MP_LIMB - LDBL_MANT_DIG; |
| } |
| } |
| else |
| { |
| fpnum.dbl = *(const double *) args[0]; |
| |
| /* Check for special values: not a number or infinity. */ |
| if (__isnan (fpnum.dbl)) |
| { |
| special = isupper (info->spec) ? "NAN" : "nan"; |
| is_neg = 0; |
| } |
| else if (__isinf (fpnum.dbl)) |
| { |
| special = isupper (info->spec) ? "INF" : "inf"; |
| is_neg = fpnum.dbl < 0; |
| } |
| else |
| { |
| fracsize = __mpn_extract_double (fp_input, |
| (sizeof (fp_input) |
| / sizeof (fp_input[0])), |
| &exponent, &is_neg, fpnum.dbl); |
| to_shift = 1 + fracsize * BITS_PER_MP_LIMB - DBL_MANT_DIG; |
| } |
| } |
| |
| if (special) |
| { |
| int width = info->width; |
| |
| if (is_neg || info->showsign || info->space) |
| --width; |
| width -= 3; |
| |
| if (!info->left && width > 0) |
| PADN (' ', width); |
| |
| if (is_neg) |
| outchar ('-'); |
| else if (info->showsign) |
| outchar ('+'); |
| else if (info->space) |
| outchar (' '); |
| |
| PRINT (special, 3); |
| |
| if (info->left && width > 0) |
| PADN (' ', width); |
| |
| return done; |
| } |
| |
| |
| /* We need three multiprecision variables. Now that we have the exponent |
| of the number we can allocate the needed memory. It would be more |
| efficient to use variables of the fixed maximum size but because this |
| would be really big it could lead to memory problems. */ |
| { |
| mp_size_t bignum_size = ((ABS (exponent) + BITS_PER_MP_LIMB - 1) |
| / BITS_PER_MP_LIMB + 4) * sizeof (mp_limb_t); |
| frac = (mp_limb_t *) alloca (bignum_size); |
| tmp = (mp_limb_t *) alloca (bignum_size); |
| scale = (mp_limb_t *) alloca (bignum_size); |
| } |
| |
| /* We now have to distinguish between numbers with positive and negative |
| exponents because the method used for the one is not applicable/efficient |
| for the other. */ |
| scalesize = 0; |
| if (exponent > 2) |
| { |
| /* |FP| >= 8.0. */ |
| int scaleexpo = 0; |
| int explog = LDBL_MAX_10_EXP_LOG; |
| int exp10 = 0; |
| const struct mp_power *tens = &_fpioconst_pow10[explog + 1]; |
| int cnt_h, cnt_l, i; |
| |
| if ((exponent + to_shift) % BITS_PER_MP_LIMB == 0) |
| { |
| MPN_COPY_DECR (frac + (exponent + to_shift) / BITS_PER_MP_LIMB, |
| fp_input, fracsize); |
| fracsize += (exponent + to_shift) / BITS_PER_MP_LIMB; |
| } |
| else |
| { |
| cy = __mpn_lshift (frac + (exponent + to_shift) / BITS_PER_MP_LIMB, |
| fp_input, fracsize, |
| (exponent + to_shift) % BITS_PER_MP_LIMB); |
| fracsize += (exponent + to_shift) / BITS_PER_MP_LIMB; |
| if (cy) |
| frac[fracsize++] = cy; |
| } |
| MPN_ZERO (frac, (exponent + to_shift) / BITS_PER_MP_LIMB); |
| |
| assert (tens > &_fpioconst_pow10[0]); |
| do |
| { |
| --tens; |
| |
| /* The number of the product of two binary numbers with n and m |
| bits respectively has m+n or m+n-1 bits. */ |
| if (exponent >= scaleexpo + tens->p_expo - 1) |
| { |
| if (scalesize == 0) |
| MPN_ASSIGN (tmp, tens->array); |
| else |
| { |
| cy = __mpn_mul (tmp, scale, scalesize, |
| &tens->array[_FPIO_CONST_OFFSET], |
| tens->arraysize - _FPIO_CONST_OFFSET); |
| tmpsize = scalesize + tens->arraysize - _FPIO_CONST_OFFSET; |
| if (cy == 0) |
| --tmpsize; |
| } |
| |
| if (MPN_GE (frac, tmp)) |
| { |
| int cnt; |
| MPN_ASSIGN (scale, tmp); |
| count_leading_zeros (cnt, scale[scalesize - 1]); |
| scaleexpo = (scalesize - 2) * BITS_PER_MP_LIMB - cnt - 1; |
| exp10 |= 1 << explog; |
| } |
| } |
| --explog; |
| } |
| while (tens > &_fpioconst_pow10[0]); |
| exponent = exp10; |
| |
| /* Optimize number representations. We want to represent the numbers |
| with the lowest number of bytes possible without losing any |
| bytes. Also the highest bit in the scaling factor has to be set |
| (this is a requirement of the MPN division routines). */ |
| if (scalesize > 0) |
| { |
| /* Determine minimum number of zero bits at the end of |
| both numbers. */ |
| for (i = 0; scale[i] == 0 && frac[i] == 0; i++) |
| ; |
| |
| /* Determine number of bits the scaling factor is misplaced. */ |
| count_leading_zeros (cnt_h, scale[scalesize - 1]); |
| |
| if (cnt_h == 0) |
| { |
| /* The highest bit of the scaling factor is already set. So |
| we only have to remove the trailing empty limbs. */ |
| if (i > 0) |
| { |
| MPN_COPY_INCR (scale, scale + i, scalesize - i); |
| scalesize -= i; |
| MPN_COPY_INCR (frac, frac + i, fracsize - i); |
| fracsize -= i; |
| } |
| } |
| else |
| { |
| if (scale[i] != 0) |
| { |
| count_trailing_zeros (cnt_l, scale[i]); |
| if (frac[i] != 0) |
| { |
| int cnt_l2; |
| count_trailing_zeros (cnt_l2, frac[i]); |
| if (cnt_l2 < cnt_l) |
| cnt_l = cnt_l2; |
| } |
| } |
| else |
| count_trailing_zeros (cnt_l, frac[i]); |
| |
| /* Now shift the numbers to their optimal position. */ |
| if (i == 0 && BITS_PER_MP_LIMB - cnt_h > cnt_l) |
| { |
| /* We cannot save any memory. So just roll both numbers |
| so that the scaling factor has its highest bit set. */ |
| |
| (void) __mpn_lshift (scale, scale, scalesize, cnt_h); |
| cy = __mpn_lshift (frac, frac, fracsize, cnt_h); |
| if (cy != 0) |
| frac[fracsize++] = cy; |
| } |
| else if (BITS_PER_MP_LIMB - cnt_h <= cnt_l) |
| { |
| /* We can save memory by removing the trailing zero limbs |
| and by packing the non-zero limbs which gain another |
| free one. */ |
| |
| (void) __mpn_rshift (scale, scale + i, scalesize - i, |
| BITS_PER_MP_LIMB - cnt_h); |
| scalesize -= i + 1; |
| (void) __mpn_rshift (frac, frac + i, fracsize - i, |
| BITS_PER_MP_LIMB - cnt_h); |
| fracsize -= frac[fracsize - i - 1] == 0 ? i + 1 : i; |
| } |
| else |
| { |
| /* We can only save the memory of the limbs which are zero. |
| The non-zero parts occupy the same number of limbs. */ |
| |
| (void) __mpn_rshift (scale, scale + (i - 1), |
| scalesize - (i - 1), |
| BITS_PER_MP_LIMB - cnt_h); |
| scalesize -= i; |
| (void) __mpn_rshift (frac, frac + (i - 1), |
| fracsize - (i - 1), |
| BITS_PER_MP_LIMB - cnt_h); |
| fracsize -= frac[fracsize - (i - 1) - 1] == 0 ? i : i - 1; |
| } |
| } |
| } |
| } |
| else if (exponent < 0) |
| { |
| /* |FP| < 1.0. */ |
| int exp10 = 0; |
| int explog = LDBL_MAX_10_EXP_LOG; |
| const struct mp_power *tens = &_fpioconst_pow10[explog + 1]; |
| mp_size_t used_limbs = fracsize - 1; |
| |
| /* Now shift the input value to its right place. */ |
| cy = __mpn_lshift (frac, fp_input, fracsize, to_shift); |
| frac[fracsize++] = cy; |
| assert (cy == 1 || (frac[fracsize - 2] == 0 && frac[0] == 0)); |
| |
| expsign = 1; |
| exponent = -exponent; |
| |
| assert (tens != &_fpioconst_pow10[0]); |
| do |
| { |
| --tens; |
| |
| if (exponent >= tens->m_expo) |
| { |
| int i, incr, cnt_h, cnt_l; |
| mp_limb_t topval[2]; |
| |
| /* The __mpn_mul function expects the first argument to be |
| bigger than the second. */ |
| if (fracsize < tens->arraysize - _FPIO_CONST_OFFSET) |
| cy = __mpn_mul (tmp, &tens->array[_FPIO_CONST_OFFSET], |
| tens->arraysize - _FPIO_CONST_OFFSET, |
| frac, fracsize); |
| else |
| cy = __mpn_mul (tmp, frac, fracsize, |
| &tens->array[_FPIO_CONST_OFFSET], |
| tens->arraysize - _FPIO_CONST_OFFSET); |
| tmpsize = fracsize + tens->arraysize - _FPIO_CONST_OFFSET; |
| if (cy == 0) |
| --tmpsize; |
| |
| count_leading_zeros (cnt_h, tmp[tmpsize - 1]); |
| incr = (tmpsize - fracsize) * BITS_PER_MP_LIMB |
| + BITS_PER_MP_LIMB - 1 - cnt_h; |
| |
| assert (incr <= tens->p_expo); |
| |
| /* If we increased the exponent by exactly 3 we have to test |
| for overflow. This is done by comparing with 10 shifted |
| to the right position. */ |
| if (incr == exponent + 3) |
| if (cnt_h <= BITS_PER_MP_LIMB - 4) |
| { |
| topval[0] = 0; |
| topval[1] |
| = ((mp_limb_t) 10) << (BITS_PER_MP_LIMB - 4 - cnt_h); |
| } |
| else |
| { |
| topval[0] = ((mp_limb_t) 10) << (BITS_PER_MP_LIMB - 4); |
| topval[1] = 0; |
| (void) __mpn_lshift (topval, topval, 2, |
| BITS_PER_MP_LIMB - cnt_h); |
| } |
| |
| /* We have to be careful when multiplying the last factor. |
| If the result is greater than 1.0 be have to test it |
| against 10.0. If it is greater or equal to 10.0 the |
| multiplication was not valid. This is because we cannot |
| determine the number of bits in the result in advance. */ |
| if (incr < exponent + 3 |
| || (incr == exponent + 3 && |
| (tmp[tmpsize - 1] < topval[1] |
| || (tmp[tmpsize - 1] == topval[1] |
| && tmp[tmpsize - 2] < topval[0])))) |
| { |
| /* The factor is right. Adapt binary and decimal |
| exponents. */ |
| exponent -= incr; |
| exp10 |= 1 << explog; |
| |
| /* If this factor yields a number greater or equal to |
| 1.0, we must not shift the non-fractional digits down. */ |
| if (exponent < 0) |
| cnt_h += -exponent; |
| |
| /* Now we optimize the number representation. */ |
| for (i = 0; tmp[i] == 0; ++i); |
| if (cnt_h == BITS_PER_MP_LIMB - 1) |
| { |
| MPN_COPY (frac, tmp + i, tmpsize - i); |
| fracsize = tmpsize - i; |
| } |
| else |
| { |
| count_trailing_zeros (cnt_l, tmp[i]); |
| |
| /* Now shift the numbers to their optimal position. */ |
| if (i == 0 && BITS_PER_MP_LIMB - 1 - cnt_h > cnt_l) |
| { |
| /* We cannot save any memory. Just roll the |
| number so that the leading digit is in a |
| separate limb. */ |
| |
| cy = __mpn_lshift (frac, tmp, tmpsize, cnt_h + 1); |
| fracsize = tmpsize + 1; |
| frac[fracsize - 1] = cy; |
| } |
| else if (BITS_PER_MP_LIMB - 1 - cnt_h <= cnt_l) |
| { |
| (void) __mpn_rshift (frac, tmp + i, tmpsize - i, |
| BITS_PER_MP_LIMB - 1 - cnt_h); |
| fracsize = tmpsize - i; |
| } |
| else |
| { |
| /* We can only save the memory of the limbs which |
| are zero. The non-zero parts occupy the same |
| number of limbs. */ |
| |
| (void) __mpn_rshift (frac, tmp + (i - 1), |
| tmpsize - (i - 1), |
| BITS_PER_MP_LIMB - 1 - cnt_h); |
| fracsize = tmpsize - (i - 1); |
| } |
| } |
| used_limbs = fracsize - 1; |
| } |
| } |
| --explog; |
| } |
| while (tens != &_fpioconst_pow10[1] && exponent > 0); |
| /* All factors but 10^-1 are tested now. */ |
| if (exponent > 0) |
| { |
| int cnt_l; |
| |
| cy = __mpn_mul_1 (tmp, frac, fracsize, 10); |
| tmpsize = fracsize; |
| assert (cy == 0 || tmp[tmpsize - 1] < 20); |
| |
| count_trailing_zeros (cnt_l, tmp[0]); |
| if (cnt_l < MIN (4, exponent)) |
| { |
| cy = __mpn_lshift (frac, tmp, tmpsize, |
| BITS_PER_MP_LIMB - MIN (4, exponent)); |
| if (cy != 0) |
| frac[tmpsize++] = cy; |
| } |
| else |
| (void) __mpn_rshift (frac, tmp, tmpsize, MIN (4, exponent)); |
| fracsize = tmpsize; |
| exp10 |= 1; |
| assert (frac[fracsize - 1] < 10); |
| } |
| exponent = exp10; |
| } |
| else |
| { |
| /* This is a special case. We don't need a factor because the |
| numbers are in the range of 0.0 <= fp < 8.0. We simply |
| shift it to the right place and divide it by 1.0 to get the |
| leading digit. (Of course this division is not really made.) */ |
| assert (0 <= exponent && exponent < 3 && |
| exponent + to_shift < BITS_PER_MP_LIMB); |
| |
| /* Now shift the input value to its right place. */ |
| cy = __mpn_lshift (frac, fp_input, fracsize, (exponent + to_shift)); |
| frac[fracsize++] = cy; |
| exponent = 0; |
| } |
| |
| { |
| int width = info->width; |
| char *buffer, *startp, *cp; |
| int chars_needed; |
| int expscale; |
| int intdig_max, intdig_no = 0; |
| int fracdig_min, fracdig_max, fracdig_no = 0; |
| int dig_max; |
| int significant; |
| |
| if (tolower (info->spec) == 'e') |
| { |
| type = info->spec; |
| intdig_max = 1; |
| fracdig_min = fracdig_max = info->prec < 0 ? 6 : info->prec; |
| chars_needed = 1 + 1 + fracdig_max + 1 + 1 + 4; |
| /* d . ddd e +- ddd */ |
| dig_max = INT_MAX; /* Unlimited. */ |
| significant = 1; /* Does not matter here. */ |
| } |
| else if (info->spec == 'f') |
| { |
| type = 'f'; |
| fracdig_min = fracdig_max = info->prec < 0 ? 6 : info->prec; |
| if (expsign == 0) |
| { |
| intdig_max = exponent + 1; |
| /* This can be really big! */ /* XXX Maybe malloc if too big? */ |
| chars_needed = exponent + 1 + 1 + fracdig_max; |
| } |
| else |
| { |
| intdig_max = 1; |
| chars_needed = 1 + 1 + fracdig_max; |
| } |
| dig_max = INT_MAX; /* Unlimited. */ |
| significant = 1; /* Does not matter here. */ |
| } |
| else |
| { |
| dig_max = info->prec < 0 ? 6 : (info->prec == 0 ? 1 : info->prec); |
| if ((expsign == 0 && exponent >= dig_max) |
| || (expsign != 0 && exponent > 4)) |
| { |
| type = isupper (info->spec) ? 'E' : 'e'; |
| fracdig_max = dig_max - 1; |
| intdig_max = 1; |
| chars_needed = 1 + 1 + fracdig_max + 1 + 1 + 4; |
| } |
| else |
| { |
| type = 'f'; |
| intdig_max = expsign == 0 ? exponent + 1 : 0; |
| fracdig_max = dig_max - intdig_max; |
| /* We need space for the significant digits and perhaps for |
| leading zeros when < 1.0. Pessimistic guess: dig_max. */ |
| chars_needed = dig_max + dig_max + 1; |
| } |
| fracdig_min = info->alt ? fracdig_max : 0; |
| significant = 0; /* We count significant digits. */ |
| } |
| |
| if (grouping) |
| /* Guess the number of groups we will make, and thus how |
| many spaces we need for separator characters. */ |
| chars_needed += __guess_grouping (intdig_max, grouping, thousands_sep); |
| |
| /* Allocate buffer for output. We need two more because while rounding |
| it is possible that we need two more characters in front of all the |
| other output. */ |
| buffer = alloca (2 + chars_needed); |
| cp = startp = buffer + 2; /* Let room for rounding. */ |
| |
| /* Do the real work: put digits in allocated buffer. */ |
| if (expsign == 0 || type != 'f') |
| { |
| assert (expsign == 0 || intdig_max == 1); |
| while (intdig_no < intdig_max) |
| { |
| ++intdig_no; |
| *cp++ = hack_digit (); |
| } |
| significant = 1; |
| if (info->alt |
| || fracdig_min > 0 |
| || (fracdig_max > 0 && (fracsize > 1 || frac[0] != 0))) |
| *cp++ = decimal; |
| } |
| else |
| { |
| /* |fp| < 1.0 and the selected type is 'f', so put "0." |
| in the buffer. */ |
| *cp++ = '0'; |
| --exponent; |
| *cp++ = decimal; |
| } |
| |
| /* Generate the needed number of fractional digits. */ |
| while (fracdig_no < fracdig_min |
| || (fracdig_no < fracdig_max && (fracsize > 1 || frac[0] != 0))) |
| { |
| ++fracdig_no; |
| *cp = hack_digit (); |
| if (*cp != '0') |
| significant = 1; |
| else if (significant == 0) |
| { |
| ++fracdig_max; |
| if (fracdig_min > 0) |
| ++fracdig_min; |
| } |
| ++cp; |
| } |
| |
| /* Do rounding. */ |
| digit = hack_digit (); |
| if (digit > '4') |
| { |
| char *tp = cp; |
| |
| if (digit == '5') |
| /* This is the critical case. */ |
| if (fracsize == 1 && frac[0] == 0) |
| /* Rest of the number is zero -> round to even. |
| (IEEE 754-1985 4.1 says this is the default rounding.) */ |
| if ((*(cp - 1) & 1) == 0) |
| goto do_expo; |
| |
| if (fracdig_no > 0) |
| { |
| /* Process fractional digits. Terminate if not rounded or |
| radix character is reached. */ |
| while (*--tp != decimal && *tp == '9') |
| *tp = '0'; |
| if (*tp != decimal) |
| /* Round up. */ |
| (*tp)++; |
| } |
| |
| if (fracdig_no == 0 || *tp == decimal) |
| { |
| /* Round the integer digits. */ |
| if (*(tp - 1) == decimal) |
| --tp; |
| |
| while (--tp >= startp && *tp == '9') |
| *tp = '0'; |
| |
| if (tp >= startp) |
| /* Round up. */ |
| (*tp)++; |
| else |
| /* It is more critical. All digits were 9's. */ |
| { |
| if (type != 'f') |
| { |
| *startp = '1'; |
| exponent += expsign == 0 ? 1 : -1; |
| } |
| else if (intdig_no == dig_max) |
| { |
| /* This is the case where for type %g the number fits |
| really in the range for %f output but after rounding |
| the number of digits is too big. */ |
| *--startp = decimal; |
| *--startp = '1'; |
| |
| if (info->alt || fracdig_no > 0) |
| { |
| /* Overwrite the old radix character. */ |
| startp[intdig_no + 2] = '0'; |
| ++fracdig_no; |
| } |
| |
| fracdig_no += intdig_no; |
| intdig_no = 1; |
| fracdig_max = intdig_max - intdig_no; |
| ++exponent; |
| /* Now we must print the exponent. */ |
| type = isupper (info->spec) ? 'E' : 'e'; |
| } |
| else |
| { |
| /* We can simply add another another digit before the |
| radix. */ |
| *--startp = '1'; |
| ++intdig_no; |
| } |
| |
| /* While rounding the number of digits can change. |
| If the number now exceeds the limits remove some |
| fractional digits. */ |
| if (intdig_no + fracdig_no > dig_max) |
| { |
| cp -= intdig_no + fracdig_no - dig_max; |
| fracdig_no -= intdig_no + fracdig_no - dig_max; |
| } |
| } |
| } |
| } |
| |
| do_expo: |
| /* Now remove unnecessary '0' at the end of the string. */ |
| while (fracdig_no > fracdig_min && *(cp - 1) == '0') |
| { |
| --cp; |
| --fracdig_no; |
| } |
| /* If we eliminate all fractional digits we perhaps also can remove |
| the radix character. */ |
| if (fracdig_no == 0 && !info->alt && *(cp - 1) == decimal) |
| --cp; |
| |
| if (grouping) |
| /* Add in separator characters, overwriting the same buffer. */ |
| cp = group_number (startp, cp, intdig_no, grouping, thousands_sep); |
| |
| /* Write the exponent if it is needed. */ |
| if (type != 'f') |
| { |
| *cp++ = type; |
| *cp++ = expsign ? '-' : '+'; |
| |
| /* Find the magnitude of the exponent. */ |
| expscale = 10; |
| while (expscale <= exponent) |
| expscale *= 10; |
| |
| if (exponent < 10) |
| /* Exponent always has at least two digits. */ |
| *cp++ = '0'; |
| else |
| do |
| { |
| expscale /= 10; |
| *cp++ = '0' + (exponent / expscale); |
| exponent %= expscale; |
| } |
| while (expscale > 10); |
| *cp++ = '0' + exponent; |
| } |
| |
| /* Compute number of characters which must be filled with the padding |
| character. */ |
| if (is_neg || info->showsign || info->space) |
| --width; |
| width -= cp - startp; |
| |
| if (!info->left && info->pad != '0' && width > 0) |
| PADN (info->pad, width); |
| |
| if (is_neg) |
| outchar ('-'); |
| else if (info->showsign) |
| outchar ('+'); |
| else if (info->space) |
| outchar (' '); |
| |
| if (!info->left && info->pad == '0' && width > 0) |
| PADN ('0', width); |
| |
| PRINT (startp, cp - startp); |
| |
| if (info->left && width > 0) |
| PADN (info->pad, width); |
| } |
| return done; |
| } |
| |
| /* Return the number of extra grouping characters that will be inserted |
| into a number with INTDIG_MAX integer digits. */ |
| |
| unsigned int |
| __guess_grouping (unsigned int intdig_max, const char *grouping, |
| wchar_t sepchar) |
| { |
| unsigned int groups; |
| |
| /* We treat all negative values like CHAR_MAX. */ |
| |
| if (*grouping == CHAR_MAX || *grouping <= 0) |
| /* No grouping should be done. */ |
| return 0; |
| |
| groups = 0; |
| while (intdig_max > (unsigned int) *grouping) |
| { |
| ++groups; |
| intdig_max -= *grouping++; |
| |
| if (*grouping == CHAR_MAX || *grouping < 0) |
| /* No more grouping should be done. */ |
| break; |
| else if (*grouping == 0) |
| { |
| /* Same grouping repeats. */ |
| groups += (intdig_max - 1) / grouping[-1]; |
| break; |
| } |
| } |
| |
| return groups; |
| } |
| |
| /* Group the INTDIG_NO integer digits of the number in [BUF,BUFEND). |
| There is guaranteed enough space past BUFEND to extend it. |
| Return the new end of buffer. */ |
| |
| static char * |
| group_number (char *buf, char *bufend, unsigned int intdig_no, |
| const char *grouping, wchar_t thousands_sep) |
| { |
| unsigned int groups = __guess_grouping (intdig_no, grouping, thousands_sep); |
| char *p; |
| |
| if (groups == 0) |
| return bufend; |
| |
| /* Move the fractional part down. */ |
| memmove (buf + intdig_no + groups, buf + intdig_no, |
| bufend - (buf + intdig_no)); |
| |
| p = buf + intdig_no + groups - 1; |
| do |
| { |
| unsigned int len = *grouping++; |
| do |
| *p-- = buf[--intdig_no]; |
| while (--len > 0); |
| *p-- = thousands_sep; |
| |
| if (*grouping == CHAR_MAX || *grouping < 0) |
| /* No more grouping should be done. */ |
| break; |
| else if (*grouping == 0) |
| /* Same grouping repeats. */ |
| --grouping; |
| } while (intdig_no > (unsigned int) *grouping); |
| |
| /* Copy the remaining ungrouped digits. */ |
| do |
| *p-- = buf[--intdig_no]; |
| while (p > buf); |
| |
| return bufend + groups; |
| } |