diff libquadmath/printf/printf_fp.c @ 68:561a7518be6b

update gcc-4.6
author Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
date Sun, 21 Aug 2011 07:07:55 +0900
parents
children 04ced10e8804
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libquadmath/printf/printf_fp.c	Sun Aug 21 07:07:55 2011 +0900
@@ -0,0 +1,1306 @@
+/* Floating point output for `printf'.
+   Copyright (C) 1995-2003, 2006-2008, 2011 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 Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <config.h>
+#include <float.h>
+#include <math.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdlib.h>
+#define NDEBUG
+#include <assert.h>
+#ifdef HAVE_ERRNO_H
+#include <errno.h>
+#endif
+#include <stdio.h>
+#include <stdarg.h>
+#include "quadmath-printf.h"
+#include "fpioconst.h"
+
+#ifdef USE_I18N_NUMBER_H
+#include "_i18n_number.h"
+#endif
+
+
+/* Macros for doing the actual output.  */
+
+#define outchar(ch)							      \
+  do									      \
+    {									      \
+      register const int outc = (ch);					      \
+      if (PUTC (outc, fp) == EOF)					      \
+	{								      \
+	  if (buffer_malloced)						      \
+	    free (wbuffer);						      \
+	  return -1;							      \
+	}								      \
+      ++done;								      \
+    } while (0)
+
+#define PRINT(ptr, wptr, len)						      \
+  do									      \
+    {									      \
+      register size_t outlen = (len);					      \
+      if (len > 20)							      \
+	{								      \
+	  if (PUT (fp, wide ? (const char *) wptr : ptr, outlen) != outlen)   \
+	    {								      \
+	      if (buffer_malloced)					      \
+		free (wbuffer);						      \
+	      return -1;						      \
+	    }								      \
+	  ptr += outlen;						      \
+	  done += outlen;						      \
+	}								      \
+      else								      \
+	{								      \
+	  if (wide)							      \
+	    while (outlen-- > 0)					      \
+	      outchar (*wptr++);					      \
+	  else								      \
+	    while (outlen-- > 0)					      \
+	      outchar (*ptr++);						      \
+	}								      \
+    } while (0)
+
+#define PADN(ch, len)							      \
+  do									      \
+    {									      \
+      if (PAD (fp, ch, len) != len)					      \
+	{								      \
+	  if (buffer_malloced)						      \
+	    free (wbuffer);						      \
+	  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 mp_size_t mpn_extract_flt128 (mp_ptr res_ptr, mp_size_t size,
+				     int *expt, int *is_neg,
+				     __float128 value) attribute_hidden;
+static unsigned int guess_grouping (unsigned int intdig_max,
+				    const char *grouping);
+
+
+static wchar_t *group_number (wchar_t *buf, wchar_t *bufend,
+			      unsigned int intdig_no, const char *grouping,
+			      wchar_t thousands_sep, int ngroups);
+
+
+int
+__quadmath_printf_fp (struct __quadmath_printf_file *fp,
+		      const struct printf_info *info,
+		      const void *const *args)
+{
+  /* The floating-point value to output.  */
+  __float128 fpnum;
+
+  /* Locale-dependent representation of decimal point.	*/
+  const char *decimal;
+  wchar_t decimalwc;
+
+  /* Locale-dependent thousands separator and grouping specification.  */
+  const char *thousands_sep = NULL;
+  wchar_t thousands_sepwc = L_('\0');
+  const char *grouping;
+
+  /* "NaN" or "Inf" for the special cases.  */
+  const char *special = NULL;
+  const wchar_t *wspecial = NULL;
+
+  /* We need just a few limbs for the input before shifting to the right
+     position.	*/
+  mp_limb_t fp_input[(FLT128_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.  */
+  wchar_t 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;
+
+  /* Nonzero if this is output on a wide character stream.  */
+  int wide = info->wide;
+
+  /* Buffer in which we produce the output.  */
+  wchar_t *wbuffer = NULL;
+  /* Flag whether wbuffer is malloc'ed or not.  */
+  int buffer_malloced = 0;
+
+  auto wchar_t hack_digit (void);
+
+  wchar_t hack_digit (void)
+    {
+      mp_limb_t hi;
+
+      if (expsign != 0 && type == 'f' && exponent-- > 0)
+	hi = 0;
+      else if (scalesize == 0)
+	{
+	  hi = frac[fracsize - 1];
+	  frac[fracsize - 1] = mpn_mul_1 (frac, frac, fracsize - 1, 10);
+	}
+      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 L_('0') + hi;
+		}
+	    }
+
+	  mp_limb_t _cy = mpn_mul_1 (frac, frac, fracsize, 10);
+	  if (_cy != 0)
+	    frac[fracsize++] = _cy;
+	}
+
+      return L_('0') + hi;
+    }
+
+  /* Figure out the decimal point character.  */
+#ifdef USE_NL_LANGINFO
+  if (info->extra == 0)
+    decimal = nl_langinfo (DECIMAL_POINT);
+  else
+    {
+      decimal = nl_langinfo (MON_DECIMAL_POINT);
+      if (*decimal == '\0')
+	decimal = nl_langinfo (DECIMAL_POINT);
+    }
+  /* The decimal point character must never be zero.  */
+  assert (*decimal != '\0');
+#elif defined USE_LOCALECONV
+  const struct lconv *lc = localeconv ();
+  if (info->extra == 0)
+    decimal = lc->decimal_point;
+  else
+    {
+      decimal = lc->mon_decimal_point;
+      if (decimal == NULL || *decimal == '\0')
+	decimal = lc->decimal_point;
+    }
+  if (decimal == NULL || *decimal == '\0')
+    decimal = ".";
+#else
+  decimal = ".";
+#endif
+#ifdef USE_NL_LANGINFO_WC
+  if (info->extra == 0)
+    decimalwc = nl_langinfo_wc (_NL_NUMERIC_DECIMAL_POINT_WC);
+  else
+    {
+      decimalwc = nl_langinfo_wc (_NL_MONETARY_DECIMAL_POINT_WC);
+      if (decimalwc == L_('\0'))
+	decimalwc = nl_langinfo_wc (_NL_NUMERIC_DECIMAL_POINT_WC);
+    }
+  /* The decimal point character must never be zero.  */
+  assert (decimalwc != L_('\0'));
+#else
+  decimalwc = L_('.');
+#endif
+
+#if defined USE_NL_LANGINFO && defined USE_NL_LANGINFO_WC
+  if (info->group)
+    {
+      if (info->extra == 0)
+	grouping = nl_langinfo (GROUPING);
+      else
+	grouping = nl_langinfo (MON_GROUPING);
+
+      if (*grouping <= 0 || *grouping == CHAR_MAX)
+	grouping = NULL;
+      else
+	{
+	  /* Figure out the thousands separator character.  */
+	  if (wide)
+	    {
+	      if (info->extra == 0)
+		thousands_sepwc = nl_langinfo_wc (_NL_NUMERIC_THOUSANDS_SEP_WC);
+	      else
+		thousands_sepwc = nl_langinfo_wc (_NL_MONETARY_THOUSANDS_SEP_WC);
+
+	      if (thousands_sepwc == L_('\0'))
+		grouping = NULL;
+	    }
+	  else
+	    {
+	      if (info->extra == 0)
+		thousands_sep = nl_langinfo (THOUSANDS_SEP);
+	      else
+		thousands_sep = nl_langinfo (MON_THOUSANDS_SEP);
+	      if (*thousands_sep == '\0')
+		grouping = NULL;
+	    }
+	}
+    }
+  else
+#elif defined USE_NL_LANGINFO
+  if (info->group && !wide)
+    {
+      if (info->extra == 0)
+	grouping = nl_langinfo (GROUPING);
+      else
+	grouping = nl_langinfo (MON_GROUPING);
+
+      if (*grouping <= 0 || *grouping == CHAR_MAX)
+	grouping = NULL;
+      else
+	{
+	  /* Figure out the thousands separator character.  */
+	  if (info->extra == 0)
+	    thousands_sep = nl_langinfo (THOUSANDS_SEP);
+	  else
+	    thousands_sep = nl_langinfo (MON_THOUSANDS_SEP);
+
+	  if (*thousands_sep == '\0')
+	    grouping = NULL;
+	}
+    }
+  else
+#elif defined USE_LOCALECONV
+  if (info->group && !wide)
+    {
+      if (info->extra == 0)
+	grouping = lc->grouping;
+      else
+	grouping = lc->mon_grouping;
+
+      if (grouping == NULL || *grouping <= 0 || *grouping == CHAR_MAX)
+	grouping = NULL;
+      else
+	{
+	  /* Figure out the thousands separator character.  */
+	  if (info->extra == 0)
+	    thousands_sep = lc->thousands_sep;
+	  else
+	    thousands_sep = lc->mon_thousands_sep;
+
+	  if (thousands_sep == NULL || *thousands_sep == '\0')
+	    grouping = NULL;
+	}
+    }
+  else
+#endif
+    grouping = NULL;
+  if (grouping != NULL && !wide)
+    /* If we are printing multibyte characters and there is a
+       multibyte representation for the thousands separator,
+       we must ensure the wide character thousands separator
+       is available, even if it is fake.  */
+    thousands_sepwc = (wchar_t) 0xfffffffe;
+
+  /* Fetch the argument value.	*/
+    {
+      fpnum = **(const __float128 **) args[0];
+
+      /* Check for special values: not a number or infinity.  */
+      if (isnanq (fpnum))
+	{
+	  ieee854_float128 u = { .value = fpnum };
+	  is_neg = u.ieee.negative != 0;
+	  if (isupper (info->spec))
+	    {
+	      special = "NAN";
+	      wspecial = L_("NAN");
+	    }
+	    else
+	      {
+		special = "nan";
+		wspecial = L_("nan");
+	      }
+	}
+      else if (isinfq (fpnum))
+	{
+	  is_neg = fpnum < 0;
+	  if (isupper (info->spec))
+	    {
+	      special = "INF";
+	      wspecial = L_("INF");
+	    }
+	  else
+	    {
+	      special = "inf";
+	      wspecial = L_("inf");
+	    }
+	}
+      else
+	{
+	  fracsize = mpn_extract_flt128 (fp_input,
+					 (sizeof (fp_input) /
+					  sizeof (fp_input[0])),
+					 &exponent, &is_neg, fpnum);
+	  to_shift = 1 + fracsize * BITS_PER_MP_LIMB - FLT128_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, wspecial, 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
+			     + (FLT128_MANT_DIG / BITS_PER_MP_LIMB > 2 ? 8 : 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 = FLT128_MAX_10_EXP_LOG;
+      int exp10 = 0;
+      const struct mp_power *powers = &_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 (powers > &_fpioconst_pow10[0]);
+      do
+	{
+	  --powers;
+
+	  /* 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 + powers->p_expo - 1)
+	    {
+	      if (scalesize == 0)
+		{
+		  if (FLT128_MANT_DIG > _FPIO_CONST_OFFSET * BITS_PER_MP_LIMB)
+		    {
+#define _FPIO_CONST_SHIFT \
+  (((FLT128_MANT_DIG + BITS_PER_MP_LIMB - 1) / BITS_PER_MP_LIMB) \
+   - _FPIO_CONST_OFFSET)
+		      /* 64bit const offset is not enough for
+			 IEEE quad long double.  */
+		      tmpsize = powers->arraysize + _FPIO_CONST_SHIFT;
+		      memcpy (tmp + _FPIO_CONST_SHIFT,
+			      &__tens[powers->arrayoff],
+			      tmpsize * sizeof (mp_limb_t));
+		      MPN_ZERO (tmp, _FPIO_CONST_SHIFT);
+		      /* Adjust exponent, as scaleexpo will be this much
+			 bigger too.  */
+		      exponent += _FPIO_CONST_SHIFT * BITS_PER_MP_LIMB;
+		    }
+		  else
+		    {
+		      tmpsize = powers->arraysize;
+		      memcpy (tmp, &__tens[powers->arrayoff],
+			      tmpsize * sizeof (mp_limb_t));
+		    }
+		}
+	      else
+		{
+		  cy = mpn_mul (tmp, scale, scalesize,
+				&__tens[powers->arrayoff
+					+ _FPIO_CONST_OFFSET],
+				powers->arraysize - _FPIO_CONST_OFFSET);
+		  tmpsize = scalesize + powers->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 (powers > &_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 = FLT128_MAX_10_EXP_LOG;
+      const struct mp_power *powers = &_fpioconst_pow10[explog + 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 (powers != &_fpioconst_pow10[0]);
+      do
+	{
+	  --powers;
+
+	  if (exponent >= powers->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 < powers->arraysize - _FPIO_CONST_OFFSET)
+		cy = mpn_mul (tmp, &__tens[powers->arrayoff
+					   + _FPIO_CONST_OFFSET],
+			      powers->arraysize - _FPIO_CONST_OFFSET,
+			      frac, fracsize);
+	      else
+		cy = mpn_mul (tmp, frac, fracsize,
+			      &__tens[powers->arrayoff + _FPIO_CONST_OFFSET],
+			      powers->arraysize - _FPIO_CONST_OFFSET);
+	      tmpsize = fracsize + powers->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 <= powers->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);
+			}
+		    }
+		}
+	    }
+	  --explog;
+	}
+      while (powers != &_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 1.0 <= |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;
+    wchar_t *wstartp, *wcp;
+    size_t chars_needed;
+    int expscale;
+    int intdig_max, intdig_no = 0;
+    int fracdig_min;
+    int fracdig_max;
+    int dig_max;
+    int significant;
+    int ngroups = 0;
+    char spec = tolower (info->spec);
+
+    if (spec == 'e')
+      {
+	type = info->spec;
+	intdig_max = 1;
+	fracdig_min = fracdig_max = info->prec < 0 ? 6 : info->prec;
+	chars_needed = 1 + 1 + (size_t) fracdig_max + 1 + 1 + 4;
+	/*	       d   .	 ddd	     e	 +-  ddd  */
+	dig_max = __INT_MAX__;		/* Unlimited.  */
+	significant = 1;		/* Does not matter here.  */
+      }
+    else if (spec == 'f')
+      {
+	type = 'f';
+	fracdig_min = fracdig_max = info->prec < 0 ? 6 : info->prec;
+	dig_max = __INT_MAX__;		/* Unlimited.  */
+	significant = 1;		/* Does not matter here.  */
+	if (expsign == 0)
+	  {
+	    intdig_max = exponent + 1;
+	    /* This can be really big!	*/  /* XXX Maybe malloc if too big? */
+	    chars_needed = (size_t) exponent + 1 + 1 + (size_t) fracdig_max;
+	  }
+	else
+	  {
+	    intdig_max = 1;
+	    chars_needed = 1 + 1 + (size_t) fracdig_max;
+	  }
+      }
+    else
+      {
+	dig_max = info->prec < 0 ? 6 : (info->prec == 0 ? 1 : info->prec);
+	if ((expsign == 0 && exponent >= dig_max)
+	    || (expsign != 0 && exponent > 4))
+	  {
+	    if ('g' - 'G' == 'e' - 'E')
+	      type = 'E' + (info->spec - 'G');
+	    else
+	      type = isupper (info->spec) ? 'E' : 'e';
+	    fracdig_max = dig_max - 1;
+	    intdig_max = 1;
+	    chars_needed = 1 + 1 + (size_t) 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.  The number of leading
+	       zeros can be as many as would be required for
+	       exponential notation with a negative two-digit
+	       exponent, which is 4.  */
+	    chars_needed = (size_t) dig_max + 1 + 4;
+	  }
+	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.  */
+	ngroups = guess_grouping (intdig_max, grouping);
+	/* Allocate one more character in case rounding increases the
+	   number of groups.  */
+	chars_needed += ngroups + 1;
+      }
+
+    /* 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.  If the amount of memory we have to allocate is too
+       large use `malloc' instead of `alloca'.  */
+    if (__builtin_expect (chars_needed >= (size_t) -1 / sizeof (wchar_t) - 2
+			  || chars_needed < fracdig_max, 0))
+      {
+	/* Some overflow occurred.  */
+#if defined HAVE_ERRNO_H && defined ERANGE
+	errno = ERANGE;
+#endif
+	return -1;
+      }
+    size_t wbuffer_to_alloc = (2 + chars_needed) * sizeof (wchar_t);
+    buffer_malloced = wbuffer_to_alloc >= 4096;
+    if (__builtin_expect (buffer_malloced, 0))
+      {
+	wbuffer = (wchar_t *) malloc (wbuffer_to_alloc);
+	if (wbuffer == NULL)
+	  /* Signal an error to the caller.  */
+	  return -1;
+      }
+    else
+      wbuffer = (wchar_t *) alloca (wbuffer_to_alloc);
+    wcp = wstartp = wbuffer + 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;
+	    *wcp++ = hack_digit ();
+	  }
+	significant = 1;
+	if (info->alt
+	    || fracdig_min > 0
+	    || (fracdig_max > 0 && (fracsize > 1 || frac[0] != 0)))
+	  *wcp++ = decimalwc;
+      }
+    else
+      {
+	/* |fp| < 1.0 and the selected type is 'f', so put "0."
+	   in the buffer.  */
+	*wcp++ = L_('0');
+	--exponent;
+	*wcp++ = decimalwc;
+      }
+
+    /* Generate the needed number of fractional digits.	 */
+    int fracdig_no = 0;
+    int added_zeros = 0;
+    while (fracdig_no < fracdig_min + added_zeros
+	   || (fracdig_no < fracdig_max && (fracsize > 1 || frac[0] != 0)))
+      {
+	++fracdig_no;
+	*wcp = hack_digit ();
+	if (*wcp++ != L_('0'))
+	  significant = 1;
+	else if (significant == 0)
+	  {
+	    ++fracdig_max;
+	    if (fracdig_min > 0)
+	      ++added_zeros;
+	  }
+      }
+
+    /* Do rounding.  */
+    digit = hack_digit ();
+    if (digit > L_('4'))
+      {
+	wchar_t *wtp = wcp;
+
+	if (digit == L_('5')
+	    && ((*(wcp - 1) != decimalwc && (*(wcp - 1) & 1) == 0)
+		|| ((*(wcp - 1) == decimalwc && (*(wcp - 2) & 1) == 0))))
+	  {
+	    /* 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.)  */
+	      goto do_expo;
+	    else if (scalesize == 0)
+	      {
+		/* Here we have to see whether all limbs are zero since no
+		   normalization happened.  */
+		size_t lcnt = fracsize;
+		while (lcnt >= 1 && frac[lcnt - 1] == 0)
+		  --lcnt;
+		if (lcnt == 0)
+		  /* Rest of the number is zero -> round to even.
+		     (IEEE 754-1985 4.1 says this is the default rounding.)  */
+		  goto do_expo;
+	      }
+	  }
+
+	if (fracdig_no > 0)
+	  {
+	    /* Process fractional digits.  Terminate if not rounded or
+	       radix character is reached.  */
+	    int removed = 0;
+	    while (*--wtp != decimalwc && *wtp == L_('9'))
+	      {
+		*wtp = L_('0');
+		++removed;
+	      }
+	    if (removed == fracdig_min && added_zeros > 0)
+	      --added_zeros;
+	    if (*wtp != decimalwc)
+	      /* Round up.  */
+	      (*wtp)++;
+	    else if (__builtin_expect (spec == 'g' && type == 'f' && info->alt
+				       && wtp == wstartp + 1
+				       && wstartp[0] == L_('0'),
+				       0))
+	      /* This is a special case: the rounded number is 1.0,
+		 the format is 'g' or 'G', and the alternative format
+		 is selected.  This means the result must be "1.".  */
+	      --added_zeros;
+	  }
+
+	if (fracdig_no == 0 || *wtp == decimalwc)
+	  {
+	    /* Round the integer digits.  */
+	    if (*(wtp - 1) == decimalwc)
+	      --wtp;
+
+	    while (--wtp >= wstartp && *wtp == L_('9'))
+	      *wtp = L_('0');
+
+	    if (wtp >= wstartp)
+	      /* Round up.  */
+	      (*wtp)++;
+	    else
+	      /* It is more critical.  All digits were 9's.  */
+	      {
+		if (type != 'f')
+		  {
+		    *wstartp = '1';
+		    exponent += expsign == 0 ? 1 : -1;
+
+		    /* The above exponent adjustment could lead to 1.0e-00,
+		       e.g. for 0.999999999.  Make sure exponent 0 always
+		       uses + sign.  */
+		    if (exponent == 0)
+		      expsign = 0;
+		  }
+		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.	 */
+		    *--wstartp = decimalwc;
+		    *--wstartp = L_('1');
+
+		    if (info->alt || fracdig_no > 0)
+		      {
+			/* Overwrite the old radix character.  */
+			wstartp[intdig_no + 2] = L_('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.  */
+		    *--wstartp = L_('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)
+		  {
+		    wcp -= 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 + added_zeros && *(wcp - 1) == L_('0'))
+      {
+	--wcp;
+	--fracdig_no;
+      }
+    /* If we eliminate all fractional digits we perhaps also can remove
+       the radix character.  */
+    if (fracdig_no == 0 && !info->alt && *(wcp - 1) == decimalwc)
+      --wcp;
+
+    if (grouping)
+      {
+	/* Rounding might have changed the number of groups.  We allocated
+	   enough memory but we need here the correct number of groups.  */
+	if (intdig_no != intdig_max)
+	  ngroups = guess_grouping (intdig_no, grouping);
+
+	/* Add in separator characters, overwriting the same buffer.  */
+	wcp = group_number (wstartp, wcp, intdig_no, grouping, thousands_sepwc,
+			    ngroups);
+      }
+
+    /* Write the exponent if it is needed.  */
+    if (type != 'f')
+      {
+	if (__builtin_expect (expsign != 0 && exponent == 4 && spec == 'g', 0))
+	  {
+	    /* This is another special case.  The exponent of the number is
+	       really smaller than -4, which requires the 'e'/'E' format.
+	       But after rounding the number has an exponent of -4.  */
+	    assert (wcp >= wstartp + 1);
+	    assert (wstartp[0] == L_('1'));
+	    memcpy (wstartp, L_("0.0001"), 6 * sizeof (wchar_t));
+	    wstartp[1] = decimalwc;
+	    if (wcp >= wstartp + 2)
+	      {
+		size_t cnt;
+		for (cnt = 0; cnt < wcp - (wstartp + 2); cnt++)
+		  wstartp[6 + cnt] = L_('0');
+		wcp += 4;
+	      }
+	    else
+	      wcp += 5;
+	  }
+	else
+	  {
+	    *wcp++ = (wchar_t) type;
+	    *wcp++ = expsign ? L_('-') : L_('+');
+
+	    /* Find the magnitude of the exponent.	*/
+	    expscale = 10;
+	    while (expscale <= exponent)
+	      expscale *= 10;
+
+	    if (exponent < 10)
+	      /* Exponent always has at least two digits.  */
+	      *wcp++ = L_('0');
+	    else
+	      do
+		{
+		  expscale /= 10;
+		  *wcp++ = L_('0') + (exponent / expscale);
+		  exponent %= expscale;
+		}
+	      while (expscale > 10);
+	    *wcp++ = L_('0') + exponent;
+	  }
+      }
+
+    /* Compute number of characters which must be filled with the padding
+       character.  */
+    if (is_neg || info->showsign || info->space)
+      --width;
+    width -= wcp - wstartp;
+
+    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);
+
+    {
+      char *buffer = NULL;
+      char *buffer_end __attribute__((__unused__)) = NULL;
+      char *cp = NULL;
+      char *tmpptr;
+
+      if (! wide)
+	{
+	  /* Create the single byte string.  */
+	  size_t decimal_len;
+	  size_t thousands_sep_len;
+	  wchar_t *copywc;
+#ifdef USE_I18N_NUMBER_H
+	  size_t factor = (info->i18n
+			   ? nl_langinfo_wc (_NL_CTYPE_MB_CUR_MAX)
+			   : 1);
+#else
+	  size_t factor = 1;
+#endif
+
+	  decimal_len = strlen (decimal);
+
+	  if (thousands_sep == NULL)
+	    thousands_sep_len = 0;
+	  else
+	    thousands_sep_len = strlen (thousands_sep);
+
+	  size_t nbuffer = (2 + chars_needed * factor + decimal_len
+			    + ngroups * thousands_sep_len);
+	  if (__builtin_expect (buffer_malloced, 0))
+	    {
+	      buffer = (char *) malloc (nbuffer);
+	      if (buffer == NULL)
+		{
+		  /* Signal an error to the caller.  */
+		  free (wbuffer);
+		  return -1;
+		}
+	    }
+	  else
+	    buffer = (char *) alloca (nbuffer);
+	  buffer_end = buffer + nbuffer;
+
+	  /* Now copy the wide character string.  Since the character
+	     (except for the decimal point and thousands separator) must
+	     be coming from the ASCII range we can esily convert the
+	     string without mapping tables.  */
+	  for (cp = buffer, copywc = wstartp; copywc < wcp; ++copywc)
+	    if (*copywc == decimalwc)
+	      memcpy (cp, decimal, decimal_len), cp += decimal_len;
+	    else if (*copywc == thousands_sepwc)
+	      mempcpy (cp, thousands_sep, thousands_sep_len), cp += thousands_sep_len;
+	    else
+	      *cp++ = (char) *copywc;
+	}
+
+      tmpptr = buffer;
+#if USE_I18N_NUMBER_H
+      if (__builtin_expect (info->i18n, 0))
+	{
+	  tmpptr = _i18n_number_rewrite (tmpptr, cp, buffer_end);
+	  cp = buffer_end;
+	  assert ((uintptr_t) buffer <= (uintptr_t) tmpptr);
+	  assert ((uintptr_t) tmpptr < (uintptr_t) buffer_end);
+	}
+#endif
+
+      PRINT (tmpptr, wstartp, wide ? wcp - wstartp : cp - tmpptr);
+
+      /* Free the memory if necessary.  */
+      if (__builtin_expect (buffer_malloced, 0))
+	{
+	  free (buffer);
+	  free (wbuffer);
+	}
+    }
+
+    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.  */
+
+static unsigned int
+guess_grouping (unsigned int intdig_max, const char *grouping)
+{
+  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 == 0)
+	{
+	  /* Same grouping repeats.  */
+	  groups += (intdig_max - 1) / grouping[-1];
+	  break;
+	}
+      else if (*grouping == CHAR_MAX || *grouping <= 0)
+	/* No more grouping should be done.  */
+	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 wchar_t *
+group_number (wchar_t *buf, wchar_t *bufend, unsigned int intdig_no,
+	      const char *grouping, wchar_t thousands_sep, int ngroups)
+{
+  wchar_t *p;
+
+  if (ngroups == 0)
+    return bufend;
+
+  /* Move the fractional part down.  */
+  memmove (buf + intdig_no + ngroups, buf + intdig_no,
+	   (bufend - (buf + intdig_no)) * sizeof (wchar_t));
+
+  p = buf + intdig_no + ngroups - 1;
+  do
+    {
+      unsigned int len = *grouping++;
+      do
+	*p-- = buf[--intdig_no];
+      while (--len > 0);
+      *p-- = thousands_sep;
+
+      if (*grouping == 0)
+	/* Same grouping repeats.  */
+	--grouping;
+      else if (*grouping == CHAR_MAX || *grouping <= 0)
+	/* No more grouping should be done.  */
+	break;
+    } while (intdig_no > (unsigned int) *grouping);
+
+  /* Copy the remaining ungrouped digits.  */
+  do
+    *p-- = buf[--intdig_no];
+  while (p > buf);
+
+  return bufend + ngroups;
+}