92 lines
2.6 KiB
C
92 lines
2.6 KiB
C
/* Compatibility functions for floating point formatting.
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Copyright (C) 1995, 1996, 1997, 1999 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If not,
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write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include <math.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <sys/param.h>
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#include <float.h>
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#include <bits/libc-lock.h>
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#ifndef FLOAT_TYPE
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# define FLOAT_TYPE double
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# define FUNC_PREFIX
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# define FLOAT_FMT_FLAG
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/* Actually we have to write (DBL_DIG + log10 (DBL_MAX_10_EXP)) but we
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don't have log10 available in the preprocessor. */
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# define MAXDIG (NDIGIT_MAX + 3)
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# if DBL_MANT_DIG == 53
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# define NDIGIT_MAX 17
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# elif DBL_MANT_DIG == 24
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# define NDIGIT_MAX 9
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# elif DBL_MANT_DIG == 56
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# define NDIGIT_MAX 18
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# else
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/* See IEEE 854 5.6, table 2 for this formula. Unfortunately we need a
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compile time constant here, so we cannot use it. */
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# error "NDIGIT_MAX must be precomputed"
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# define NDIGIT_MAX (lrint (ceil (M_LN2 / M_LN10 * DBL_MANT_DIG + 1.0)))
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# endif
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#endif
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#define APPEND(a, b) APPEND2 (a, b)
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#define APPEND2(a, b) a##b
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#define FCVT_BUFFER APPEND (FUNC_PREFIX, fcvt_buffer)
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#define ECVT_BUFFER APPEND (FUNC_PREFIX, ecvt_buffer)
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static char FCVT_BUFFER[MAXDIG];
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static char ECVT_BUFFER[MAXDIG];
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char *
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APPEND (FUNC_PREFIX, fcvt) (value, ndigit, decpt, sign)
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FLOAT_TYPE value;
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int ndigit, *decpt, *sign;
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{
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(void) APPEND (FUNC_PREFIX, fcvt_r) (value, ndigit, decpt, sign,
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FCVT_BUFFER, MAXDIG);
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return FCVT_BUFFER;
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}
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char *
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APPEND (FUNC_PREFIX, ecvt) (value, ndigit, decpt, sign)
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FLOAT_TYPE value;
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int ndigit, *decpt, *sign;
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{
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(void) APPEND (FUNC_PREFIX, ecvt_r) (value, ndigit, decpt, sign,
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ECVT_BUFFER, MAXDIG);
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return ECVT_BUFFER;
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}
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char *
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APPEND (FUNC_PREFIX, gcvt) (value, ndigit, buf)
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FLOAT_TYPE value;
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int ndigit;
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char *buf;
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{
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sprintf (buf, "%.*" FLOAT_FMT_FLAG "g", MIN (ndigit, NDIGIT_MAX), value);
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return buf;
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}
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