111 lines
2.6 KiB
C
111 lines
2.6 KiB
C
/* GCC Quad-Precision Math Library
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Copyright (C) 2010 Free Software Foundation, Inc.
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Written by Francois-Xavier Coudert <fxcoudert@gcc.gnu.org>
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This file is part of the libiberty library.
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Libiberty is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public
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License as published by the Free Software Foundation; either
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version 2 of the License, or (at your option) any later version.
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Libiberty 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 libiberty; see the file COPYING.LIB. If
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not, write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
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Boston, MA 02110-1301, USA. */
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#include "quadmath.h"
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#include <stdio.h>
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#include <string.h>
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#define ABS(x) ((x) >= 0 ? (x) : -(x))
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static void
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format (char * res, const __float128 x, size_t n)
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{
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char buffer[1024];
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char *p;
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memset (buffer, 0, sizeof(buffer));
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g_Qfmt (buffer, &x, n + 1, sizeof(buffer) - 3);
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p = buffer + (*buffer == '-' ? 1 : 0);
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// The sign is the easiest part
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res[0] = (signbitq (x) ? '-' : '+');
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if (*p == '.')
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{
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// We have a number smaller than 1, without exponent
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int exp = 0;
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char *c;
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for (c = p+1; *c == '0'; c++)
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exp++;
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// We move the string "exp" characters left
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size_t l = strlen (p+1+exp);
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memcpy (res + 2, p + 1 + exp, l);
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memset (res + 2 + l, '0', n - l + 1);
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sprintf (res + n + 3, "e-%02d", exp + 1);
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res[1] = res[2];
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res[2] = '.';
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return;
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}
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// Now, do we already have an exponent
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char *c;
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for (c = p; *c && *c != 'e'; c++)
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;
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if (*c)
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{
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int exp = strtol (c + 1, NULL, 10);
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size_t l = c - p;
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memcpy (res + 1, p, l);
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if (l <= n + 1)
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memset (res + 1 + l, '0', (int) n - l + 2);
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sprintf (res + n + 3, "e%c%02d", exp >= 0 ? '+' : '-', ABS(exp));
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return;
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}
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else
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{
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// If we have no exponent, normalize and add the exponent
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for (c = p; *c && *c != '.'; c++)
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;
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res[1] = *p;
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res[2] = '.';
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size_t l = c - p;
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memcpy (res + 3, p + 1, l);
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size_t l2 = strlen (c + 1);
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memcpy (res + 2 + l, c + 1, l2);
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memset (res + 2 + l + l2, '0', n - (l + l2) + 1);
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sprintf (res + n + 3, "e+%02d", l - 1);
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return;
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}
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}
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void
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quadmath_dtoaq (char *s, size_t size, size_t n, __float128 x)
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{
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char buffer[1024];
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memset (buffer, 0, sizeof(buffer));
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format (buffer, x, n);
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memcpy (s, buffer, size);
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}
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