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$FreeBSD$
--- /dev/null Wed Jan 10 00:32:20 2001
+++ Sources/Util/fcvt.c Wed Jan 10 00:31:59 2001
@@ -0,0 +1,139 @@
+/* Compatibility functions for floating point formatting, reentrant versions.
+ Copyright (C) 1995, 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ 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. */
+
+#include <ctype.h>
+#include <errno.h>
+#include <float.h>
+#include <math.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/param.h>
+
+extern int errno;
+
+#if DBL_MANT_DIG == 53
+# define NDIGIT_MAX 17
+#else
+/*
+ * See IEEE 854 5.6, table 2 for this formula. Unfortunately we need a
+ * compile time constant here, so we cannot use it.
+ */
+# error "NDIGIT_MAX must be precomputed"
+# define NDIGIT_MAX (lrint (ceil (M_LN2 / M_LN10 * DBL_MANT_DIG + 1.0)))
+#endif
+#define MAXDIG (NDIGIT_MAX + 3)
+#define signbit(x) (((x)<(0))?(1):(0))
+
+static char *FCVT_BUFFER[MAXDIG];
+
+static int fcvt_r(double value, int ndigit, int *decpt, int *sign, char *buf, \
+ size_t len)
+{
+ int n, i;
+ int left;
+
+ if (buf == NULL)
+ {
+ errno = EINVAL;
+ return -1;
+ }
+
+ left = 0;
+ if (finite(value))
+ {
+ *sign = signbit(value) != 0;
+ if (*sign)
+ value = -value;
+
+ if (ndigit < 0)
+ {
+
+ while (ndigit < 0)
+ {
+ double new_value = value * 0.1;
+
+ if (new_value < 1.0)
+ {
+ ndigit = 0;
+ break;
+ }
+
+ value = new_value;
+ ++left;
+ ++ndigit;
+ }
+ }
+ }
+ else
+ *sign = 0;
+
+ n = snprintf(buf, len, "%.*f", MIN(ndigit, NDIGIT_MAX), value);
+
+ if (n >= len)
+ return -1;
+
+ i = 0;
+ while (i < n && isdigit(buf[i]))
+ ++i;
+ *decpt = i;
+
+ if (i == 0)
+ return 0;
+
+ if (i < n)
+ {
+ do
+ ++i;
+ while (i < n && !isdigit(buf[i]));
+
+ if (*decpt == 1 && buf[0] == '0' && value != 0.0)
+ {
+ --*decpt;
+
+ while (i < n && buf[i] == '0')
+ {
+ --*decpt;
+ ++i;
+ }
+ }
+
+ memmove(&buf[MAX(*decpt, 0)], &buf[i], n - i);
+ buf[n - (i - MAX(*decpt, 0))] = '\0';
+ }
+
+ if (left)
+ {
+ *decpt += left;
+ if (--len > n)
+ {
+ while (left-- > 0 && n < len)
+ buf[n++] = '0';
+ buf[n] = '\0';
+ }
+ }
+
+ return 0;
+}
+
+char *fcvt(double value, int ndigit, int *decpt, int *sign)
+{
+ fcvt_r(value, ndigit, decpt, sign, (char *)FCVT_BUFFER, MAXDIG);
+ return (char *)FCVT_BUFFER;
+}
+
|
