1 /*
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright © 2022 Keith Packard
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above
14 * copyright notice, this list of conditions and the following
15 * disclaimer in the documentation and/or other materials provided
16 * with the distribution.
17 *
18 * 3. Neither the name of the copyright holder nor the names of its
19 * contributors may be used to endorse or promote products derived
20 * from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
26 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
27 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
28 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
29 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
31 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
33 * OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35
36 #define _GNU_SOURCE
37 #include "dtoa_engine.h"
38 #include <_ansi.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <math.h>
42
43 int
ecvt_r(double invalue,int ndigit,int * decpt,int * sign,char * buf,size_t len)44 ecvt_r (double invalue,
45 int ndigit,
46 int *decpt,
47 int *sign,
48 char *buf,
49 size_t len)
50 {
51 struct dtoa dtoa;
52 char *digits = dtoa.digits;
53 int ngot;
54
55 if (ndigit < 0)
56 ndigit = 0;
57
58 if ((size_t) ndigit > len - 1)
59 return -1;
60
61 if (!isfinite(invalue)) {
62 *sign = invalue < 0;
63 *decpt = 0;
64 if (isnan(invalue))
65 digits = "nan";
66 else
67 digits = "inf";
68 ngot = 3;
69 if (ndigit < ngot)
70 ngot = ndigit;
71 ndigit = ngot;
72 } else {
73 ngot = __dtoa_engine(invalue, &dtoa, ndigit, false, 0);
74 *sign = !!(dtoa.flags & DTOA_MINUS);
75 *decpt = dtoa.exp + 1;
76 }
77 memset(buf, '0', ndigit);
78 memcpy(buf, digits, ngot);
79 buf[ndigit] = '\0';
80 return 0;
81 }
82
