1 /* Copyright (c) 2005, Dmitry Xmelkov
2 All rights reserved.
3
4 Redistribution and use in source and binary forms, with or without
5 modification, are permitted provided that the following conditions are met:
6
7 * Redistributions of source code must retain the above copyright
8 notice, this list of conditions and the following disclaimer.
9 * Redistributions in binary form must reproduce the above copyright
10 notice, this list of conditions and the following disclaimer in
11 the documentation and/or other materials provided with the
12 distribution.
13 * Neither the name of the copyright holders nor the names of
14 contributors may be used to endorse or promote products derived
15 from this software without specific prior written permission.
16
17 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
18 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
21 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27 POSSIBILITY OF SUCH DAMAGE. */
28
29 /* $Id: dtostre.c 2241 2011-05-11 12:59:48Z joerg_wunsch $ */
30
31 #include <stdlib.h>
32 #include <avr/pgmspace.h>
33 #include "ftoa_engine.h"
34 #include "sectionname.h"
35
36 ATTRIBUTE_CLIB_SECTION
37 char *
dtostre(double val,char * sbeg,unsigned char prec,unsigned char flags)38 dtostre (double val, char *sbeg, unsigned char prec, unsigned char flags)
39 {
40 __attribute__((progmem)) static const char str_nan[2][4] =
41 {"nan", "NAN"};
42 __attribute__((progmem)) static const char str_inf[2][sizeof(str_nan[0])] =
43 {"inf", "INF"};
44 char *d; /* dst */
45 const char *s; /* src */
46 signed char exp;
47 unsigned char vtype;
48
49 if (prec > 7) prec = 7;
50
51 exp = __ftoa_engine (val, sbeg, prec, 0);
52 d = s = sbeg;
53 vtype = *s++;
54
55 if ((vtype & FTOA_MINUS) && !(vtype & FTOA_NAN)) /* like 'Glibc' */
56 *d++ = '-';
57 else if (flags & DTOSTR_PLUS_SIGN)
58 *d++ = '+';
59 else if (flags & DTOSTR_ALWAYS_SIGN)
60 *d++ = ' ';
61
62 if (vtype & FTOA_NAN) {
63 s = str_nan[0];
64 goto copy;
65 }
66
67 if (vtype & FTOA_INF) {
68 s = str_inf[0];
69 copy:
70 if (flags & DTOSTR_UPPERCASE)
71 s += sizeof(str_nan[0]);
72 strcpy_P (d, s);
73 goto ret;
74 }
75
76 /* mantissa */
77 if ( (*d++ = *s++) != '1')
78 vtype &= ~FTOA_CARRY; /* for possible exponent "-00" */
79 if (prec) {
80 unsigned char c1, c2;
81 c1 = '.';
82 do {
83 c2 = *s++;
84 *d++ = c1;
85 c1 = c2;
86 } while (--prec);
87 *d++ = c1;
88 }
89
90 /* exponent */
91 *d++ = (flags & DTOSTR_UPPERCASE) ? 'E' : 'e';
92 if (exp < 0) {
93 *d++ = '-';
94 exp = -exp;
95 } else if (exp == 0 && (vtype & FTOA_CARRY) != 0) {
96 *d++ = '-';
97 } else {
98 *d++ = '+';
99 }
100 for (prec = '0'; exp >= 10; exp -= 10)
101 prec += 1;
102 *d++ = prec;
103 *d++ = '0' + exp;
104 *d = 0;
105
106 ret:
107 return sbeg;
108 }
109 /*** end of file ***/
110