hexnan.c revision 174678 
1/****************************************************************
2
3The author of this software is David M. Gay.
4
5Copyright (C) 2000 by Lucent Technologies
6All Rights Reserved
7
8Permission to use, copy, modify, and distribute this software and
9its documentation for any purpose and without fee is hereby
10granted, provided that the above copyright notice appear in all
11copies and that both that the copyright notice and this
12permission notice and warranty disclaimer appear in supporting
13documentation, and that the name of Lucent or any of its entities
14not be used in advertising or publicity pertaining to
15distribution of the software without specific, written prior
16permission.
17
18LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
19INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
20IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
21SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
22WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
23IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
24ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
25THIS SOFTWARE.
26
27****************************************************************/
28
29/* Please send bug reports to David M. Gay (dmg at acm dot org,
30 * with " at " changed at "@" and " dot " changed to ".").	*/
31
32/* $FreeBSD: head/contrib/gdtoa/hexnan.c 174678 2007-12-16 21:13:54Z das $ */
33
34#include "gdtoaimp.h"
35
36 static void
37#ifdef KR_headers
38L_shift(x, x1, i) ULong *x; ULong *x1; int i;
39#else
40L_shift(ULong *x, ULong *x1, int i)
41#endif
42{
43	int j;
44
45	i = 8 - i;
46	i <<= 2;
47	j = ULbits - i;
48	do {
49		*x |= x[1] << j;
50		x[1] >>= i;
51		} while(++x < x1);
52	}
53
54 int
55#ifdef KR_headers
56hexnan(sp, fpi, x0)
57	CONST char **sp; FPI *fpi; ULong *x0;
58#else
59hexnan( CONST char **sp, FPI *fpi, ULong *x0)
60#endif
61{
62	ULong c, h, *x, *x1, *xe;
63	CONST char *s;
64	int havedig, hd0, i, nbits;
65
66	if (!hexdig['0'])
67		hexdig_init_D2A();
68	nbits = fpi->nbits;
69	x = x0 + (nbits >> kshift);
70	if (nbits & kmask)
71		x++;
72	*--x = 0;
73	x1 = xe = x;
74	havedig = hd0 = i = 0;
75	s = *sp;
76
77	/* FreeBSD local: Accept (but ignore) the '0x' prefix. */
78	if (s[1] == '0' && (s[2] == 'x' || s[2] == 'X'))
79		s += 2;
80
81	while(c = *(CONST unsigned char*)++s) {
82		if (!(h = hexdig[c])) {
83#if 0
84			if (c <= ' ') {
85				if (hd0 < havedig) {
86					if (x < x1 && i < 8)
87						L_shift(x, x1, i);
88					if (x <= x0) {
89						i = 8;
90						continue;
91						}
92					hd0 = havedig;
93					*--x = 0;
94					x1 = x;
95					i = 0;
96					}
97				continue;
98				}
99			if (/*(*/ c == ')' && havedig) {
100				*sp = s + 1;
101				break;
102				}
103#endif
104			break;
105			}
106		havedig++;
107		if (++i > 8) {
108			if (x <= x0)
109				continue;
110			i = 1;
111			*--x = 0;
112			}
113		*x = (*x << 4) | h & 0xf;
114		}
115	if (havedig && x < x1 && i < 8)
116		L_shift(x, x1, i);
117	if (x > x0) {
118		x1 = x0;
119		do *x1++ = *x++;
120			while(x <= xe);
121		do *x1++ = 0;
122			while(x1 <= xe);
123		}
124	else {
125		/* truncate high-order word if necessary */
126		if ( (i = nbits & (ULbits-1)) !=0)
127			*xe &= ((ULong)0xffffffff) >> (ULbits - i);
128		}
129	if (havedig) {
130	for(x1 = xe;; --x1) {
131		if (*x1 != 0)
132			break;
133		if (x1 == x0) {
134			*x1 = 1;
135			break;
136			}
137		}
138	}
139
140	/*
141	 * FreeBSD local: Accept all the sequences allowed by C99 and update
142	 * the tail pointer correctly. Don't accept any invalid sequences.
143	 */
144	if (c == '\0')	/* nan() calls this, too; tolerate a missing ')' */
145		return STRTOG_NaNbits;
146	if (c != ')') {
147		while(c = *(CONST unsigned char*)++s) {
148			if (c == ')')
149				break;
150			if (!isalnum(c) && c != '_')
151				return STRTOG_NaNbits;
152		}
153	}
154	*sp = s + 1;
155	return STRTOG_NaNbits;
156	}
157