hexnan.c revision 267654 
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#include "gdtoaimp.h"
33
34 static void
35#ifdef KR_headers
36L_shift(x, x1, i) ULong *x; ULong *x1; int i;
37#else
38L_shift(ULong *x, ULong *x1, int i)
39#endif
40{
41	int j;
42
43	i = 8 - i;
44	i <<= 2;
45	j = ULbits - i;
46	do {
47		*x |= x[1] << j;
48		x[1] >>= i;
49		} while(++x < x1);
50	}
51
52 int
53#ifdef KR_headers
54hexnan(sp, fpi, x0)
55	CONST char **sp; FPI *fpi; ULong *x0;
56#else
57hexnan( CONST char **sp, FPI *fpi, ULong *x0)
58#endif
59{
60	ULong c, h, *x, *x1, *xe;
61	CONST char *s;
62	int havedig, hd0, i, nbits;
63
64	if (!hexdig['0'])
65		hexdig_init_D2A();
66	nbits = fpi->nbits;
67	x = x0 + (nbits >> kshift);
68	if (nbits & kmask)
69		x++;
70	*--x = 0;
71	x1 = xe = x;
72	havedig = hd0 = i = 0;
73	s = *sp;
74	/* allow optional initial 0x or 0X */
75	while((c = *(CONST unsigned char*)(s+1)) && c <= ' ')
76		++s;
77	if (s[1] == '0' && (s[2] == 'x' || s[2] == 'X')
78	 && *(CONST unsigned char*)(s+3) > ' ')
79		s += 2;
80	while((c = *(CONST unsigned char*)++s)) {
81		if (!(h = hexdig[c])) {
82			if (c <= ' ') {
83				if (hd0 < havedig) {
84					if (x < x1 && i < 8)
85						L_shift(x, x1, i);
86					if (x <= x0) {
87						i = 8;
88						continue;
89						}
90					hd0 = havedig;
91					*--x = 0;
92					x1 = x;
93					i = 0;
94					}
95				while(*(CONST unsigned char*)(s+1) <= ' ')
96					++s;
97				if (s[1] == '0' && (s[2] == 'x' || s[2] == 'X')
98				 && *(CONST unsigned char*)(s+3) > ' ')
99					s += 2;
100				continue;
101				}
102			if (/*(*/ c == ')' && havedig) {
103				*sp = s + 1;
104				break;
105				}
106#ifndef GDTOA_NON_PEDANTIC_NANCHECK
107			do {
108				if (/*(*/ c == ')') {
109					*sp = s + 1;
110					break;
111					}
112				} while((c = *++s));
113#endif
114			return STRTOG_NaN;
115			}
116		havedig++;
117		if (++i > 8) {
118			if (x <= x0)
119				continue;
120			i = 1;
121			*--x = 0;
122			}
123		*x = (*x << 4) | (h & 0xf);
124		}
125	if (!havedig)
126		return STRTOG_NaN;
127	if (x < x1 && i < 8)
128		L_shift(x, x1, i);
129	if (x > x0) {
130		x1 = x0;
131		do *x1++ = *x++;
132			while(x <= xe);
133		do *x1++ = 0;
134			while(x1 <= xe);
135		}
136	else {
137		/* truncate high-order word if necessary */
138		if ( (i = nbits & (ULbits-1)) !=0)
139			*xe &= ((ULong)0xffffffff) >> (ULbits - i);
140		}
141	for(x1 = xe;; --x1) {
142		if (*x1 != 0)
143			break;
144		if (x1 == x0) {
145			*x1 = 1;
146			break;
147			}
148		}
149	return STRTOG_NaNbits;
150	}
151