1/****************************************************************
2
3The author of this software is David M. Gay.
4
5Copyright (C) 1998 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 int
35#ifdef KR_headers
36strtoIg(s00, se, fpi, exp, B, rvp) CONST char *s00; char **se; FPI *fpi; Long *exp; Bigint **B; int *rvp;
37#else
38strtoIg(CONST char *s00, char **se, FPI *fpi, Long *exp, Bigint **B, int *rvp)
39#endif
40{
41	Bigint *b, *b1;
42	int i, nb, nw, nw1, rv, rv1, swap;
43	unsigned int nb1, nb11;
44	Long e1;
45
46	b = *B;
47	rv = strtodg(s00, se, fpi, exp, b->x);
48	if (!(rv & STRTOG_Inexact)) {
49		B[1] = 0;
50		return *rvp = rv;
51		}
52	e1 = exp[0];
53	rv1 = rv ^ STRTOG_Inexact;
54	b1 = Balloc(b->k);
55	Bcopy(b1, b);
56	nb = fpi->nbits;
57	nb1 = nb & 31;
58	nb11 = (nb1 - 1) & 31;
59	nw = b->wds;
60	nw1 = nw - 1;
61	if (rv & STRTOG_Inexlo) {
62		swap = 0;
63		b1 = increment(b1);
64		if ((rv & STRTOG_Retmask) == STRTOG_Zero) {
65			if (fpi->sudden_underflow) {
66				b1->x[0] = 0;
67				b1->x[nw1] = 1L << nb11;
68				rv1 += STRTOG_Normal - STRTOG_Zero;
69				rv1 &= ~STRTOG_Underflow;
70				goto swapcheck;
71				}
72			rv1 &= STRTOG_Inexlo | STRTOG_Underflow | STRTOG_Zero;
73			rv1 |= STRTOG_Inexhi | STRTOG_Denormal;
74			goto swapcheck;
75			}
76		if (b1->wds > nw
77		 || (nb1 && b1->x[nw1] & 1L << nb1)) {
78			if (++e1 > fpi->emax)
79				rv1 = STRTOG_Infinite | STRTOG_Inexhi;
80			rshift(b1, 1);
81			}
82		else if ((rv & STRTOG_Retmask) == STRTOG_Denormal) {
83			if (b1->x[nw1] & 1L << nb11) {
84				rv1 += STRTOG_Normal - STRTOG_Denormal;
85				rv1 &= ~STRTOG_Underflow;
86				}
87			}
88		}
89	else {
90		swap = STRTOG_Neg;
91		if ((rv & STRTOG_Retmask) == STRTOG_Infinite) {
92			b1 = set_ones(b1, nb);
93			e1 = fpi->emax;
94			rv1 = STRTOG_Normal | STRTOG_Inexlo;
95			goto swapcheck;
96			}
97		decrement(b1);
98		if ((rv & STRTOG_Retmask) == STRTOG_Denormal) {
99			for(i = nw1; !b1->x[i]; --i)
100				if (!i) {
101					rv1 = STRTOG_Zero | STRTOG_Inexlo;
102					break;
103					}
104			goto swapcheck;
105			}
106		if (!(b1->x[nw1] & 1L << nb11)) {
107			if (e1 == fpi->emin) {
108				if (fpi->sudden_underflow)
109					rv1 += STRTOG_Zero - STRTOG_Normal;
110				else
111					rv1 += STRTOG_Denormal - STRTOG_Normal;
112				rv1 |= STRTOG_Underflow;
113				}
114			else {
115				b1 = lshift(b1, 1);
116				b1->x[0] |= 1;
117				--e1;
118				}
119			}
120		}
121 swapcheck:
122	if (swap ^ (rv & STRTOG_Neg)) {
123		rvp[0] = rv1;
124		rvp[1] = rv;
125		B[0] = b1;
126		B[1] = b;
127		exp[1] = exp[0];
128		exp[0] = e1;
129		}
130	else {
131		rvp[0] = rv;
132		rvp[1] = rv1;
133		B[1] = b1;
134		exp[1] = e1;
135		}
136	return rv;
137	}
138