1/* $NetBSD: strtoIg.c,v 1.5 2021/05/06 16:15:33 christos Exp $ */
2
3/****************************************************************
4
5The author of this software is David M. Gay.
6
7Copyright (C) 1998 by Lucent Technologies
8All Rights Reserved
9
10Permission to use, copy, modify, and distribute this software and
11its documentation for any purpose and without fee is hereby
12granted, provided that the above copyright notice appear in all
13copies and that both that the copyright notice and this
14permission notice and warranty disclaimer appear in supporting
15documentation, and that the name of Lucent or any of its entities
16not be used in advertising or publicity pertaining to
17distribution of the software without specific, written prior
18permission.
19
20LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
21INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
22IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
23SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
24WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
25IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
26ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
27THIS SOFTWARE.
28
29****************************************************************/
30
31/* Please send bug reports to David M. Gay (dmg at acm dot org,
32 * with " at " changed at "@" and " dot " changed to ".").	*/
33
34#include "gdtoaimp.h"
35
36 int
37#ifdef KR_headers
38strtoIg(s00, se, fpi, exp, B, rvp) CONST char *s00; char **se; CONST FPI *fpi; Long *exp; Bigint **B; int *rvp;
39#else
40strtoIg(CONST char *s00, char **se, CONST FPI *fpi, Long *exp, Bigint **B, int *rvp)
41#endif
42{
43	Bigint *b, *b1;
44	int i, nb, nw, nw1, rv, rv1, swap;
45	unsigned int nb1, nb11;
46	Long e1;
47
48	b = *B;
49	rv = strtodg(s00, se, fpi, exp, b->x);
50	if (rv == STRTOG_NoMemory)
51		return rv;
52	if (!(rv & STRTOG_Inexact)) {
53		B[1] = 0;
54		return *rvp = rv;
55		}
56	e1 = exp[0];
57	rv1 = rv ^ STRTOG_Inexact;
58	b1 = Balloc(b->k);
59	if (b1 == NULL)
60		return STRTOG_NoMemory;
61	Bcopy(b1, b);
62	nb = fpi->nbits;
63	nb1 = nb & 31;
64	nb11 = (nb1 - 1) & 31;
65	nw = b->wds;
66	nw1 = nw - 1;
67	if (rv & STRTOG_Inexlo) {
68		swap = 0;
69		b1 = increment(b1);
70		if ((rv & STRTOG_Retmask) == STRTOG_Zero) {
71			if (fpi->sudden_underflow) {
72				b1->x[0] = 0;
73				b1->x[nw1] = 1L << nb11;
74				rv1 += STRTOG_Normal - STRTOG_Zero;
75				rv1 &= ~STRTOG_Underflow;
76				goto swapcheck;
77				}
78			rv1 &= STRTOG_Inexlo | STRTOG_Underflow | STRTOG_Zero;
79			rv1 |= STRTOG_Inexhi | STRTOG_Denormal;
80			goto swapcheck;
81			}
82		if (b1->wds > nw
83		 || (nb1 && b1->x[nw1] & 1L << nb1)) {
84			if (++e1 > fpi->emax)
85				rv1 = STRTOG_Infinite | STRTOG_Inexhi;
86			rshift(b1, 1);
87			}
88		else if ((rv & STRTOG_Retmask) == STRTOG_Denormal) {
89			if (b1->x[nw1] & 1L << nb11) {
90				rv1 += STRTOG_Normal - STRTOG_Denormal;
91				rv1 &= ~STRTOG_Underflow;
92				}
93			}
94		}
95	else {
96		swap = STRTOG_Neg;
97		if ((rv & STRTOG_Retmask) == STRTOG_Infinite) {
98			b1 = set_ones(b1, nb);
99			e1 = fpi->emax;
100			rv1 = STRTOG_Normal | STRTOG_Inexlo;
101			goto swapcheck;
102			}
103		decrement(b1);
104		if ((rv & STRTOG_Retmask) == STRTOG_Denormal) {
105			for(i = nw1; !b1->x[i]; --i)
106				if (!i) {
107					rv1 = STRTOG_Zero | STRTOG_Inexlo;
108					break;
109					}
110			goto swapcheck;
111			}
112		if (!(b1->x[nw1] & 1L << nb11)) {
113			if (e1 == fpi->emin) {
114				if (fpi->sudden_underflow)
115					rv1 += STRTOG_Zero - STRTOG_Normal;
116				else
117					rv1 += STRTOG_Denormal - STRTOG_Normal;
118				rv1 |= STRTOG_Underflow;
119				}
120			else {
121				b1 = lshift(b1, 1);
122				if (b1 == NULL)
123					return STRTOG_NoMemory;
124				b1->x[0] |= 1;
125				--e1;
126				}
127			}
128		}
129 swapcheck:
130	if (swap ^ (rv & STRTOG_Neg)) {
131		rvp[0] = rv1;
132		rvp[1] = rv;
133		B[0] = b1;
134		B[1] = b;
135		exp[1] = exp[0];
136		exp[0] = e1;
137		}
138	else {
139		rvp[0] = rv;
140		rvp[1] = rv1;
141		B[1] = b1;
142		exp[1] = e1;
143		}
144	return rv;
145	}
146