xref: /illumos-gate/usr/src/lib/libc/sparcv9/fp/_Qp_qtox.c (revision 0250c53ad267726f2438e3c6556199a0bbf588a2)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright (c) 1994-1997, by Sun Microsystems, Inc.
24  * All rights reserved.
25  */
26 
27 #include "quad.h"
28 
29 /*
30  * _Qp_qtox(x) returns (long)*x.
31  */
32 long
33 _Qp_qtox(const union longdouble *x)
34 {
35 	long		i, round;
36 	unsigned int	xm, fsr;
37 
38 	xm = x->l.msw & 0x7fffffff;
39 
40 	__quad_getfsrp(&fsr);
41 
42 	/* handle nan, inf, and out-of-range cases */
43 	if (xm >= 0x403e0000) {
44 		if (x->l.msw == 0xc03e0000 && x->l.frac2 == 0 &&
45 		    (x->l.frac3 & 0xfffe0000) == 0) {
46 			/* return largest negative 64 bit int */
47 			i = 0x8000000000000000ul;
48 			if ((x->l.frac3 & 0x1ffff) | x->l.frac4) {
49 				/* signal inexact */
50 				if (fsr & FSR_NXM) {
51 					__quad_fqtox(x, &i);
52 				} else {
53 					fsr = (fsr & ~FSR_CEXC) | FSR_NXA |
54 					    FSR_NXC;
55 					__quad_setfsrp(&fsr);
56 				}
57 			}
58 			return (i);
59 		}
60 		i = ((x->l.msw & 0x80000000)? 0x8000000000000000ul :
61 		    0x7fffffffffffffffl);
62 		if (fsr & FSR_NVM) {
63 			__quad_fqtox(x, &i);
64 		} else {
65 			fsr = (fsr & ~FSR_CEXC) | FSR_NVA | FSR_NVC;
66 			__quad_setfsrp(&fsr);
67 		}
68 		return (i);
69 	}
70 	if (xm < 0x3fff0000) {
71 		i = 0l;
72 		if (xm | x->l.frac2 | x->l.frac3 | x->l.frac4) {
73 			/* signal inexact */
74 			if (fsr & FSR_NXM) {
75 				__quad_fqtox(x, &i);
76 			} else {
77 				fsr = (fsr & ~FSR_CEXC) | FSR_NXA | FSR_NXC;
78 				__quad_setfsrp(&fsr);
79 			}
80 		}
81 		return (i);
82 	}
83 
84 	/* now x is in the range of 64 bit int */
85 	i = 0x4000000000000000l | ((long) (xm & 0xffff) << 46) |
86 	    ((long) x->l.frac2 << 14) | (x->l.frac3 >> 18);
87 	round = i & ((1l << (0x403d - (xm >> 16))) - 1);
88 	i >>= (0x403d - (xm >> 16));
89 	if (x->l.msw & 0x80000000)
90 		i = -i;
91 	if (round | (x->l.frac3 & 0x3ffff) | x->l.frac4) {
92 		/* signal inexact */
93 		if (fsr & FSR_NXM) {
94 			__quad_fqtox(x, &i);
95 		} else {
96 			fsr = (fsr & ~FSR_CEXC) | FSR_NXA | FSR_NXC;
97 			__quad_setfsrp(&fsr);
98 		}
99 	}
100 	return (i);
101 }
102