xref: /onnv-gate/usr/src/lib/libc/sparc/fp/_Q_lltoq.c (revision 0:68f95e015346)
1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate  * CDDL HEADER START
3*0Sstevel@tonic-gate  *
4*0Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*0Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
6*0Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
7*0Sstevel@tonic-gate  * with the License.
8*0Sstevel@tonic-gate  *
9*0Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*0Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
11*0Sstevel@tonic-gate  * See the License for the specific language governing permissions
12*0Sstevel@tonic-gate  * and limitations under the License.
13*0Sstevel@tonic-gate  *
14*0Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
15*0Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*0Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
17*0Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
18*0Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
19*0Sstevel@tonic-gate  *
20*0Sstevel@tonic-gate  * CDDL HEADER END
21*0Sstevel@tonic-gate  */
22*0Sstevel@tonic-gate /*
23*0Sstevel@tonic-gate  * Copyright (c) 1994-1997, by Sun Microsystems, Inc.
24*0Sstevel@tonic-gate  * All rights reserved.
25*0Sstevel@tonic-gate  */
26*0Sstevel@tonic-gate 
27*0Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
28*0Sstevel@tonic-gate 
29*0Sstevel@tonic-gate #include "quad.h"
30*0Sstevel@tonic-gate 
31*0Sstevel@tonic-gate /*
32*0Sstevel@tonic-gate  * _Q_lltoq(x) returns (long double)x.
33*0Sstevel@tonic-gate  */
34*0Sstevel@tonic-gate union longdouble
_Q_lltoq(long long x)35*0Sstevel@tonic-gate _Q_lltoq(long long x)
36*0Sstevel@tonic-gate {
37*0Sstevel@tonic-gate 	union longdouble	z;
38*0Sstevel@tonic-gate 	unsigned int		s, e;
39*0Sstevel@tonic-gate 
40*0Sstevel@tonic-gate 	/* extract the sign */
41*0Sstevel@tonic-gate 	s = 0;
42*0Sstevel@tonic-gate 	if (x < 0) {
43*0Sstevel@tonic-gate 		if ((unsigned long long) x == 0x8000000000000000ull) {
44*0Sstevel@tonic-gate 			/* largest negative 64 bit int */
45*0Sstevel@tonic-gate 			Z.l.msw = 0xc03e0000;
46*0Sstevel@tonic-gate 			Z.l.frac2 = Z.l.frac3 = Z.l.frac4 = 0;
47*0Sstevel@tonic-gate 			QUAD_RETURN(Z);
48*0Sstevel@tonic-gate 		}
49*0Sstevel@tonic-gate 		x = -x;
50*0Sstevel@tonic-gate 		s = 0x80000000;
51*0Sstevel@tonic-gate 	} else if (x == 0) {
52*0Sstevel@tonic-gate 		Z.l.msw = Z.l.frac2 = Z.l.frac3 = Z.l.frac4 = 0;
53*0Sstevel@tonic-gate 		QUAD_RETURN(Z);
54*0Sstevel@tonic-gate 	}
55*0Sstevel@tonic-gate 
56*0Sstevel@tonic-gate 	/* find the most significant bit */
57*0Sstevel@tonic-gate 	for (e = 62; (x & (1ll << e)) == 0; e--)
58*0Sstevel@tonic-gate 		;
59*0Sstevel@tonic-gate 
60*0Sstevel@tonic-gate 	if (e > 48) {
61*0Sstevel@tonic-gate 		Z.l.msw = ((unsigned long long) x >> (e - 16)) & 0xffff;
62*0Sstevel@tonic-gate 		Z.l.frac2 = (unsigned long long) x >> (e - 48);
63*0Sstevel@tonic-gate 		Z.l.frac3 = (unsigned long long) x << (80 - e);
64*0Sstevel@tonic-gate 	} else if (e > 16) {
65*0Sstevel@tonic-gate 		Z.l.msw = ((unsigned long long) x >> (e - 16)) & 0xffff;
66*0Sstevel@tonic-gate 		Z.l.frac2 = (unsigned long long) x << (48 - e);
67*0Sstevel@tonic-gate 		Z.l.frac3 = 0;
68*0Sstevel@tonic-gate 	} else {
69*0Sstevel@tonic-gate 		Z.l.msw = ((unsigned long long) x << (16 - e)) & 0xffff;
70*0Sstevel@tonic-gate 		Z.l.frac2 = Z.l.frac3 = 0;
71*0Sstevel@tonic-gate 	}
72*0Sstevel@tonic-gate 	Z.l.frac4 = 0;
73*0Sstevel@tonic-gate 	Z.l.msw |= s | ((e + 0x3fff) << 16);
74*0Sstevel@tonic-gate 	QUAD_RETURN(Z);
75*0Sstevel@tonic-gate }
76