xref: /titanic_41/usr/src/lib/libc/port/fp/finite.c (revision 4496171313bed39e96f21bc2f9faf2868e267ae3)
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 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*	Copyright (c) 1988 AT&T	*/
30 /*	  All Rights Reserved  	*/
31 
32 
33 /*	IEEE recommended functions */
34 
35 #pragma weak finite = _finite
36 #pragma weak fpclass = _fpclass
37 #pragma weak unordered = _unordered
38 
39 #include "synonyms.h"
40 #include <values.h>
41 #include "fpparts.h"
42 
43 #define	P754_NOFAULT 1		/* avoid generating extra code */
44 #include <ieeefp.h>
45 
46 /*
47  * FINITE(X)
48  * finite(x) returns 1 if x > -inf and x < +inf and 0 otherwise
49  * NaN returns 0
50  */
51 
52 int
53 finite(double x)
54 {
55 	return ((EXPONENT(x) != MAXEXP));
56 }
57 
58 /*
59  * UNORDERED(x,y)
60  * unordered(x,y) returns 1 if x is unordered with y, otherwise
61  * it returns 0; x is unordered with y if either x or y is NAN
62  */
63 
64 int
65 unordered(double x, double y)
66 {
67 	if ((EXPONENT(x) == MAXEXP) && (HIFRACTION(x) || LOFRACTION(x)))
68 		return (1);
69 	if ((EXPONENT(y) == MAXEXP) && (HIFRACTION(y) || LOFRACTION(y)))
70 		return (1);
71 	return (0);
72 }
73 
74 /*
75  * FPCLASS(X)
76  * fpclass(x) returns the floating point class x belongs to
77  */
78 
79 fpclass_t
80 fpclass(double x)
81 {
82 	int	sign, exp;
83 
84 	exp = EXPONENT(x);
85 	sign = SIGNBIT(x);
86 	if (exp == 0) { /* de-normal or zero */
87 		if (HIFRACTION(x) || LOFRACTION(x)) /* de-normal */
88 			return (sign ? FP_NDENORM : FP_PDENORM);
89 		else
90 			return (sign ? FP_NZERO : FP_PZERO);
91 	}
92 	if (exp == MAXEXP) { /* infinity or NaN */
93 		if ((HIFRACTION(x) == 0) && (LOFRACTION(x) == 0)) /* infinity */
94 			return (sign ? FP_NINF : FP_PINF);
95 		else
96 			if (QNANBIT(x))
97 			/* hi-bit of mantissa set - quiet nan */
98 				return (FP_QNAN);
99 			else	return (FP_SNAN);
100 	}
101 	/* if we reach here we have non-zero normalized number */
102 	return (sign ? FP_NNORM : FP_PNORM);
103 }
104