xref: /illumos-gate/usr/src/lib/libc/port/fp/finite.c (revision 7257d1b4)
17c478bd9Sstevel@tonic-gate /*
27c478bd9Sstevel@tonic-gate  * CDDL HEADER START
37c478bd9Sstevel@tonic-gate  *
47c478bd9Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*7257d1b4Sraf  * Common Development and Distribution License (the "License").
6*7257d1b4Sraf  * You may not use this file except in compliance with the License.
77c478bd9Sstevel@tonic-gate  *
87c478bd9Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
97c478bd9Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
107c478bd9Sstevel@tonic-gate  * See the License for the specific language governing permissions
117c478bd9Sstevel@tonic-gate  * and limitations under the License.
127c478bd9Sstevel@tonic-gate  *
137c478bd9Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
147c478bd9Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
157c478bd9Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
167c478bd9Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
177c478bd9Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
187c478bd9Sstevel@tonic-gate  *
197c478bd9Sstevel@tonic-gate  * CDDL HEADER END
207c478bd9Sstevel@tonic-gate  */
21*7257d1b4Sraf 
227c478bd9Sstevel@tonic-gate /*
23*7257d1b4Sraf  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
247c478bd9Sstevel@tonic-gate  * Use is subject to license terms.
257c478bd9Sstevel@tonic-gate  */
267c478bd9Sstevel@tonic-gate 
277c478bd9Sstevel@tonic-gate /*	Copyright (c) 1988 AT&T	*/
287c478bd9Sstevel@tonic-gate /*	  All Rights Reserved  	*/
297c478bd9Sstevel@tonic-gate 
30*7257d1b4Sraf #pragma ident	"%Z%%M%	%I%	%E% SMI"
317c478bd9Sstevel@tonic-gate 
327c478bd9Sstevel@tonic-gate /*	IEEE recommended functions */
337c478bd9Sstevel@tonic-gate 
34*7257d1b4Sraf #pragma weak _finite = finite
35*7257d1b4Sraf #pragma weak _fpclass = fpclass
36*7257d1b4Sraf #pragma weak _unordered = unordered
377c478bd9Sstevel@tonic-gate 
38*7257d1b4Sraf #include "lint.h"
397c478bd9Sstevel@tonic-gate #include <values.h>
407c478bd9Sstevel@tonic-gate #include "fpparts.h"
417c478bd9Sstevel@tonic-gate 
427c478bd9Sstevel@tonic-gate #define	P754_NOFAULT 1		/* avoid generating extra code */
437c478bd9Sstevel@tonic-gate #include <ieeefp.h>
447c478bd9Sstevel@tonic-gate 
457c478bd9Sstevel@tonic-gate /*
467c478bd9Sstevel@tonic-gate  * FINITE(X)
477c478bd9Sstevel@tonic-gate  * finite(x) returns 1 if x > -inf and x < +inf and 0 otherwise
487c478bd9Sstevel@tonic-gate  * NaN returns 0
497c478bd9Sstevel@tonic-gate  */
507c478bd9Sstevel@tonic-gate 
517c478bd9Sstevel@tonic-gate int
finite(double x)527c478bd9Sstevel@tonic-gate finite(double x)
537c478bd9Sstevel@tonic-gate {
547c478bd9Sstevel@tonic-gate 	return ((EXPONENT(x) != MAXEXP));
557c478bd9Sstevel@tonic-gate }
567c478bd9Sstevel@tonic-gate 
577c478bd9Sstevel@tonic-gate /*
587c478bd9Sstevel@tonic-gate  * UNORDERED(x,y)
597c478bd9Sstevel@tonic-gate  * unordered(x,y) returns 1 if x is unordered with y, otherwise
607c478bd9Sstevel@tonic-gate  * it returns 0; x is unordered with y if either x or y is NAN
617c478bd9Sstevel@tonic-gate  */
627c478bd9Sstevel@tonic-gate 
637c478bd9Sstevel@tonic-gate int
unordered(double x,double y)647c478bd9Sstevel@tonic-gate unordered(double x, double y)
657c478bd9Sstevel@tonic-gate {
667c478bd9Sstevel@tonic-gate 	if ((EXPONENT(x) == MAXEXP) && (HIFRACTION(x) || LOFRACTION(x)))
677c478bd9Sstevel@tonic-gate 		return (1);
687c478bd9Sstevel@tonic-gate 	if ((EXPONENT(y) == MAXEXP) && (HIFRACTION(y) || LOFRACTION(y)))
697c478bd9Sstevel@tonic-gate 		return (1);
707c478bd9Sstevel@tonic-gate 	return (0);
717c478bd9Sstevel@tonic-gate }
727c478bd9Sstevel@tonic-gate 
737c478bd9Sstevel@tonic-gate /*
747c478bd9Sstevel@tonic-gate  * FPCLASS(X)
757c478bd9Sstevel@tonic-gate  * fpclass(x) returns the floating point class x belongs to
767c478bd9Sstevel@tonic-gate  */
777c478bd9Sstevel@tonic-gate 
787c478bd9Sstevel@tonic-gate fpclass_t
fpclass(double x)797c478bd9Sstevel@tonic-gate fpclass(double x)
807c478bd9Sstevel@tonic-gate {
817c478bd9Sstevel@tonic-gate 	int	sign, exp;
827c478bd9Sstevel@tonic-gate 
837c478bd9Sstevel@tonic-gate 	exp = EXPONENT(x);
847c478bd9Sstevel@tonic-gate 	sign = SIGNBIT(x);
857c478bd9Sstevel@tonic-gate 	if (exp == 0) { /* de-normal or zero */
867c478bd9Sstevel@tonic-gate 		if (HIFRACTION(x) || LOFRACTION(x)) /* de-normal */
877c478bd9Sstevel@tonic-gate 			return (sign ? FP_NDENORM : FP_PDENORM);
887c478bd9Sstevel@tonic-gate 		else
897c478bd9Sstevel@tonic-gate 			return (sign ? FP_NZERO : FP_PZERO);
907c478bd9Sstevel@tonic-gate 	}
917c478bd9Sstevel@tonic-gate 	if (exp == MAXEXP) { /* infinity or NaN */
927c478bd9Sstevel@tonic-gate 		if ((HIFRACTION(x) == 0) && (LOFRACTION(x) == 0)) /* infinity */
937c478bd9Sstevel@tonic-gate 			return (sign ? FP_NINF : FP_PINF);
947c478bd9Sstevel@tonic-gate 		else
957c478bd9Sstevel@tonic-gate 			if (QNANBIT(x))
967c478bd9Sstevel@tonic-gate 			/* hi-bit of mantissa set - quiet nan */
977c478bd9Sstevel@tonic-gate 				return (FP_QNAN);
987c478bd9Sstevel@tonic-gate 			else	return (FP_SNAN);
997c478bd9Sstevel@tonic-gate 	}
1007c478bd9Sstevel@tonic-gate 	/* if we reach here we have non-zero normalized number */
1017c478bd9Sstevel@tonic-gate 	return (sign ? FP_NNORM : FP_PNORM);
1027c478bd9Sstevel@tonic-gate }
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