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      1 /*	$NetBSD: fpu_getexp.c,v 1.5 2011/07/18 07:44:30 isaki Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1995  Ken Nakata
      5  *	All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. Neither the name of the author nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  *
     31  *	@(#)fpu_getexp.c	10/8/95
     32  */
     33 
     34 #include <sys/cdefs.h>
     35 __KERNEL_RCSID(0, "$NetBSD: fpu_getexp.c,v 1.5 2011/07/18 07:44:30 isaki Exp $");
     36 
     37 #include <sys/types.h>
     38 
     39 #include "fpu_emulate.h"
     40 
     41 struct fpn *
     42 fpu_getexp(struct fpemu *fe)
     43 {
     44 	struct fpn *fp = &fe->fe_f2;
     45 
     46 	fe->fe_fpsr &= ~FPSR_EXCP; /* clear all exceptions */
     47 
     48 	if (fp->fp_class == FPC_INF) {
     49 		fp = fpu_newnan(fe);
     50 		fe->fe_fpsr |= FPSR_OPERR;
     51 	} else if (fp->fp_class == FPC_NUM) { /* a number */
     52 		fpu_explode(fe, &fe->fe_f3, FTYPE_LNG, &fp->fp_exp);
     53 		fp = &fe->fe_f3;
     54 	} else if (fp->fp_class == FPC_SNAN) { /* signaling NaN */
     55 		fe->fe_fpsr |= FPSR_SNAN;
     56 	} /* else if fp == zero or fp == quiet NaN, return itself */
     57 	return fp;
     58 }
     59 
     60 struct fpn *
     61 fpu_getman(struct fpemu *fe)
     62 {
     63 	struct fpn *fp = &fe->fe_f2;
     64 
     65 	fe->fe_fpsr &= ~FPSR_EXCP; /* clear all exceptions */
     66 
     67 	if (fp->fp_class == FPC_INF) {
     68 		fp = fpu_newnan(fe);
     69 		fe->fe_fpsr |= FPSR_OPERR;
     70 	} else if (fp->fp_class == FPC_NUM) { /* a number */
     71 		fp->fp_exp = 0;
     72 	} else if (fp->fp_class == FPC_SNAN) { /* signaling NaN */
     73 		fe->fe_fpsr |= FPSR_SNAN;
     74 	} /* else if fp == zero or fp == quiet NaN, return itself */
     75 	return fp;
     76 }
     77