54 lines
		
	
	
	
		
			1.4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
		
		
			
		
	
	
			54 lines
		
	
	
	
		
			1.4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
|   | /* IEEE754 floating point arithmetic
 | ||
|  |  * double precision: common utilities | ||
|  |  */ | ||
|  | /*
 | ||
|  |  * MIPS floating point support | ||
|  |  * Copyright (C) 1994-2000 Algorithmics Ltd. | ||
|  |  * http://www.algor.co.uk
 | ||
|  |  * | ||
|  |  * ######################################################################## | ||
|  |  * | ||
|  |  *  This program is free software; you can distribute it and/or modify it | ||
|  |  *  under the terms of the GNU General Public License (Version 2) as | ||
|  |  *  published by the Free Software Foundation. | ||
|  |  * | ||
|  |  *  This program is distributed in the hope it will be useful, but WITHOUT | ||
|  |  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | ||
|  |  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License | ||
|  |  *  for more details. | ||
|  |  * | ||
|  |  *  You should have received a copy of the GNU General Public License along | ||
|  |  *  with this program; if not, write to the Free Software Foundation, Inc., | ||
|  |  *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA. | ||
|  |  * | ||
|  |  * ######################################################################## | ||
|  |  */ | ||
|  | 
 | ||
|  | 
 | ||
|  | #include "ieee754dp.h"
 | ||
|  | 
 | ||
|  | /* close to ieeep754dp_logb
 | ||
|  | */ | ||
|  | ieee754dp ieee754dp_frexp(ieee754dp x, int *eptr) | ||
|  | { | ||
|  | 	COMPXDP; | ||
|  | 	CLEARCX; | ||
|  | 	EXPLODEXDP; | ||
|  | 
 | ||
|  | 	switch (xc) { | ||
|  | 	case IEEE754_CLASS_SNAN: | ||
|  | 	case IEEE754_CLASS_QNAN: | ||
|  | 	case IEEE754_CLASS_INF: | ||
|  | 	case IEEE754_CLASS_ZERO: | ||
|  | 		*eptr = 0; | ||
|  | 		return x; | ||
|  | 	case IEEE754_CLASS_DNORM: | ||
|  | 		DPDNORMX; | ||
|  | 		break; | ||
|  | 	case IEEE754_CLASS_NORM: | ||
|  | 		break; | ||
|  | 	} | ||
|  | 	*eptr = xe + 1; | ||
|  | 	return builddp(xs, -1 + DP_EBIAS, xm & ~DP_HIDDEN_BIT); | ||
|  | } |