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      1 /*	$NetBSD: fixunssfdi_ieee754.c,v 1.1 2013/08/24 00:51:48 matt Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1992, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This software was developed by the Computer Systems Engineering group
      8  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
      9  * contributed to Berkeley.
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  * 2. Redistributions in binary form must reproduce the above copyright
     17  *    notice, this list of conditions and the following disclaimer in the
     18  *    documentation and/or other materials provided with the distribution.
     19  * 3. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 #if defined(LIBC_SCCS) && !defined(lint)
     38 __RCSID("$NetBSD: fixunssfdi_ieee754.c,v 1.1 2013/08/24 00:51:48 matt Exp $");
     39 #endif /* LIBC_SCCS and not lint */
     40 
     41 #if defined(SOFTFLOAT) || defined(__ARM_EABI__)
     42 #include "softfloat/softfloat-for-gcc.h"
     43 #endif
     44 
     45 #include "quad.h"
     46 #include <limits.h>
     47 #include <machine/ieee.h>
     48 
     49 /*
     50  * Convert float to unsigned quad.
     51  * Not sure what to do with negative numbers---for now, anything out
     52  * of range becomes UQUAD_MAX.
     53  */
     54 u_quad_t
     55 __fixunssfdi(float x)
     56 {
     57 	const union ieee_single_u ux = { .sngu_f = x };
     58 	signed int exp = ux.sngu_exp - SNG_EXP_BIAS;
     59 	u_quad_t r;
     60 
     61 	if (ux.sngu_sign)
     62 		return UQUAD_MAX;
     63 	if (exp > 63)
     64 		return UQUAD_MAX;
     65 	if (exp < 0)
     66 		return 0;
     67 
     68 	r = 1 << SNG_FRACBITS;		/* implicit bit */
     69 	r |= ux.sngu_frac;
     70 	exp -= SNG_FRACBITS;
     71 	if (exp == 0)
     72 		return r;
     73 	if (exp < 0)
     74 		return r >> -exp;
     75 
     76 	return r << exp;
     77 }
     78