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      1 /*-
      2  * Copyright (c) 2003, Steven G. Kargl
      3  * All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice unmodified, this list of conditions, and the following
     10  *    disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  *
     15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     25  */
     26 
     27 #include <sys/cdefs.h>
     28 __FBSDID("$FreeBSD$");
     29 
     30 #include <float.h>
     31 #ifdef __i386__
     32 #include <ieeefp.h>
     33 #endif
     34 
     35 #include "fpmath.h"
     36 #include "math.h"
     37 #include "math_private.h"
     38 
     39 long double
     40 roundl(long double x)
     41 {
     42 	long double t;
     43 	uint16_t hx;
     44 
     45 	GET_LDBL_EXPSIGN(hx, x);
     46 	if ((hx & 0x7fff) == 0x7fff)
     47 		return (x + x);
     48 
     49 	ENTERI();
     50 
     51 	if (!(hx & 0x8000)) {
     52 		t = floorl(x);
     53 		if (t - x <= -0.5L)
     54 			t += 1;
     55 		RETURNI(t);
     56 	} else {
     57 		t = floorl(-x);
     58 		if (t + x <= -0.5L)
     59 			t += 1;
     60 		RETURNI(-t);
     61 	}
     62 }
     63