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/* $OpenBSD: ashrdi3.c,v 1.7 2015/10/01 02:32:07 guenther Exp $ */
/*-
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This software was developed by the Computer Systems Engineering group
* at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
* contributed to Berkeley.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "quad.h"
/*
* Shift a (signed) quad value right (arithmetic shift right).
*/
quad_t
__ashrdi3(quad_t a, qshift_t shift)
{
union uu aa;
if (shift == 0)
return(a);
aa.q = a;
if (shift >= INT_BITS) {
int s;
/*
* Smear bits rightward using the machine's right-shift
* method, whether that is sign extension or zero fill,
* to get the `sign word' s. Note that shifting by
* INT_BITS is undefined, so we shift (INT_BITS-1),
* then 1 more, to get our answer.
*/
s = (aa.sl[H] >> (INT_BITS - 1)) >> 1;
aa.ul[L] = aa.sl[H] >> (shift - INT_BITS);
aa.ul[H] = s;
} else {
aa.ul[L] = (aa.ul[L] >> shift) |
(aa.ul[H] << (INT_BITS - shift));
aa.sl[H] >>= shift;
}
return (aa.q);
}
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