11573Srgrimes/*- 21573Srgrimes * Copyright (c) 1992, 1993 31573Srgrimes * The Regents of the University of California. All rights reserved. 41573Srgrimes * 51573Srgrimes * This software was developed by the Computer Systems Engineering group 61573Srgrimes * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 71573Srgrimes * contributed to Berkeley. 81573Srgrimes * 91573Srgrimes * Redistribution and use in source and binary forms, with or without 101573Srgrimes * modification, are permitted provided that the following conditions 111573Srgrimes * are met: 121573Srgrimes * 1. Redistributions of source code must retain the above copyright 131573Srgrimes * notice, this list of conditions and the following disclaimer. 141573Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 151573Srgrimes * notice, this list of conditions and the following disclaimer in the 161573Srgrimes * documentation and/or other materials provided with the distribution. 171573Srgrimes * 4. Neither the name of the University nor the names of its contributors 181573Srgrimes * may be used to endorse or promote products derived from this software 191573Srgrimes * without specific prior written permission. 201573Srgrimes * 211573Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 221573Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 231573Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 241573Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 251573Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 261573Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 271573Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 281573Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 291573Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 301573Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 311573Srgrimes * SUCH DAMAGE. 321573Srgrimes */ 331573Srgrimes 341573Srgrimes#if defined(LIBC_SCCS) && !defined(lint) 351573Srgrimesstatic char sccsid[] = "@(#)ashrdi3.c 8.1 (Berkeley) 6/4/93"; 361573Srgrimes#endif /* LIBC_SCCS and not lint */ 3792986Sobrien#include <sys/cdefs.h> 3892986Sobrien__FBSDID("$FreeBSD$"); 391573Srgrimes 401573Srgrimes#include "quad.h" 411573Srgrimes 421573Srgrimes/* 431573Srgrimes * Shift a (signed) quad value right (arithmetic shift right). 441573Srgrimes */ 451573Srgrimesquad_t 461573Srgrimes__ashrdi3(a, shift) 471573Srgrimes quad_t a; 481573Srgrimes qshift_t shift; 491573Srgrimes{ 501573Srgrimes union uu aa; 511573Srgrimes 521573Srgrimes aa.q = a; 531573Srgrimes if (shift >= LONG_BITS) { 541573Srgrimes long s; 551573Srgrimes 561573Srgrimes /* 571573Srgrimes * Smear bits rightward using the machine's right-shift 581573Srgrimes * method, whether that is sign extension or zero fill, 591573Srgrimes * to get the `sign word' s. Note that shifting by 601573Srgrimes * LONG_BITS is undefined, so we shift (LONG_BITS-1), 611573Srgrimes * then 1 more, to get our answer. 621573Srgrimes */ 631573Srgrimes s = (aa.sl[H] >> (LONG_BITS - 1)) >> 1; 641573Srgrimes aa.ul[L] = shift >= QUAD_BITS ? s : 651573Srgrimes aa.sl[H] >> (shift - LONG_BITS); 661573Srgrimes aa.ul[H] = s; 671573Srgrimes } else if (shift > 0) { 681573Srgrimes aa.ul[L] = (aa.ul[L] >> shift) | 691573Srgrimes (aa.ul[H] << (LONG_BITS - shift)); 701573Srgrimes aa.sl[H] >>= shift; 711573Srgrimes } 721573Srgrimes return (aa.q); 731573Srgrimes} 74