1df8bae1dSRodney W. Grimes /*- 2df8bae1dSRodney W. Grimes * Copyright (c) 1992, 1993 3df8bae1dSRodney W. Grimes * The Regents of the University of California. All rights reserved. 4df8bae1dSRodney W. Grimes * 5df8bae1dSRodney W. Grimes * This software was developed by the Computer Systems Engineering group 6df8bae1dSRodney W. Grimes * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 7df8bae1dSRodney W. Grimes * contributed to Berkeley. 8df8bae1dSRodney W. Grimes * 9df8bae1dSRodney W. Grimes * Redistribution and use in source and binary forms, with or without 10df8bae1dSRodney W. Grimes * modification, are permitted provided that the following conditions 11df8bae1dSRodney W. Grimes * are met: 12df8bae1dSRodney W. Grimes * 1. Redistributions of source code must retain the above copyright 13df8bae1dSRodney W. Grimes * notice, this list of conditions and the following disclaimer. 14df8bae1dSRodney W. Grimes * 2. Redistributions in binary form must reproduce the above copyright 15df8bae1dSRodney W. Grimes * notice, this list of conditions and the following disclaimer in the 16df8bae1dSRodney W. Grimes * documentation and/or other materials provided with the distribution. 17fbbd9655SWarner Losh * 3. Neither the name of the University nor the names of its contributors 18df8bae1dSRodney W. Grimes * may be used to endorse or promote products derived from this software 19df8bae1dSRodney W. Grimes * without specific prior written permission. 20df8bae1dSRodney W. Grimes * 21df8bae1dSRodney W. Grimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22df8bae1dSRodney W. Grimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23df8bae1dSRodney W. Grimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24df8bae1dSRodney W. Grimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25df8bae1dSRodney W. Grimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26df8bae1dSRodney W. Grimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27df8bae1dSRodney W. Grimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28df8bae1dSRodney W. Grimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29df8bae1dSRodney W. Grimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30df8bae1dSRodney W. Grimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31df8bae1dSRodney W. Grimes * SUCH DAMAGE. 32df8bae1dSRodney W. Grimes */ 33df8bae1dSRodney W. Grimes 34ab0de15bSDavid E. O'Brien #include <sys/cdefs.h> 35ab0de15bSDavid E. O'Brien __FBSDID("$FreeBSD$"); 36ab0de15bSDavid E. O'Brien 37aab719f0SBenno Rice #include <libkern/quad.h> 38df8bae1dSRodney W. Grimes 39df8bae1dSRodney W. Grimes /* 40df8bae1dSRodney W. Grimes * Shift a (signed) quad value right (arithmetic shift right). 41df8bae1dSRodney W. Grimes */ 42df8bae1dSRodney W. Grimes quad_t 43*4a8dea8cSEd Maste __ashrdi3(quad_t a, qshift_t shift) 44df8bae1dSRodney W. Grimes { 45df8bae1dSRodney W. Grimes union uu aa; 46df8bae1dSRodney W. Grimes 47df8bae1dSRodney W. Grimes aa.q = a; 48df8bae1dSRodney W. Grimes if (shift >= LONG_BITS) { 49df8bae1dSRodney W. Grimes long s; 50df8bae1dSRodney W. Grimes 51df8bae1dSRodney W. Grimes /* 52df8bae1dSRodney W. Grimes * Smear bits rightward using the machine's right-shift 53df8bae1dSRodney W. Grimes * method, whether that is sign extension or zero fill, 54df8bae1dSRodney W. Grimes * to get the `sign word' s. Note that shifting by 55df8bae1dSRodney W. Grimes * LONG_BITS is undefined, so we shift (LONG_BITS-1), 56df8bae1dSRodney W. Grimes * then 1 more, to get our answer. 57df8bae1dSRodney W. Grimes */ 58df8bae1dSRodney W. Grimes s = (aa.sl[H] >> (LONG_BITS - 1)) >> 1; 59df8bae1dSRodney W. Grimes aa.ul[L] = shift >= QUAD_BITS ? s : 60df8bae1dSRodney W. Grimes aa.sl[H] >> (shift - LONG_BITS); 61df8bae1dSRodney W. Grimes aa.ul[H] = s; 62df8bae1dSRodney W. Grimes } else if (shift > 0) { 63df8bae1dSRodney W. Grimes aa.ul[L] = (aa.ul[L] >> shift) | 64df8bae1dSRodney W. Grimes (aa.ul[H] << (LONG_BITS - shift)); 65df8bae1dSRodney W. Grimes aa.sl[H] >>= shift; 66df8bae1dSRodney W. Grimes } 67df8bae1dSRodney W. Grimes return (aa.q); 68df8bae1dSRodney W. Grimes } 69