1 /* $NetBSD: ashrdi3.c,v 1.4 2012/08/06 02:31:54 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 #if 0 39 static char sccsid[] = "@(#)ashrdi3.c 8.1 (Berkeley) 6/4/93"; 40 #else 41 __RCSID("$NetBSD: ashrdi3.c,v 1.4 2012/08/06 02:31:54 matt Exp $"); 42 #endif 43 #endif /* LIBC_SCCS and not lint */ 44 45 #include "quad.h" 46 47 ARM_EABI_ALIAS(__aeabi_lasr, __ashrdi3) /* no semicolon */ 48 49 /* 50 * Shift a (signed) quad value right (arithmetic shift right). 51 */ 52 quad_t 53 __ashrdi3(quad_t a, qshift_t shift) 54 { 55 union uu aa; 56 57 if (shift == 0) 58 return(a); 59 aa.q = a; 60 if (shift >= INT_BITS) { 61 int s; 62 63 /* 64 * Smear bits rightward using the machine's right-shift 65 * method, whether that is sign extension or zero fill, 66 * to get the `sign word' s. Note that shifting by 67 * INT_BITS is undefined, so we shift (INT_BITS-1), 68 * then 1 more, to get our answer. 69 */ 70 /* LINTED inherits machine dependency */ 71 s = (aa.sl[H] >> (INT_BITS - 1)) >> 1; 72 /* LINTED inherits machine dependency*/ 73 aa.ul[L] = aa.sl[H] >> (shift - INT_BITS); 74 aa.ul[H] = s; 75 } else { 76 aa.ul[L] = (aa.ul[L] >> shift) | 77 (aa.ul[H] << (unsigned int)(INT_BITS - shift)); 78 /* LINTED inherits machine dependency */ 79 aa.sl[H] >>= shift; 80 } 81 return (aa.q); 82 } 83