153434Sbostic /*- 2*61156Sbostic * Copyright (c) 1992, 1993 3*61156Sbostic * The Regents of the University of California. All rights reserved. 453434Sbostic * 553794Sbostic * This software was developed by the Computer Systems Engineering group 653794Sbostic * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 753794Sbostic * contributed to Berkeley. 853794Sbostic * 953434Sbostic * %sccs.include.redist.c% 1053434Sbostic */ 1153434Sbostic 1253434Sbostic #if defined(LIBC_SCCS) && !defined(lint) 13*61156Sbostic static char sccsid[] = "@(#)ashrdi3.c 8.1 (Berkeley) 06/04/93"; 1453434Sbostic #endif /* LIBC_SCCS and not lint */ 1553434Sbostic 1653794Sbostic #include "quad.h" 1753459Sbostic 1853794Sbostic /* 1953794Sbostic * Shift a (signed) quad value right (arithmetic shift right). 2053794Sbostic */ 2154431Sbostic quad_t __ashrdi3(a,shift)2254431Sbostic__ashrdi3(a, shift) 2354431Sbostic quad_t a; 2454431Sbostic qshift_t shift; 2553434Sbostic { 2653794Sbostic union uu aa; 2753434Sbostic 2853794Sbostic aa.q = a; 2953794Sbostic if (shift >= LONG_BITS) { 3053794Sbostic long s; 3153434Sbostic 3253794Sbostic /* 3353794Sbostic * Smear bits rightward using the machine's right-shift 3453794Sbostic * method, whether that is sign extension or zero fill, 3553794Sbostic * to get the `sign word' s. Note that shifting by 3653794Sbostic * LONG_BITS is undefined, so we shift (LONG_BITS-1), 3753794Sbostic * then 1 more, to get our answer. 3853794Sbostic */ 3953794Sbostic s = (aa.sl[H] >> (LONG_BITS - 1)) >> 1; 4053794Sbostic aa.ul[L] = shift >= QUAD_BITS ? s : 4153794Sbostic aa.sl[H] >> (shift - LONG_BITS); 4253794Sbostic aa.ul[H] = s; 4353794Sbostic } else if (shift > 0) { 4453794Sbostic aa.ul[L] = (aa.ul[L] >> shift) | 4553794Sbostic (aa.ul[H] << (LONG_BITS - shift)); 4653794Sbostic aa.sl[H] >>= shift; 4753794Sbostic } 4853794Sbostic return (aa.q); 4953434Sbostic } 50