153444Sbostic /*- 253444Sbostic * Copyright (c) 1992 The Regents of the University of California. 353444Sbostic * All rights reserved. 453444Sbostic * 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 * 953444Sbostic * %sccs.include.redist.c% 1053444Sbostic */ 1153444Sbostic 1253444Sbostic #if defined(LIBC_SCCS) && !defined(lint) 13*54431Sbostic static char sccsid[] = "@(#)subdi3.c 5.5 (Berkeley) 06/25/92"; 1453444Sbostic #endif /* LIBC_SCCS and not lint */ 1553444Sbostic 1653794Sbostic #include "quad.h" 1753459Sbostic 1853794Sbostic /* 1953794Sbostic * Subtract two quad values. This is trivial since a one-bit carry 2053794Sbostic * from a single u_long difference x-y occurs if and only if (x-y) > x. 2153794Sbostic */ 22*54431Sbostic quad_t 23*54431Sbostic __subdi3(a, b) 24*54431Sbostic quad_t a, b; 2553444Sbostic { 2653794Sbostic union uu aa, bb, diff; 2753444Sbostic 2853794Sbostic aa.q = a; 2953794Sbostic bb.q = b; 3053794Sbostic diff.ul[L] = aa.ul[L] - bb.ul[L]; 3153794Sbostic diff.ul[H] = aa.ul[H] - bb.ul[H] - (diff.ul[L] > aa.ul[L]); 3253794Sbostic return (diff.q); 3353444Sbostic } 34