11dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project/* $OpenBSD: div.c,v 1.5 2005/08/08 08:05:36 espie Exp $ */ 21dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project/* 31dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Copyright (c) 1990 Regents of the University of California. 41dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * All rights reserved. 51dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 61dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * This code is derived from software contributed to Berkeley by 71dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Chris Torek. 81dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 91dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Redistribution and use in source and binary forms, with or without 101dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * modification, are permitted provided that the following conditions 111dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * are met: 121dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 1. Redistributions of source code must retain the above copyright 131dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * notice, this list of conditions and the following disclaimer. 141dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 2. Redistributions in binary form must reproduce the above copyright 151dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * notice, this list of conditions and the following disclaimer in the 161dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * documentation and/or other materials provided with the distribution. 171dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 3. Neither the name of the University nor the names of its contributors 181dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * may be used to endorse or promote products derived from this software 191dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * without specific prior written permission. 201dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 211dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 221dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 231dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 241dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 251dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 261dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 271dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 281dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 291dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 301dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 311dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * SUCH DAMAGE. 321dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 331dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 341dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include <stdlib.h> /* div_t */ 351dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 361dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Projectdiv_t 371dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Projectdiv(int num, int denom) 381dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project{ 391dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project div_t r; 401dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 411dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project r.quot = num / denom; 421dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project r.rem = num % denom; 431dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* 441dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * The ANSI standard says that |r.quot| <= |n/d|, where 451dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * n/d is to be computed in infinite precision. In other 461dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * words, we should always truncate the quotient towards 471dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 0, never -infinity. 481dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 491dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Machine division and remainer may work either way when 501dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * one or both of n or d is negative. If only one is 511dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * negative and r.quot has been truncated towards -inf, 521dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * r.rem will have the same sign as denom and the opposite 531dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * sign of num; if both are negative and r.quot has been 541dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * truncated towards -inf, r.rem will be positive (will 551dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * have the opposite sign of num). These are considered 561dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * `wrong'. 571dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 581dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * If both are num and denom are positive, r will always 591dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * be positive. 601dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 611dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * This all boils down to: 621dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * if num >= 0, but r.rem < 0, we got the wrong answer. 631dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * In that case, to get the right answer, add 1 to r.quot and 641dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * subtract denom from r.rem. 651dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 661dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (num >= 0 && r.rem < 0) { 671dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project r.quot++; 681dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project r.rem -= denom; 691dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 701dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (r); 711dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project} 72