quad.h revision 1541
11541Srgrimes/*- 21541Srgrimes * Copyright (c) 1992, 1993 31541Srgrimes * The Regents of the University of California. All rights reserved. 41541Srgrimes * 51541Srgrimes * This software was developed by the Computer Systems Engineering group 61541Srgrimes * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 71541Srgrimes * contributed to Berkeley. 81541Srgrimes * 91541Srgrimes * Redistribution and use in source and binary forms, with or without 101541Srgrimes * modification, are permitted provided that the following conditions 111541Srgrimes * are met: 121541Srgrimes * 1. Redistributions of source code must retain the above copyright 131541Srgrimes * notice, this list of conditions and the following disclaimer. 141541Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 151541Srgrimes * notice, this list of conditions and the following disclaimer in the 161541Srgrimes * documentation and/or other materials provided with the distribution. 171541Srgrimes * 3. All advertising materials mentioning features or use of this software 181541Srgrimes * must display the following acknowledgement: 191541Srgrimes * This product includes software developed by the University of 201541Srgrimes * California, Berkeley and its contributors. 211541Srgrimes * 4. Neither the name of the University nor the names of its contributors 221541Srgrimes * may be used to endorse or promote products derived from this software 231541Srgrimes * without specific prior written permission. 241541Srgrimes * 251541Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 261541Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 271541Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 281541Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 291541Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 301541Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 311541Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 321541Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 331541Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 341541Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 351541Srgrimes * SUCH DAMAGE. 361541Srgrimes * 371541Srgrimes * @(#)quad.h 8.1 (Berkeley) 6/4/93 381541Srgrimes */ 391541Srgrimes 401541Srgrimes/* 411541Srgrimes * Quad arithmetic. 421541Srgrimes * 431541Srgrimes * This library makes the following assumptions: 441541Srgrimes * 451541Srgrimes * - The type long long (aka quad_t) exists. 461541Srgrimes * 471541Srgrimes * - A quad variable is exactly twice as long as `long'. 481541Srgrimes * 491541Srgrimes * - The machine's arithmetic is two's complement. 501541Srgrimes * 511541Srgrimes * This library can provide 128-bit arithmetic on a machine with 128-bit 521541Srgrimes * quads and 64-bit longs, for instance, or 96-bit arithmetic on machines 531541Srgrimes * with 48-bit longs. 541541Srgrimes */ 551541Srgrimes 561541Srgrimes#include <sys/types.h> 571541Srgrimes#include <limits.h> 581541Srgrimes 591541Srgrimes/* 601541Srgrimes * Depending on the desired operation, we view a `long long' (aka quad_t) in 611541Srgrimes * one or more of the following formats. 621541Srgrimes */ 631541Srgrimesunion uu { 641541Srgrimes quad_t q; /* as a (signed) quad */ 651541Srgrimes quad_t uq; /* as an unsigned quad */ 661541Srgrimes long sl[2]; /* as two signed longs */ 671541Srgrimes u_long ul[2]; /* as two unsigned longs */ 681541Srgrimes}; 691541Srgrimes 701541Srgrimes/* 711541Srgrimes * Define high and low longwords. 721541Srgrimes */ 731541Srgrimes#define H _QUAD_HIGHWORD 741541Srgrimes#define L _QUAD_LOWWORD 751541Srgrimes 761541Srgrimes/* 771541Srgrimes * Total number of bits in a quad_t and in the pieces that make it up. 781541Srgrimes * These are used for shifting, and also below for halfword extraction 791541Srgrimes * and assembly. 801541Srgrimes */ 811541Srgrimes#define QUAD_BITS (sizeof(quad_t) * CHAR_BIT) 821541Srgrimes#define LONG_BITS (sizeof(long) * CHAR_BIT) 831541Srgrimes#define HALF_BITS (sizeof(long) * CHAR_BIT / 2) 841541Srgrimes 851541Srgrimes/* 861541Srgrimes * Extract high and low shortwords from longword, and move low shortword of 871541Srgrimes * longword to upper half of long, i.e., produce the upper longword of 881541Srgrimes * ((quad_t)(x) << (number_of_bits_in_long/2)). (`x' must actually be u_long.) 891541Srgrimes * 901541Srgrimes * These are used in the multiply code, to split a longword into upper 911541Srgrimes * and lower halves, and to reassemble a product as a quad_t, shifted left 921541Srgrimes * (sizeof(long)*CHAR_BIT/2). 931541Srgrimes */ 941541Srgrimes#define HHALF(x) ((x) >> HALF_BITS) 951541Srgrimes#define LHALF(x) ((x) & ((1 << HALF_BITS) - 1)) 961541Srgrimes#define LHUP(x) ((x) << HALF_BITS) 971541Srgrimes 981541Srgrimesextern u_quad_t __qdivrem __P((u_quad_t u, u_quad_t v, u_quad_t *rem)); 991541Srgrimes 1001541Srgrimes/* 1011541Srgrimes * XXX 1021541Srgrimes * Compensate for gcc 1 vs gcc 2. Gcc 1 defines ?sh?di3's second argument 1031541Srgrimes * as u_quad_t, while gcc 2 correctly uses int. Unfortunately, we still use 1041541Srgrimes * both compilers. 1051541Srgrimes */ 1061541Srgrimes#if __GNUC__ >= 2 1071541Srgrimestypedef unsigned int qshift_t; 1081541Srgrimes#else 1091541Srgrimestypedef u_quad_t qshift_t; 1101541Srgrimes#endif 111