quad.h revision 1.1
1/* $NetBSD: quad.h,v 1.4.2.1 1995/10/12 15:17:26 jtc 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. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the University of 22 * California, Berkeley and its contributors. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 * 39 * @(#)quad.h 8.1 (Berkeley) 6/4/93 40 */ 41 42/* 43 * Quad arithmetic. 44 * 45 * This library makes the following assumptions: 46 * 47 * - The type long long (aka quad_t) exists. 48 * 49 * - A quad variable is exactly twice as long as `long'. 50 * 51 * - The machine's arithmetic is two's complement. 52 * 53 * This library can provide 128-bit arithmetic on a machine with 128-bit 54 * quads and 64-bit longs, for instance, or 96-bit arithmetic on machines 55 * with 48-bit longs. 56 */ 57 58#include <sys/types.h> 59#include <limits.h> 60 61/* 62 * Depending on the desired operation, we view a `long long' (aka quad_t) in 63 * one or more of the following formats. 64 */ 65union uu { 66 quad_t q; /* as a (signed) quad */ 67 u_quad_t uq; /* as an unsigned quad */ 68 long sl[2]; /* as two signed longs */ 69 u_long ul[2]; /* as two unsigned longs */ 70}; 71 72/* 73 * Define high and low longwords. 74 */ 75#define H _QUAD_HIGHWORD 76#define L _QUAD_LOWWORD 77 78/* 79 * Total number of bits in a quad_t and in the pieces that make it up. 80 * These are used for shifting, and also below for halfword extraction 81 * and assembly. 82 */ 83#define QUAD_BITS (sizeof(quad_t) * CHAR_BIT) 84#define LONG_BITS (sizeof(long) * CHAR_BIT) 85#define HALF_BITS (sizeof(long) * CHAR_BIT / 2) 86 87/* 88 * Extract high and low shortwords from longword, and move low shortword of 89 * longword to upper half of long, i.e., produce the upper longword of 90 * ((quad_t)(x) << (number_of_bits_in_long/2)). (`x' must actually be u_long.) 91 * 92 * These are used in the multiply code, to split a longword into upper 93 * and lower halves, and to reassemble a product as a quad_t, shifted left 94 * (sizeof(long)*CHAR_BIT/2). 95 */ 96#define HHALF(x) ((u_long)(x) >> HALF_BITS) 97#define LHALF(x) ((u_long)(x) & (((long)1 << HALF_BITS) - 1)) 98#define LHUP(x) ((u_long)(x) << HALF_BITS) 99 100extern u_quad_t __qdivrem __P((u_quad_t u, u_quad_t v, u_quad_t *rem)); 101 102/* 103 * XXX 104 * Compensate for gcc 1 vs gcc 2. Gcc 1 defines ?sh?di3's second argument 105 * as u_quad_t, while gcc 2 correctly uses int. Unfortunately, we still use 106 * both compilers. 107 */ 108#if __GNUC__ >= 2 109typedef unsigned int qshift_t; 110#else 111typedef u_quad_t qshift_t; 112#endif 113