quad.h revision 128019
1219820Sjeff/*- 2219820Sjeff * Copyright (c) 1992, 1993 3219820Sjeff * The Regents of the University of California. All rights reserved. 4219820Sjeff * 5219820Sjeff * This software was developed by the Computer Systems Engineering group 6219820Sjeff * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 7219820Sjeff * contributed to Berkeley. 8219820Sjeff * 9219820Sjeff * Redistribution and use in source and binary forms, with or without 10219820Sjeff * modification, are permitted provided that the following conditions 11219820Sjeff * are met: 12219820Sjeff * 1. Redistributions of source code must retain the above copyright 13219820Sjeff * notice, this list of conditions and the following disclaimer. 14219820Sjeff * 2. Redistributions in binary form must reproduce the above copyright 15219820Sjeff * notice, this list of conditions and the following disclaimer in the 16219820Sjeff * documentation and/or other materials provided with the distribution. 17219820Sjeff * 4. Neither the name of the University nor the names of its contributors 18219820Sjeff * may be used to endorse or promote products derived from this software 19219820Sjeff * without specific prior written permission. 20219820Sjeff * 21219820Sjeff * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22219820Sjeff * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23219820Sjeff * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24219820Sjeff * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25219820Sjeff * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26219820Sjeff * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27219820Sjeff * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28219820Sjeff * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29219820Sjeff * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30219820Sjeff * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31219820Sjeff * SUCH DAMAGE. 32219820Sjeff * 33219820Sjeff * @(#)quad.h 8.1 (Berkeley) 6/4/93 34219820Sjeff * $FreeBSD: head/sys/libkern/quad.h 128019 2004-04-07 20:46:16Z imp $ 35219820Sjeff */ 36219820Sjeff 37219820Sjeff#ifndef _LIBKERN_QUAD_H 38219820Sjeff#define _LIBKERN_QUAD_H 39219820Sjeff 40219820Sjeff/* 41219820Sjeff * Quad arithmetic. 42219820Sjeff * 43219820Sjeff * This library makes the following assumptions: 44219820Sjeff * 45219820Sjeff * - The type long long (aka quad_t) exists. 46219820Sjeff * 47219820Sjeff * - A quad variable is exactly twice as long as `long'. 48219820Sjeff * 49219820Sjeff * - The machine's arithmetic is two's complement. 50219820Sjeff * 51219820Sjeff * This library can provide 128-bit arithmetic on a machine with 128-bit 52219820Sjeff * quads and 64-bit longs, for instance, or 96-bit arithmetic on machines 53219820Sjeff * with 48-bit longs. 54219820Sjeff */ 55219820Sjeff 56219820Sjeff#include <sys/cdefs.h> 57219820Sjeff#include <sys/types.h> 58219820Sjeff#include <sys/limits.h> 59219820Sjeff#include <sys/syslimits.h> 60219820Sjeff 61219820Sjeff/* 62219820Sjeff * Depending on the desired operation, we view a `long long' (aka quad_t) in 63219820Sjeff * one or more of the following formats. 64219820Sjeff */ 65219820Sjeffunion uu { 66219820Sjeff quad_t q; /* as a (signed) quad */ 67219820Sjeff quad_t uq; /* as an unsigned quad */ 68219820Sjeff long sl[2]; /* as two signed longs */ 69219820Sjeff u_long ul[2]; /* as two unsigned longs */ 70219820Sjeff}; 71219820Sjeff 72219820Sjeff/* 73219820Sjeff * Define high and low longwords. 74219820Sjeff */ 75219820Sjeff#define H _QUAD_HIGHWORD 76219820Sjeff#define L _QUAD_LOWWORD 77219820Sjeff 78219820Sjeff/* 79219820Sjeff * Total number of bits in a quad_t and in the pieces that make it up. 80219820Sjeff * These are used for shifting, and also below for halfword extraction 81219820Sjeff * and assembly. 82219820Sjeff */ 83219820Sjeff#define QUAD_BITS (sizeof(quad_t) * CHAR_BIT) 84219820Sjeff#define LONG_BITS (sizeof(long) * CHAR_BIT) 85219820Sjeff#define HALF_BITS (sizeof(long) * CHAR_BIT / 2) 86219820Sjeff 87219820Sjeff/* 88219820Sjeff * Extract high and low shortwords from longword, and move low shortword of 89219820Sjeff * longword to upper half of long, i.e., produce the upper longword of 90219820Sjeff * ((quad_t)(x) << (number_of_bits_in_long/2)). (`x' must actually be u_long.) 91219820Sjeff * 92219820Sjeff * These are used in the multiply code, to split a longword into upper 93219820Sjeff * and lower halves, and to reassemble a product as a quad_t, shifted left 94219820Sjeff * (sizeof(long)*CHAR_BIT/2). 95219820Sjeff */ 96219820Sjeff#define HHALF(x) ((x) >> HALF_BITS) 97219820Sjeff#define LHALF(x) ((x) & ((1 << HALF_BITS) - 1)) 98219820Sjeff#define LHUP(x) ((x) << HALF_BITS) 99219820Sjeff 100219820Sjeffquad_t __divdi3(quad_t a, quad_t b); 101219820Sjeffquad_t __moddi3(quad_t a, quad_t b); 102219820Sjeffu_quad_t __qdivrem(u_quad_t u, u_quad_t v, u_quad_t *rem); 103219820Sjeffu_quad_t __udivdi3(u_quad_t a, u_quad_t b); 104219820Sjeffu_quad_t __umoddi3(u_quad_t a, u_quad_t b); 105219820Sjeffint __ucmpdi2(u_quad_t a, u_quad_t b); 106219820Sjeff 107219820Sjefftypedef unsigned int qshift_t; 108219820Sjeff#endif /* _LIBKERN_QUAD_H */ 109219820Sjeff