quad.h revision 50477
1240116Smarcel/*- 2240116Smarcel * Copyright (c) 1992, 1993 3240116Smarcel * The Regents of the University of California. All rights reserved. 4240116Smarcel * 5240116Smarcel * This software was developed by the Computer Systems Engineering group 6240116Smarcel * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 7240116Smarcel * contributed to Berkeley. 8240116Smarcel * 9240116Smarcel * Redistribution and use in source and binary forms, with or without 10240116Smarcel * modification, are permitted provided that the following conditions 11240116Smarcel * are met: 12240116Smarcel * 1. Redistributions of source code must retain the above copyright 13240116Smarcel * notice, this list of conditions and the following disclaimer. 14240116Smarcel * 2. Redistributions in binary form must reproduce the above copyright 15240116Smarcel * notice, this list of conditions and the following disclaimer in the 16240116Smarcel * documentation and/or other materials provided with the distribution. 17240116Smarcel * 3. All advertising materials mentioning features or use of this software 18240116Smarcel * must display the following acknowledgement: 19240116Smarcel * This product includes software developed by the University of 20240116Smarcel * California, Berkeley and its contributors. 21240116Smarcel * 4. Neither the name of the University nor the names of its contributors 22240116Smarcel * may be used to endorse or promote products derived from this software 23240116Smarcel * without specific prior written permission. 24240116Smarcel * 25240116Smarcel * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26240116Smarcel * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27240116Smarcel * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28240116Smarcel * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29240116Smarcel * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30240116Smarcel * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31240116Smarcel * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32240116Smarcel * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33240116Smarcel * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34240116Smarcel * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35240116Smarcel * SUCH DAMAGE. 36240116Smarcel * 37240116Smarcel * @(#)quad.h 8.1 (Berkeley) 6/4/93 38240116Smarcel * $FreeBSD: head/sys/libkern/quad.h 50477 1999-08-28 01:08:13Z peter $ 39240116Smarcel */ 40240116Smarcel 41240116Smarcel/* 42240116Smarcel * Quad arithmetic. 43240116Smarcel * 44240116Smarcel * This library makes the following assumptions: 45240116Smarcel * 46240116Smarcel * - The type long long (aka quad_t) exists. 47240116Smarcel * 48240116Smarcel * - A quad variable is exactly twice as long as `long'. 49240116Smarcel * 50240116Smarcel * - The machine's arithmetic is two's complement. 51240116Smarcel * 52240116Smarcel * This library can provide 128-bit arithmetic on a machine with 128-bit 53240116Smarcel * quads and 64-bit longs, for instance, or 96-bit arithmetic on machines 54240116Smarcel * with 48-bit longs. 55240116Smarcel */ 56240116Smarcel 57240116Smarcel#include <sys/cdefs.h> 58240116Smarcel#include <sys/types.h> 59240116Smarcel#include <limits.h> 60240116Smarcel 61240116Smarcel/* 62240116Smarcel * Depending on the desired operation, we view a `long long' (aka quad_t) in 63240116Smarcel * one or more of the following formats. 64240116Smarcel */ 65240116Smarcelunion uu { 66240116Smarcel quad_t q; /* as a (signed) quad */ 67240116Smarcel quad_t uq; /* as an unsigned quad */ 68240116Smarcel long sl[2]; /* as two signed longs */ 69240116Smarcel u_long ul[2]; /* as two unsigned longs */ 70240116Smarcel}; 71240116Smarcel 72240116Smarcel/* 73240116Smarcel * Define high and low longwords. 74240116Smarcel */ 75240116Smarcel#define H _QUAD_HIGHWORD 76240116Smarcel#define L _QUAD_LOWWORD 77240116Smarcel 78240116Smarcel/* 79240116Smarcel * Total number of bits in a quad_t and in the pieces that make it up. 80240116Smarcel * These are used for shifting, and also below for halfword extraction 81240116Smarcel * and assembly. 82240116Smarcel */ 83240116Smarcel#define QUAD_BITS (sizeof(quad_t) * CHAR_BIT) 84240116Smarcel#define LONG_BITS (sizeof(long) * CHAR_BIT) 85240116Smarcel#define HALF_BITS (sizeof(long) * CHAR_BIT / 2) 86240116Smarcel 87240116Smarcel/* 88240116Smarcel * Extract high and low shortwords from longword, and move low shortword of 89240116Smarcel * longword to upper half of long, i.e., produce the upper longword of 90240116Smarcel * ((quad_t)(x) << (number_of_bits_in_long/2)). (`x' must actually be u_long.) 91240116Smarcel * 92240116Smarcel * These are used in the multiply code, to split a longword into upper 93240116Smarcel * and lower halves, and to reassemble a product as a quad_t, shifted left 94240116Smarcel * (sizeof(long)*CHAR_BIT/2). 95240116Smarcel */ 96240116Smarcel#define HHALF(x) ((x) >> HALF_BITS) 97240116Smarcel#define LHALF(x) ((x) & ((1 << HALF_BITS) - 1)) 98240116Smarcel#define LHUP(x) ((x) << HALF_BITS) 99240116Smarcel 100240116Smarcelquad_t __divdi3 __P((quad_t a, quad_t b)); 101240116Smarcelquad_t __moddi3 __P((quad_t a, quad_t b)); 102240116Smarcelu_quad_t __qdivrem __P((u_quad_t u, u_quad_t v, u_quad_t *rem)); 103240116Smarcelu_quad_t __udivdi3 __P((u_quad_t a, u_quad_t b)); 104240116Smarcelu_quad_t __umoddi3 __P((u_quad_t a, u_quad_t b)); 105240116Smarcel 106240116Smarcel/* 107240116Smarcel * XXX 108240116Smarcel * Compensate for gcc 1 vs gcc 2. Gcc 1 defines ?sh?di3's second argument 109240116Smarcel * as u_quad_t, while gcc 2 correctly uses int. Unfortunately, we still use 110240116Smarcel * both compilers. 111240116Smarcel */ 112240116Smarcel#if __GNUC__ >= 2 113240116Smarceltypedef unsigned int qshift_t; 114240116Smarcel#else 115240116Smarceltypedef u_quad_t qshift_t; 116240116Smarcel#endif 117240116Smarcel