quad.h revision 50477
190792Sgshapiro/*- 2261363Sgshapiro * Copyright (c) 1992, 1993 390792Sgshapiro * The Regents of the University of California. All rights reserved. 490792Sgshapiro * 590792Sgshapiro * This software was developed by the Computer Systems Engineering group 690792Sgshapiro * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 790792Sgshapiro * contributed to Berkeley. 890792Sgshapiro * 990792Sgshapiro * Redistribution and use in source and binary forms, with or without 1090792Sgshapiro * modification, are permitted provided that the following conditions 1190792Sgshapiro * are met: 1290792Sgshapiro * 1. Redistributions of source code must retain the above copyright 1390792Sgshapiro * notice, this list of conditions and the following disclaimer. 1490792Sgshapiro * 2. Redistributions in binary form must reproduce the above copyright 15266692Sgshapiro * notice, this list of conditions and the following disclaimer in the 1690792Sgshapiro * documentation and/or other materials provided with the distribution. 1790792Sgshapiro * 3. All advertising materials mentioning features or use of this software 1890792Sgshapiro * must display the following acknowledgement: 1990792Sgshapiro * This product includes software developed by the University of 20157001Sgshapiro * California, Berkeley and its contributors. 2190792Sgshapiro * 4. Neither the name of the University nor the names of its contributors 2290792Sgshapiro * may be used to endorse or promote products derived from this software 2390792Sgshapiro * without specific prior written permission. 2490792Sgshapiro * 2590792Sgshapiro * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 2690792Sgshapiro * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27120256Sgshapiro * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28120256Sgshapiro * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29120256Sgshapiro * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30120256Sgshapiro * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31120256Sgshapiro * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32120256Sgshapiro * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 3390792Sgshapiro * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 3490792Sgshapiro * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3590792Sgshapiro * SUCH DAMAGE. 3690792Sgshapiro * 3790792Sgshapiro * @(#)quad.h 8.1 (Berkeley) 6/4/93 3890792Sgshapiro * $FreeBSD: head/sys/libkern/quad.h 50477 1999-08-28 01:08:13Z peter $ 3990792Sgshapiro */ 4090792Sgshapiro 4190792Sgshapiro/* 4290792Sgshapiro * Quad arithmetic. 4390792Sgshapiro * 4490792Sgshapiro * This library makes the following assumptions: 4590792Sgshapiro * 4690792Sgshapiro * - The type long long (aka quad_t) exists. 4790792Sgshapiro * 4890792Sgshapiro * - A quad variable is exactly twice as long as `long'. 4990792Sgshapiro * 5090792Sgshapiro * - The machine's arithmetic is two's complement. 5190792Sgshapiro * 5290792Sgshapiro * This library can provide 128-bit arithmetic on a machine with 128-bit 5390792Sgshapiro * quads and 64-bit longs, for instance, or 96-bit arithmetic on machines 5490792Sgshapiro * with 48-bit longs. 5590792Sgshapiro */ 5690792Sgshapiro 5790792Sgshapiro#include <sys/cdefs.h> 5890792Sgshapiro#include <sys/types.h> 5990792Sgshapiro#include <limits.h> 6090792Sgshapiro 6190792Sgshapiro/* 6290792Sgshapiro * Depending on the desired operation, we view a `long long' (aka quad_t) in 6390792Sgshapiro * one or more of the following formats. 6490792Sgshapiro */ 6590792Sgshapirounion uu { 66141858Sgshapiro quad_t q; /* as a (signed) quad */ 6790792Sgshapiro quad_t uq; /* as an unsigned quad */ 6890792Sgshapiro long sl[2]; /* as two signed longs */ 6990792Sgshapiro u_long ul[2]; /* as two unsigned longs */ 7090792Sgshapiro}; 7190792Sgshapiro 7290792Sgshapiro/* 7390792Sgshapiro * Define high and low longwords. 7490792Sgshapiro */ 7590792Sgshapiro#define H _QUAD_HIGHWORD 7690792Sgshapiro#define L _QUAD_LOWWORD 7790792Sgshapiro 7890792Sgshapiro/* 7990792Sgshapiro * Total number of bits in a quad_t and in the pieces that make it up. 8090792Sgshapiro * These are used for shifting, and also below for halfword extraction 8190792Sgshapiro * and assembly. 8290792Sgshapiro */ 8390792Sgshapiro#define QUAD_BITS (sizeof(quad_t) * CHAR_BIT) 8490792Sgshapiro#define LONG_BITS (sizeof(long) * CHAR_BIT) 8590792Sgshapiro#define HALF_BITS (sizeof(long) * CHAR_BIT / 2) 8690792Sgshapiro 8790792Sgshapiro/* 8890792Sgshapiro * Extract high and low shortwords from longword, and move low shortword of 89141858Sgshapiro * longword to upper half of long, i.e., produce the upper longword of 9090792Sgshapiro * ((quad_t)(x) << (number_of_bits_in_long/2)). (`x' must actually be u_long.) 9190792Sgshapiro * 9290792Sgshapiro * These are used in the multiply code, to split a longword into upper 9390792Sgshapiro * and lower halves, and to reassemble a product as a quad_t, shifted left 9490792Sgshapiro * (sizeof(long)*CHAR_BIT/2). 9590792Sgshapiro */ 9690792Sgshapiro#define HHALF(x) ((x) >> HALF_BITS) 9790792Sgshapiro#define LHALF(x) ((x) & ((1 << HALF_BITS) - 1)) 9890792Sgshapiro#define LHUP(x) ((x) << HALF_BITS) 9990792Sgshapiro 10090792Sgshapiroquad_t __divdi3 __P((quad_t a, quad_t b)); 10190792Sgshapiroquad_t __moddi3 __P((quad_t a, quad_t b)); 10290792Sgshapirou_quad_t __qdivrem __P((u_quad_t u, u_quad_t v, u_quad_t *rem)); 10390792Sgshapirou_quad_t __udivdi3 __P((u_quad_t a, u_quad_t b)); 10490792Sgshapirou_quad_t __umoddi3 __P((u_quad_t a, u_quad_t b)); 10590792Sgshapiro 10690792Sgshapiro/* 10790792Sgshapiro * XXX 10890792Sgshapiro * Compensate for gcc 1 vs gcc 2. Gcc 1 defines ?sh?di3's second argument 10990792Sgshapiro * as u_quad_t, while gcc 2 correctly uses int. Unfortunately, we still use 11090792Sgshapiro * both compilers. 11190792Sgshapiro */ 11290792Sgshapiro#if __GNUC__ >= 2 11390792Sgshapirotypedef unsigned int qshift_t; 11490792Sgshapiro#else 11590792Sgshapirotypedef u_quad_t qshift_t; 11690792Sgshapiro#endif 11790792Sgshapiro