freebsd-src/sys/libkern/quad.h

117 lines
4.2 KiB
C

/*-
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This software was developed by the Computer Systems Engineering group
* at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
* contributed to Berkeley.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)quad.h 8.1 (Berkeley) 6/4/93
* $Id: quad.h,v 1.3 1995/12/26 13:24:48 bde Exp $
*/
/*
* Quad arithmetic.
*
* This library makes the following assumptions:
*
* - The type long long (aka quad_t) exists.
*
* - A quad variable is exactly twice as long as `long'.
*
* - The machine's arithmetic is two's complement.
*
* This library can provide 128-bit arithmetic on a machine with 128-bit
* quads and 64-bit longs, for instance, or 96-bit arithmetic on machines
* with 48-bit longs.
*/
#include <sys/cdefs.h>
#include <sys/types.h>
#include <limits.h>
/*
* Depending on the desired operation, we view a `long long' (aka quad_t) in
* one or more of the following formats.
*/
union uu {
quad_t q; /* as a (signed) quad */
quad_t uq; /* as an unsigned quad */
long sl[2]; /* as two signed longs */
u_long ul[2]; /* as two unsigned longs */
};
/*
* Define high and low longwords.
*/
#define H _QUAD_HIGHWORD
#define L _QUAD_LOWWORD
/*
* Total number of bits in a quad_t and in the pieces that make it up.
* These are used for shifting, and also below for halfword extraction
* and assembly.
*/
#define QUAD_BITS (sizeof(quad_t) * CHAR_BIT)
#define LONG_BITS (sizeof(long) * CHAR_BIT)
#define HALF_BITS (sizeof(long) * CHAR_BIT / 2)
/*
* Extract high and low shortwords from longword, and move low shortword of
* longword to upper half of long, i.e., produce the upper longword of
* ((quad_t)(x) << (number_of_bits_in_long/2)). (`x' must actually be u_long.)
*
* These are used in the multiply code, to split a longword into upper
* and lower halves, and to reassemble a product as a quad_t, shifted left
* (sizeof(long)*CHAR_BIT/2).
*/
#define HHALF(x) ((x) >> HALF_BITS)
#define LHALF(x) ((x) & ((1 << HALF_BITS) - 1))
#define LHUP(x) ((x) << HALF_BITS)
quad_t __divdi3 __P((quad_t a, quad_t b));
quad_t __moddi3 __P((quad_t a, quad_t b));
u_quad_t __qdivrem __P((u_quad_t u, u_quad_t v, u_quad_t *rem));
u_quad_t __udivdi3 __P((u_quad_t a, u_quad_t b));
u_quad_t __umoddi3 __P((u_quad_t a, u_quad_t b));
/*
* XXX
* Compensate for gcc 1 vs gcc 2. Gcc 1 defines ?sh?di3's second argument
* as u_quad_t, while gcc 2 correctly uses int. Unfortunately, we still use
* both compilers.
*/
#if __GNUC__ >= 2
typedef unsigned int qshift_t;
#else
typedef u_quad_t qshift_t;
#endif