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Diffstat (limited to 'lib/libstand/quad.h')
-rw-r--r-- | lib/libstand/quad.h | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/lib/libstand/quad.h b/lib/libstand/quad.h new file mode 100644 index 0000000..0ff27ff --- /dev/null +++ b/lib/libstand/quad.h @@ -0,0 +1,112 @@ +/*- + * 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. + * 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 + * $FreeBSD$ + */ + +/* + * 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(quad_t a, quad_t b); +quad_t __moddi3(quad_t a, quad_t b); +u_quad_t __qdivrem(u_quad_t u, u_quad_t v, u_quad_t *rem); +u_quad_t __udivdi3(u_quad_t a, u_quad_t b); +u_quad_t __umoddi3(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 |