7e6cabd06e
Renumber cluase 4 to 3, per what everybody else did when BSD granted them permission to remove clause 3. My insistance on keeping the same numbering for legal reasons is too pedantic, so give up on that point. Submitted by: Jan Schaumann <jschauma@stevens.edu> Pull Request: https://github.com/freebsd/freebsd/pull/96
88 lines
3.7 KiB
C
88 lines
3.7 KiB
C
/*
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* Copyright (c) 1992, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This software was developed by the Computer Systems Engineering group
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* at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
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* contributed to Berkeley.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)fpu_arith.h 8.1 (Berkeley) 6/11/93
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* $NetBSD: fpu_arith.h,v 1.3 2000/07/24 04:11:03 mycroft Exp $
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* $FreeBSD$
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*/
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/*
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* Extended-precision arithmetic.
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*
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* We hold the notion of a `carry register', which may or may not be a
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* machine carry bit or register. On the SPARC, it is just the machine's
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* carry bit.
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*
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* In the worst case, you can compute the carry from x+y as
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* (unsigned)(x + y) < (unsigned)x
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* and from x+y+c as
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* ((unsigned)(x + y + c) <= (unsigned)x && (y|c) != 0)
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* for example.
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*/
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/* set up for extended-precision arithemtic */
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#define FPU_DECL_CARRY
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/*
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* We have three kinds of add:
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* add with carry: r = x + y + c
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* add (ignoring current carry) and set carry: c'r = x + y + 0
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* add with carry and set carry: c'r = x + y + c
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* The macros use `C' for `use carry' and `S' for `set carry'.
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* Note that the state of the carry is undefined after ADDC and SUBC,
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* so if all you have for these is `add with carry and set carry',
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* that is OK.
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*
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* The same goes for subtract, except that we compute x - y - c.
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*
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* Finally, we have a way to get the carry into a `regular' variable,
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* or set it from a value. SET_CARRY turns 0 into no-carry, nonzero
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* into carry; GET_CARRY sets its argument to 0 or 1.
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*/
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#define FPU_ADDC(r, x, y) \
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__asm __volatile("addx %1,%2,%0" : "=r"(r) : "r"(x), "r"(y))
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#define FPU_ADDS(r, x, y) \
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__asm __volatile("addcc %1,%2,%0" : "=r"(r) : "r"(x), "r"(y))
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#define FPU_ADDCS(r, x, y) \
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__asm __volatile("addxcc %1,%2,%0" : "=r"(r) : "r"(x), "r"(y))
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#define FPU_SUBC(r, x, y) \
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__asm __volatile("subx %1,%2,%0" : "=r"(r) : "r"(x), "r"(y))
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#define FPU_SUBS(r, x, y) \
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__asm __volatile("subcc %1,%2,%0" : "=r"(r) : "r"(x), "r"(y))
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#define FPU_SUBCS(r, x, y) \
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__asm __volatile("subxcc %1,%2,%0" : "=r"(r) : "r"(x), "r"(y))
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#define FPU_GET_CARRY(r) __asm __volatile("addx %%g0,%%g0,%0" : "=r"(r))
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#define FPU_SET_CARRY(v) __asm __volatile("addcc %0,-1,%%g0" : : "r"(v))
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#define FPU_SHL1_BY_ADD /* shift left 1 faster by ADDC than (a<<1)|(b>>31) */
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