text: /*	$OpenBSD: fpu_arith.h,v 1.1 2003/07/21 18:41:30 jason Exp $	*/
  
  /*
   * 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.
   *
   * 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, Lawrence Berkeley Laboratory.
   *
   * 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.
   *
   *	@(#)fpu_arith.h	8.1 (Berkeley) 6/11/93
   *	$NetBSD: fpu_arith.h,v 1.3 2000/07/24 04:11:03 mycroft Exp $
   * $FreeBSD: src/lib/libc/sparc64/fpu/fpu_arith.h,v 1.2 2002/03/22 23:41:59 obrien Exp $
   */
  
  /*
   * Extended-precision arithmetic.
   *
   * We hold the notion of a `carry register', which may or may not be a
   * machine carry bit or register.  On the SPARC, it is just the machine's
   * carry bit.
   *
   * In the worst case, you can compute the carry from x+y as
   *	(unsigned)(x + y) < (unsigned)x
   * and from x+y+c as
   *	((unsigned)(x + y + c) <= (unsigned)x && (y|c) != 0)
   * for example.
   */
  
  /* set up for extended-precision arithemtic */
  #define	FPU_DECL_CARRY
  
  /*
   * We have three kinds of add:
   *	add with carry:					  r = x + y + c
   *	add (ignoring current carry) and set carry:	c'r = x + y + 0
   *	add with carry and set carry:			c'r = x + y + c
   * The macros use `C' for `use carry' and `S' for `set carry'.
   * Note that the state of the carry is undefined after ADDC and SUBC,
   * so if all you have for these is `add with carry and set carry',
   * that is OK.
   *
   * The same goes for subtract, except that we compute x - y - c.
   *
   * Finally, we have a way to get the carry into a `regular' variable,
   * or set it from a value.  SET_CARRY turns 0 into no-carry, nonzero
   * into carry; GET_CARRY sets its argument to 0 or 1.
   */
  #define	FPU_ADDC(r, x, y) \
  	__asm __volatile("addx %1,%2,%0" : "=r"(r) : "r"(x), "r"(y))
  #define	FPU_ADDS(r, x, y) \
  	__asm __volatile("addcc %1,%2,%0" : "=r"(r) : "r"(x), "r"(y))
  #define	FPU_ADDCS(r, x, y) \
  	__asm __volatile("addxcc %1,%2,%0" : "=r"(r) : "r"(x), "r"(y))
  #define	FPU_SUBC(r, x, y) \
  	__asm __volatile("subx %1,%2,%0" : "=r"(r) : "r"(x), "r"(y))
  #define	FPU_SUBS(r, x, y) \
  	__asm __volatile("subcc %1,%2,%0" : "=r"(r) : "r"(x), "r"(y))
  #define	FPU_SUBCS(r, x, y) \
  	__asm __volatile("subxcc %1,%2,%0" : "=r"(r) : "r"(x), "r"(y))
  
  #define	FPU_GET_CARRY(r) __asm __volatile("addx %%g0,%%g0,%0" : "=r"(r))
  #define	FPU_SET_CARRY(v) __asm __volatile("addcc %0,-1,%%g0" : : "r"(v))
  
  #define	FPU_SHL1_BY_ADD	/* shift left 1 faster by ADDC than (a<<1)|(b>>31) */
  