/*      $NetBSD: fpu_int.c,v 1.12 2013/03/19 09:17:17 isaki Exp $       */

/*
* Copyright (c) 1995 Ken Nakata
* All rights reserved.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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_int.c
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: fpu_int.c,v 1.12 2013/03/19 09:17:17 isaki Exp $");

#include <sys/types.h>

#include <machine/reg.h>

#include "fpu_arith.h"
#include "fpu_emulate.h"

/* FINTRZ - always round to zero */
struct fpn *
fpu_intrz(struct fpemu *fe)
{
       struct fpn *x = &fe->fe_f2;
       int sh, clr, mask, i;

       /* special cases first */
       if (x->fp_class != FPC_NUM) {
               return x;
       }
       /* when |x| < 1.0 */
       if (x->fp_exp < 0) {
               x->fp_class = FPC_ZERO;
               x->fp_mant[0] = x->fp_mant[1] = x->fp_mant[2] = 0;
               return x;
       }

       /* real work */
       sh = FP_NMANT - 1 - x->fp_exp;
       if (sh <= 0) {
               return x;
       }

       clr = 2 - sh / 32;
       mask = (0xffffffff << (sh % 32));

       for (i = 2; i > clr; i--) {
               x->fp_mant[i] = 0;
       }
       x->fp_mant[i] &= mask;

       return x;
}

/* FINT */
struct fpn *
fpu_int(struct fpemu *fe)
{
       struct fpn *x = &fe->fe_f2;
       int rsh;

       /* special cases first */
       if (x->fp_class != FPC_NUM) {
               return x;
       }

       rsh = FP_NMANT - 1 - x->fp_exp;
       if (rsh <= FP_NG) {
               return x;
       }

       /* shift to the right */
       x->fp_exp = 0;
       fpu_shr(x, rsh - FP_NG);

       /* round according to FPCR round mode */
       fpu_round(fe, x);

       /* shift it back to the left */
       x->fp_exp = FP_NMANT - 1;
       fpu_norm(x);

       return x;
}