/*

 * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>

 *

 * Permission is hereby granted, free of charge, to any person obtaining 

 * a copy of this software and associated documentation files (the

 * "Software"), to deal in the Software without restriction, including

 * without limitation the rights to use, copy, modify, merge, publish,

 * distribute, sublicense, and/or sell copies of the Software, and to

 * permit persons to whom the Software is furnished to do so, subject to

 * the following conditions:

 *

 * The above copyright notice and this permission notice shall be 

 * included in all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 

 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 

 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS

 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN

 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN

 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

 * SOFTWARE.

 */

#include "inner.h"

/* see inner.h */

uint32_t

br_divrem(uint32_t hi, uint32_t lo, uint32_t d, uint32_t *r)

{

  /* TODO: optimize this */

  uint32_t q;

  uint32_t ch, cf;

  int k;

  q = 0;

  ch = EQ(hi, d);

  hi = MUX(ch, 0, hi);

  for (k = 31; k > 0; k --) {

    int j;

    uint32_t w, ctl, hi2, lo2;

    j = 32 - k;

    w = (hi << j) | (lo >> k);

    ctl = GE(w, d) | (hi >> k);

    hi2 = (w - d) >> j;

    lo2 = lo - (d << k);

    hi = MUX(ctl, hi2, hi);

    lo = MUX(ctl, lo2, lo);

    q |= ctl << k;

  }

  cf = GE(lo, d) | hi;

  q |= cf;

  *r = MUX(cf, lo - d, lo);

  return q;

}