/* Compute remainder and a congruent to the quotient.
  Copyright (C) 1997-2018 Free Software Foundation, Inc.
  This file is part of the GNU C Library.
  Contributed by Ulrich Drepper <[email protected]>, 1997 and
                 Jakub Jelinek <[email protected]>, 1999.

  The GNU C Library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.

  The GNU C Library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with the GNU C Library; if not, see
  <http://www.gnu.org/licenses/>.  */

#include "quadmath-imp.h"

static const __float128 zero = 0.0;


__float128
remquoq (__float128 x, __float128 y, int *quo)
{
 int64_t hx,hy;
 uint64_t sx,lx,ly,qs;
 int cquo;

 GET_FLT128_WORDS64 (hx, lx, x);
 GET_FLT128_WORDS64 (hy, ly, y);
 sx = hx & 0x8000000000000000ULL;
 qs = sx ^ (hy & 0x8000000000000000ULL);
 hy &= 0x7fffffffffffffffLL;
 hx &= 0x7fffffffffffffffLL;

 /* Purge off exception values.  */
 if ((hy | ly) == 0)
   return (x * y) / (x * y);                   /* y = 0 */
 if ((hx >= 0x7fff000000000000LL)              /* x not finite */
     || ((hy >= 0x7fff000000000000LL)          /* y is NaN */
         && (((hy - 0x7fff000000000000LL) | ly) != 0)))
   return (x * y) / (x * y);

 if (hy <= 0x7ffbffffffffffffLL)
   x = fmodq (x, 8 * y);              /* now x < 8y */

 if (((hx - hy) | (lx - ly)) == 0)
   {
     *quo = qs ? -1 : 1;
     return zero * x;
   }

 x  = fabsq (x);
 y  = fabsq (y);
 cquo = 0;

 if (hy <= 0x7ffcffffffffffffLL && x >= 4 * y)
   {
     x -= 4 * y;
     cquo += 4;
   }
 if (hy <= 0x7ffdffffffffffffLL && x >= 2 * y)
   {
     x -= 2 * y;
     cquo += 2;
   }

 if (hy < 0x0002000000000000LL)
   {
     if (x + x > y)
       {
         x -= y;
         ++cquo;
         if (x + x >= y)
           {
             x -= y;
             ++cquo;
           }
       }
   }
 else
   {
     __float128 y_half = 0.5Q * y;
     if (x > y_half)
       {
         x -= y;
         ++cquo;
         if (x >= y_half)
           {
             x -= y;
             ++cquo;
           }
       }
   }

 *quo = qs ? -cquo : cquo;

 /* Ensure correct sign of zero result in round-downward mode.  */
 if (x == 0)
   x = 0;
 if (sx)
   x = -x;
 return x;
}