Subversion Repositories openrisc

/* e_fmodl.c -- long double version of e_fmod.c.

 * Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.

 */

/*

 * ====================================================

 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.

 *

 * Developed at SunPro, a Sun Microsystems, Inc. business.

 * Permission to use, copy, modify, and distribute this

 * software is freely granted, provided that this notice

 * is preserved.

 * ====================================================

 */

/* remainderq(x,p)

 * Return :

 *      returns  x REM p  =  x - [x/p]*p as if in infinite

 *      precise arithmetic, where [x/p] is the (infinite bit)

 *      integer nearest x/p (in half way case choose the even one).

 * Method :

 *      Based on fmodq() return x-[x/p]chopped*p exactlp.

 */

#include "quadmath-imp.h"

static const __float128 zero = 0.0Q;

__float128

remainderq (__float128 x, __float128 p)

{

  int64_t hx,hp;

  uint64_t sx,lx,lp;

  __float128 p_half;

  GET_FLT128_WORDS64(hx,lx,x);

  GET_FLT128_WORDS64(hp,lp,p);

  sx = hx&0x8000000000000000ULL;

  hp &= 0x7fffffffffffffffLL;

  hx &= 0x7fffffffffffffffLL;

  /* purge off exception values */

  if((hp|lp)==0) return (x*p)/(x*p);     /* p = 0 */

  if((hx>=0x7fff000000000000LL)||                       /* x not finite */

    ((hp>=0x7fff000000000000LL)&&                       /* p is NaN */

    (((hp-0x7fff000000000000LL)|lp)!=0)))

      return (x*p)/(x*p);

  if (hp<=0x7ffdffffffffffffLL) x = fmodq (x,p+p);      /* now x < 2p */

  if (((hx-hp)|(lx-lp))==0) return zero*x;

  x  = fabsq(x);

  p  = fabsq(p);

  if (hp<0x0002000000000000LL) {

      if(x+x>p) {

          x-=p;

          if(x+x>=p) x -= p;

      }

  } else {

      p_half = 0.5Q*p;

      if(x>p_half) {

          x-=p;

          if(x>=p_half) x -= p;

      }

  }

  GET_FLT128_MSW64(hx,x);

  SET_FLT128_MSW64(x,hx^sx);

  return x;

}