1  /* s_nearbyintl.c -- long double version of s_nearbyint.c.
       2   * Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
       3   */
       4  
       5  /*
       6   * ====================================================
       7   * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
       8   *
       9   * Developed at SunPro, a Sun Microsystems, Inc. business.
      10   * Permission to use, copy, modify, and distribute this
      11   * software is freely granted, provided that this notice
      12   * is preserved.
      13   * ====================================================
      14   */
      15  
      16  /*
      17   * nearbyintq(x)
      18   * Return x rounded to integral value according to the prevailing
      19   * rounding mode.
      20   * Method:
      21   *	Using floating addition.
      22   * Exception:
      23   *	Inexact flag raised if x not equal to rintq(x).
      24   */
      25  
      26  #include "quadmath-imp.h"
      27  
      28  static const __float128
      29  TWO112[2]={
      30    5.19229685853482762853049632922009600E+33Q, /* 0x406F000000000000, 0 */
      31   -5.19229685853482762853049632922009600E+33Q  /* 0xC06F000000000000, 0 */
      32  };
      33  
      34  __float128 nearbyintq(__float128 x)
      35  {
      36  	fenv_t env;
      37  	int64_t i0,j0,sx;
      38  	uint64_t i1 __attribute__ ((unused));
      39  	__float128 w,t;
      40  	GET_FLT128_WORDS64(i0,i1,x);
      41  	sx = (((uint64_t)i0)>>63);
      42  	j0 = ((i0>>48)&0x7fff)-0x3fff;
      43  	if(j0<112) {
      44  	    if(j0<0) {
      45  		feholdexcept (&env);
      46  	        w = TWO112[sx] + math_opt_barrier (x);
      47  	        t = w-TWO112[sx];
      48  		math_force_eval (t);
      49  	        fesetenv (&env);
      50  		GET_FLT128_MSW64(i0,t);
      51  		SET_FLT128_MSW64(t,(i0&0x7fffffffffffffffLL)|(sx<<63));
      52  	        return t;
      53  	    }
      54  	} else {
      55  	    if(j0==0x4000) return x+x;	/* inf or NaN */
      56  	    else return x;		/* x is integral */
      57  	}
      58  	feholdexcept (&env);
      59  	w = TWO112[sx] + math_opt_barrier (x);
      60  	t = w-TWO112[sx];
      61  	math_force_eval (t);
      62  	fesetenv (&env);
      63  	return t;
      64  }