1  /* s_rintl.c -- long double version of s_rint.c.
       2   */
       3  
       4  /*
       5   * ====================================================
       6   * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
       7   *
       8   * Developed at SunPro, a Sun Microsystems, Inc. business.
       9   * Permission to use, copy, modify, and distribute this
      10   * software is freely granted, provided that this notice
      11   * is preserved.
      12   * ====================================================
      13   */
      14  
      15  #if defined (LIBM_SCCS) && ! defined (lint)
      16  static char rcsid[] = "$NetBSD: $";
      17  #endif
      18  
      19  /*
      20   * rintl(x)
      21   * Return x rounded to integral value according to the prevailing
      22   * rounding mode.
      23   * Method:
      24   *	Using floating addition.
      25   * Exception:
      26   *	Inexact flag raised if x not equal to rintl(x).
      27   */
      28  
      29  #define NO_MATH_REDIRECT
      30  #include <math.h>
      31  #include <math_private.h>
      32  #include <libm-alias-ldouble.h>
      33  #include <math-use-builtins.h>
      34  
      35  _Float128
      36  __rintl (_Float128 x)
      37  {
      38  #if USE_RINTL_BUILTIN
      39    return __builtin_rintl (x);
      40  #else
      41    /* Use generic implementation.  */
      42    static const _Float128
      43      TWO112[2] = {
      44  		 5.19229685853482762853049632922009600E+33L, /* 0x406F000000000000, 0 */
      45  		 -5.19229685853482762853049632922009600E+33L  /* 0xC06F000000000000, 0 */
      46    };
      47    int64_t i0, j0, sx;
      48    uint64_t i1 __attribute__ ((unused));
      49    _Float128 w, t;
      50    GET_LDOUBLE_WORDS64 (i0, i1, x);
      51    sx = (((uint64_t) i0) >> 63);
      52    j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
      53    if (j0 < 112)
      54      {
      55        if (j0 < 0)
      56  	{
      57  	  w = TWO112[sx] + x;
      58  	  t = w - TWO112[sx];
      59  	  GET_LDOUBLE_MSW64 (i0, t);
      60  	  SET_LDOUBLE_MSW64 (t, (i0 & 0x7fffffffffffffffLL) | (sx << 63));
      61  	  return t;
      62  	}
      63      }
      64    else
      65      {
      66        if (j0 == 0x4000)
      67  	return x + x;		/* inf or NaN  */
      68        else
      69  	return x;		/* x is integral  */
      70      }
      71    w = TWO112[sx] + x;
      72    return w - TWO112[sx];
      73  #endif /* ! USE_RINTL_BUILTIN  */
      74  }
      75  libm_alias_ldouble (__rint, rint)