1  /* s_frexpl.c -- long double version of s_frexp.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  #if defined(LIBM_SCCS) && !defined(lint)
      17  static char rcsid[] = "$NetBSD: $";
      18  #endif
      19  
      20  /*
      21   * for non-zero x
      22   *	x = frexpq(arg,&exp);
      23   * return a long double fp quantity x such that 0.5 <= |x| <1.0
      24   * and the corresponding binary exponent "exp". That is
      25   *	arg = x*2^exp.
      26   * If arg is inf, 0.0, or NaN, then frexpq(arg,&exp) returns arg
      27   * with *exp=0.
      28   */
      29  
      30  #include "quadmath-imp.h"
      31  
      32  static const __float128
      33  two114 = 2.0769187434139310514121985316880384E+34Q; /* 0x4071000000000000, 0 */
      34  
      35  __float128 frexpq(__float128 x, int *eptr)
      36  {
      37  	uint64_t hx, lx, ix;
      38  	GET_FLT128_WORDS64(hx,lx,x);
      39  	ix = 0x7fffffffffffffffULL&hx;
      40  	*eptr = 0;
      41  	if(ix>=0x7fff000000000000ULL||((ix|lx)==0)) return x + x;/* 0,inf,nan */
      42  	if (ix<0x0001000000000000ULL) {		/* subnormal */
      43  	    x *= two114;
      44  	    GET_FLT128_MSW64(hx,x);
      45  	    ix = hx&0x7fffffffffffffffULL;
      46  	    *eptr = -114;
      47  	}
      48  	*eptr += (ix>>48)-16382;
      49  	hx = (hx&0x8000ffffffffffffULL) | 0x3ffe000000000000ULL;
      50  	SET_FLT128_MSW64(x,hx);
      51  	return x;
      52  }