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      1 /* s_nearbyintl.c -- long double version of s_nearbyint.c.
      2  * Conversion to IEEE quad long double by Jakub Jelinek, jj (at) 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 }
     65