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      1 /* s_floorl.c -- long double version of s_floor.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 #if defined(LIBM_SCCS) && !defined(lint)
     17 static char rcsid[] = "NetBSD: ";
     18 #endif
     19 
     20 /*
     21  * floorq(x)
     22  * Return x rounded toward -inf to integral value
     23  * Method:
     24  *	Bit twiddling.
     25  */
     26 
     27 #define NO_MATH_REDIRECT
     28 
     29 #include "quadmath-imp.h"
     30 
     31 __float128 floorq(__float128 x)
     32 {
     33 	int64_t i0,i1,j0;
     34 	uint64_t i,j;
     35 	GET_FLT128_WORDS64(i0,i1,x);
     36 	j0 = ((i0>>48)&0x7fff)-0x3fff;
     37 	if(j0<48) {
     38 	    if(j0<0) {
     39 		/* return 0*sign(x) if |x|<1 */
     40 		if(i0>=0) {i0=i1=0;}
     41 		else if(((i0&0x7fffffffffffffffLL)|i1)!=0)
     42 		    { i0=0xbfff000000000000ULL;i1=0;}
     43 	    } else {
     44 		i = (0x0000ffffffffffffULL)>>j0;
     45 		if(((i0&i)|i1)==0) return x; /* x is integral */
     46 		if(i0<0) i0 += (0x0001000000000000LL)>>j0;
     47 		i0 &= (~i); i1=0;
     48 	    }
     49 	} else if (j0>111) {
     50 	    if(j0==0x4000) return x+x;	/* inf or NaN */
     51 	    else return x;		/* x is integral */
     52 	} else {
     53 	    i = -1ULL>>(j0-48);
     54 	    if((i1&i)==0) return x;	/* x is integral */
     55 	    if(i0<0) {
     56 		if(j0==48) i0+=1;
     57 		else {
     58 		    j = i1+(1LL<<(112-j0));
     59 		    if(j<i1) i0 +=1 ; 	/* got a carry */
     60 		    i1=j;
     61 		}
     62 	    }
     63 	    i1 &= (~i);
     64 	}
     65 	SET_FLT128_WORDS64(x,i0,i1);
     66 	return x;
     67 }
     68