1 /* @(#)s_floor.c 5.1 93/09/24 */
3 * ====================================================
4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
6 * Developed at SunPro, a Sun Microsystems, Inc. business.
7 * Permission to use, copy, modify, and distribute this
8 * software is freely granted, provided that this notice
10 * ====================================================
12 * $NetBSD: s_floor.c,v 1.13 2009/02/16 01:27:36 lukem Exp $
17 * Return x rounded toward -inf to integral value
21 * Inexact flag raised if x not equal to floor(x).
25 #include "math_private.h"
27 static const double huge = 1.0e300;
34 EXTRACT_WORDS(i0,i1,x);
35 jj0 = ((i0>>20)&0x7ff)-0x3ff;
37 if(jj0<0) { /* raise inexact if x != 0 */
38 if(huge+x>0.0) {/* return 0*sign(x) if |x|<1 */
40 else if(((i0&0x7fffffff)|i1)!=0)
41 { i0=0xbff00000;i1=0;}
44 i = (0x000fffff)>>jj0;
45 if(((i0&i)|i1)==0) return x; /* x is integral */
46 if(huge+x>0.0) { /* raise inexact flag */
47 if(i0<0) i0 += (0x00100000)>>jj0;
52 if(jj0==0x400) return x+x; /* inf or NaN */
53 else return x; /* x is integral */
55 i = ((u_int32_t)(0xffffffff))>>(jj0-20);
56 if((i1&i)==0) return x; /* x is integral */
57 if(huge+x>0.0) { /* raise inexact flag */
62 if(j<(u_int32_t)i1) i0 +=1 ; /* got a carry */
69 INSERT_WORDS(x,i0,i1);