2 /* @(#)s_floor.c 5.1 93/09/24 */
4 * ====================================================
5 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
7 * Developed at SunPro, a Sun Microsystems, Inc. business.
8 * Permission to use, copy, modify, and distribute this
9 * software is freely granted, provided that this notice
11 * ====================================================
14 #if defined(LIBM_SCCS) && !defined(lint)
15 static char rcsid[] = "$NetBSD: s_floor.c,v 1.8 1995/05/10 20:47:20 jtc Exp $";
20 * Return x rounded toward -inf to integral value
24 * Inexact flag raised if x not equal to floor(x).
28 #include "math_private.h"
31 static const double huge = 1.0e300;
33 static double huge = 1.0e300;
37 double floor(double x)
45 EXTRACT_WORDS(i0,i1,x);
46 j0 = ((i0>>20)&0x7ff)-0x3ff;
48 if(j0<0) { /* raise inexact if x != 0 */
49 if(huge+x>0.0) {/* return 0*sign(x) if |x|<1 */
51 else if(((i0&0x7fffffff)|i1)!=0)
52 { i0=0xbff00000;i1=0;}
56 if(((i0&i)|i1)==0) return x; /* x is integral */
57 if(huge+x>0.0) { /* raise inexact flag */
58 if(i0<0) i0 += (0x00100000)>>j0;
63 if(j0==0x400) return x+x; /* inf or NaN */
64 else return x; /* x is integral */
66 i = ((u_int32_t)(0xffffffff))>>(j0-20);
67 if((i1&i)==0) return x; /* x is integral */
68 if(huge+x>0.0) { /* raise inexact flag */
73 if(j<i1) i0 +=1 ; /* got a carry */
80 INSERT_WORDS(x,i0,i1);