1 /* @(#)s_ceil.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 * ====================================================
14 static char rcsid[] = "$FreeBSD$";
19 * Return x rounded toward -inf to integral value
23 * Inexact flag raised if x not equal to ceil(x).
27 #include "math_private.h"
29 static const double huge = 1.0e300;
36 EXTRACT_WORDS(i0,i1,x);
37 j0 = ((i0>>20)&0x7ff)-0x3ff;
39 if(j0<0) { /* raise inexact if x != 0 */
40 if(huge+x>0.0) {/* return 0*sign(x) if |x|<1 */
41 if(i0<0) {i0=0x80000000;i1=0;}
42 else if((i0|i1)!=0) { i0=0x3ff00000;i1=0;}
46 if(((i0&i)|i1)==0) return x; /* x is integral */
47 if(huge+x>0.0) { /* raise inexact flag */
48 if(i0>0) i0 += (0x00100000)>>j0;
53 if(j0==0x400) return x+x; /* inf or NaN */
54 else return x; /* x is integral */
56 i = ((u_int32_t)(0xffffffff))>>(j0-20);
57 if((i1&i)==0) return x; /* x is integral */
58 if(huge+x>0.0) { /* raise inexact flag */
62 j = i1 + (1<<(52-j0));
63 if(j<i1) i0+=1; /* got a carry */
70 INSERT_WORDS(x,i0,i1);