xref: /minix/lib/libm/src/s_ceilf.c (revision ebfedea0)
1 /* s_ceilf.c -- float version of s_ceil.c.
2  * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
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 #include <sys/cdefs.h>
17 #if defined(LIBM_SCCS) && !defined(lint)
18 __RCSID("$NetBSD: s_ceilf.c,v 1.8 2008/04/25 22:21:53 christos Exp $");
19 #endif
20 
21 #include "math.h"
22 #include "math_private.h"
23 
24 static const float huge = 1.0e30;
25 
26 float
27 ceilf(float x)
28 {
29 	int32_t i0,jj0;
30 	u_int32_t i;
31 
32 	GET_FLOAT_WORD(i0,x);
33 	jj0 = ((i0>>23)&0xff)-0x7f;
34 	if(jj0<23) {
35 	    if(jj0<0) { 	/* raise inexact if x != 0 */
36 		if(huge+x>(float)0.0) {/* return 0*sign(x) if |x|<1 */
37 		    if(i0<0) {i0=0x80000000;}
38 		    else if(i0!=0) { i0=0x3f800000;}
39 		}
40 	    } else {
41 		i = (0x007fffff)>>jj0;
42 		if((i0&i)==0) return x; /* x is integral */
43 		if(huge+x>(float)0.0) {	/* raise inexact flag */
44 		    if(i0>0) i0 += (0x00800000)>>jj0;
45 		    i0 &= (~i);
46 		}
47 	    }
48 	} else {
49 	    if(jj0==0x80) return x+x;	/* inf or NaN */
50 	    else return x;		/* x is integral */
51 	}
52 	SET_FLOAT_WORD(x,i0);
53 	return x;
54 }
55