xref: /netbsd-src/lib/libm/src/s_ceilf.c (revision 3b01aba77a7a698587faaae455bbfe740923c1f5)
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 1.6 1999/07/02 15:37:42 simonb Exp $");
19 #endif
20 
21 #include "math.h"
22 #include "math_private.h"
23 
24 #ifdef __STDC__
25 static const float huge = 1.0e30;
26 #else
27 static float huge = 1.0e30;
28 #endif
29 
30 #ifdef __STDC__
31 	float ceilf(float x)
32 #else
33 	float ceilf(x)
34 	float x;
35 #endif
36 {
37 	int32_t i0,j0;
38 	u_int32_t i;
39 
40 	GET_FLOAT_WORD(i0,x);
41 	j0 = ((i0>>23)&0xff)-0x7f;
42 	if(j0<23) {
43 	    if(j0<0) { 	/* raise inexact if x != 0 */
44 		if(huge+x>(float)0.0) {/* return 0*sign(x) if |x|<1 */
45 		    if(i0<0) {i0=0x80000000;}
46 		    else if(i0!=0) { i0=0x3f800000;}
47 		}
48 	    } else {
49 		i = (0x007fffff)>>j0;
50 		if((i0&i)==0) return x; /* x is integral */
51 		if(huge+x>(float)0.0) {	/* raise inexact flag */
52 		    if(i0>0) i0 += (0x00800000)>>j0;
53 		    i0 &= (~i);
54 		}
55 	    }
56 	} else {
57 	    if(j0==0x80) return x+x;	/* inf or NaN */
58 	    else return x;		/* x is integral */
59 	}
60 	SET_FLOAT_WORD(x,i0);
61 	return x;
62 }
63