1/* s_floorf.c -- float version of s_floor.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#if defined(LIBM_SCCS) && !defined(lint)
17static char rcsid[] = "$NetBSD: s_floorf.c,v 1.4 1995/05/10 20:47:22 jtc Exp $";
18#endif
19
20/*
21 * floorf(x)
22 * Return x rounded toward -inf to integral value
23 * Method:
24 *	Bit twiddling.
25 * Exception:
26 *	Inexact flag raised if x not equal to floorf(x).
27 */
28
29#include "math.h"
30#include "math_private.h"
31
32#ifdef __STDC__
33static const float huge = 1.0e30;
34#else
35static float huge = 1.0e30;
36#endif
37
38#ifdef __STDC__
39	float __floorf(float x)
40#else
41	float __floorf(x)
42	float x;
43#endif
44{
45	int32_t i0,j0;
46	u_int32_t i;
47	GET_FLOAT_WORD(i0,x);
48	j0 = ((i0>>23)&0xff)-0x7f;
49	if(j0<23) {
50	    if(j0<0) { 	/* raise inexact if x != 0 */
51		if(huge+x>(float)0.0) {/* return 0*sign(x) if |x|<1 */
52		    if(i0>=0) {i0=0;}
53		    else if((i0&0x7fffffff)!=0)
54			{ i0=0xbf800000;}
55		}
56	    } else {
57		i = (0x007fffff)>>j0;
58		if((i0&i)==0) return x; /* x is integral */
59		if(huge+x>(float)0.0) {	/* raise inexact flag */
60		    if(i0<0) i0 += (0x00800000)>>j0;
61		    i0 &= (~i);
62		}
63	    }
64	} else {
65	    if(j0==0x80) return x+x;	/* inf or NaN */
66	    else return x;		/* x is integral */
67	}
68	SET_FLOAT_WORD(x,i0);
69	return x;
70}
71weak_alias (__floorf, floorf)
72