1*2fe8fb19SBen Gras /* s_floorf.c -- float version of s_floor.c.
2*2fe8fb19SBen Gras * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3*2fe8fb19SBen Gras */
4*2fe8fb19SBen Gras
5*2fe8fb19SBen Gras /*
6*2fe8fb19SBen Gras * ====================================================
7*2fe8fb19SBen Gras * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8*2fe8fb19SBen Gras *
9*2fe8fb19SBen Gras * Developed at SunPro, a Sun Microsystems, Inc. business.
10*2fe8fb19SBen Gras * Permission to use, copy, modify, and distribute this
11*2fe8fb19SBen Gras * software is freely granted, provided that this notice
12*2fe8fb19SBen Gras * is preserved.
13*2fe8fb19SBen Gras * ====================================================
14*2fe8fb19SBen Gras */
15*2fe8fb19SBen Gras
16*2fe8fb19SBen Gras #include <sys/cdefs.h>
17*2fe8fb19SBen Gras #if defined(LIBM_SCCS) && !defined(lint)
18*2fe8fb19SBen Gras __RCSID("$NetBSD: s_floorf.c,v 1.8 2008/04/25 22:21:53 christos Exp $");
19*2fe8fb19SBen Gras #endif
20*2fe8fb19SBen Gras
21*2fe8fb19SBen Gras /*
22*2fe8fb19SBen Gras * floorf(x)
23*2fe8fb19SBen Gras * Return x rounded toward -inf to integral value
24*2fe8fb19SBen Gras * Method:
25*2fe8fb19SBen Gras * Bit twiddling.
26*2fe8fb19SBen Gras * Exception:
27*2fe8fb19SBen Gras * Inexact flag raised if x not equal to floorf(x).
28*2fe8fb19SBen Gras */
29*2fe8fb19SBen Gras
30*2fe8fb19SBen Gras #include "math.h"
31*2fe8fb19SBen Gras #include "math_private.h"
32*2fe8fb19SBen Gras
33*2fe8fb19SBen Gras static const float huge = 1.0e30;
34*2fe8fb19SBen Gras
35*2fe8fb19SBen Gras float
floorf(float x)36*2fe8fb19SBen Gras floorf(float x)
37*2fe8fb19SBen Gras {
38*2fe8fb19SBen Gras int32_t i0,jj0;
39*2fe8fb19SBen Gras u_int32_t i;
40*2fe8fb19SBen Gras GET_FLOAT_WORD(i0,x);
41*2fe8fb19SBen Gras jj0 = ((i0>>23)&0xff)-0x7f;
42*2fe8fb19SBen Gras if(jj0<23) {
43*2fe8fb19SBen Gras if(jj0<0) { /* raise inexact if x != 0 */
44*2fe8fb19SBen Gras if(huge+x>(float)0.0) {/* return 0*sign(x) if |x|<1 */
45*2fe8fb19SBen Gras if(i0>=0) {i0=0;}
46*2fe8fb19SBen Gras else if((i0&0x7fffffff)!=0)
47*2fe8fb19SBen Gras { i0=0xbf800000;}
48*2fe8fb19SBen Gras }
49*2fe8fb19SBen Gras } else {
50*2fe8fb19SBen Gras i = (0x007fffff)>>jj0;
51*2fe8fb19SBen Gras if((i0&i)==0) return x; /* x is integral */
52*2fe8fb19SBen Gras if(huge+x>(float)0.0) { /* raise inexact flag */
53*2fe8fb19SBen Gras if(i0<0) i0 += (0x00800000)>>jj0;
54*2fe8fb19SBen Gras i0 &= (~i);
55*2fe8fb19SBen Gras }
56*2fe8fb19SBen Gras }
57*2fe8fb19SBen Gras } else {
58*2fe8fb19SBen Gras if(jj0==0x80) return x+x; /* inf or NaN */
59*2fe8fb19SBen Gras else return x; /* x is integral */
60*2fe8fb19SBen Gras }
61*2fe8fb19SBen Gras SET_FLOAT_WORD(x,i0);
62*2fe8fb19SBen Gras return x;
63*2fe8fb19SBen Gras }
64