Update.
[glibc.git] / sysdeps / libm-ieee754 / s_floorf.c
blobe8822b088492064b7bef37a302a1a8e8cfc410f0
1 /* s_floorf.c -- float version of s_floor.c.
2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3 */
5 /*
6 * ====================================================
7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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 * ====================================================
16 #if defined(LIBM_SCCS) && !defined(lint)
17 static char rcsid[] = "$NetBSD: s_floorf.c,v 1.4 1995/05/10 20:47:22 jtc Exp $";
18 #endif
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).
29 #include "math.h"
30 #include "math_private.h"
32 #ifdef __STDC__
33 static const float huge = 1.0e30;
34 #else
35 static float huge = 1.0e30;
36 #endif
38 #ifdef __STDC__
39 float __floorf(float x)
40 #else
41 float __floorf(x)
42 float x;
43 #endif
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;}
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);
64 } else {
65 if(j0==0x80) return x+x; /* inf or NaN */
66 else return x; /* x is integral */
68 SET_FLOAT_WORD(x,i0);
69 return x;
71 weak_alias (__floorf, floorf)