1*05a0b428SJohn Marino /* s_floorf.c -- float version of s_floor.c.
2*05a0b428SJohn Marino * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3*05a0b428SJohn Marino */
4*05a0b428SJohn Marino
5*05a0b428SJohn Marino /*
6*05a0b428SJohn Marino * ====================================================
7*05a0b428SJohn Marino * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8*05a0b428SJohn Marino *
9*05a0b428SJohn Marino * Developed at SunPro, a Sun Microsystems, Inc. business.
10*05a0b428SJohn Marino * Permission to use, copy, modify, and distribute this
11*05a0b428SJohn Marino * software is freely granted, provided that this notice
12*05a0b428SJohn Marino * is preserved.
13*05a0b428SJohn Marino * ====================================================
14*05a0b428SJohn Marino */
15*05a0b428SJohn Marino
16*05a0b428SJohn Marino /*
17*05a0b428SJohn Marino * floorf(x)
18*05a0b428SJohn Marino * Return x rounded toward -inf to integral value
19*05a0b428SJohn Marino * Method:
20*05a0b428SJohn Marino * Bit twiddling.
21*05a0b428SJohn Marino * Exception:
22*05a0b428SJohn Marino * Inexact flag raised if x not equal to floorf(x).
23*05a0b428SJohn Marino */
24*05a0b428SJohn Marino
25*05a0b428SJohn Marino #include "math.h"
26*05a0b428SJohn Marino #include "math_private.h"
27*05a0b428SJohn Marino
28*05a0b428SJohn Marino static const float huge = 1.0e30;
29*05a0b428SJohn Marino
30*05a0b428SJohn Marino float
floorf(float x)31*05a0b428SJohn Marino floorf(float x)
32*05a0b428SJohn Marino {
33*05a0b428SJohn Marino int32_t i0,jj0;
34*05a0b428SJohn Marino u_int32_t i;
35*05a0b428SJohn Marino GET_FLOAT_WORD(i0,x);
36*05a0b428SJohn Marino jj0 = ((i0>>23)&0xff)-0x7f;
37*05a0b428SJohn Marino if(jj0<23) {
38*05a0b428SJohn Marino if(jj0<0) { /* raise inexact if x != 0 */
39*05a0b428SJohn Marino if(huge+x>(float)0.0) {/* return 0*sign(x) if |x|<1 */
40*05a0b428SJohn Marino if(i0>=0) {i0=0;}
41*05a0b428SJohn Marino else if((i0&0x7fffffff)!=0)
42*05a0b428SJohn Marino { i0=0xbf800000;}
43*05a0b428SJohn Marino }
44*05a0b428SJohn Marino } else {
45*05a0b428SJohn Marino i = (0x007fffff)>>jj0;
46*05a0b428SJohn Marino if((i0&i)==0) return x; /* x is integral */
47*05a0b428SJohn Marino if(huge+x>(float)0.0) { /* raise inexact flag */
48*05a0b428SJohn Marino if(i0<0) i0 += (0x00800000)>>jj0;
49*05a0b428SJohn Marino i0 &= (~i);
50*05a0b428SJohn Marino }
51*05a0b428SJohn Marino }
52*05a0b428SJohn Marino } else {
53*05a0b428SJohn Marino if(jj0==0x80) return x+x; /* inf or NaN */
54*05a0b428SJohn Marino else return x; /* x is integral */
55*05a0b428SJohn Marino }
56*05a0b428SJohn Marino SET_FLOAT_WORD(x,i0);
57*05a0b428SJohn Marino return x;
58*05a0b428SJohn Marino }
59