1*05a0b428SJohn Marino /* s_tanf.c -- float version of s_tan.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 #include "math.h"
17*05a0b428SJohn Marino #include "math_private.h"
18*05a0b428SJohn Marino
19*05a0b428SJohn Marino float
tanf(float x)20*05a0b428SJohn Marino tanf(float x)
21*05a0b428SJohn Marino {
22*05a0b428SJohn Marino float y[2],z=0.0;
23*05a0b428SJohn Marino int32_t n, ix;
24*05a0b428SJohn Marino
25*05a0b428SJohn Marino GET_FLOAT_WORD(ix,x);
26*05a0b428SJohn Marino
27*05a0b428SJohn Marino /* |x| ~< pi/4 */
28*05a0b428SJohn Marino ix &= 0x7fffffff;
29*05a0b428SJohn Marino if(ix <= 0x3f490fda) return __kernel_tanf(x,z,1);
30*05a0b428SJohn Marino
31*05a0b428SJohn Marino /* tan(Inf or NaN) is NaN */
32*05a0b428SJohn Marino else if (ix>=0x7f800000) return x-x; /* NaN */
33*05a0b428SJohn Marino
34*05a0b428SJohn Marino /* argument reduction needed */
35*05a0b428SJohn Marino else {
36*05a0b428SJohn Marino n = __ieee754_rem_pio2f(x,y);
37*05a0b428SJohn Marino return __kernel_tanf(y[0],y[1],1-((n&1)<<1)); /* 1 -- n even
38*05a0b428SJohn Marino -1 -- n odd */
39*05a0b428SJohn Marino }
40*05a0b428SJohn Marino }
41