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