1 /* sf_tan.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 "fdlibm.h"
17
18 float
tanf(float x)19 tanf(float x)
20 {
21 float y[2], z = 0.0;
22 __int32_t n, ix;
23
24 GET_FLOAT_WORD(ix, x);
25
26 /* |x| ~< pi/4 */
27 ix &= 0x7fffffff;
28 if (ix <= 0x3f490fda)
29 return __kernel_tanf(x, z, 1);
30
31 /* tan(Inf or NaN) is NaN */
32 else if (!FLT_UWORD_IS_FINITE(ix))
33 return __math_invalidf(x); /* NaN */
34
35 /* argument reduction needed */
36 else {
37 n = __rem_pio2f(x, y);
38 return __kernel_tanf(y[0], y[1], 1 - ((n & 1) << 1)); /* 1 -- n even
39 -1 -- n odd */
40 }
41 }
42
43 _MATH_ALIAS_f_f(tan)
44
