1df930be7Sderaadt /* s_tanf.c -- float version of s_tan.c.
2df930be7Sderaadt * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3df930be7Sderaadt */
4df930be7Sderaadt
5df930be7Sderaadt /*
6df930be7Sderaadt * ====================================================
7df930be7Sderaadt * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8df930be7Sderaadt *
9df930be7Sderaadt * Developed at SunPro, a Sun Microsystems, Inc. business.
10df930be7Sderaadt * Permission to use, copy, modify, and distribute this
11df930be7Sderaadt * software is freely granted, provided that this notice
12df930be7Sderaadt * is preserved.
13df930be7Sderaadt * ====================================================
14df930be7Sderaadt */
15df930be7Sderaadt
16df930be7Sderaadt #include "math.h"
17df930be7Sderaadt #include "math_private.h"
18df930be7Sderaadt
19*e7beb4a7Smillert float
tanf(float x)20*e7beb4a7Smillert tanf(float x)
21df930be7Sderaadt {
22df930be7Sderaadt float y[2],z=0.0;
23df930be7Sderaadt int32_t n, ix;
24df930be7Sderaadt
25df930be7Sderaadt GET_FLOAT_WORD(ix,x);
26df930be7Sderaadt
27df930be7Sderaadt /* |x| ~< pi/4 */
28df930be7Sderaadt ix &= 0x7fffffff;
29df930be7Sderaadt if(ix <= 0x3f490fda) return __kernel_tanf(x,z,1);
30df930be7Sderaadt
31df930be7Sderaadt /* tan(Inf or NaN) is NaN */
32df930be7Sderaadt else if (ix>=0x7f800000) return x-x; /* NaN */
33df930be7Sderaadt
34df930be7Sderaadt /* argument reduction needed */
35df930be7Sderaadt else {
36df930be7Sderaadt n = __ieee754_rem_pio2f(x,y);
37df930be7Sderaadt return __kernel_tanf(y[0],y[1],1-((n&1)<<1)); /* 1 -- n even
38df930be7Sderaadt -1 -- n odd */
39df930be7Sderaadt }
40df930be7Sderaadt }
41