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 #ifdef __STDC__
tanf(float x)19 	float tanf(float x)
20 #else
21 	float tanf(x)
22 	float x;
23 #endif
24 {
25 	float y[2],z=0.0;
26 	__int32_t n,ix;
27 
28 	GET_FLOAT_WORD(ix,x);
29 
30     /* |x| ~< pi/4 */
31 	ix &= 0x7fffffff;
32 	if(ix <= 0x3f490fda) return __kernel_tanf(x,z,1);
33 
34     /* tan(Inf or NaN) is NaN */
35 	else if (!FLT_UWORD_IS_FINITE(ix)) return x-x;		/* NaN */
36 
37     /* argument reduction needed */
38 	else {
39 	    n = __ieee754_rem_pio2f(x,y);
40 	    return __kernel_tanf(y[0],y[1],1-((n&1)<<1)); /*   1 -- n even
41 							      -1 -- n odd */
42 	}
43 }
44 
45 #ifdef _DOUBLE_IS_32BITS
46 
47 #ifdef __STDC__
tan(double x)48 	double tan(double x)
49 #else
50 	double tan(x)
51 	double x;
52 #endif
53 {
54 	return (double) tanf((float) x);
55 }
56 
57 #endif /* defined(_DOUBLE_IS_32BITS) */
58