46 lines
1.1 KiB
C
46 lines
1.1 KiB
C
/* s_tanf.c -- float version of s_tan.c.
|
|
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
|
|
*/
|
|
|
|
/*
|
|
* ====================================================
|
|
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
|
|
*
|
|
* Developed at SunPro, a Sun Microsystems, Inc. business.
|
|
* Permission to use, copy, modify, and distribute this
|
|
* software is freely granted, provided that this notice
|
|
* is preserved.
|
|
* ====================================================
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
#if defined(LIBM_SCCS) && !defined(lint)
|
|
__RCSID("$NetBSD: s_tanf.c,v 1.7 2002/05/26 22:01:58 wiz Exp $");
|
|
#endif
|
|
|
|
#include "math.h"
|
|
#include "math_private.h"
|
|
|
|
float
|
|
tanf(float x)
|
|
{
|
|
float y[2],z=0.0;
|
|
int32_t n, ix;
|
|
|
|
GET_FLOAT_WORD(ix,x);
|
|
|
|
/* |x| ~< pi/4 */
|
|
ix &= 0x7fffffff;
|
|
if(ix <= 0x3f490fda) return __kernel_tanf(x,z,1);
|
|
|
|
/* tan(Inf or NaN) is NaN */
|
|
else if (ix>=0x7f800000) return x-x; /* NaN */
|
|
|
|
/* argument reduction needed */
|
|
else {
|
|
n = __ieee754_rem_pio2f(x,y);
|
|
return __kernel_tanf(y[0],y[1],1-((n&1)<<1)); /* 1 -- n even
|
|
-1 -- n odd */
|
|
}
|
|
}
|