5980be9b3c
This work is based in part on code from NetBSD libm, libc and kernel. The library is partly public domain and partly BSD-style licensed.
46 lines
1.1 KiB
C
46 lines
1.1 KiB
C
/* s_tanf.c -- float version of s_tan.c.
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* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
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*/
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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#include <sys/cdefs.h>
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#if defined(LIBM_SCCS) && !defined(lint)
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__RCSID("$NetBSD: s_tanf.c,v 1.7 2002/05/26 22:01:58 wiz Exp $");
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#endif
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#include "math.h"
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#include "math_private.h"
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float
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tanf(float x)
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{
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float y[2],z=0.0;
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int32_t n, ix;
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GET_FLOAT_WORD(ix,x);
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/* |x| ~< pi/4 */
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ix &= 0x7fffffff;
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if(ix <= 0x3f490fda) return __kernel_tanf(x,z,1);
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/* tan(Inf or NaN) is NaN */
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else if (ix>=0x7f800000) return x-x; /* NaN */
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/* argument reduction needed */
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else {
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n = __ieee754_rem_pio2f(x,y);
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return __kernel_tanf(y[0],y[1],1-((n&1)<<1)); /* 1 -- n even
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-1 -- n odd */
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}
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}
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