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.
62 lines
1.3 KiB
C
62 lines
1.3 KiB
C
/* s_cosf.c -- float version of s_cos.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_cosf.c,v 1.9 2007/08/20 16:01:39 drochner Exp $");
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#endif
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#include "namespace.h"
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#include "math.h"
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#include "math_private.h"
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#if 0 /* notyet */
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#ifdef __weak_alias
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__weak_alias(cosf, _cosf)
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#endif
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#endif
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#if 0
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static const float one=1.0;
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#endif
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float
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cosf(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 <= 0x3f490fd8) return __kernel_cosf(x,z);
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/* cos(Inf or NaN) is NaN */
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else if (ix>=0x7f800000) return x-x;
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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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switch(n&3) {
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case 0: return __kernel_cosf(y[0],y[1]);
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case 1: return -__kernel_sinf(y[0],y[1],1);
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case 2: return -__kernel_cosf(y[0],y[1]);
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default:
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return __kernel_sinf(y[0],y[1],1);
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}
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}
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}
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