69 lines
1.4 KiB
C
69 lines
1.4 KiB
C
/* sf_cos.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 "fdlibm.h"
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#ifdef __STDC__
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static const float one=1.0;
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#else
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static float one=1.0;
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#endif
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#ifdef __STDC__
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float cosf(float x)
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#else
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float cosf(x)
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float x;
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#endif
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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 (!FLT_UWORD_IS_FINITE(ix)) 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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#ifdef _DOUBLE_IS_32BITS
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#ifdef __STDC__
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double cos(double x)
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#else
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double cos(x)
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double x;
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#endif
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{
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return (double) cosf((float) x);
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}
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#endif /* defined(_DOUBLE_IS_32BITS) */
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