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64 lines
1.6 KiB
C
64 lines
1.6 KiB
C
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/* ef_sinh.c -- float version of e_sinh.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, shuge = 1.0e37;
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#else
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static float one = 1.0, shuge = 1.0e37;
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#endif
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#ifdef __STDC__
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float __ieee754_sinhf(float x)
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#else
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float __ieee754_sinhf(x)
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float x;
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#endif
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{
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float t,w,h;
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__int32_t ix,jx;
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GET_FLOAT_WORD(jx,x);
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ix = jx&0x7fffffff;
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/* x is INF or NaN */
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if(!FLT_UWORD_IS_FINITE(ix)) return x+x;
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h = 0.5;
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if (jx<0) h = -h;
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/* |x| in [0,22], return sign(x)*0.5*(E+E/(E+1))) */
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if (ix < 0x41b00000) { /* |x|<22 */
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if (ix<0x31800000) /* |x|<2**-28 */
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if(shuge+x>one) return x;/* sinh(tiny) = tiny with inexact */
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t = expm1f(fabsf(x));
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if(ix<0x3f800000) return h*((float)2.0*t-t*t/(t+one));
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return h*(t+t/(t+one));
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}
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/* |x| in [22, log(maxdouble)] return 0.5*exp(|x|) */
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if (ix<=FLT_UWORD_LOG_MAX) return h*__ieee754_expf(fabsf(x));
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/* |x| in [log(maxdouble), overflowthresold] */
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if (ix<=FLT_UWORD_LOG_2MAX) {
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w = __ieee754_expf((float)0.5*fabsf(x));
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t = h*w;
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return t*w;
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}
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/* |x| > overflowthresold, sinh(x) overflow */
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return x*shuge;
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}
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