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/* e_sinhf.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 "math.h" |
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#include "math_private.h" |
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static const float one = 1.0, shuge = 1.0e37; |
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float |
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sinhf(float x) |
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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(ix>=0x7f800000) 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 < 0x42b17180) return h*expf(fabsf(x)); |
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/* |x| in [log(maxdouble), overflowthresold] */ |
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if (ix<=0x42b2d4fc) { |
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w = 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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DEF_STD(sinhf); |