1 | /* ef_sinh.c -- float version of e_sinh.c. |
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2 | * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. |
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3 | */ |
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4 | |
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5 | /* |
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6 | * ==================================================== |
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7 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
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8 | * |
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9 | * Developed at SunPro, a Sun Microsystems, Inc. business. |
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10 | * Permission to use, copy, modify, and distribute this |
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11 | * software is freely granted, provided that this notice |
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12 | * is preserved. |
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13 | * ==================================================== |
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14 | */ |
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15 | |
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16 | #include "fdlibm.h" |
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17 | |
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18 | #ifdef __STDC__ |
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19 | static const float one = 1.0, shuge = 1.0e37; |
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20 | #else |
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21 | static float one = 1.0, shuge = 1.0e37; |
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22 | #endif |
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23 | |
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24 | #ifdef __STDC__ |
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25 | float __ieee754_sinhf(float x) |
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26 | #else |
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27 | float __ieee754_sinhf(x) |
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28 | float x; |
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29 | #endif |
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30 | { |
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31 | float t,w,h; |
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32 | __int32_t ix,jx; |
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33 | |
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34 | GET_FLOAT_WORD(jx,x); |
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35 | ix = jx&0x7fffffff; |
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36 | |
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37 | /* x is INF or NaN */ |
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38 | if(!FLT_UWORD_IS_FINITE(ix)) return x+x; |
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39 | |
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40 | h = 0.5; |
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41 | if (jx<0) h = -h; |
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42 | /* |x| in [0,22], return sign(x)*0.5*(E+E/(E+1))) */ |
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43 | if (ix < 0x41b00000) { /* |x|<22 */ |
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44 | if (ix<0x31800000) /* |x|<2**-28 */ |
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45 | if(shuge+x>one) return x;/* sinh(tiny) = tiny with inexact */ |
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46 | t = expm1f(fabsf(x)); |
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47 | if(ix<0x3f800000) return h*((float)2.0*t-t*t/(t+one)); |
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48 | return h*(t+t/(t+one)); |
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49 | } |
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50 | |
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51 | /* |x| in [22, log(maxdouble)] return 0.5*exp(|x|) */ |
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52 | if (ix<=FLT_UWORD_LOG_MAX) return h*__ieee754_expf(fabsf(x)); |
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53 | |
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54 | /* |x| in [log(maxdouble), overflowthresold] */ |
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55 | if (ix<=FLT_UWORD_LOG_2MAX) { |
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56 | w = __ieee754_expf((float)0.5*fabsf(x)); |
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57 | t = h*w; |
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58 | return t*w; |
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59 | } |
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60 | |
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61 | /* |x| > overflowthresold, sinh(x) overflow */ |
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62 | return x*shuge; |
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63 | } |
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