| 1 | /* sf_asinh.c -- float version of s_asinh.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 |
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| 20 | #else |
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| 21 | static float |
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| 22 | #endif |
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| 23 | one = 1.0000000000e+00, /* 0x3F800000 */ |
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| 24 | ln2 = 6.9314718246e-01, /* 0x3f317218 */ |
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| 25 | huge= 1.0000000000e+30; |
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| 26 | |
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| 27 | #ifdef __STDC__ |
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| 28 | float asinhf(float x) |
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| 29 | #else |
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| 30 | float asinhf(x) |
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| 31 | float x; |
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| 32 | #endif |
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| 33 | { |
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| 34 | float t,w; |
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| 35 | __int32_t hx,ix; |
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| 36 | GET_FLOAT_WORD(hx,x); |
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| 37 | ix = hx&0x7fffffff; |
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| 38 | if(ix>=0x7f800000) return x+x; /* x is inf or NaN */ |
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| 39 | if(ix< 0x31800000) { /* |x|<2**-28 */ |
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| 40 | if(huge+x>one) return x; /* return x inexact except 0 */ |
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| 41 | } |
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| 42 | if(ix>0x4d800000) { /* |x| > 2**28 */ |
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| 43 | w = logf(fabsf(x))+ln2; |
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| 44 | } else if (ix>0x40000000) { /* 2**28 > |x| > 2.0 */ |
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| 45 | t = fabsf(x); |
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| 46 | w = logf((float)2.0*t+one/(sqrtf(x*x+one)+t)); |
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| 47 | } else { /* 2.0 > |x| > 2**-28 */ |
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| 48 | t = x*x; |
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| 49 | w =log1pf(fabsf(x)+t/(one+sqrtf(one+t))); |
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| 50 | } |
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| 51 | if(hx>0) return w; else return -w; |
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| 52 | } |
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| 53 | |
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| 54 | #ifdef _DOUBLE_IS_32BITS |
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| 55 | |
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| 56 | #ifdef __STDC__ |
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| 57 | double asinh(double x) |
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| 58 | #else |
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| 59 | double asinh(x) |
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| 60 | double x; |
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| 61 | #endif |
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| 62 | { |
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| 63 | return (double) asinhf((float) x); |
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| 64 | } |
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| 65 | |
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| 66 | #endif /* defined(_DOUBLE_IS_32BITS) */ |
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