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Diffstat (limited to 'src/math/e_atanh.c')
-rw-r--r-- | src/math/e_atanh.c | 59 |
1 files changed, 0 insertions, 59 deletions
diff --git a/src/math/e_atanh.c b/src/math/e_atanh.c deleted file mode 100644 index 45f1c966..00000000 --- a/src/math/e_atanh.c +++ /dev/null @@ -1,59 +0,0 @@ - -/* @(#)e_atanh.c 1.3 95/01/18 */ -/* - * ==================================================== - * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. - * - * Developed at SunSoft, a Sun Microsystems, Inc. business. - * Permission to use, copy, modify, and distribute this - * software is freely granted, provided that this notice - * is preserved. - * ==================================================== - * - */ - -/* atanh(x) - * Method : - * 1.Reduced x to positive by atanh(-x) = -atanh(x) - * 2.For x>=0.5 - * 1 2x x - * atanh(x) = --- * log(1 + -------) = 0.5 * log1p(2 * --------) - * 2 1 - x 1 - x - * - * For x<0.5 - * atanh(x) = 0.5*log1p(2x+2x*x/(1-x)) - * - * Special cases: - * atanh(x) is NaN if |x| > 1 with signal; - * atanh(NaN) is that NaN with no signal; - * atanh(+-1) is +-INF with signal. - * - */ - -#include <math.h> -#include "math_private.h" - -static const double one = 1.0, huge = 1e300; -static const double zero = 0.0; - -double -atanh(double x) -{ - double t; - int32_t hx,ix; - uint32_t lx; - EXTRACT_WORDS(hx,lx,x); - ix = hx&0x7fffffff; - if ((ix|((lx|(-lx))>>31))>0x3ff00000) /* |x|>1 */ - return (x-x)/(x-x); - if(ix==0x3ff00000) - return x/zero; - if(ix<0x3e300000&&(huge+x)>zero) return x; /* x<2**-28 */ - SET_HIGH_WORD(x,ix); - if(ix<0x3fe00000) { /* x < 0.5 */ - t = x+x; - t = 0.5*log1p(t+t*x/(one-x)); - } else - t = 0.5*log1p((x+x)/(one-x)); - if(hx>=0) return t; else return -t; -} |