792e51b721
This patch adds the long double functions missing in newlib to Cygwin.
Apart from some self-written additions (exp10l, finite{f,l}, isinf{f,l},
isnan{f,l}, pow10l) the files are taken from the Mingw-w64 math lib.
Minor changes were required, e.g. substitue _WIN64 with __x86_64__ and
fixing __FLT_RPT_DOMAIN/__FLT_RPT_ERANGE for Cygwin.
Cygwin:
* math: New subdir with math functions.
* Makefile.in (VPATH): Add math subdir.
(MATH_OFILES): List of object files collected from building files in
math subdir.
(DLL_OFILES): Add $(MATH_OFILES).
${CURDIR}/libm.a: Add $(MATH_OFILES) to build.
* common.din: Add new functions from math subdir.
* i686.din: Align to new math subdir. Remove functions now commonly
available.
* x86_64.din: Ditto.
* math.h: math.h wrapper to define mingw structs used in some files in
math subdir.
* include/cygwin/version.h: Bump API minor version.
newlib:
* libc/include/complex.h: Add prototypes for complex long double
functions. Only define for Cygwin.
* libc/include/math.h: Additionally enable prototypes of long double
functions for Cygwin. Add Cygwin-only prototypes for dreml, sincosl,
exp10l and pow10l. Explain why we don't add them to newlib.
* libc/include/tgmath.h: Enable long double handling on Cygwin.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
35 lines
941 B
C
35 lines
941 B
C
/**
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* This file has no copyright assigned and is placed in the Public Domain.
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* This file is part of the mingw-w64 runtime package.
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* No warranty is given; refer to the file DISCLAIMER.PD within this package.
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*/
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#include <math.h>
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#include <errno.h>
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#include "fastmath.h"
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/* atanh (x) = 0.5 * log ((1.0 + x)/(1.0 - x)) */
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long double atanhl (long double x)
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{
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long double z;
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if (isnan (x))
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return x;
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z = fabsl (x);
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if (z == 1.0L)
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{
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errno = ERANGE;
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return (x > 0 ? INFINITY : -INFINITY);
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}
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if ( z > 1.0L)
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{
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errno = EDOM;
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return nanl("");
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}
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/* Rearrange formula to avoid precision loss for small x.
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atanh(x) = 0.5 * log ((1.0 + x)/(1.0 - x))
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= 0.5 * log1p ((1.0 + x)/(1.0 - x) - 1.0)
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= 0.5 * log1p ((1.0 + x - 1.0 + x) /(1.0 - x))
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= 0.5 * log1p ((2.0 * x ) / (1.0 - x)) */
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z = 0.5L * __fast_log1pl ((z + z) / (1.0L - z));
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return x >= 0 ? z : -z;
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}
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