diff options
author | Eric Andersen <andersen@codepoet.org> | 2001-05-10 00:40:28 +0000 |
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committer | Eric Andersen <andersen@codepoet.org> | 2001-05-10 00:40:28 +0000 |
commit | 1077fa4d772832f77a677ce7fb7c2d513b959e3f (patch) | |
tree | 579bee13fb0b58d2800206366ec2caecbb15f3fc /libm/ldouble/coshl.c | |
parent | 22358dd7ce7bb49792204b698f01a6f69b9c8e08 (diff) |
uClibc now has a math library. muahahahaha!
-Erik
Diffstat (limited to 'libm/ldouble/coshl.c')
-rw-r--r-- | libm/ldouble/coshl.c | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/libm/ldouble/coshl.c b/libm/ldouble/coshl.c new file mode 100644 index 000000000..46212ae44 --- /dev/null +++ b/libm/ldouble/coshl.c @@ -0,0 +1,89 @@ +/* coshl.c + * + * Hyperbolic cosine, long double precision + * + * + * + * SYNOPSIS: + * + * long double x, y, coshl(); + * + * y = coshl( x ); + * + * + * + * DESCRIPTION: + * + * Returns hyperbolic cosine of argument in the range MINLOGL to + * MAXLOGL. + * + * cosh(x) = ( exp(x) + exp(-x) )/2. + * + * + * + * ACCURACY: + * + * Relative error: + * arithmetic domain # trials peak rms + * IEEE +-10000 30000 1.1e-19 2.8e-20 + * + * + * ERROR MESSAGES: + * + * message condition value returned + * cosh overflow |x| > MAXLOGL+LOGE2L INFINITYL + * + * + */ + + +/* +Cephes Math Library Release 2.7: May, 1998 +Copyright 1985, 1991, 1998 by Stephen L. Moshier +*/ + +#include <math.h> +extern long double MAXLOGL, MAXNUML, LOGE2L; +#ifdef ANSIPROT +extern long double expl ( long double ); +extern int isnanl ( long double ); +#else +long double expl(), isnanl(); +#endif +#ifdef INFINITIES +extern long double INFINITYL; +#endif +#ifdef NANS +extern long double NANL; +#endif + +long double coshl(x) +long double x; +{ +long double y; + +#ifdef NANS +if( isnanl(x) ) + return(x); +#endif +if( x < 0 ) + x = -x; +if( x > (MAXLOGL + LOGE2L) ) + { + mtherr( "coshl", OVERFLOW ); +#ifdef INFINITIES + return( INFINITYL ); +#else + return( MAXNUML ); +#endif + } +if( x >= (MAXLOGL - LOGE2L) ) + { + y = expl(0.5L * x); + y = (0.5L * y) * y; + return(y); + } +y = expl(x); +y = 0.5L * (y + 1.0L / y); +return( y ); +} |