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authorEric Andersen <andersen@codepoet.org>2001-05-10 00:40:28 +0000
committerEric Andersen <andersen@codepoet.org>2001-05-10 00:40:28 +0000
commit1077fa4d772832f77a677ce7fb7c2d513b959e3f (patch)
tree579bee13fb0b58d2800206366ec2caecbb15f3fc /libm/ldouble/coshl.c
parent22358dd7ce7bb49792204b698f01a6f69b9c8e08 (diff)
uClibc now has a math library. muahahahaha!
-Erik
Diffstat (limited to 'libm/ldouble/coshl.c')
-rw-r--r--libm/ldouble/coshl.c89
1 files changed, 89 insertions, 0 deletions
diff --git a/libm/ldouble/coshl.c b/libm/ldouble/coshl.c
new file mode 100644
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+/* 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 );
+}