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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/double/sinh.c
parent22358dd7ce7bb49792204b698f01a6f69b9c8e08 (diff)
uClibc now has a math library. muahahahaha!
-Erik
Diffstat (limited to 'libm/double/sinh.c')
-rw-r--r--libm/double/sinh.c148
1 files changed, 148 insertions, 0 deletions
diff --git a/libm/double/sinh.c b/libm/double/sinh.c
new file mode 100644
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+++ b/libm/double/sinh.c
@@ -0,0 +1,148 @@
+/* sinh.c
+ *
+ * Hyperbolic sine
+ *
+ *
+ *
+ * SYNOPSIS:
+ *
+ * double x, y, sinh();
+ *
+ * y = sinh( x );
+ *
+ *
+ *
+ * DESCRIPTION:
+ *
+ * Returns hyperbolic sine of argument in the range MINLOG to
+ * MAXLOG.
+ *
+ * The range is partitioned into two segments. If |x| <= 1, a
+ * rational function of the form x + x**3 P(x)/Q(x) is employed.
+ * Otherwise the calculation is sinh(x) = ( exp(x) - exp(-x) )/2.
+ *
+ *
+ *
+ * ACCURACY:
+ *
+ * Relative error:
+ * arithmetic domain # trials peak rms
+ * DEC +- 88 50000 4.0e-17 7.7e-18
+ * IEEE +-MAXLOG 30000 2.6e-16 5.7e-17
+ *
+ */
+
+/*
+Cephes Math Library Release 2.8: June, 2000
+Copyright 1984, 1995, 2000 by Stephen L. Moshier
+*/
+
+#include <math.h>
+
+#ifdef UNK
+static double P[] = {
+-7.89474443963537015605E-1,
+-1.63725857525983828727E2,
+-1.15614435765005216044E4,
+-3.51754964808151394800E5
+};
+static double Q[] = {
+/* 1.00000000000000000000E0,*/
+-2.77711081420602794433E2,
+ 3.61578279834431989373E4,
+-2.11052978884890840399E6
+};
+#endif
+
+#ifdef DEC
+static unsigned short P[] = {
+0140112,0015377,0042731,0163255,
+0142043,0134721,0146177,0123761,
+0143464,0122706,0034353,0006017,
+0144653,0140536,0157665,0054045
+};
+static unsigned short Q[] = {
+/*0040200,0000000,0000000,0000000,*/
+0142212,0155404,0133513,0022040,
+0044015,0036723,0173271,0011053,
+0145400,0150407,0023710,0001034
+};
+#endif
+
+#ifdef IBMPC
+static unsigned short P[] = {
+0x3cd6,0xe8bb,0x435f,0xbfe9,
+0xf4fe,0x398f,0x773a,0xc064,
+0x6182,0xc71d,0x94b8,0xc0c6,
+0xab05,0xdbf6,0x782b,0xc115
+};
+static unsigned short Q[] = {
+/*0x0000,0x0000,0x0000,0x3ff0,*/
+0x6484,0x96e9,0x5b60,0xc071,
+0x2245,0x7ed7,0xa7ba,0x40e1,
+0x0044,0xe4f9,0x1a20,0xc140
+};
+#endif
+
+#ifdef MIEEE
+static unsigned short P[] = {
+0xbfe9,0x435f,0xe8bb,0x3cd6,
+0xc064,0x773a,0x398f,0xf4fe,
+0xc0c6,0x94b8,0xc71d,0x6182,
+0xc115,0x782b,0xdbf6,0xab05
+};
+static unsigned short Q[] = {
+0xc071,0x5b60,0x96e9,0x6484,
+0x40e1,0xa7ba,0x7ed7,0x2245,
+0xc140,0x1a20,0xe4f9,0x0044
+};
+#endif
+
+#ifdef ANSIPROT
+extern double fabs ( double );
+extern double exp ( double );
+extern double polevl ( double, void *, int );
+extern double p1evl ( double, void *, int );
+#else
+double fabs(), exp(), polevl(), p1evl();
+#endif
+extern double INFINITY, MINLOG, MAXLOG, LOGE2;
+
+double sinh(x)
+double x;
+{
+double a;
+
+#ifdef MINUSZERO
+if( x == 0.0 )
+ return(x);
+#endif
+a = fabs(x);
+if( (x > (MAXLOG + LOGE2)) || (x > -(MINLOG-LOGE2) ) )
+ {
+ mtherr( "sinh", DOMAIN );
+ if( x > 0 )
+ return( INFINITY );
+ else
+ return( -INFINITY );
+ }
+if( a > 1.0 )
+ {
+ if( a >= (MAXLOG - LOGE2) )
+ {
+ a = exp(0.5*a);
+ a = (0.5 * a) * a;
+ if( x < 0 )
+ a = -a;
+ return(a);
+ }
+ a = exp(a);
+ a = 0.5*a - (0.5/a);
+ if( x < 0 )
+ a = -a;
+ return(a);
+ }
+
+a *= a;
+return( x + x * a * (polevl(a,P,3)/p1evl(a,Q,3)) );
+}