From 1077fa4d772832f77a677ce7fb7c2d513b959e3f Mon Sep 17 00:00:00 2001 From: Eric Andersen Date: Thu, 10 May 2001 00:40:28 +0000 Subject: uClibc now has a math library. muahahahaha! -Erik --- libm/float/facf.c | 106 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 106 insertions(+) create mode 100644 libm/float/facf.c (limited to 'libm/float/facf.c') diff --git a/libm/float/facf.c b/libm/float/facf.c new file mode 100644 index 000000000..c69738897 --- /dev/null +++ b/libm/float/facf.c @@ -0,0 +1,106 @@ +/* facf.c + * + * Factorial function + * + * + * + * SYNOPSIS: + * + * float y, facf(); + * int i; + * + * y = facf( i ); + * + * + * + * DESCRIPTION: + * + * Returns factorial of i = 1 * 2 * 3 * ... * i. + * fac(0) = 1.0. + * + * Due to machine arithmetic bounds the largest value of + * i accepted is 33 in single precision arithmetic. + * Greater values, or negative ones, + * produce an error message and return MAXNUM. + * + * + * + * ACCURACY: + * + * For i < 34 the values are simply tabulated, and have + * full machine accuracy. + * + */ + +/* +Cephes Math Library Release 2.0: April, 1987 +Copyright 1984, 1987 by Stephen L. Moshier +Direct inquiries to 30 Frost Street, Cambridge, MA 02140 +*/ + +#include + +/* Factorials of integers from 0 through 33 */ +static float factbl[] = { + 1.00000000000000000000E0, + 1.00000000000000000000E0, + 2.00000000000000000000E0, + 6.00000000000000000000E0, + 2.40000000000000000000E1, + 1.20000000000000000000E2, + 7.20000000000000000000E2, + 5.04000000000000000000E3, + 4.03200000000000000000E4, + 3.62880000000000000000E5, + 3.62880000000000000000E6, + 3.99168000000000000000E7, + 4.79001600000000000000E8, + 6.22702080000000000000E9, + 8.71782912000000000000E10, + 1.30767436800000000000E12, + 2.09227898880000000000E13, + 3.55687428096000000000E14, + 6.40237370572800000000E15, + 1.21645100408832000000E17, + 2.43290200817664000000E18, + 5.10909421717094400000E19, + 1.12400072777760768000E21, + 2.58520167388849766400E22, + 6.20448401733239439360E23, + 1.55112100433309859840E25, + 4.03291461126605635584E26, + 1.0888869450418352160768E28, + 3.04888344611713860501504E29, + 8.841761993739701954543616E30, + 2.6525285981219105863630848E32, + 8.22283865417792281772556288E33, + 2.6313083693369353016721801216E35, + 8.68331761881188649551819440128E36 +}; +#define MAXFACF 33 + +extern float MAXNUMF; + +#ifdef ANSIC +float facf( int i ) +#else +float facf(i) +int i; +#endif +{ + +if( i < 0 ) + { + mtherr( "facf", SING ); + return( MAXNUMF ); + } + +if( i > MAXFACF ) + { + mtherr( "facf", OVERFLOW ); + return( MAXNUMF ); + } + +/* Get answer from table for small i. */ +return( factbl[i] ); +} -- cgit v1.2.3