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Diffstat (limited to 'libm/float/polevlf.c')
| -rw-r--r-- | libm/float/polevlf.c | 99 | 
1 files changed, 99 insertions, 0 deletions
| diff --git a/libm/float/polevlf.c b/libm/float/polevlf.c new file mode 100644 index 000000000..7d7b4d0b7 --- /dev/null +++ b/libm/float/polevlf.c @@ -0,0 +1,99 @@ +/*							polevlf.c + *							p1evlf.c + * + *	Evaluate polynomial + * + * + * + * SYNOPSIS: + * + * int N; + * float x, y, coef[N+1], polevlf[]; + * + * y = polevlf( x, coef, N ); + * + * + * + * DESCRIPTION: + * + * Evaluates polynomial of degree N: + * + *                     2          N + * y  =  C  + C x + C x  +...+ C x + *        0    1     2          N + * + * Coefficients are stored in reverse order: + * + * coef[0] = C  , ..., coef[N] = C  . + *            N                   0 + * + *  The function p1evl() assumes that coef[N] = 1.0 and is + * omitted from the array.  Its calling arguments are + * otherwise the same as polevl(). + * + * + * SPEED: + * + * In the interest of speed, there are no checks for out + * of bounds arithmetic.  This routine is used by most of + * the functions in the library.  Depending on available + * equipment features, the user may wish to rewrite the + * program in microcode or assembly language. + * + */ + + +/* +Cephes Math Library Release 2.1:  December, 1988 +Copyright 1984, 1987, 1988 by Stephen L. Moshier +Direct inquiries to 30 Frost Street, Cambridge, MA 02140 +*/ + +#include <math.h> + +float polevlf( float xx, float *coef, int N ) +{ +float ans, x; +float *p; +int i; + +x = xx; +p = coef; +ans = *p++; + +/* +for( i=0; i<N; i++ ) +	ans = ans * x  +  *p++; +*/ + +i = N; +do +	ans = ans * x  +  *p++; +while( --i ); + +return( ans ); +} + +/*							p1evl()	*/ +/*                                          N + * Evaluate polynomial when coefficient of x  is 1.0. + * Otherwise same as polevl. + */ + +float p1evlf( float xx, float *coef, int N ) +{ +float ans, x; +float *p; +int i; + +x = xx; +p = coef; +ans = x + *p++; +i = N-1; + +do +	ans = ans * x  + *p++; +while( --i ); + +return( ans ); +} | 
