mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-14 11:33:46 +00:00
94 lines
2.3 KiB
C
94 lines
2.3 KiB
C
/* origin: OpenBSD /usr/src/lib/libm/src/polevll.c */
|
|
/*
|
|
* Copyright (c) 2008 Stephen L. Moshier <steve@moshier.net>
|
|
*
|
|
* Permission to use, copy, modify, and distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
|
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
|
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
|
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
*/
|
|
/*
|
|
* Evaluate polynomial
|
|
*
|
|
*
|
|
* SYNOPSIS:
|
|
*
|
|
* int N;
|
|
* long double x, y, coef[N+1], polevl[];
|
|
*
|
|
* y = polevll( 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 p1evll() assumes that coef[N] = 1.0 and is
|
|
* omitted from the array. Its calling arguments are
|
|
* otherwise the same as polevll().
|
|
*
|
|
*
|
|
* 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.
|
|
*
|
|
*/
|
|
|
|
#include "libm.h"
|
|
|
|
#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
|
|
#else
|
|
/*
|
|
* Polynomial evaluator:
|
|
* P[0] x^n + P[1] x^(n-1) + ... + P[n]
|
|
*/
|
|
long double __polevll(long double x, const long double *P, int n)
|
|
{
|
|
long double y;
|
|
|
|
y = *P++;
|
|
do {
|
|
y = y * x + *P++;
|
|
} while (--n);
|
|
|
|
return y;
|
|
}
|
|
|
|
/*
|
|
* Polynomial evaluator:
|
|
* x^n + P[0] x^(n-1) + P[1] x^(n-2) + ... + P[n]
|
|
*/
|
|
long double __p1evll(long double x, const long double *P, int n)
|
|
{
|
|
long double y;
|
|
|
|
n -= 1;
|
|
y = x + *P++;
|
|
do {
|
|
y = y * x + *P++;
|
|
} while (--n);
|
|
|
|
return y;
|
|
}
|
|
#endif
|