/usr/share/sdcc/lib/src/tancotf.c is in sdcc-libraries 2.9.0-5.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 | /* tancotf.c: Computes tan or cot of a 32-bit float as outlined in [1]
Copyright (C) 2001, 2002 Jesus Calvino-Fraga, jesusc@ieee.org
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/* [1] William James Cody and W. M. Waite. _Software manual for the
elementary functions_, Englewood Cliffs, N.J.:Prentice-Hall, 1980. */
/* Version 1.0 - Initial release */
#include <math.h>
#include <errno.h>
#define P0 0.100000000E+1
#define P1 -0.958017723E-1
#define Q0 0.100000000E+1
#define Q1 -0.429135777E+0
#define Q2 0.971685835E-2
#define C1 1.5703125
#define C2 4.83826794897E-4
#define P(f,g) (P1*g*f+f)
#define Q(g) ((Q2*g+Q1)*g+Q0)
//A reasonable choice for YMAX is the integer part of B**(t/2)*PI/2:
#define YMAX 6433.0
float tancotf(const float x, const int iscotan)
{
float f, g, xn, xnum, xden;
int n;
if (fabsf(x) > YMAX)
{
errno = ERANGE;
return 0.0;
}
/*Round x*2*PI to the nearest integer*/
n=(x*TWO_O_PI+(x>0.0?0.5:-0.5)); /*works for +-x*/
xn=n;
xnum=(int)x;
xden=x-xnum;
f=((xnum-xn*C1)+xden)-xn*C2;
if (fabsf(f) < EPS)
{
xnum = f;
xden = 1.0;
}
else
{
g = f*f;
xnum = P(f,g);
xden = Q(g);
}
if(n&1)
//xn is odd
{
if(iscotan) return (-xnum/xden);
else return (-xden/xnum);
}
else
{
if(iscotan) return (xden/xnum);
else return (xnum/xden);
}
}
|