Return to cos.c CVS log

Up to [MW Coherent from dump] / coherent / b / lib / libm

Annotation of coherent/b/lib/libm/cos.c, revision 1.1

1.1     ! root        1: /*
        !             2:  * libm/cos.c
        !             3:  * Evaluate the cosine function.
        !             4:  */
        !             5: 
        !             6: #include <math.h>
        !             7: 
        !             8: #if    EMU87
        !             9: #include "emumath.h"
        !            10: #endif
        !            11: 
        !            12: /*
        !            13:  * (Hart 2923, 19.96)
        !            14:  */
        !            15: static readonly double sintab[] ={
        !            16:         0.523598775598298873071308e+00,
        !            17:        -0.239245962039350458667960e-01,
        !            18:         0.327953194428661969081000e-03,
        !            19:        -0.214071976918198811800000e-05,
        !            20:         0.815125650404748400000000e-08,
        !            21:        -0.203153509377510000000000e-10,
        !            22:         0.355397103280000000000000e-13
        !            23: };
        !            24: 
        !            25: /*
        !            26:  * (Hart 3824, 19.45)
        !            27:  */
        !            28: static readonly double costab[] ={
        !            29:         0.99999999999999999996415,
        !            30:        -0.30842513753404245242414,
        !            31:         0.01585434424381541089754,
        !            32:        -0.00032599188692668755044,
        !            33:         0.00000359086044588581953,
        !            34:        -0.00000002461136382637005,
        !            35:         0.00000000011500497024263,
        !            36:        -0.00000000000038577620372
        !            37: };
        !            38: 
        !            39: double
        !            40: cos(x) double x;
        !            41: {
        !            42:        double r;
        !            43:        register int s;
        !            44: 
        !            45:        if ((x = modf(x/(2.0*PI), &r)) < 0.0) {
        !            46:                x += 1.0;
        !            47:                r -= 1.0;
        !            48:        }
        !            49:        s = 0;
        !            50:        if (x > 0.5) {
        !            51:                s = 1;
        !            52:                x -= 0.5;
        !            53:        }
        !            54:        if (x > 0.25) {
        !            55:                s ^= 1;
        !            56:                x = 0.5 - x;
        !            57:        }
        !            58:        if (x > 0.125) {
        !            59:                x = 3.0 - 12.0*x;
        !            60:                r = x*_pol(x*x, sintab, 7);
        !            61:        } else {
        !            62:                x *= 8.0;
        !            63:                r = _pol(x*x, costab, 8);
        !            64:        }
        !            65:        return s ? -r : r;
        !            66: }
        !            67: 
        !            68: /* end of libm/cos.c */

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.