intutil.c

/* Copyright (c) 2019 by NEC Corporation
 * This file is part of ve-jit */
#include "intutil.h"
#ifdef __cplusplus
extern "C" {
#endif //}

int const bitcount[256] = {
    0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4,
    1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
    1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
    2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
    1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
    2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
    2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
    3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
    1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
    2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
    2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
    3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
    2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
    3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
    3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
    4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8,
};

int const multiplyDeBruijnBitPosition2[32] = 
{
    0, 1, 28, 2, 29, 14, 24, 3, 30, 22, 20, 15, 25, 17, 4, 8, 
    31, 27, 13, 23, 21, 19, 16, 7, 26, 12, 18, 6, 11, 5, 10, 9
};

void fastdiv_make(struct fastdiv *d, uint32_t divisor)
{
    uint32_t l, r, e;
    uint64_t m;

    d->_odiv = divisor;
    // Modifed [ejk]
    l = ulog2(divisor);
    if (divisor & (divisor - 1)) {      // non-power-of-two?
        m = 1ULL << (l + 32);
        d->mul = (uint32_t)(m / divisor);
        r = (uint32_t)m - d->mul * divisor;
        e = divisor - r;
        if (e < (1UL << l)) {
            ++d->mul;
            d->add = 0;
        } else {
            d->add = d->mul;
        }
        d->shift = 32+l;                // <-- VE mod
    } else {                            // power-of-two divisor
        //printf(" divisor=%u,l=%d\n",divisor,l);
        d->mul = 1;
        d->add = 0;
        d->shift = (divisor<=1? 0: l);
    }
}

#ifdef __cplusplus //{
} //extern "C"
#endif
// vim: ts=4 sw=4 et cindent cino=^=l0,\:.5s,=-.5s,N-s,g.5s,b1 cinkeys=0{,0},0),\:,0#,!^F,o,O,e,0=break