shithub: mc

ref: ff88594df5c5df6fb8f227ab8e5df3529ba6e72f
dir: /lib/math/poly-impl.myr/

use std

/* See [Mul16], section 5.1 */
pkg math =
        pkglocal const horner_poly32 : (x : flt32, a : flt32[:] -> flt32)
        pkglocal const horner_poly64 : (x : flt64, a : flt64[:] -> flt64)

        pkglocal const horner_polyu32 : (x : flt32, a : uint32[:] -> flt32)
        pkglocal const horner_polyu64 : (x : flt64, a : uint64[:] -> flt64)
;;

extern const fma32 : (x : flt32, y : flt32, z : flt32 -> flt32)
extern const fma64 : (x : flt64, y : flt64, z : flt64 -> flt64)

const horner_poly32 = {x : flt32, a : flt32[:]
        var r : flt32 = 0.0
        for var j = a.len - 1; j >= 0; j--
                r = fma32(r, x, a[j])
        ;;
        -> r
}

const horner_poly64 = {x : flt64, a : flt64[:]
        var r : flt64 = 0.0
        for var j = a.len - 1; j >= 0; j--
                r = fma64(r, x, a[j])
        ;;
        -> r
}

const horner_polyu32 = {x : flt32, a : uint32[:]
        var r : flt32 = 0.0
        for var j = a.len - 1; j >= 0; j--
                r = fma32(r, x, std.flt32frombits(a[j]))
        ;;
        -> r
}

const horner_polyu64 = {x : flt64, a : uint64[:]
        var r : flt64 = 0.0
        for var j = a.len - 1; j >= 0; j--
                r = fma64(r, x, std.flt64frombits(a[j]))
        ;;
        -> r
}

/* TODO: add Knuth's method */