/* origin: FreeBSD /usr/src/lib/msun/src/e_j1f.c */

/*

 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.

 */

/*

 * ====================================================

 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.

 *

 * Developed at SunPro, a Sun Microsystems, Inc. business.

 * Permission to use, copy, modify, and distribute this

 * software is freely granted, provided that this notice

 * is preserved.

 * ====================================================

 */

use super::{cosf, fabsf, logf, sinf, sqrtf};

const INVSQRTPI: f32 = 5.6418961287e-01; /* 0x3f106ebb */

const TPI: f32 = 6.3661974669e-01; /* 0x3f22f983 */

fn common(ix: u32, x: f32, y1: bool, sign: bool) -> f32 {

    let z: f64;

    let mut s: f64;

    let c: f64;

    let mut ss: f64;

    let mut cc: f64;

    s = sinf(x) as f64;

    if y1 {

        s = -s;

    }

    c = cosf(x) as f64;

    cc = s - c;

    if ix < 0x7f000000 {

        ss = -s - c;

        z = cosf(2.0 * x) as f64;

        if s * c > 0.0 {

            cc = z / ss;

        } else {

            ss = z / cc;

        }

        if ix < 0x58800000 {

            if y1 {

                ss = -ss;

            }

            cc = (ponef(x) as f64) * cc - (qonef(x) as f64) * ss;

        }

    }

    if sign {

        cc = -cc;

    }

    return (((INVSQRTPI as f64) * cc) / (sqrtf(x) as f64)) as f32;

}

/* R0/S0 on [0,2] */

const R00: f32 = -6.2500000000e-02; /* 0xbd800000 */

const R01: f32 = 1.4070566976e-03; /* 0x3ab86cfd */

const R02: f32 = -1.5995563444e-05; /* 0xb7862e36 */

const R03: f32 = 4.9672799207e-08; /* 0x335557d2 */

const S01: f32 = 1.9153760746e-02; /* 0x3c9ce859 */

const S02: f32 = 1.8594678841e-04; /* 0x3942fab6 */

const S03: f32 = 1.1771846857e-06; /* 0x359dffc2 */

const S04: f32 = 5.0463624390e-09; /* 0x31ad6446 */

const S05: f32 = 1.2354227016e-11; /* 0x2d59567e */

/// First order of the [Bessel function](https://en.wikipedia.org/wiki/Bessel_function) of the first kind (f32).

pub fn j1f(x: f32) -> f32 {

    let mut z: f32;

    let r: f32;

    let s: f32;

    let mut ix: u32;

    let sign: bool;

    ix = x.to_bits();

    sign = (ix >> 31) != 0;

    ix &= 0x7fffffff;

    if ix >= 0x7f800000 {

        return 1.0 / (x * x);

    }

    if ix >= 0x40000000 {

        /* |x| >= 2 */

        return common(ix, fabsf(x), false, sign);

    }

    if ix >= 0x39000000 {

        /* |x| >= 2**-13 */

        z = x * x;

        r = z * (R00 + z * (R01 + z * (R02 + z * R03)));

        s = 1.0 + z * (S01 + z * (S02 + z * (S03 + z * (S04 + z * S05))));

        z = 0.5 + r / s;

    } else {

        z = 0.5;

    }

    return z * x;

}

const U0: [f32; 5] = [

    -1.9605709612e-01, /* 0xbe48c331 */

    5.0443872809e-02,  /* 0x3d4e9e3c */

    -1.9125689287e-03, /* 0xbafaaf2a */

    2.3525259166e-05,  /* 0x37c5581c */

    -9.1909917899e-08, /* 0xb3c56003 */

];

const V0: [f32; 5] = [

    1.9916731864e-02, /* 0x3ca3286a */

    2.0255257550e-04, /* 0x3954644b */

    1.3560879779e-06, /* 0x35b602d4 */

    6.2274145840e-09, /* 0x31d5f8eb */

    1.6655924903e-11, /* 0x2d9281cf */

];

/// First order of the [Bessel function](https://en.wikipedia.org/wiki/Bessel_function) of the second kind (f32).

pub fn y1f(x: f32) -> f32 {

    let z: f32;

    let u: f32;

    let v: f32;

    let ix: u32;

    ix = x.to_bits();

    if (ix & 0x7fffffff) == 0 {

        return -1.0 / 0.0;

    }

    if (ix >> 31) != 0 {

        return 0.0 / 0.0;

    }

    if ix >= 0x7f800000 {

        return 1.0 / x;

    }

    if ix >= 0x40000000 {

        /* |x| >= 2.0 */

        return common(ix, x, true, false);

    }

    if ix < 0x33000000 {

        /* x < 2**-25 */

        return -TPI / x;

    }

    z = x * x;

    u = U0[0] + z * (U0[1] + z * (U0[2] + z * (U0[3] + z * U0[4])));

    v = 1.0 + z * (V0[0] + z * (V0[1] + z * (V0[2] + z * (V0[3] + z * V0[4]))));

    return x * (u / v) + TPI * (j1f(x) * logf(x) - 1.0 / x);

}

/* For x >= 8, the asymptotic expansions of pone is

 *      1 + 15/128 s^2 - 4725/2^15 s^4 - ...,   where s = 1/x.

 * We approximate pone by

 *      pone(x) = 1 + (R/S)

 * where  R = pr0 + pr1*s^2 + pr2*s^4 + ... + pr5*s^10

 *        S = 1 + ps0*s^2 + ... + ps4*s^10

 * and

 *      | pone(x)-1-R/S | <= 2  ** ( -60.06)

 */

const PR8: [f32; 6] = [

    /* for x in [inf, 8]=1/[0,0.125] */

    0.0000000000e+00, /* 0x00000000 */

    1.1718750000e-01, /* 0x3df00000 */

    1.3239480972e+01, /* 0x4153d4ea */

    4.1205184937e+02, /* 0x43ce06a3 */

    3.8747453613e+03, /* 0x45722bed */

    7.9144794922e+03, /* 0x45f753d6 */

];

const PS8: [f32; 5] = [

    1.1420736694e+02, /* 0x42e46a2c */

    3.6509309082e+03, /* 0x45642ee5 */

    3.6956207031e+04, /* 0x47105c35 */

    9.7602796875e+04, /* 0x47bea166 */

    3.0804271484e+04, /* 0x46f0a88b */

];

const PR5: [f32; 6] = [

    /* for x in [8,4.5454]=1/[0.125,0.22001] */

    1.3199052094e-11, /* 0x2d68333f */

    1.1718749255e-01, /* 0x3defffff */

    6.8027510643e+00, /* 0x40d9b023 */

    1.0830818176e+02, /* 0x42d89dca */

    5.1763616943e+02, /* 0x440168b7 */

    5.2871520996e+02, /* 0x44042dc6 */

];

const PS5: [f32; 5] = [

    5.9280597687e+01, /* 0x426d1f55 */

    9.9140142822e+02, /* 0x4477d9b1 */

    5.3532670898e+03, /* 0x45a74a23 */

    7.8446904297e+03, /* 0x45f52586 */

    1.5040468750e+03, /* 0x44bc0180 */

];

const PR3: [f32; 6] = [

    3.0250391081e-09, /* 0x314fe10d */

    1.1718686670e-01, /* 0x3defffab */

    3.9329774380e+00, /* 0x407bb5e7 */

    3.5119403839e+01, /* 0x420c7a45 */

    9.1055007935e+01, /* 0x42b61c2a */

    4.8559066772e+01, /* 0x42423c7c */

];

const PS3: [f32; 5] = [

    3.4791309357e+01, /* 0x420b2a4d */

    3.3676245117e+02, /* 0x43a86198 */

    1.0468714600e+03, /* 0x4482dbe3 */

    8.9081134033e+02, /* 0x445eb3ed */

    1.0378793335e+02, /* 0x42cf936c */

];

const PR2: [f32; 6] = [

    /* for x in [2.8570,2]=1/[0.3499,0.5] */

    1.0771083225e-07, /* 0x33e74ea8 */

    1.1717621982e-01, /* 0x3deffa16 */

    2.3685150146e+00, /* 0x401795c0 */

    1.2242610931e+01, /* 0x4143e1bc */

    1.7693971634e+01, /* 0x418d8d41 */

    5.0735230446e+00, /* 0x40a25a4d */

];

const PS2: [f32; 5] = [

    2.1436485291e+01, /* 0x41ab7dec */

    1.2529022980e+02, /* 0x42fa9499 */

    2.3227647400e+02, /* 0x436846c7 */

    1.1767937469e+02, /* 0x42eb5bd7 */

    8.3646392822e+00, /* 0x4105d590 */

];

fn ponef(x: f32) -> f32 {

    let p: &[f32; 6];

    let q: &[f32; 5];

    let z: f32;

    let r: f32;

    let s: f32;

    let mut ix: u32;

    ix = x.to_bits();

    ix &= 0x7fffffff;

    if ix >= 0x41000000 {

        p = &PR8;

        q = &PS8;

    } else if ix >= 0x409173eb {

        p = &PR5;

        q = &PS5;

    } else if ix >= 0x4036d917 {

        p = &PR3;

        q = &PS3;

    } else

    /*ix >= 0x40000000*/

    {

        p = &PR2;

        q = &PS2;

    }

    z = 1.0 / (x * x);

    r = p[0] + z * (p[1] + z * (p[2] + z * (p[3] + z * (p[4] + z * p[5]))));

    s = 1.0 + z * (q[0] + z * (q[1] + z * (q[2] + z * (q[3] + z * q[4]))));

    return 1.0 + r / s;

}

/* For x >= 8, the asymptotic expansions of qone is

 *      3/8 s - 105/1024 s^3 - ..., where s = 1/x.

 * We approximate pone by

 *      qone(x) = s*(0.375 + (R/S))

 * where  R = qr1*s^2 + qr2*s^4 + ... + qr5*s^10

 *        S = 1 + qs1*s^2 + ... + qs6*s^12

 * and

 *      | qone(x)/s -0.375-R/S | <= 2  ** ( -61.13)

 */

const QR8: [f32; 6] = [

    /* for x in [inf, 8]=1/[0,0.125] */

    0.0000000000e+00,  /* 0x00000000 */

    -1.0253906250e-01, /* 0xbdd20000 */

    -1.6271753311e+01, /* 0xc1822c8d */

    -7.5960174561e+02, /* 0xc43de683 */

    -1.1849806641e+04, /* 0xc639273a */

    -4.8438511719e+04, /* 0xc73d3683 */

];

const QS8: [f32; 6] = [

    1.6139537048e+02,  /* 0x43216537 */

    7.8253862305e+03,  /* 0x45f48b17 */

    1.3387534375e+05,  /* 0x4802bcd6 */

    7.1965775000e+05,  /* 0x492fb29c */

    6.6660125000e+05,  /* 0x4922be94 */

    -2.9449025000e+05, /* 0xc88fcb48 */

];

const QR5: [f32; 6] = [

    /* for x in [8,4.5454]=1/[0.125,0.22001] */

    -2.0897993405e-11, /* 0xadb7d219 */

    -1.0253904760e-01, /* 0xbdd1fffe */

    -8.0564479828e+00, /* 0xc100e736 */

    -1.8366960144e+02, /* 0xc337ab6b */

    -1.3731937256e+03, /* 0xc4aba633 */

    -2.6124443359e+03, /* 0xc523471c */

];

const QS5: [f32; 6] = [

    8.1276550293e+01,  /* 0x42a28d98 */

    1.9917987061e+03,  /* 0x44f8f98f */

    1.7468484375e+04,  /* 0x468878f8 */

    4.9851425781e+04,  /* 0x4742bb6d */

    2.7948074219e+04,  /* 0x46da5826 */

    -4.7191835938e+03, /* 0xc5937978 */

];

const QR3: [f32; 6] = [

    -5.0783124372e-09, /* 0xb1ae7d4f */

    -1.0253783315e-01, /* 0xbdd1ff5b */

    -4.6101160049e+00, /* 0xc0938612 */

    -5.7847221375e+01, /* 0xc267638e */

    -2.2824453735e+02, /* 0xc3643e9a */

    -2.1921012878e+02, /* 0xc35b35cb */

];

const QS3: [f32; 6] = [

    4.7665153503e+01,  /* 0x423ea91e */

    6.7386511230e+02,  /* 0x4428775e */

    3.3801528320e+03,  /* 0x45534272 */

    5.5477290039e+03,  /* 0x45ad5dd5 */

    1.9031191406e+03,  /* 0x44ede3d0 */

    -1.3520118713e+02, /* 0xc3073381 */

];

const QR2: [f32; 6] = [

    /* for x in [2.8570,2]=1/[0.3499,0.5] */

    -1.7838172539e-07, /* 0xb43f8932 */

    -1.0251704603e-01, /* 0xbdd1f475 */

    -2.7522056103e+00, /* 0xc0302423 */

    -1.9663616180e+01, /* 0xc19d4f16 */

    -4.2325313568e+01, /* 0xc2294d1f */

    -2.1371921539e+01, /* 0xc1aaf9b2 */

];

const QS2: [f32; 6] = [

    2.9533363342e+01,  /* 0x41ec4454 */

    2.5298155212e+02,  /* 0x437cfb47 */

    7.5750280762e+02,  /* 0x443d602e */

    7.3939318848e+02,  /* 0x4438d92a */

    1.5594900513e+02,  /* 0x431bf2f2 */

    -4.9594988823e+00, /* 0xc09eb437 */

];

fn qonef(x: f32) -> f32 {

    let p: &[f32; 6];

    let q: &[f32; 6];

    let s: f32;

    let r: f32;

    let z: f32;

    let mut ix: u32;

    ix = x.to_bits();

    ix &= 0x7fffffff;

    if ix >= 0x41000000 {

        p = &QR8;

        q = &QS8;

    } else if ix >= 0x409173eb {

        p = &QR5;

        q = &QS5;

    } else if ix >= 0x4036d917 {

        p = &QR3;

        q = &QS3;

    } else

    /*ix >= 0x40000000*/

    {

        p = &QR2;

        q = &QS2;

    }

    z = 1.0 / (x * x);

    r = p[0] + z * (p[1] + z * (p[2] + z * (p[3] + z * (p[4] + z * p[5]))));

    s = 1.0 + z * (q[0] + z * (q[1] + z * (q[2] + z * (q[3] + z * (q[4] + z * q[5])))));

    return (0.375 + r / s) / x;

}

// PowerPC tests are failing on LLVM 13: https://github.com/rust-lang/rust/issues/88520

#[cfg(not(target_arch = "powerpc64"))]

#[cfg(test)]

mod tests {

    use super::{j1f, y1f};

    #[test]

    fn test_j1f_2488() {

        // 0x401F3E49

        assert_eq!(j1f(2.4881766_f32), 0.49999475_f32);

    }

    #[test]

    fn test_y1f_2002() {

        //allow slightly different result on x87

        let res = y1f(2.0000002_f32);

        if cfg!(all(target_arch = "x86", not(target_feature = "sse2"))) && (res == -0.10703231_f32)

        {

            return;

        }

        assert_eq!(res, -0.10703229_f32);

    }

}