// -*-C++-*-

#ifndef VEC_VSX_DOUBLE2_H
#define VEC_VSX_DOUBLE2_H

#include "floatprops.h"
#include "mathfuncs.h"
#include "vec_base.h"

#include <cmath>

// VSX intrinsics
#include <altivec.h>

#if defined __clang__
#define __vector vector
#define __pixel pixel
#define __bool bool
#elif defined __gcc__
#undef vector
#undef pixel
#undef bool
#elif defined __xlC__
#define __bool bool
#else
#error "Unknown compiler"
#endif

namespace vecmathlib {

#define VECMATHLIB_HAVE_VEC_DOUBLE_2
template <> struct boolvec<double, 2>;
template <> struct intvec<double, 2>;
template <> struct realvec<double, 2>;

template <> struct boolvec<double, 2> : floatprops<double> {
  static int const size = 2;
  typedef bool scalar_t;
  typedef __vector __bool long long bvector_t;
  static int const alignment = sizeof(bvector_t);

  static_assert(size * sizeof(real_t) == sizeof(bvector_t),
                "vector size is wrong");

private:
  // true values are -1, false values are 0
  // truth values are interpreted bit-wise
  static uint_t from_bool(bool a) { return -int_t(a); }
  static bool to_bool(uint_t a) { return a; }

public:
  typedef boolvec boolvec_t;
  typedef intvec<real_t, size> intvec_t;
  typedef realvec<real_t, size> realvec_t;

  // Short names for type casts
  typedef real_t R;
  typedef int_t I;
  typedef uint_t U;
  typedef realvec_t RV;
  typedef intvec_t IV;
  typedef boolvec_t BV;
  typedef floatprops<real_t> FP;
  typedef mathfuncs<realvec_t> MF;

  bvector_t v;

  boolvec() {}
  // Can't have a non-trivial copy constructor; if so, objects won't
  // be passed in registers
  // boolvec(boolvec const& x): v(x.v) {}
  // boolvec& operator=(boolvec const& x) { return v=x.v, *this; }
  boolvec(bvector_t x) : v(x) {}
  boolvec(bool a)
      : v((bvector_t)vec_splats((unsigned long long)from_bool(a))) {}
  boolvec(bool const *as) {
    for (int d = 0; d < size; ++d)
      set_elt(d, as[d]);
  }

  operator bvector_t() const { return v; }
  bool operator[](int n) const {
    return to_bool(vecmathlib::get_elt<BV, bvector_t, uint_t>(v, n));
  }
  boolvec &set_elt(int n, bool a) {
    return vecmathlib::set_elt<BV, bvector_t, uint_t>(v, n, from_bool(a)),
           *this;
  }

  intvec_t as_int() const;      // defined after intvec
  intvec_t convert_int() const; // defined after intvec

  boolvec operator!() const { return vec_nor(v, v); }

  boolvec operator&&(boolvec x) const { return vec_and(v, x.v); }
  boolvec operator||(boolvec x) const { return vec_or(v, x.v); }
  boolvec operator==(boolvec x) const { return !(*this != x); }
  boolvec operator!=(boolvec x) const { return vec_xor(v, x.v); }

  bool all() const { return vec_all_ne(v, BV(false)); }
  bool any() const { return vec_any_ne(v, BV(false)); }

  // ifthen(condition, then-value, else-value)
  boolvec_t ifthen(boolvec_t x, boolvec_t y) const;
  intvec_t ifthen(intvec_t x, intvec_t y) const;    // defined after intvec
  realvec_t ifthen(realvec_t x, realvec_t y) const; // defined after realvec
};

template <> struct intvec<double, 2> : floatprops<double> {
  static int const size = 2;
  typedef int_t scalar_t;
  typedef __vector signed long long ivector_t;
  static int const alignment = sizeof(ivector_t);

  static_assert(size * sizeof(real_t) == sizeof(ivector_t),
                "vector size is wrong");

  typedef boolvec<real_t, size> boolvec_t;
  typedef intvec intvec_t;
  typedef realvec<real_t, size> realvec_t;

  // Short names for type casts
  typedef real_t R;
  typedef int_t I;
  typedef uint_t U;
  typedef realvec_t RV;
  typedef intvec_t IV;
  typedef boolvec_t BV;
  typedef floatprops<real_t> FP;
  typedef mathfuncs<realvec_t> MF;

  ivector_t v;

  intvec() {}
  // Can't have a non-trivial copy constructor; if so, objects won't
  // be passed in registers
  // intvec(intvec const& x): v(x.v) {}
  // intvec& operator=(intvec const& x) { return v=x.v, *this; }
  intvec(ivector_t x) : v(x) {}
  intvec(int_t a) : v(vec_splats((long long)a)) {}
  intvec(int_t const *as) {
    for (int d = 0; d < size; ++d)
      set_elt(d, as[d]);
  }
  static intvec iota() { return (__vector signed long long){0, 1}; }

  operator ivector_t() const { return v; }
  int_t operator[](int n) const {
    return vecmathlib::get_elt<IV, ivector_t, int_t>(v, n);
  }
  intvec_t &set_elt(int n, int_t a) {
    return vecmathlib::set_elt<IV, ivector_t, int_t>(v, n, a), *this;
  }

  // Vector casts do not change the bit battern
  boolvec_t as_bool() const { return (__vector __bool long long)v; }
  boolvec_t convert_bool() const { return *this != IV(I(0)); }
  realvec_t as_float() const;      // defined after realvec
  realvec_t convert_float() const; // defined after realvec

  // Permutation control words
private:
  // 0123 4567 -> 1436
  // exchange pairs
  static __vector unsigned char perm_int_swap() {
    return (__vector unsigned char){4,  5,  6,  7,  16, 17, 18, 19,
                                    12, 13, 14, 15, 24, 25, 26, 27};
  }
  // 0123 4567 -> 0426
  // broadcast high elements of pairs
  static __vector unsigned char perm_int_bchi() {
    return (__vector unsigned char){0, 1, 2,  3,  16, 17, 18, 19,
                                    8, 9, 10, 11, 24, 25, 26, 27};
  }

public:
  intvec operator+() const { return *this; }
  intvec operator-() const { return vec_neg(v); }

  intvec operator+(intvec x) const { return vec_add(v, x.v); }
  intvec operator-(intvec x) const { return vec_sub(v, x.v); }
  intvec operator*(intvec x) const { return vec_mul(v, x.v); }
  intvec operator/(intvec x) const { return vec_div(v, x.v); }
  intvec operator%(intvec x) const { return *this - *this / x * x; }

  intvec &operator+=(intvec const &x) { return *this = *this + x; }
  intvec &operator-=(intvec const &x) { return *this = *this - x; }
  intvec &operator*=(intvec const &x) { return *this = *this * x; }
  intvec &operator/=(intvec const &x) { return *this = *this / x; }
  intvec &operator%=(intvec const &x) { return *this = *this % x; }

  intvec operator~() const {
    return (__vector signed long long)vec_nor((__vector signed int)v,
                                              (__vector signed int)v);
  }

  intvec operator&(intvec x) const {
    return (__vector signed long long)vec_and((__vector signed int)v,
                                              (__vector signed int)x.v);
  }
  intvec operator|(intvec x) const {
    return (__vector signed long long)vec_or((__vector signed int)v,
                                             (__vector signed int)x.v);
  }
  intvec operator^(intvec x) const {
    return (__vector signed long long)vec_xor((__vector signed int)v,
                                              (__vector signed int)x.v);
  }

  intvec &operator&=(intvec const &x) { return *this = *this & x; }
  intvec &operator|=(intvec const &x) { return *this = *this | x; }
  intvec &operator^=(intvec const &x) { return *this = *this ^ x; }

  intvec_t bitifthen(intvec_t x, intvec_t y) const;

  intvec lsr(int_t n) const { return lsr(IV(n)); }
  intvec_t rotate(int_t n) const;
  intvec operator>>(int_t n) const { return *this >> IV(n); }
  intvec operator<<(int_t n) const { return *this << IV(n); }
  intvec &operator>>=(int_t n) { return *this = *this >> n; }
  intvec &operator<<=(int_t n) { return *this = *this << n; }

  intvec lsr(intvec n) const {
    // return vec_sr(v, (__vector unsigned long long)n.v);
    intvec r;
    for (int i = 0; i < size; ++i) {
      r.set_elt(i, U((*this)[i]) >> U(n[i]));
    }
    return r;
  }
  intvec_t rotate(intvec_t n) const;
  intvec operator>>(intvec n) const {
    // return vec_sra(v, (__vector unsigned long long)n.v);
    intvec r;
    for (int i = 0; i < size; ++i) {
      r.set_elt(i, (*this)[i] >> n[i]);
    }
    return r;
  }
  intvec operator<<(intvec n) const {
    // return vec_sl(v, (__vector unsigned long long)n.v);
    intvec r;
    for (int i = 0; i < size; ++i) {
      r.set_elt(i, (*this)[i] << n[i]);
    }
    return r;
  }
  intvec &operator>>=(intvec n) { return *this = *this >> n; }
  intvec &operator<<=(intvec n) { return *this = *this << n; }

  intvec_t clz() const;
  intvec_t popcount() const;

  boolvec_t operator==(intvec const &x) const {
    // return vec_cmpeq(v, x.v);
    __vector signed int a = (__vector signed int)v;
    __vector signed int b = (__vector signed int)x.v;
    __vector __bool int c = vec_cmpeq(a, b);
    __vector __bool int cx = vec_perm(c, c, perm_int_swap());
    __vector __bool int r = vec_and(c, cx);
    return (__vector __bool long long)r;
  }
  boolvec_t operator!=(intvec const &x) const { return !(*this == x); }
  boolvec_t operator<(intvec const &x) const {
    __vector signed int a = (__vector signed int)v;
    __vector signed int b = (__vector signed int)x.v;
    __vector __bool int lt = vec_cmplt(a, b);
    __vector __bool int eq = vec_cmpeq(a, b);
    __vector unsigned int ua = (__vector unsigned int)v;
    __vector unsigned int ub = (__vector unsigned int)x.v;
    __vector __bool int ult = vec_cmplt(ua, ub);
    __vector __bool int ultx = vec_perm(ult, ult, perm_int_swap());
    __vector __bool int r = vec_or(lt, vec_and(eq, ultx));
    r = vec_perm(r, r, perm_int_bchi());
    return (__vector __bool long long)r;
  }
  boolvec_t operator<=(intvec const &x) const { return !(*this > x); }
  boolvec_t operator>(intvec const &x) const { return x < *this; }
  boolvec_t operator>=(intvec const &x) const { return !(*this < x); }

  intvec_t abs() const;
  boolvec_t isignbit() const { return (*this >> (bits - 1)).as_bool(); }
  intvec_t max(intvec_t x) const;
  intvec_t min(intvec_t x) const;
};

template <> struct realvec<double, 2> : floatprops<double> {
  static int const size = 2;
  typedef real_t scalar_t;
  typedef __vector double vector_t;
  static int const alignment = sizeof(vector_t);

  static char const *name() { return "<VSX:2*double>"; }
  void barrier() { __asm__("" : "+v"(v)); }

  static_assert(size * sizeof(real_t) == sizeof(vector_t),
                "vector size is wrong");

  typedef boolvec<real_t, size> boolvec_t;
  typedef intvec<real_t, size> intvec_t;
  typedef realvec realvec_t;

  // Short names for type casts
  typedef real_t R;
  typedef int_t I;
  typedef uint_t U;
  typedef realvec_t RV;
  typedef intvec_t IV;
  typedef boolvec_t BV;
  typedef floatprops<real_t> FP;
  typedef mathfuncs<realvec_t> MF;

  vector_t v;

  realvec() {}
  // Can't have a non-trivial copy constructor; if so, objects won't
  // be passed in registers
  // realvec(realvec const& x): v(x.v) {}
  // realvec& operator=(realvec const& x) { return v=x.v, *this; }
  realvec(vector_t x) : v(x) {}
  realvec(real_t a) : v(vec_splats(a)) {}
  realvec(real_t const *as) {
    for (int d = 0; d < size; ++d)
      set_elt(d, as[d]);
  }

  operator vector_t() const { return v; }
  real_t operator[](int n) const {
    return vecmathlib::get_elt<RV, vector_t, real_t>(v, n);
  }
  realvec_t &set_elt(int n, real_t a) {
    return vecmathlib::set_elt<RV, vector_t, real_t>(v, n, a), *this;
  }

  typedef vecmathlib::mask_t<realvec_t> mask_t;

  static realvec_t loada(real_t const *p) {
    VML_ASSERT(intptr_t(p) % alignment == 0);
    return vec_xld2(0, (real_t *)p);
  }
  static realvec_t loadu(real_t const *p) {
    // TODO: Can this handle unaligned access?
    return vec_xld2(0, (real_t *)p);
  }
  static realvec_t loadu(real_t const *p, std::ptrdiff_t ioff) {
    VML_ASSERT(intptr_t(p) % alignment == 0);
    if (ioff % realvec::size == 0)
      return loada(p + ioff);
    return loadu(p + ioff);
  }
  realvec_t loada(real_t const *p, mask_t const &m) const {
    VML_ASSERT(intptr_t(p) % alignment == 0);
    if (__builtin_expect(all(m.m), true)) {
      return loada(p);
    } else {
      return m.m.ifthen(loada(p), *this);
    }
  }
  realvec_t loadu(real_t const *p, mask_t const &m) const {
    if (__builtin_expect(m.all_m, true)) {
      return loadu(p);
    } else {
      return m.m.ifthen(loadu(p), *this);
    }
  }
  realvec_t loadu(real_t const *p, std::ptrdiff_t ioff, mask_t const &m) const {
    VML_ASSERT(intptr_t(p) % alignment == 0);
    if (ioff % realvec::size == 0)
      return loada(p + ioff, m);
    return loadu(p + ioff, m);
  }

  void storea(real_t *p) const {
    VML_ASSERT(intptr_t(p) % alignment == 0);
    vec_xstd2(v, 0, p);
  }
  void storeu(real_t *p) const {
    // Vector stores would require vector loads, which would need to
    // be atomic
    // TODO: see <https://developer.apple.com/hardwaredrivers/ve/alignment.html>
    // for good ideas
    p[0] = (*this)[0];
    p[1] = (*this)[1];
  }
  void storeu(real_t *p, std::ptrdiff_t ioff) const {
    VML_ASSERT(intptr_t(p) % alignment == 0);
    if (ioff % realvec::size == 0)
      return storea(p + ioff);
    storeu(p + ioff);
  }
  void storea(real_t *p, mask_t const &m) const {
    VML_ASSERT(intptr_t(p) % alignment == 0);
    if (__builtin_expect(m.all_m, true)) {
      storea(p);
    } else {
      // Use vec_ste?
      if (m.m[0])
        p[0] = (*this)[0];
      if (m.m[1])
        p[1] = (*this)[1];
    }
  }
  void storeu(real_t *p, mask_t const &m) const {
    if (__builtin_expect(m.all_m, true)) {
      storeu(p);
    } else {
      // Use vec_ste?
      if (m.m[0])
        p[0] = (*this)[0];
      if (m.m[1])
        p[1] = (*this)[1];
    }
  }
  void storeu(real_t *p, std::ptrdiff_t ioff, mask_t const &m) const {
    VML_ASSERT(intptr_t(p) % alignment == 0);
    if (ioff % realvec::size == 0)
      return storea(p + ioff, m);
    storeu(p + ioff, m);
  }

  intvec_t as_int() const { return (__vector signed long long)v; }
  intvec_t convert_int() const { return MF::vml_convert_int(*this); }

  realvec operator+() const { return *this; }
  realvec operator-() const { return RV(0.0) - *this; }

  realvec operator+(realvec x) const { return vec_add(v, x.v); }
  realvec operator-(realvec x) const { return vec_sub(v, x.v); }
  realvec operator*(realvec x) const { return vec_mul(v, x.v); }
  realvec operator/(realvec x) const { return vec_div(v, x.v); }

  realvec &operator+=(realvec const &x) { return *this = *this + x; }
  realvec &operator-=(realvec const &x) { return *this = *this - x; }
  realvec &operator*=(realvec const &x) { return *this = *this * x; }
  realvec &operator/=(realvec const &x) { return *this = *this / x; }

  real_t maxval() const { return vml_std::fmax((*this)[0], (*this)[1]); }
  real_t minval() const { return vml_std::fmin((*this)[0], (*this)[1]); }
  real_t prod() const { return (*this)[0] * (*this)[1]; }
  real_t sum() const { return (*this)[0] + (*this)[1]; }

  boolvec_t operator==(realvec const &x) const { return vec_cmpeq(v, x.v); }
  boolvec_t operator!=(realvec const &x) const { return !(*this == x); }
  boolvec_t operator<(realvec const &x) const { return vec_cmplt(v, x.v); }
  boolvec_t operator<=(realvec const &x) const { return vec_cmple(v, x.v); }
  boolvec_t operator>(realvec const &x) const { return vec_cmpgt(v, x.v); }
  boolvec_t operator>=(realvec const &x) const { return vec_cmpge(v, x.v); }

  realvec acos() const { return MF::vml_acos(*this); }
  realvec acosh() const { return MF::vml_acosh(*this); }
  realvec asin() const { return MF::vml_asin(*this); }
  realvec asinh() const { return MF::vml_asinh(*this); }
  realvec atan() const { return MF::vml_atan(*this); }
  realvec atan2(realvec y) const { return MF::vml_atan2(*this, y); }
  realvec atanh() const { return MF::vml_atanh(*this); }
  realvec cbrt() const { return MF::vml_cbrt(*this); }
  realvec ceil() const { return vec_ceil(v); }
  realvec copysign(realvec y) const { return MF::vml_copysign(*this, y); }
  realvec cos() const { return MF::vml_cos(*this); }
  realvec cosh() const { return MF::vml_cosh(*this); }
  realvec exp() const { return MF::vml_exp(*this); }
  realvec exp10() const { return MF::vml_exp10(*this); }
  realvec exp2() const { return MF::vml_exp2(*this); }
  realvec expm1() const { return MF::vml_expm1(*this); }
  realvec fabs() const { return vec_abs(v); }
  realvec fdim(realvec y) const { return MF::vml_fdim(*this, y); }
  realvec floor() const { return vec_floor(v); }
  realvec fma(realvec y, realvec z) const { return vec_madd(v, y.v, z.v); }
  realvec fmax(realvec y) const { return vec_max(v, y.v); }
  realvec fmin(realvec y) const { return vec_min(v, y.v); }
  realvec fmod(realvec y) const { return MF::vml_fmod(*this, y); }
  realvec frexp(intvec_t *r) const { return MF::vml_frexp(*this, r); }
  realvec hypot(realvec y) const { return MF::vml_hypot(*this, y); }
  intvec_t ilogb() const { return MF::vml_ilogb(*this); }
  boolvec_t isfinite() const { return MF::vml_isfinite(*this); }
  boolvec_t isinf() const { return MF::vml_isinf(*this); }
  boolvec_t isnan() const { return MF::vml_isnan(*this); }
  boolvec_t isnormal() const { return MF::vml_isnormal(*this); }
  realvec ldexp(int_t n) const { return MF::vml_ldexp(*this, n); }
  realvec ldexp(intvec_t n) const { return MF::vml_ldexp(*this, n); }
  realvec log() const { return MF::vml_log(*this); }
  realvec log10() const { return MF::vml_log10(*this); }
  realvec log1p() const { return MF::vml_log1p(*this); }
  realvec log2() const { return MF::vml_log2(*this); }
  realvec_t mad(realvec_t y, realvec_t z) const {
    return MF::vml_mad(*this, y, z);
  }
  realvec nextafter(realvec y) const { return MF::vml_nextafter(*this, y); }
  realvec pow(realvec y) const { return MF::vml_pow(*this, y); }
  realvec rcp() const {
    realvec x = *this;
    realvec r = vec_re(v); // this is only an approximation
    // TODO: use fma
    // Note: don't rewrite this expression, this may introduce
    // cancellation errors
    r += r * (RV(1.0) - x * r); // two Newton iterations (see vml_rcp)
    r += r * (RV(1.0) - x * r);
    return r;
  }
  realvec remainder(realvec y) const { return MF::vml_remainder(*this, y); }
  realvec rint() const { return vec_round(v); /* sic! */ }
  realvec round() const { return MF::vml_round(*this); }
  realvec rsqrt() const { return RV(1.0) / sqrt(); }
  boolvec_t signbit() const { return MF::vml_signbit(*this); }
  realvec sin() const { return MF::vml_sin(*this); }
  realvec sinh() const { return MF::vml_sinh(*this); }
  realvec sqrt() const { return vec_sqrt(v); }
  realvec tan() const { return MF::vml_tan(*this); }
  realvec tanh() const { return MF::vml_tanh(*this); }
  realvec trunc() const { return vec_trunc(v); }
};

// boolvec definitions

inline intvec<double, 2> boolvec<double, 2>::as_int() const {
  return (__vector signed long long)v;
}

inline intvec<double, 2> boolvec<double, 2>::convert_int() const {
  return -(__vector signed long long)v;
}

inline boolvec<double, 2> boolvec<double, 2>::ifthen(boolvec_t x,
                                                     boolvec_t y) const {
  return vec_sel(y.v, x.v, v);
}

inline intvec<double, 2> boolvec<double, 2>::ifthen(intvec_t x,
                                                    intvec_t y) const {
  return vec_sel(y.v, x.v, v);
}

inline realvec<double, 2> boolvec<double, 2>::ifthen(realvec_t x,
                                                     realvec_t y) const {
  return vec_sel(y.v, x.v, v);
}

// intvec definitions

inline intvec<double, 2> intvec<double, 2>::abs() const {
  return MF::vml_abs(*this);
}

inline realvec<double, 2> intvec<double, 2>::as_float() const {
  return (__vector double)v;
}

inline intvec<double, 2> intvec<double, 2>::bitifthen(intvec_t x,
                                                      intvec_t y) const {
  return MF::vml_bitifthen(*this, x, y);
}

inline intvec<double, 2> intvec<double, 2>::clz() const {
  return MF::vml_clz(*this);
}

inline realvec<double, 2> intvec<double, 2>::convert_float() const {
  // return vec_ctd(v, 0);
  return MF::vml_convert_float(*this);
}

inline intvec<double, 2> intvec<double, 2>::max(intvec_t x) const {
  return MF::vml_max(*this, x);
}

inline intvec<double, 2> intvec<double, 2>::min(intvec_t x) const {
  return MF::vml_min(*this, x);
}

inline intvec<double, 2> intvec<double, 2>::popcount() const {
  return MF::vml_popcount(*this);
}

inline intvec<double, 2> intvec<double, 2>::rotate(int_t n) const {
  return MF::vml_rotate(*this, n);
}

inline intvec<double, 2> intvec<double, 2>::rotate(intvec_t n) const {
  return MF::vml_rotate(*this, n);
}

} // namespace vecmathlib

#endif // #ifndef VEC_VSX_DOUBLE2_H