// ======================================================================== //
// Copyright 2009-2017 Intel Corporation                                    //
//                                                                          //
// Licensed under the Apache License, Version 2.0 (the "License");          //
// you may not use this file except in compliance with the License.         //
// You may obtain a copy of the License at                                  //
//                                                                          //
//     http://www.apache.org/licenses/LICENSE-2.0                           //
//                                                                          //
// Unless required by applicable law or agreed to in writing, software      //
// distributed under the License is distributed on an "AS IS" BASIS,        //
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. //
// See the License for the specific language governing permissions and      //
// limitations under the License.                                           //
// ======================================================================== //

#pragma once

namespace embree
{ 
  /* 8-wide AVX-512 64bit double type */
  template<>
    struct vdouble<8>
  {
    typedef vboold8 Bool;

    enum  { size = 8 }; // number of SIMD elements
    union {              // data
      __m512d v; 
      double i[8]; 
    };
    
    ////////////////////////////////////////////////////////////////////////////////
    /// Constructors, Assignment & Cast Operators
    ////////////////////////////////////////////////////////////////////////////////
       
    __forceinline vdouble() {}
    __forceinline vdouble(const vdouble8& t) { v = t.v; }
    __forceinline vdouble8& operator=(const vdouble8& f) { v = f.v; return *this; }

    __forceinline vdouble(const __m512d& t) { v = t; }
    __forceinline operator __m512d () const { return v; }
    __forceinline operator __m256d () const { return _mm512_castpd512_pd256(v); }

    __forceinline vdouble(const double i) {
      v = _mm512_set_1to8_pd(i);
    }
    
    __forceinline vdouble(const double a, const double b, const double c, const double d) {
      v = _mm512_set_4to8_pd(d,c,b,a);      
    }

    __forceinline vdouble(const double a0 , const double a1 , const double a2 , const double a3, 
                        const double a4 , const double a5 , const double a6 , const double a7)
    {
      v = _mm512_set_8to8_pd(a7,a6,a5,a4,a3,a2,a1,a0);
    }
   
    
    ////////////////////////////////////////////////////////////////////////////////
    /// Constants
    ////////////////////////////////////////////////////////////////////////////////
    
    __forceinline vdouble( ZeroTy   ) : v(_mm512_setzero_pd()) {}
    __forceinline vdouble( OneTy    ) : v(_mm512_set_1to8_pd(1)) {}
    __forceinline vdouble( StepTy   ) : v(_mm512_set_8to8_pd(7.0,6.0,5.0,4.0,3.0,2.0,1.0,0.0)) {}
    __forceinline vdouble( ReverseStepTy )   : v(_mm512_setr_pd(7.0,6.0,5.0,4.0,3.0,2.0,1.0,0.0)) {}

    __forceinline static vdouble8 zero() { return _mm512_setzero_pd(); }
    __forceinline static vdouble8 one () { return _mm512_set_1to8_pd(1); }
    __forceinline static vdouble8 neg_one () { return _mm512_set_1to8_pd(-1); }

    ////////////////////////////////////////////////////////////////////////////////
    /// Loads and Stores
    ////////////////////////////////////////////////////////////////////////////////

    static __forceinline void store_nt(void *__restrict__ ptr, const vdouble8& a) {
      _mm512_stream_si512(ptr,_mm512_castpd_si512(a));
    }

    static __forceinline vdouble8 loadu(const void* addr)
    {
      return _mm512_loadu_si512(addr);
    }

    static __forceinline vdouble8 load(const vdouble8* addr) {
      return _mm512_load_si512(addr);
    }

    static __forceinline vdouble8 load(const double* addr) {
      return _mm512_load_si512(addr);
    }

    static __forceinline void store(void* ptr, const vdouble8& v) {
      _mm512_store_si512(ptr,_mm512_castpd_si512(v));
    }

    static __forceinline void storeu(void* ptr, const vdouble8& v ) {
      _mm512_storeu_si512(ptr,_mm512_castpd_si512(v));
    }

    static __forceinline void storeu(const vboold8& mask, double* ptr, const vdouble8& f ) {
      _mm512_mask_storeu_pd(ptr,mask,f);
    }

    static __forceinline void store(const vboold8& mask, void* addr, const vdouble8& v2) {
      _mm512_mask_store_pd(addr,mask,v2);
    }

  /* pass by value to avoid compiler generating inefficient code */
    static __forceinline void storeu_compact(const vboold8 mask,void * addr, const vdouble8& reg) {
      _mm512_mask_compressstoreu_pd(addr,mask,reg);
    }

    static __forceinline vdouble8 compact64bit(const vboold8& mask, vdouble8& v) {
      return _mm512_mask_compress_pd(v,mask,v);
    }

    static __forceinline vdouble8 compact(const vboold8& mask, vdouble8& v) {
      return _mm512_mask_compress_pd(v,mask,v);
    }

    static __forceinline vdouble8 compact(const vboold8& mask, const vdouble8& a, vdouble8& b) {
      return _mm512_mask_compress_pd(a,mask,b);
    }


    ////////////////////////////////////////////////////////////////////////////////
    /// Array Access
    ////////////////////////////////////////////////////////////////////////////////
    
    __forceinline       double& operator[](const size_t index)       { assert(index < 8); return i[index]; }
    __forceinline const double& operator[](const size_t index) const { assert(index < 8); return i[index]; }

  };
  
  ////////////////////////////////////////////////////////////////////////////////
  /// Unary Operators
  ////////////////////////////////////////////////////////////////////////////////

  __forceinline const vdouble8 asDouble  ( const __m512&   a ) { return _mm512_castps_si512(a); }
  __forceinline const vdouble8 operator +( const vdouble8& a ) { return a; }
  __forceinline const vdouble8 operator -( const vdouble8& a ) { return _mm512_sub_pd(_mm512_setzero_pd(), a); }

  ////////////////////////////////////////////////////////////////////////////////
  /// Binary Operators
  ////////////////////////////////////////////////////////////////////////////////

  __forceinline const vdouble8 operator +( const vdouble8& a, const vdouble8& b ) { return _mm512_add_pd(a, b); }
  __forceinline const vdouble8 operator +( const vdouble8& a, const double b    ) { return a + vdouble8(b); }
  __forceinline const vdouble8 operator +( const double    a, const vdouble8& b ) { return vdouble8(a) + b; }

  __forceinline const vdouble8 operator -( const vdouble8& a, const vdouble8& b ) { return _mm512_sub_pd(a, b); }
  __forceinline const vdouble8 operator -( const vdouble8& a, const double b    ) { return a - vdouble8(b); }
  __forceinline const vdouble8 operator -( const double    a, const vdouble8& b ) { return vdouble8(a) - b; }

  __forceinline const vdouble8 operator *( const vdouble8& a, const vdouble8& b ) { return _mm512_mul_pd(a, b); }
  __forceinline const vdouble8 operator *( const vdouble8& a, const double b    ) { return a * vdouble8(b); }
  __forceinline const vdouble8 operator *( const double    a, const vdouble8& b ) { return vdouble8(a) * b; }

  __forceinline const vdouble8 operator &( const vdouble8& a, const vdouble8& b ) { return _mm512_and_pd(a, b); }
  __forceinline const vdouble8 operator &( const vdouble8& a, const double b    ) { return a & vdouble8(b); }
  __forceinline const vdouble8 operator &( const double    a, const vdouble8& b ) { return vdouble8(a) & b; }

  __forceinline const vdouble8 operator |( const vdouble8& a, const vdouble8& b ) { return _mm512_or_pd(a, b); }
  __forceinline const vdouble8 operator |( const vdouble8& a, const double b    ) { return a | vdouble8(b); }
  __forceinline const vdouble8 operator |( const double    a, const vdouble8& b ) { return vdouble8(a) | b; }

  __forceinline const vdouble8 operator ^( const vdouble8& a, const vdouble8& b ) { return _mm512_xor_pd(a, b); }
  __forceinline const vdouble8 operator ^( const vdouble8& a, const double b    ) { return a ^ vdouble8(b); }
  __forceinline const vdouble8 operator ^( const double    a, const vdouble8& b ) { return vdouble8(a) ^ b; }

  __forceinline const vdouble8 operator <<( const vdouble8& a, const unsigned int n ) { return _mm512_castsi512_pd(_mm512_slli_epi64(_mm512_castpd_si512(a), n)); }
  __forceinline const vdouble8 operator >>( const vdouble8& a, const unsigned int n ) { return _mm512_castsi512_pd(_mm512_srai_epi64(_mm512_castpd_si512(a), n)); }

  __forceinline const vdouble8 operator <<( const vdouble8& a, const vlong8& n ) { return _mm512_castsi512_pd(_mm512_sllv_epi64(_mm512_castpd_si512(a), n)); }
  __forceinline const vdouble8 operator >>( const vdouble8& a, const vlong8& n ) { return _mm512_castsi512_pd(_mm512_srav_epi64(_mm512_castpd_si512(a), n)); }

  __forceinline const vdouble8 sll ( const vdouble8& a, const unsigned int b ) { return  _mm512_castsi512_pd(_mm512_slli_epi64(_mm512_castpd_si512(a), b)); }
  __forceinline const vdouble8 sra ( const vdouble8& a, const unsigned int b ) { return  _mm512_castsi512_pd(_mm512_srai_epi64(_mm512_castpd_si512(a), b)); }
  __forceinline const vdouble8 srl ( const vdouble8& a, const unsigned int b ) { return  _mm512_castsi512_pd(_mm512_srli_epi64(_mm512_castpd_si512(a), b)); }
  
  __forceinline const vdouble8 min( const vdouble8& a, const vdouble8& b ) { return _mm512_min_pd(a, b); }
  __forceinline const vdouble8 min( const vdouble8& a, const double b    ) { return min(a,vdouble8(b)); }
  __forceinline const vdouble8 min( const double    a, const vdouble8& b ) { return min(vdouble8(a),b); }

  __forceinline const vdouble8 max( const vdouble8& a, const vdouble8& b ) { return _mm512_max_pd(a, b); }
  __forceinline const vdouble8 max( const vdouble8& a, const double b    ) { return max(a,vdouble8(b)); }
  __forceinline const vdouble8 max( const double    a, const vdouble8& b ) { return max(vdouble8(a),b); }
  
  __forceinline const vdouble8 mask_add(const vboold8& mask, vdouble8& c, const vdouble8& a, const vdouble8& b) { return _mm512_mask_add_pd(c,mask,a,b); }
  __forceinline const vdouble8 mask_sub(const vboold8& mask, vdouble8& c, const vdouble8& a, const vdouble8& b) { return _mm512_mask_sub_pd(c,mask,a,b); }

  __forceinline const vdouble8 mask_and(const vboold8& m,vdouble8& c, const vdouble8& a, const vdouble8& b) { return _mm512_mask_and_pd(c,m,a,b); }
  __forceinline const vdouble8 mask_or (const vboold8& m,vdouble8& c, const vdouble8& a, const vdouble8& b) { return _mm512_mask_or_pd(c,m,a,b); }

  ////////////////////////////////////////////////////////////////////////////////
  /// Assignment Operators
  ////////////////////////////////////////////////////////////////////////////////

  __forceinline vdouble8& operator +=( vdouble8& a, const vdouble8& b ) { return a = a + b; }
  __forceinline vdouble8& operator +=( vdouble8& a, const double    b ) { return a = a + b; }
  
  __forceinline vdouble8& operator -=( vdouble8& a, const vdouble8& b ) { return a = a - b; }
  __forceinline vdouble8& operator -=( vdouble8& a, const double    b ) { return a = a - b; }

  __forceinline vdouble8& operator *=( vdouble8& a, const vdouble8& b ) { return a = a * b; }
  __forceinline vdouble8& operator *=( vdouble8& a, const double    b ) { return a = a * b; }
  
  __forceinline vdouble8& operator &=( vdouble8& a, const vdouble8& b ) { return a = a & b; }
  __forceinline vdouble8& operator &=( vdouble8& a, const double    b ) { return a = a & b; }
  
  __forceinline vdouble8& operator |=( vdouble8& a, const vdouble8& b ) { return a = a | b; }
  __forceinline vdouble8& operator |=( vdouble8& a, const double    b ) { return a = a | b; }
  
  __forceinline vdouble8& operator <<=( vdouble8& a, const double b ) { return a = a << b; }
  __forceinline vdouble8& operator >>=( vdouble8& a, const double b ) { return a = a >> b; }


  ////////////////////////////////////////////////////////////////////////////////
  /// Comparison Operators + Select
  ////////////////////////////////////////////////////////////////////////////////

  __forceinline const vboold8 operator ==( const vdouble8& a, const vdouble8& b ) { return _mm512_cmp_pd_mask(a,b,_MM_CMPINT_EQ); }
  __forceinline const vboold8 operator ==( const vdouble8& a, const double b    ) { return a == vdouble8(b); }
  __forceinline const vboold8 operator ==( const double    a, const vdouble8& b ) { return vdouble8(a) == b; }
  
  __forceinline const vboold8 operator !=( const vdouble8& a, const vdouble8& b ) { return _mm512_cmp_pd_mask(a,b,_MM_CMPINT_NE); }
  __forceinline const vboold8 operator !=( const vdouble8& a, const double b    ) { return a != vdouble8(b); }
  __forceinline const vboold8 operator !=( const double    a, const vdouble8& b ) { return vdouble8(a) != b; }
  
  __forceinline const vboold8 operator < ( const vdouble8& a, const vdouble8& b ) { return _mm512_cmp_pd_mask(a,b,_MM_CMPINT_LT); }
  __forceinline const vboold8 operator < ( const vdouble8& a, const double b    ) { return a <  vdouble8(b); }
  __forceinline const vboold8 operator < ( const double    a, const vdouble8& b ) { return vdouble8(a) <  b; }
  
  __forceinline const vboold8 operator >=( const vdouble8& a, const vdouble8& b ) { return _mm512_cmp_pd_mask(a,b,_MM_CMPINT_GE); }
  __forceinline const vboold8 operator >=( const vdouble8& a, const double    b ) { return a >= vdouble8(b); }
  __forceinline const vboold8 operator >=( const double    a, const vdouble8& b ) { return vdouble8(a) >= b; }

  __forceinline const vboold8 operator > ( const vdouble8& a, const vdouble8& b ) { return _mm512_cmp_pd_mask(a,b,_MM_CMPINT_GT); }
  __forceinline const vboold8 operator > ( const vdouble8& a, const double    b ) { return a >  vdouble8(b); }
  __forceinline const vboold8 operator > ( const double    a, const vdouble8& b ) { return vdouble8(a) >  b; }

  __forceinline const vboold8 operator <=( const vdouble8& a, const vdouble8& b ) { return _mm512_cmp_pd_mask(a,b,_MM_CMPINT_LE); }
  __forceinline const vboold8 operator <=( const vdouble8& a, const double    b ) { return a <= vdouble8(b); }
  __forceinline const vboold8 operator <=( const double    a, const vdouble8& b ) { return vdouble8(a) <= b; }

  __forceinline vboold8 eq(const vdouble8& a, const vdouble8& b) { return _mm512_cmp_pd_mask(a,b,_MM_CMPINT_EQ); }
  __forceinline vboold8 ne(const vdouble8& a, const vdouble8& b) { return _mm512_cmp_pd_mask(a,b,_MM_CMPINT_NE); }
  __forceinline vboold8 lt(const vdouble8& a, const vdouble8& b) { return _mm512_cmp_pd_mask(a,b,_MM_CMPINT_LT); }
  __forceinline vboold8 ge(const vdouble8& a, const vdouble8& b) { return _mm512_cmp_pd_mask(a,b,_MM_CMPINT_GE); }
  __forceinline vboold8 gt(const vdouble8& a, const vdouble8& b) { return _mm512_cmp_pd_mask(a,b,_MM_CMPINT_GT); }
  __forceinline vboold8 le(const vdouble8& a, const vdouble8& b) { return _mm512_cmp_pd_mask(a,b,_MM_CMPINT_LE); }
    
  __forceinline vboold8 eq(const vboold8 mask, const vdouble8& a, const vdouble8& b) { return _mm512_mask_cmp_pd_mask(mask,a,b,_MM_CMPINT_EQ); }
  __forceinline vboold8 ne(const vboold8 mask, const vdouble8& a, const vdouble8& b) { return _mm512_mask_cmp_pd_mask(mask,a,b,_MM_CMPINT_NE); }
  __forceinline vboold8 lt(const vboold8 mask, const vdouble8& a, const vdouble8& b) { return _mm512_mask_cmp_pd_mask(mask,a,b,_MM_CMPINT_LT); }
  __forceinline vboold8 ge(const vboold8 mask, const vdouble8& a, const vdouble8& b) { return _mm512_mask_cmp_pd_mask(mask,a,b,_MM_CMPINT_GE); }
  __forceinline vboold8 gt(const vboold8 mask, const vdouble8& a, const vdouble8& b) { return _mm512_mask_cmp_pd_mask(mask,a,b,_MM_CMPINT_GT); }
  __forceinline vboold8 le(const vboold8 mask, const vdouble8& a, const vdouble8& b) { return _mm512_mask_cmp_pd_mask(mask,a,b,_MM_CMPINT_LE); }

  __forceinline const vdouble8 select( const vboold8& m, const vdouble8& t, const vdouble8& f ) {
    return _mm512_mask_or_pd(f,m,t,t); 
  }

  __forceinline void xchg(const vboold8& m, vdouble8& a, vdouble8& b) {
    const vdouble8 c = a; a = select(m,b,a); b = select(m,c,b);
  }

  __forceinline vboold8 test(const vboold8& m, const vdouble8& a, const vdouble8& b) {
    return _mm512_mask_test_epi64_mask(m,_mm512_castpd_si512(a),_mm512_castpd_si512(b));
  }

  __forceinline vboold8 test(const vdouble8& a, const vdouble8& b) {
    return _mm512_test_epi64_mask(_mm512_castpd_si512(a),_mm512_castpd_si512(b));
  }

  ////////////////////////////////////////////////////////////////////////////////
  // Movement/Shifting/Shuffling Functions
  ////////////////////////////////////////////////////////////////////////////////

  __forceinline vdouble8 shuffle (const vdouble8& x,int perm32 ) { return _mm512_permutex_pd(x,perm32); }
  __forceinline vdouble8 shuffle4(const vdouble8& x,int perm128) { return _mm512_shuffle_f64x2(x,x,perm128); }
  
  template<int D, int C, int B, int A> __forceinline vdouble8 shuffle   (const vdouble8& v) { return _mm512_permutex_pd(v,(int)_MM_SHUF_PERM(D,C,B,A)); }
  template<int A>                      __forceinline vdouble8 shuffle   (const vdouble8& x) { return shuffle<A,A,A,A>(v); }

  template<int D, int C, int B, int A> __forceinline vdouble8 shuffle4(const vdouble8& v) { return shuffle4(v,(int)_MM_SHUF_PERM(D,C,B,A)); }
  template<int A>                      __forceinline vdouble8 shuffle4(const vdouble8& x) { return shuffle4<A,A,A,A>(x); }

  template<int i>
    __forceinline vdouble8 align_shift_right(const vdouble8& a, const vdouble8& b)
  {
    return _mm512_alignr_pd(a,b,i); 
  };

  __forceinline double toScalar(const vdouble8& a)
  {
    return _mm256_cvtsd_f64(_mm512_castpd512_pd256(a));
  }

  ////////////////////////////////////////////////////////////////////////////////
  /// Reductions
  ////////////////////////////////////////////////////////////////////////////////

  __forceinline double reduce_add(const vdouble8& a) { return _mm512_reduce_add_pd(a); }
  __forceinline double reduce_min(const vdouble8& a) { return _mm512_reduce_min_pd(a); }
  __forceinline double reduce_max(const vdouble8& a) { return _mm512_reduce_max_pd(a); }
  
  __forceinline vdouble8 vreduce_min2(const vdouble8& x) {                                     return min(x,shuffle(x,_MM_SHUF_PERM(2,3,0,1))); }
  __forceinline vdouble8 vreduce_min4(const vdouble8& y) { const vdouble8 x = vreduce_min2(y); return min(x,shuffle(x,_MM_SHUF_PERM(1,0,3,2))); }
  __forceinline vdouble8 vreduce_min (const vdouble8& y) { const vdouble8 x = vreduce_min4(y); return min(x,shuffle4(x,_MM_SHUF_PERM(1,0,3,2))); }

  __forceinline vdouble8 vreduce_max2(const vdouble8& x) {                                     return max(x,shuffle(x,_MM_SHUF_PERM(1,0,3,2))); }
  __forceinline vdouble8 vreduce_max4(const vdouble8& y) { const vdouble8 x = vreduce_max2(y); return max(x,shuffle(x,_MM_SHUF_PERM(2,3,0,1))); }
  __forceinline vdouble8 vreduce_max (const vdouble8& y) { const vdouble8 x = vreduce_max4(y); return max(x,shuffle4(x,_MM_SHUF_PERM(1,0,3,2))); }

  __forceinline vdouble8 vreduce_and2(const vdouble8& x) {                                     return x & shuffle(x,_MM_SHUF_PERM(1,0,3,2)); }
  __forceinline vdouble8 vreduce_and4(const vdouble8& y) { const vdouble8 x = vreduce_and2(y); return x & shuffle(x,_MM_SHUF_PERM(2,3,0,1)); }
  __forceinline vdouble8 vreduce_and (const vdouble8& y) { const vdouble8 x = vreduce_and4(y); return x & shuffle4(x,_MM_SHUF_PERM(1,0,3,2)); }

  __forceinline vdouble8 vreduce_or2(const vdouble8& x) {                                    return x | shuffle(x,_MM_SHUF_PERM(1,0,3,2)); }
  __forceinline vdouble8 vreduce_or4(const vdouble8& y) { const vdouble8 x = vreduce_or2(y); return x | shuffle(x,_MM_SHUF_PERM(2,3,0,1)); }
  __forceinline vdouble8 vreduce_or (const vdouble8& y) { const vdouble8 x = vreduce_or4(y); return x | shuffle4(x,_MM_SHUF_PERM(1,0,3,2)); }

  __forceinline vdouble8 vreduce_add2(const vdouble8& x) {                                     return x + shuffle(x,_MM_SHUF_PERM(1,0,3,2)); }
  __forceinline vdouble8 vreduce_add4(const vdouble8& y) { const vdouble8 x = vreduce_add2(y); return x + shuffle(x,_MM_SHUF_PERM(2,3,0,1)); }
  __forceinline vdouble8 vreduce_add (const vdouble8& y) { const vdouble8 x = vreduce_add4(y); return x + shuffle4(x,_MM_SHUF_PERM(1,0,3,2)); }

  ////////////////////////////////////////////////////////////////////////////////
  /// Memory load and store operations
  ////////////////////////////////////////////////////////////////////////////////

  __forceinline vdouble8 permute(const vdouble8& v, const vlong8& index) {
    return _mm512_permutexvar_pd(index,v);  
  }

  __forceinline vdouble8 reverse(const vdouble8& a) {
    return permute(a,vlong8(reverse_step));
  }
  
  ////////////////////////////////////////////////////////////////////////////////
  /// Output Operators
  ////////////////////////////////////////////////////////////////////////////////
  
  __forceinline std::ostream& operator<<(std::ostream& cout, const vdouble8& v)
  {
    cout << "<" << v[0];
    for (size_t i=1; i<8; i++) cout << ", " << v[i];
    cout << ">";
    return cout;
  }
}