#ifndef OPENMM_VECTORIZE_H_
#define OPENMM_VECTORIZE_H_

/* -------------------------------------------------------------------------- *
 *                                   OpenMM                                   *
 * -------------------------------------------------------------------------- *
 * This is part of the OpenMM molecular simulation toolkit originating from   *
 * Simbios, the NIH National Center for Physics-Based Simulation of           *
 * Biological Structures at Stanford, funded under the NIH Roadmap for        *
 * Medical Research, grant U54 GM072970. See https://simtk.org.               *
 *                                                                            *
 * Portions copyright (c) 2013 Stanford University and the Authors.           *
 * Authors: Peter Eastman                                                     *
 * Contributors:                                                              *
 *                                                                            *
 * Permission is hereby granted, free of charge, to any person obtaining a    *
 * copy of this software and associated documentation files (the "Software"), *
 * to deal in the Software without restriction, including without limitation  *
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,   *
 * and/or sell copies of the Software, and to permit persons to whom the      *
 * Software is furnished to do so, subject to the following conditions:       *
 *                                                                            *
 * The above copyright notice and this permission notice shall be included in *
 * all copies or substantial portions of the Software.                        *
 *                                                                            *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR *
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,   *
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL    *
 * THE AUTHORS, CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,    *
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR      *
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE  *
 * USE OR OTHER DEALINGS IN THE SOFTWARE.                                     *
 * -------------------------------------------------------------------------- */

#include <smmintrin.h>


// This file defines classes and functions to simplify vectorizing code with SSE.

class ivec4;

/**
 * A four element vector of floats.
 */
class fvec4 {
public:
    __m128 val;
    
    fvec4() {}
    fvec4(float v) : val(_mm_set1_ps(v)) {}
    fvec4(float v1, float v2, float v3, float v4) : val(_mm_set_ps(v4, v3, v2, v1)) {}
    fvec4(__m128 v) : val(v) {}
    fvec4(const float* v) : val(_mm_loadu_ps(v)) {}
    operator __m128() const {
        return val;
    }
    float operator[](int i) const {
        int resultBits = _mm_extract_ps(val, i);
        return *((float*) &resultBits);
    }
    void store(float* v) const {
        _mm_storeu_ps(v, val);
    }
    fvec4 operator+(fvec4 other) const {
        return _mm_add_ps(val, other);
    }
    fvec4 operator-(fvec4 other) const {
        return _mm_sub_ps(val, other);
    }
    fvec4 operator*(fvec4 other) const {
        return _mm_mul_ps(val, other);
    }
    fvec4 operator/(fvec4 other) const {
        return _mm_div_ps(val, other);
    }
    void operator+=(fvec4 other) {
        val = _mm_add_ps(val, other);
    }
    void operator-=(fvec4 other) {
        val = _mm_sub_ps(val, other);
    }
    void operator*=(fvec4 other) {
        val = _mm_mul_ps(val, other);
    }
    void operator/=(fvec4 other) {
        val = _mm_div_ps(val, other);
    }
    fvec4 operator-() const {
        return _mm_sub_ps(_mm_set1_ps(0.0f), val);
    }
    fvec4 operator&(fvec4 other) const {
        return _mm_and_ps(val, other);
    }
    fvec4 operator==(fvec4 other) const {
        return _mm_cmpeq_ps(val, other);
    }
    fvec4 operator!=(fvec4 other) const {
        return _mm_cmpneq_ps(val, other);
    }
    fvec4 operator>(fvec4 other) const {
        return _mm_cmpgt_ps(val, other);
    }
    fvec4 operator<(fvec4 other) const {
        return _mm_cmplt_ps(val, other);
    }
    fvec4 operator>=(fvec4 other) const {
        return _mm_cmpge_ps(val, other);
    }
    fvec4 operator<=(fvec4 other) const {
        return _mm_cmple_ps(val, other);
    }
    operator ivec4() const;
};

/**
 * A four element vector of ints.
 */
class ivec4 {
public:
    __m128i val;
    
    ivec4() {}
    ivec4(int v) : val(_mm_set1_epi32(v)) {}
    ivec4(int v1, int v2, int v3, int v4) : val(_mm_set_epi32(v4, v3, v2, v1)) {}
    ivec4(__m128i v) : val(v) {}
    ivec4(const int* v) : val(_mm_loadu_si128((const __m128i*) v)) {}
    operator __m128i() const {
        return val;
    }
    int operator[](int i) const {
        return _mm_extract_epi32(val, i);
    }
    void store(int* v) const {
        _mm_storeu_si128((__m128i*) v, val);
    }
    ivec4 operator+(ivec4 other) const {
        return _mm_add_epi32(val, other);
    }
    ivec4 operator-(ivec4 other) const {
        return _mm_sub_epi32(val, other);
    }
    ivec4 operator*(ivec4 other) const {
        return _mm_mul_epi32(val, other);
    }
    void operator+=(ivec4 other) {
        val = _mm_add_epi32(val, other);
    }
    void operator-=(ivec4 other) {
        val = _mm_sub_epi32(val, other);
    }
    void operator*=(ivec4 other) {
        val = _mm_mul_epi32(val, other);
    }
    ivec4 operator-() const {
        return _mm_sub_epi32(_mm_set1_epi32(0), val);
    }
    ivec4 operator&(ivec4 other) const {
        return _mm_and_si128(val, other);
    }
    ivec4 operator==(ivec4 other) const {
        return _mm_cmpeq_epi32(val, other);
    }
    operator fvec4() const;
};

// Conversion operators.

inline fvec4::operator ivec4() const {
    return _mm_cvttps_epi32(val);
}

inline ivec4::operator fvec4() const {
    return _mm_cvtepi32_ps(val);
}

// Functions that operate on fvec4s.

static inline fvec4 floor(fvec4 v) {
    return fvec4(_mm_floor_ps(v.val));
}

static inline fvec4 ceil(fvec4 v) {
    return fvec4(_mm_ceil_ps(v.val));
}

static inline fvec4 round(fvec4 v) {
    return fvec4(_mm_round_ps(v.val, _MM_FROUND_TO_NEAREST_INT));
}

static inline fvec4 min(fvec4 v1, fvec4 v2) {
    return fvec4(_mm_min_ps(v1.val, v2.val));
}

static inline fvec4 max(fvec4 v1, fvec4 v2) {
    return fvec4(_mm_max_ps(v1.val, v2.val));
}

static inline fvec4 abs(fvec4 v) {
    static const __m128 mask = _mm_castsi128_ps(_mm_set1_epi32(0x7FFFFFFF));
    return fvec4(_mm_and_ps(v.val, mask));
}

static inline fvec4 sqrt(fvec4 v) {
    return fvec4(_mm_sqrt_ps(v.val));
}

static inline float dot3(fvec4 v1, fvec4 v2) {
    return _mm_cvtss_f32(_mm_dp_ps(v1, v2, 0x71));
}

static inline float dot4(fvec4 v1, fvec4 v2) {
    return _mm_cvtss_f32(_mm_dp_ps(v1, v2, 0xF1));
}

// Functions that operate on ivec4s.

static inline ivec4 min(ivec4 v1, ivec4 v2) {
    return ivec4(_mm_min_epi32(v1.val, v2.val));
}

static inline ivec4 max(ivec4 v1, ivec4 v2) {
    return ivec4(_mm_max_epi32(v1.val, v2.val));
}

static inline ivec4 abs(ivec4 v) {
    return ivec4(_mm_abs_epi32(v.val));
}

// Mathematical operators involving a scalar and a vector.

static inline fvec4 operator+(float v1, fvec4 v2) {
    return fvec4(v1)+v2;
}

static inline fvec4 operator-(float v1, fvec4 v2) {
    return fvec4(v1)-v2;
}

static inline fvec4 operator*(float v1, fvec4 v2) {
    return fvec4(v1)*v2;
}

static inline fvec4 operator/(float v1, fvec4 v2) {
    return fvec4(v1)/v2;
}

#endif /*OPENMM_VECTORIZE_H_*/

