/*******************************************************************************
 *
 * MIT License
 *
 * Copyright (c) 2019 Advanced Micro Devices, Inc.
 *
 * 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
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 * furnished to do so, subject to the following conditions:
 *
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 *******************************************************************************/

#ifndef GUARD_MIOPEN_DROPOUT_HPP_
#define GUARD_MIOPEN_DROPOUT_HPP_

#include <miopen/common.hpp>
#include <miopen/miopen.h>
#include <miopen/object.hpp>
#include <miopen/handle.hpp>
#include <miopen/tensor.hpp>
#include <miopen/tensor_ops.hpp>

#define MAX_PRNG_STATE (256 * 64)
#define MAX_WORKITEM_NUM (256 * 4096)

struct xorwowStates
{
    // Xorshift values (160 bits)
    unsigned int x;
    unsigned int y;
    unsigned int z;
    unsigned int w;
    unsigned int v;

    // Weyl sequence value
    unsigned int d;
};

using prngStates = xorwowStates;

namespace miopen {

struct DropoutDescriptor : miopenDropoutDescriptor
{
    DropoutDescriptor();

    float dropout;
    Data_t pstates;
    size_t stateSizeInBytes;
    unsigned long long seed;
    bool use_mask;
    bool state_evo;
    miopenRNGType_t rng_mode;

    miopenDataType_t dataType_;

    void InitPRNGState(Handle& handle,
                       Data_t prng_states,
                       size_t prng_stateSizeInBytes,
                       unsigned long long prng_seed) const;

    void DropoutForward(Handle& handle,
                        const TensorDescriptor& noise_shape,
                        const TensorDescriptor& xDesc,
                        ConstData_t x,
                        const TensorDescriptor& yDesc,
                        Data_t y,
                        Data_t reserveSpace,
                        size_t reserveSpaceSizeInBytes,
                        size_t in_offset    = 0,
                        size_t out_offset   = 0,
                        size_t rsvsp_offset = 0) const;

    void DropoutBackward(Handle& handle,
                         const TensorDescriptor& noise_shape,
                         const TensorDescriptor& dyDesc,
                         ConstData_t dy,
                         const TensorDescriptor& dxDesc,
                         Data_t dx,
                         Data_t reserveSpace,
                         size_t reserveSpaceSizeInBytes,
                         size_t in_offset    = 0,
                         size_t out_offset   = 0,
                         size_t rsvsp_offset = 0) const;
};

std::ostream& operator<<(std::ostream& stream, const DropoutDescriptor& x);

} // namespace miopen
MIOPEN_DEFINE_OBJECT(miopenDropoutDescriptor, miopen::DropoutDescriptor);

#endif // GUARD_MIOPEN_DROPOUT_HPP_