/*
 * Copyright (c) 2015-2018, NVIDIA CORPORATION.  All rights reserved.
 *
 * 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.
 *
 */

#ifndef LLMPUTIL_H_
#define LLMPUTIL_H_

/** \file
 *  \brief OpenMP utility routines for LLVM compilers
 */

#include "gbldefs.h"
#include "global.h"
#include "symtab.h"

/** Uplevel data structure containing a list of shared variables for the region
 * nest that this uplevel belongs to.  The shared variables in this structure
 * are represented as a list of unique sptrs.
 */
typedef struct {
  int *vals;      /* Array containing shared var sptrs */
  int vals_size;  /* Total allocated slots in vals */
  int vals_count; /* Traditionally "available" or vals_avl */
  DTYPE dtype;    ///< The true dtype containing fields and their offsets
  SPTR parent;    /* sptr of its parent */
  /* TODO: Consider using a hashset to speed-unique lookup */
} LLUplevel;

/** First private variable:
 * This information is necessary to generate code that allows a particular task
 * to know which variables are stored in its allocated memory (task memory).
 * First privates for the task have to be stored in that memory.
 */
typedef struct _llprivate_t {
  int shared_sptr;  /**< Represents the caller's copy */
  int private_sptr; /**< Represents the callee's copy (local) */
} LLFirstPrivate;

/// Task data structure containing a list of private variables for the task.
typedef struct {
  int scope_sptr;        /**< Outlined task's scope sptr (BMPSCOPE ST_BLOCK) */
  int task_sptr;         /**< Outlined function representing the task */
  LLFirstPrivate *privs; /**< Array of private sptrs for this task */
  int privs_count;
  int privs_size;
  int actual_size; /**< Bytes in task: First priv size + base task size */
} LLTask;

/// Data attributes for each data reference used in an OpenMP target region.
typedef enum {
  // No flags
    OMP_TGT_MAPTYPE_NONE            = 0x000,
  // copy data from host to device
    OMP_TGT_MAPTYPE_TO              = 0x001,
  // copy data from device to host
    OMP_TGT_MAPTYPE_FROM            = 0x002,
  // copy regardless of the reference count
    OMP_TGT_MAPTYPE_ALWAYS          = 0x004,
  // force unmapping of data
    OMP_TGT_MAPTYPE_DELETE          = 0x008,
  // map the pointer as well as the pointee
    OMP_TGT_MAPTYPE_PTR_AND_OBJ     = 0x010,
  // pass device base address to kernel
    OMP_TGT_MAPTYPE_TARGET_PARAM    = 0x020,
  // return base device address of mapped data
    OMP_TGT_MAPTYPE_RETURN_PARAM    = 0x040,
  // private variable - not mapped
    OMP_TGT_MAPTYPE_PRIVATE         = 0x080,
  // copy by value - not mapped
    OMP_TGT_MAPTYPE_LITERAL         = 0x100,
  // mapping is implicit
    OMP_TGT_MAPTYPE_IMPLICIT        = 0x200,
  // member of struct, member given by 4 MSBs - 1
    OMP_TGT_MAPTYPE_MEMBER_OF       = 0xffff000000000000
} tgt_map_type;


/** Combined construct mode for the target region.
 *
 */
typedef enum {
  mode_none_target,
  mode_target,
  mode_target_teams,
  mode_target_teams_distribute,
  mode_target_teams_distribute_parallel_for,
  mode_target_teams_distribute_parallel_for_simd,
  mode_target_parallel,
  mode_target_parallel_for,
  mode_target_parallel_for_simd,
  mode_target_data_enter_region,
  mode_target_data_exit_region,
  mode_target_data_region,
} OMP_TARGET_MODE;

/* Obtain a previously created task object, where scope_sptr is the BMPSCOPE
 * scope sptr containing the task.
 */
extern LLTask *llmp_get_task(int scope_sptr);

/* Return the task base size without any private values being stored. */
extern int llmp_task_get_base_task_size(void);

/* Return the task's total size including task metadata and priv vars */
extern int llmp_task_get_size(LLTask *task);

/* Set the task function sptr */
extern void llmp_task_set_fnsptr(LLTask *task, int task_sptr);

/* Return a task a object associated to 'task_sptr' */
extern LLTask *llmp_task_get_by_fnsptr(int task_sptr);

/* Returns the sptr of the 'private' (local to the callee) copy of the
 * private variable represented by 'sptr'.
 */
extern int llmp_task_get_private(const LLTask *task, int sptr, int incl);

/// \brief Uniquely add a shared variable
int llmp_add_shared_var(LLUplevel *up, int shared_sptr);

/// \brief Return a new key (index) into our table of all uplevels
int llmp_get_next_key(void);

/**
   \brief ...
 */
int llmp_task_add_loopvar(LLTask *task, int num, DTYPE dtype);

/**
   \brief Add a private sptr to the task object.
   priv:   sptr to the private copy of the private variable.
           ADDRESSP is called to set the offset to the kmpc task
           object where this private data will live during program
           execution.
 /
 */
int llmp_task_add_private(LLTask *task, int shared_sptr, SPTR private_sptr);

/**
   \brief ...
 */
int llmp_task_get_base_task_size(void);

/**
   \brief ...
 */
int llmp_task_get_private(const LLTask *task, int sptr, int encl);

/**
   \brief ...
 */
INT llmp_task_get_privoff(int sptr, const LLTask *task);

/**
   \brief ...
 */
int llmp_task_get_size(LLTask *task);

/**
   \brief ...
 */
int llmp_uplevel_has_parent(int uplevel);

/**
   \brief Create task object that can be searched for later using \p scope_sptr
   \param scope_sptr ...
 */
LLTask *llmp_create_task(int scope_sptr);

/**
   \brief ...
 */
LLTask *llmp_get_task(int scope_sptr);

/**
   \brief ...
 */
LLTask *llmp_task_get_by_fnsptr(int task_sptr);

/// \brief Retrieve an LLUplevel instance by key
LLUplevel *llmp_create_uplevel_bykey(int key);

/**
   \brief Create an LLUplevel instance
   \param stblock_sptr Block where this region nest begins.
   This is used as a key into the global list of all uplevels.
 */
LLUplevel *llmp_create_uplevel(int uplevel_sptr);

/// \brief Obtain a previously created uplevel
LLUplevel *llmp_get_uplevel(int uplevel_sptr);

/** Return an uplevel pointer if it has an entry in uplevel table
    or NULL if there is no entry.
 */
LLUplevel *llmp_has_uplevel(int uplevel_sptr);

/**
   \brief ...
 */
void dump_all_uplevel(void);

/**
   \brief ...
 */
void dump_uplevel(LLUplevel *up);

/**
   \brief ...
 */
void llmp_add_shared_var_charlen(LLUplevel *up, int shared_sptr);

/**
   \brief ...
 */
void llmp_append_uplevel(int from_sptr, int to_sptr);

/**
   \brief ...
 */
void llmp_concur_add_shared_var(int uplevel_sptr, int shared_sptr);

/**
   \brief ...
 */
void llmp_reset_uplevel(void);

/**
   \brief Return symbol pointer of its parent.
 */
SPTR llmp_get_parent_sptr(SPTR);

/**
   \brief Create a task object if it does not already exist for \p scope_sptr
   Add a private sptr to the task object.  shared, priv: See
   llmp_task_add_private
 */
void llmp_task_add(int scope_sptr, int shared_sptr, SPTR private_sptr);

/**
   \brief ...
 */
void llmp_task_set_fnsptr(LLTask *task, int task_sptr);

/**
   \brief Set the dtype (actual struct of member pointers)
 */
void llmp_uplevel_set_dtype(LLUplevel *up, DTYPE dtype);

/**
   \brief Set uplevel parent field.
 */
void llmp_uplevel_set_parent(SPTR uplevel_sptr, SPTR parent_sptr);

/**
   \brief Return outermost uplevel of current region.
 */
LLUplevel *llmp_outermost_uplevel(SPTR child);

/**
   \brief Return uplevel pointer of current uplevel's parent
 */
LLUplevel *llmp_parent_uplevel(SPTR child);

#endif /* LLMPUTIL_H_ */