//===----------------------------------------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.txt for details.
//
//===----------------------------------------------------------------------===//


#include "compiler_if_host.h"

#include <malloc.h>
#ifndef TARGET_WINNT
#include <alloca.h>
#endif // TARGET_WINNT

// Global counter on host. 
// This variable is used if P2OPT_offload_do_data_persistence == 2.
// The variable used to identify offload constructs contained in one procedure.
// Increment of OFFLOAD_CALL_COUNT is inserted at entries of HOST routines with
// offload constructs.
static int offload_call_count = 0;

extern "C" OFFLOAD OFFLOAD_TARGET_ACQUIRE(
    TARGET_TYPE      target_type,
    int              target_number,
    int              is_optional,
    _Offload_status* status,
    const char*      file,
    uint64_t         line
)
{
    bool retval;
    OFFLOAD ofld;

    // initialize status
    if (status != 0) {
        status->result = OFFLOAD_UNAVAILABLE;
        status->device_number = -1;
        status->data_sent = 0;
        status->data_received = 0;
    }

    // make sure libray is initialized
    retval = __offload_init_library();

    // OFFLOAD_TIMER_INIT must follow call to __offload_init_library
    OffloadHostTimerData * timer_data = OFFLOAD_TIMER_INIT(file, line);

    OFFLOAD_TIMER_START(timer_data, c_offload_host_total_offload);

    OFFLOAD_TIMER_START(timer_data, c_offload_host_initialize);

    // initialize all devices is init_type is on_offload_all
    if (retval && __offload_init_type == c_init_on_offload_all) {
        for (int i = 0; i < mic_engines_total; i++) {
             mic_engines[i].init();
        }
    }
    OFFLOAD_TIMER_STOP(timer_data, c_offload_host_initialize);

    OFFLOAD_TIMER_START(timer_data, c_offload_host_target_acquire);

    if (target_type == TARGET_HOST) {
        // Host always available
        retval = true;
    }
    else if (target_type == TARGET_MIC) {
        if (target_number >= -1) {
            if (retval) {
                if (target_number >= 0) {
                    // User provided the device number
                    target_number = target_number % mic_engines_total;
                }
                else {
                    // use device 0
                    target_number = 0;
                }

                // reserve device in ORSL
                if (is_optional) {
                    if (!ORSL::try_reserve(target_number)) {
                        target_number = -1;
                    }
                }
                else {
                    if (!ORSL::reserve(target_number)) {
                        target_number = -1;
                    }
                }

                // initialize device
                if (target_number >= 0 &&
                    __offload_init_type == c_init_on_offload) {
                    OFFLOAD_TIMER_START(timer_data, c_offload_host_initialize);
                    mic_engines[target_number].init();
                    OFFLOAD_TIMER_STOP(timer_data, c_offload_host_initialize);
                }
            }
            else {
                // fallback to CPU
                target_number = -1;
            }

            if (target_number < 0 || !retval) {
                if (!is_optional && status == 0) {
                    LIBOFFLOAD_ERROR(c_device_is_not_available);
                    exit(1);
                }

                retval = false;
            }
        }
        else {
            LIBOFFLOAD_ERROR(c_invalid_device_number);
            exit(1);
        }
    }

    if (retval) {
        ofld = new OffloadDescriptor(target_number, status,
                                     !is_optional, false, timer_data);
        OFFLOAD_TIMER_HOST_MIC_NUM(timer_data, target_number);
        Offload_Report_Prolog(timer_data);
        OFFLOAD_DEBUG_TRACE_1(2, timer_data->offload_number, c_offload_start,
                              "Starting offload: target_type = %d, "
                              "number = %d, is_optional = %d\n",
                              target_type, target_number, is_optional);

        OFFLOAD_TIMER_STOP(timer_data, c_offload_host_target_acquire);
    }
    else {
        ofld = NULL;

        OFFLOAD_TIMER_STOP(timer_data, c_offload_host_target_acquire);
        OFFLOAD_TIMER_STOP(timer_data, c_offload_host_total_offload);
        offload_report_free_data(timer_data);
    }

    return ofld;
}

extern "C" OFFLOAD OFFLOAD_TARGET_ACQUIRE1(
    const int*  device_num,
    const char* file,
    uint64_t    line
)
{
    int target_number;

    // make sure libray is initialized and at least one device is available
    if (!__offload_init_library()) {
        LIBOFFLOAD_ERROR(c_device_is_not_available);
        exit(1);
    }

    // OFFLOAD_TIMER_INIT must follow call to __offload_init_library

    OffloadHostTimerData * timer_data = OFFLOAD_TIMER_INIT(file, line);

    OFFLOAD_TIMER_START(timer_data, c_offload_host_total_offload);

    OFFLOAD_TIMER_START(timer_data, c_offload_host_initialize);

    if (__offload_init_type == c_init_on_offload_all) {
        for (int i = 0; i < mic_engines_total; i++) {
             mic_engines[i].init();
        }
    }

    OFFLOAD_TIMER_STOP(timer_data, c_offload_host_initialize);

    OFFLOAD_TIMER_START(timer_data, c_offload_host_target_acquire);

    // use default device number if it is not provided
    if (device_num != 0) {
        target_number = *device_num;
    }
    else {
        target_number = __omp_device_num;
    }

    // device number should be a non-negative integer value
    if (target_number < 0) {
        LIBOFFLOAD_ERROR(c_omp_invalid_device_num);
        exit(1);
    }

    // should we do this for OpenMP?
    target_number %= mic_engines_total;

    // reserve device in ORSL
    if (!ORSL::reserve(target_number)) {
        LIBOFFLOAD_ERROR(c_device_is_not_available);
        exit(1);
    }

    // initialize device(s)
    OFFLOAD_TIMER_START(timer_data, c_offload_host_initialize);

    if (__offload_init_type == c_init_on_offload) {
        mic_engines[target_number].init();
    }

    OFFLOAD_TIMER_STOP(timer_data, c_offload_host_initialize);

    OFFLOAD ofld =
        new OffloadDescriptor(target_number, 0, true, true, timer_data);

    OFFLOAD_TIMER_HOST_MIC_NUM(timer_data, target_number);

    Offload_Report_Prolog(timer_data);

    OFFLOAD_DEBUG_TRACE_1(2, timer_data->offload_number, c_offload_start,
                          "Starting OpenMP offload, device = %d\n",
                          target_number);

    OFFLOAD_TIMER_STOP(timer_data, c_offload_host_target_acquire);

    return ofld;
}

int offload_offload_wrap(
    OFFLOAD ofld,
    const char *name,
    int is_empty,
    int num_vars,
    VarDesc *vars,
    VarDesc2 *vars2,
    int num_waits,
    const void **waits,
    const void **signal,
    int entry_id,
    const void *stack_addr
)
{
    bool ret = ofld->offload(name, is_empty, vars, vars2, num_vars,
                             waits, num_waits, signal, entry_id, stack_addr);
    if (!ret || signal == 0) {
        delete ofld;
    }
    return ret;
}

extern "C" int OFFLOAD_OFFLOAD1(
    OFFLOAD ofld,
    const char *name,
    int is_empty,
    int num_vars,
    VarDesc *vars,
    VarDesc2 *vars2,
    int num_waits,
    const void **waits,
    const void **signal
)
{
    return offload_offload_wrap(ofld, name, is_empty,
                            num_vars, vars, vars2,
                            num_waits, waits,
                            signal, NULL, NULL);
}

extern "C" int OFFLOAD_OFFLOAD2(
    OFFLOAD ofld,
    const char *name,
    int is_empty,
    int num_vars,
    VarDesc *vars,
    VarDesc2 *vars2,
    int num_waits,
    const void** waits,
    const void** signal,
    int entry_id,
    const void *stack_addr
)
{
    return offload_offload_wrap(ofld, name, is_empty,
                            num_vars, vars, vars2,
                            num_waits, waits,
                            signal, entry_id, stack_addr);
}

extern "C" int OFFLOAD_OFFLOAD(
    OFFLOAD ofld,
    const char *name,
    int is_empty,
    int num_vars,
    VarDesc *vars,
    VarDesc2 *vars2,
    int num_waits,
    const void **waits,
    const void *signal,
    int entry_id,
    const void *stack_addr
)
{
    // signal is passed by reference now
    const void **signal_new = (signal != 0) ? &signal : 0;
    const void **waits_new = 0;
    int num_waits_new = 0;

    // remove NULL values from the list of signals to wait for
    if (num_waits > 0) {
        waits_new = (const void**) alloca(sizeof(void*) * num_waits);
        for (int i = 0; i < num_waits; i++) {
            if (waits[i] != 0) {
                waits_new[num_waits_new++] = waits[i];
            }
        }
    }

    return OFFLOAD_OFFLOAD1(ofld, name, is_empty,
                            num_vars, vars, vars2,
                            num_waits_new, waits_new,
                            signal_new);
}

extern "C" int OFFLOAD_CALL_COUNT()
{
    offload_call_count++;
    return offload_call_count;
}