Using ALFRED Prototype
======================
To use ALFRED prototype you need to:

1. Generate the LLVM IR of your program, as we describe in :ref:`compilation-label`
2. Configure ScEpTIC and your target architecture, as we describe in :ref:`configuration-label`
3. Configure the energy model of the target MCU, as we describe in :ref:`energy-model-label`
4. Configure ALFRED, as we describe in :ref:`alfred-configuration-label`
5. Configure the :ref:`performance-analysis-label` and/or :ref:`memory-usage-analysis-label`
6. Execute ScEpTIC anaysis, as we describe in :ref:`execute-sceptic-label`

Example Configuration for ALFRED
********************************
We provide here a portion of ScEpTIC configuration file that captures all the parameters introduced by ALFRED.
Note that the example below makes ScEpTIC to instrument the program with ratchet checkpoint strategy and then applies ALFRED pipeline.

::

    from ScEpTIC.AST.misc.virtual_memory_enum import VirtualMemoryEnum
    from ScEpTIC.emulator.energy.msp430 import MSP430EnergyCalculator

    run_energy_measure         = True
    run_memory_size_measure    = True

    memory_size_config = {
        'double_buffer_for_anomalies': True,
        'global_variables_default_memory': VirtualMemoryEnum.NON_VOLATILE,
    }

    clock_frequency = '8Mhz'

    program_configuration = {
        'ir_function_prefix': '@', #llvm ir function name prefix
        'main_function_name': 'main',
        'before_restore_function_name': 'sceptic_before_restore',
        'after_restore_function_name': 'sceptic_after_restore',
        'before_checkpoint_function_name': 'sceptic_before_checkpoint',
        'after_checkpoint_function_name': 'sceptic_after_checkpoint',
        'program_transformations': ['ratchet', 'virtual_memory']
    }

    energy_simulation_config = {
        'use_trigger_calls': False,
        'trigger_call_to_checkpoint_probability_range': [0, 10, 1],
        'simulate_power_failures': True,
        'clock_cycles_between_power_failures': 50000,
    }

    msp430fr5969_datasheet = {
        'registers': 10,
        'current_consumption': {
            '8Mhz': {
                'frequency': '8M',
                'voltage': '3',
                'n_waits': '0',
                'I_am_ram': '585u',
                'I_am_fram_uni': '1220u',
                'I_am_fram': '890u',
                'I_am_fram_hit': '0.75',
            },
            '16Mhz': {
                'frequency': '16M',
                'voltage': '3',
                'n_waits': '1',
                'I_am_ram': '1070u',
                'I_am_fram_uni': '1845u',
                'I_am_fram': '1420u',
                'I_am_fram_hit': '0.75',
            },
        },
        'ADC': {
            'T_off_on': '100n',
            'T_sampling': '1u',
            'I_min': '145u',
            'I_max': '185u',
            'N_init': '3',
            'N_off': '1',
            'N_transfer_ops': '1',
            'I_to_consider': 'min',
        },
    }

    mcu_datasheet = msp430fr5969_datasheet['current_consumption'][clock_frequency]

    energy_calculator = MSP430EnergyCalculator(mcu_datasheet, msp430fr5969_datasheet['registers'], msp430fr5969_datasheet['ADC'])
    n_min_function = lambda x: energy_calculator.n_min_function(x)

    transformation_options = {
        "virtual_memory": {
            "n_min_function": n_min_function,
            "optimize_saved_registers": True,
        },
        "ratchet": {
            "functions_with_outside_frame_accesses": ["function_name"],
            "optimize_saved_registers": True,
        }
    }