FUTestbenchGenerator.cc

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/*
    Copyright (c) 2002-2010 Tampere University.
 
    This file is part of TTA-Based Codesign Environment (TCE).
 
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    Software is furnished to do so, subject to the following conditions:
 
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/**
 * @file FUTestbenchGenerator.cc
 *
 * Implementation of FUTestbenchGenerator class.
 *
 * @author Pekka Jääskeläinen 2006 (pekka.jaaskelainen-no.spam-tut.fi)
 * @author Otto Esko 2010 (otto.esko-no.spam-tut.fi)
 * @note rating: red
 */
 
#include <string>
#include <sstream>
#include <vector>
#include <boost/random.hpp>
#include <boost/nondet_random.hpp>
#include <ctime>
#include <stdint.h>
#include "HDBManager.hh"
#include "FUEntry.hh"
#include "TestbenchGenerator.hh"
#include "FUTestbenchGenerator.hh"
#include "FUArchitecture.hh"
#include "FunctionUnit.hh"
#include "Machine.hh"
#include "MachineState.hh"
#include "MachineStateBuilder.hh"
#include "MemorySystem.hh"
#include "OutputPortState.hh"
#include "InputPortState.hh"
#include "FUPortImplementation.hh"
#include "FUImplementation.hh"
#include "HWOperation.hh"
#include "StringTools.hh"
#include "Conversion.hh"
 
using std::string;
using std::vector;
using std::ifstream;
using std::ofstream;
 
#define STIMULUS_PER_OP 10
#define INDENT "   "
 
FUTestbenchGenerator::FUTestbenchGenerator(HDB::FUEntry* fu): 
    fuEntry_(fu), fuImpl_(NULL), fuArch_(NULL), msm_(NULL), inputPorts_(),
    outputPorts_(), opcodePort_(), machine_(NULL), memSystem_(NULL) {
}
 
FUTestbenchGenerator::~FUTestbenchGenerator() {
 
    if (msm_) {
        delete(msm_);
    }
    if (machine_) {
        delete(machine_);
    }
    if (memSystem_) {
        delete(memSystem_);
    }
}
 
 
void
FUTestbenchGenerator::generateTestbench(std::ofstream& file) {
 
    fuImpl_ = &fuEntry_->implementation();
    fuArch_ = &fuEntry_->architecture();
    
    createMachineState();
    parseFuPorts();
    createTbInstantiation();
    createStimulus();
    createTbCode();
    writeTestbench(file, fuImpl_);
}
 
/**
 * Create a machine architecture object model with the tested FU in it
 */
void
FUTestbenchGenerator::createMachineState() {
 
    machine_ = new TTAMachine::Machine();
    machine_->addFunctionUnit(fuArch_->architecture());
 
    MachineStateBuilder msmBuilder;
    
    memSystem_ = new MemorySystem(*machine_);
 
    msm_ = msmBuilder.build(*machine_, *memSystem_);
}
 
 
void 
FUTestbenchGenerator::parseFuPorts() {
 
    // divide ports into input and output ports
    for (int i = 0; i < fuArch_->architecture().portCount(); i++) {
        const std::string portName = fuArch_->architecture().port(i)->name();
        PortState& simulatedPort = 
            msm_->portState(portName, fuArch_->architecture().name());
 
        if (fuArch_->architecture().port(i)->isOpcodeSetting())
            opcodePort_ = portName;
 
        if (dynamic_cast<OutputPortState*>(&simulatedPort)) {
            outputPorts_.push_back(portName);
        } else if (dynamic_cast<InputPortState*>(&simulatedPort)) {
            inputPorts_.push_back(portName);
        } else if (&simulatedPort == &NullPortState::instance()) {
            InvalidData e(__FILE__, __LINE__, "ImplementationTester",
                          "Port not found in state");
            throw e;
        } else {
            InvalidData e(__FILE__, __LINE__, "ImplementationTester",
                          "Port " + portName + " has unknown direction.");
            throw e;
        }
    }
}
 
/**
 * Creates component declaration, connection signals and connects FU component
 * to testbench
 */
void
FUTestbenchGenerator::createTbInstantiation() {
 
    bindingStream() 
        << INDENT << "for tested_fu_0 : fu_under_test use entity work.";
    bindingStream() << fuImpl_->moduleName() << ";" << std::endl;
    
    declarationStream()
        << INDENT << "component fu_under_test" << std::endl
        << INDENT INDENT << "port(" << std::endl;
    
    instantiationStream()
        << INDENT << "tested_fu_0\t:\tfu_under_test " << std::endl
        << INDENT INDENT << "port map (" << std::endl;
 
    for (int i = 0; i < fuImpl_->architecturePortCount(); ++i) {
        HDB::FUPortImplementation& port = fuImpl_->architecturePort(i);
        // this might not always work..
        const int portWidth = fuArch_->architecture().port(i)->width();
        const bool isInput = 
            ContainerTools::containsValue(
                inputPorts_, port.architecturePort());
        declarationStream() 
            << INDENT INDENT << port.name() << "\t: ";
        signalStream()
            << INDENT << "signal " << port.name() << "\t: ";
        instantiationStream()
            << INDENT INDENT INDENT << port.name() << " => " << port.name();
 
        if (isInput)
            declarationStream() << "in";
        else
            declarationStream() << "out";
 
        declarationStream()
            << " std_logic_vector("
            << portWidth - 1 << " downto 0);" << std::endl;
 
        signalStream()
            << "std_logic_vector("
            << portWidth - 1 << " downto 0);" << std::endl;
 
        if (isInput) {
            declarationStream()
                << INDENT INDENT << port.loadPort() 
                << "\t: in  std_logic;" << std::endl;
 
            signalStream()
                << INDENT << "signal " << port.loadPort() 
                << "\t: std_logic_vector(1-1 downto 0);" << std::endl;
 
            instantiationStream()
                << "," << std::endl
                << INDENT INDENT INDENT << port.loadPort() << " => " 
                << port.loadPort() << "(0)";
        }
        if (i < fuImpl_->architecturePortCount() - 1) {
            instantiationStream() << "," << std::endl;
        } else {
            if (fuImpl_->opcodePort() != "") {
                declarationStream()
                    << INDENT INDENT << fuImpl_->opcodePort() << "\t: "
                    << "in" << " std_logic_vector("
                    << fuImpl_->maxOpcodeWidth() - 1 << " downto 0);"
                    << std::endl;
                instantiationStream()
                    << "," << std::endl
                    << INDENT INDENT INDENT 
                    << fuImpl_->opcodePort() 
                    << " => " << fuImpl_->opcodePort();
                signalStream()
                    << INDENT << "signal " << fuImpl_->opcodePort() << "\t: ";
                signalStream()
                    << "std_logic_vector("
                    << fuImpl_->maxOpcodeWidth() - 1 
                    << " downto 0);" << std::endl;
            }
        }
    }
    instantiationStream() 
        << "," << std::endl
        << INDENT INDENT INDENT
        << fuImpl_->clkPort() << " => " << fuImpl_->clkPort() 
        << "," << std::endl
        << INDENT INDENT INDENT
        << fuImpl_->rstPort() << " => " << fuImpl_->rstPort() 
        << "," << std::endl
        << INDENT INDENT INDENT
        << fuImpl_->glockPort() << " => " << fuImpl_->glockPort() 
        << ");";
 
    declarationStream()
        << INDENT INDENT << fuImpl_->glockPort() << "\t: in  std_logic;" 
        << std::endl
        << INDENT INDENT << fuImpl_->rstPort()   << "\t: in  std_logic;" 
        << std::endl
        << INDENT INDENT << fuImpl_->clkPort()   << "\t: in  std_logic);" 
        << std::endl
        << INDENT << "end component;" 
        << std::endl;
 
    signalStream()
        << INDENT << "signal " << fuImpl_->glockPort() << "\t: std_logic;" 
        << std::endl
        << INDENT << "signal " << fuImpl_->rstPort() << "\t: std_logic;" 
        << std::endl
        << INDENT << "signal " << fuImpl_->clkPort() << "\t: std_logic;"
        << std::endl;
}
 
 
/**
 * Creates input and output data tables
 *
 * Creates input and output data tables and control signals for the testbench.
 * Every operation is tested STIMULUS_PER_OP times and command execution is
 * pipelined. Only fully pipelined FUs are supported.
 */
void
FUTestbenchGenerator::createStimulus() {
 
    FUState& simFU = msm_->fuState(fuArch_->architecture().name());
    assert(&simFU != &NullFUState::instance());
 
    // stimulus for each port in each clock cycle
    PortDataArray inputStimulus;
 
    // stimulus for load ports. Notice that all load ports get the same
    // signal!
    // TODO: Exploit this when supporting non-fully pipelined operations
    //       (if latency(op N) > latency(op N+1) there needs to be no-load
    //       cycles when switching operations)
    vector<uint32_t> loadStimulus;
 
    // operations started in each clock cycle (names)
    vector<string> startedOperations;
 
    // expected output for each port in each clock cycle
    PortDataArray outputs;
 
    // initialize a random number generator for the stimuli
    boost::uniform_int<> distribution(INT_MIN, INT_MAX);
    boost::mt19937 rng;
    rng.seed(time(NULL));
    boost::variate_generator<boost::mt19937&, boost::uniform_int<> >
        randomNumber(rng, distribution);
 
    const int cyclesToSimulate = STIMULUS_PER_OP;
    for (int opIndex = 0; opIndex < fuArch_->architecture().operationCount(); 
         ++opIndex) {
        const string operation = 
            fuArch_->architecture().operation(opIndex)->name();
 
        for (int i = 0; i < cyclesToSimulate; i++) {
            startedOperations.push_back(operation);
 
            // generate stimulus for each port
            for (std::size_t i = 0; i < inputPorts_.size(); ++i) {
                const string portName = inputPorts_.at(i);
                writeInputPortStimulus(
                    inputStimulus, 
                    operation, portName, (uint32_t)randomNumber());
            }
            
            // load signal stimulus
            uint32_t loadOnThisCycle = 1;
            loadStimulus.push_back(loadOnThisCycle);
 
            readValuesFromOutPorts(outputs);
            // advance the simulation clock
            simFU.endClock();
            simFU.advanceClock();
        }
    }
    // flush the pipeline
    int lastOpIndex = fuArch_->architecture().operationCount()-1;
    int pipelineClearCycles =
        fuArch_->architecture().operation(lastOpIndex)->latency();
    for (int i = 0; i < pipelineClearCycles; i++) {
        if (fuArch_->architecture().operationCount() > 1) {
            // insert dummy values for opcode port
            const string operation = 
                fuArch_->architecture().operation(lastOpIndex)->name();
            startedOperations.push_back(operation);
        }
        for (std::size_t j = 0; j < inputPorts_.size(); ++j) {
            const string portName = inputPorts_.at(j);
            // operation does not matter
            const string operation = 
                fuArch_->architecture().operation(lastOpIndex)->name();
            uint32_t inputStim = 0;
            writeInputPortStimulus(
                inputStimulus, operation, portName, inputStim);
        }
        // no load on these cycles
        uint32_t loadStim = 0;
        loadStimulus.push_back(loadStim);
        
        readValuesFromOutPorts(outputs);
        // advance the simulation clock
        simFU.endClock();
        simFU.advanceClock();
    }
    createStimulusArrays(
        inputStimulus, loadStimulus, startedOperations, outputs);
    
    int waitCycles = 
        fuArch_->architecture().operation(startedOperations.at(0))->latency();
    // TODO: change this when supporting different pipelines
    int opCount = fuArch_->architecture().operationCount();
    int latencyOfLastOp =
        fuArch_->architecture().operation(opCount-1)->latency();
    int totalCycles = 
        STIMULUS_PER_OP * opCount + latencyOfLastOp;
    writeTbConstants(totalCycles, waitCycles);
}
 
 
/**
 * Writes the testbench main process code
 */
void
FUTestbenchGenerator::createTbCode() {
 
    for (std::size_t i = 0; i < inputPorts_.size(); ++i) {
        const std::string portName = inputPorts_.at(i);
        const std::string hwDataPortName = 
            fuImpl_->portImplementationByArchitectureName(portName).name();
        const std::string hwLoadPortName = 
            fuImpl_->
            portImplementationByArchitectureName(portName).loadPort();
        tbCodeStream()
            << INDENT INDENT 
            << hwDataPortName << " <= " << hwDataPortName << "_data("
            << "current_cycle);" << std::endl
            << INDENT INDENT << hwLoadPortName << " <= " 
            << hwLoadPortName << "_data(current_cycle);" << std::endl;        
    }
    
    if (fuArch_->architecture().operationCount() > 1) {
        tbCodeStream() 
            << INDENT INDENT 
            << fuImpl_->opcodePort() 
            << " <= " << fuImpl_->opcodePort() << "_data(current_cycle); ";
    }
 
    tbCodeStream()
        << std::endl << std::endl
        << INDENT INDENT 
        << "if current_cycle >= IGNORE_OUTPUT_COUNT then" << std::endl;
 
    for (std::size_t i = 0; i < outputPorts_.size(); ++i) {
        const std::string portName = outputPorts_.at(i);
        const std::string hwDataPortName = 
            fuImpl_->portImplementationByArchitectureName(portName).name();
        tbCodeStream() 
            << INDENT INDENT INDENT 
            << "assert " << hwDataPortName << " = " << hwDataPortName 
            << "_data(current_cycle)" << std::endl
            << INDENT INDENT INDENT INDENT 
            << "report lf & \"TCE Assert: Verification failed at cycle \" "
            << "& integer'image(current_cycle) & \" for output " << i << "\"" << std::endl
            << INDENT INDENT INDENT INDENT <<"& \" actual: \" "
            << "& to_hstring(" << hwDataPortName << ")" 
            << std::endl
            << INDENT INDENT INDENT INDENT << "& " 
            << "\" expected: \" & to_hstring(" << hwDataPortName
            << "_data(current_cycle))  severity error;" 
            << std::endl << std::endl;
    }
 
    tbCodeStream()
        << INDENT INDENT 
        << "end if;" << std::endl;
}
 
/**
 * Writes input data to the given port and saves the input value to an array
 *
 * @param inputs PortDataArray containing input ports
 * @param operation Name of the triggered operation
 * @param portName Name of the port where data is written to
 * @param stimulus Input data
 */
void
FUTestbenchGenerator::writeInputPortStimulus(
    PortDataArray& inputs,
    const std::string& operation, 
    const std::string& portName, uint32_t stimulus) {
 
    string operationString = "";
    PortState* simulatedPort = NULL;
    bool isOpcodePort = false;
    // fetch the virtual opcode setting port for the triggered operation
    if (portName == opcodePort_) {
        operationString = 
            StringTools::stringToLower(
                std::string(".") + operation);
        isOpcodePort = true;
    }
 
    simulatedPort = &msm_->portState(
        portName + operationString,
        fuArch_->architecture().name());
    
    const int inputWidth = simulatedPort->value().width();
    SimValue value(inputWidth);
 
    int wantedBits = inputWidth;
    if (isShiftOrRotOp(operation) && isOpcodePort
        && inputWidth > 5) {
        // log2(32) = 5 bits needed to express max shift
        wantedBits = 5;
    }
    stimulus = truncateStimulus(stimulus, wantedBits);
 
    inputs[portName].push_back(stimulus);
    value = stimulus;
    simulatedPort->setValue(value);
}
 
/**
 * Reads data from output ports and saves the values to an array
 *
 * @param outputs PortDataArray containing the output ports
 */
void 
FUTestbenchGenerator::readValuesFromOutPorts(PortDataArray& outputs) {
 
    for (std::size_t i = 0; i < outputPorts_.size(); ++i) {
        const string portName = outputPorts_.at(i);
 
        PortState* simulatedPort = NULL;
        simulatedPort = &msm_->portState(
            portName, fuArch_->architecture().name());
 
        outputs[portName].push_back(
            simulatedPort->value().intValue());
    }
}
 
/**
 * Writes input, output and control signal data to output streams
 *
 * @param inputStimulus Input port data
 * @param loadStimulus Load port data
 * @param operations Triggered operations
 * @param outputStimulus Output port data
 */
void 
FUTestbenchGenerator::createStimulusArrays(
    PortDataArray& inputStimulus, 
    std::vector<uint32_t>& loadStimulus,
    std::vector<std::string>& operations, PortDataArray& outputStimulus) {
 
    // input array(s)
    for (PortDataArray::iterator i = inputStimulus.begin();
         i != inputStimulus.end(); i++) {
        HDB::FUPortImplementation* port = 
            &fuImpl_->portImplementationByArchitectureName((*i).first);
        const string hwPortName = port->name();
        const int hwPortWidth = 
            fuArch_->architecture().port((*i).first)->width();
        vector<uint32_t> data = i->second;
        writeStimulusArray(inputArrayStream(), data, hwPortName, hwPortWidth);
 
        const string loadPortName = port->loadPort();
        if (!loadPortName.empty()) {
            int loadPortWidth = 1;
            writeStimulusArray(loadArrayStream(), loadStimulus, loadPortName,
                               loadPortWidth);
        }
    }
    
    // opcode arrays
    // Special case so we can print the operation names to the testbench
    const int operationsInFU = fuArch_->architecture().operationCount(); 
    if (operationsInFU > 1) {
        const string hwPortName = fuImpl_->opcodePort();
        const int hwPortWidth = fuImpl_->maxOpcodeWidth();
        opcodeArrayStream()
            << INDENT INDENT
            << "type " << hwPortName << "_data_array is array "
            << "(natural range <>) of"  << std::endl << INDENT INDENT INDENT
            << "std_logic_vector(" << hwPortWidth - 1 << " downto 0);" 
            << std::endl << std::endl
            << INDENT INDENT
            << "constant "<< hwPortName << "_data : " << hwPortName 
            << "_data_array :=" << std::endl;
        
        for (std::size_t i = 0; i < operations.size(); ++i) {
            uint32_t input = fuImpl_->opcode(operations.at(i));
            std::string inputAsBinaryLiteral = 
                Conversion::toBinary(input, hwPortWidth);
            opcodeArrayStream() << INDENT INDENT;
            if (i == 0) {
                opcodeArrayStream() << "(";
            } else {
                opcodeArrayStream() << " ";
            }
            opcodeArrayStream() << "\"" << inputAsBinaryLiteral << "\"";
            if (i == operations.size() - 1) {
                opcodeArrayStream() << ");";
            } else {
                opcodeArrayStream() << ",";
            }
            opcodeArrayStream()
                << "\t -- @" << i << " = " << input << " (" 
                << operations.at(i) << ")" << std::endl;
        }
    }
    
    // output arrays
    for (PortDataArray::iterator i = outputStimulus.begin();
         i != outputStimulus.end(); ++i) {
        const std::string hwPortName = 
            fuImpl_->portImplementationByArchitectureName((*i).first).name();
        const int hwPortWidth = 
            fuArch_->architecture().port((*i).first)->width();
        vector<uint32_t> data = i->second;
        writeStimulusArray(outputArrayStream(), data, hwPortName, 
                           hwPortWidth);
    }
}
 
 
/**
 * Test if operation is shift or rotation operation
 *
 * @param operation Name of the operation
 * @return Is operation shift or rotate
 */
bool
FUTestbenchGenerator::isShiftOrRotOp(const std::string& operation) const {
 
    string opName = StringTools::stringToLower(operation);
    
    if (opName == "shl" || opName == "shr" || opName == "shru") {
        return true;
    } else if (opName == "rotl" || opName == "rotr") {
        return true;
    }
    return false;
}
 
/**
 * Truncates shift operand to log2(32) bits
 *
 * @param operand Operand to be truncated
 * @return Truncated operand
 */
uint32_t
FUTestbenchGenerator::truncateStimulus(uint32_t operand, int nBits) const {
    
    if (nBits < 0) {
        InvalidData exc(__FILE__, __LINE__, "ImplementationTester",
                        "Negative amount f wanted bits");
        throw exc;
    }
 
    unsigned int dataWidth = 32;
    uint32_t truncated =
        (operand << (dataWidth - nBits) >> (dataWidth - nBits));
    return truncated;
}