RegisterQuantityCheck.cc

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/**
 * @file RegisterQuantityCheck.cc
 * 
 * Implementation of RegisterQuantityCheck class.
 * 
 * Checks that given machine has enough registers.
 *
 * @author Heikki Kultala (hkultala-no.spam-cs.tut.fi)
 * @author Esa Määttä 2008 (esa.maatta-no.spam-tut.fi)
 * @note rating: red
 */
 
#include "RegisterFile.hh"
#include "Machine.hh"
#include "Guard.hh" 
#include "AssocTools.hh"
 
#include "Conversion.hh"
 
#include "RegisterQuantityCheck.hh"
#include "FullyConnectedCheck.hh"
#include "MachineCheckResults.hh"
 
RegisterQuantityCheck::RegisterQuantityCheck() : 
    MachineCheck("Checks that machine has enough registers") {}
 
RegisterQuantityCheck::~RegisterQuantityCheck() {}
 
 
/**
 * Checks register quantities, just returns false if problems where found.
 *
 * @param mach Machine to be checked for registers resources.
 * @param results MachineCheckResults where possible errors are added.
 * @return True if no problems were found during testing, false otherwise.
 */
bool 
RegisterQuantityCheck::check(const TTAMachine::Machine& mach) const {
    std::set<Register> guardRegs;
    const std::set<std::string> ignoreRFs; //empty, no ignore
 
    // find all registers that can be used for guards
    findGuardRegisters(mach, guardRegs, ignoreRFs);
 
    // check if enough predicate registers
    if (!checkPredRegs(guardRegs.size(), NULL)) {
        return false;
    }
 
    // count all integer registers
    unsigned int intRegs = countIntRegisters(mach, guardRegs, ignoreRFs);
 
    // check if enough integer registers
    if (missingIntRegs(intRegs, NULL, fullyConCheck_.check(mach))) {
        return false;
    }
 
    return true;
}
 
 
/**
 * Checks register quantities.
 *
 * Stores errors during checking to a MachineCheckResults object given as a
 * parameter.
 *
 * @param mach Machine to be checked for registers resources.
 * @param results MachineCheckResults where possible errors are added.
 * @return True if no problems were found during testing, false otherwise.
 */
bool 
RegisterQuantityCheck::check(
    const TTAMachine::Machine& mach, 
    MachineCheckResults& results) const {
 
    const std::set<std::string> empty;
    return RegisterQuantityCheck::checkWithIgnore(mach, results, empty);
}
 
 
/**
 * Checks register quantities with an option to ignore some RFs.
 *
 * Can be passed a list of RFs names that are ignored regarding the test.
 *
 * @param mach Machine to be checked for registers resources.
 * @param ignoreRFs A sorted list of RFs to be ignored while checking the
 *        needed registers.
 * @return True if no problems were found during testing, false otherwise.
 */
bool 
RegisterQuantityCheck::checkWithIgnore(
    const TTAMachine::Machine& mach, 
    const std::set<std::string>& ignoreRFs) const {
 
    std::set<Register> guardRegs;
 
    // find all registers that can be used for guards
    findGuardRegisters(mach, guardRegs, ignoreRFs);
 
    // check if enough predicate registers
    if (!checkPredRegs(guardRegs.size(), NULL)) {
        return false;
    }
 
    // count all integer registers
    unsigned int intRegs = countIntRegisters(mach, guardRegs, ignoreRFs);
 
    // check if enough integer registers
    if (missingIntRegs(intRegs, NULL, fullyConCheck_.check(mach))) {
        return false;
    }
 
    return true;
}
 
 
/**
 * Checks register quantities with an option to ignore some RFs.
 *
 * Can be passed a list of RFs names that are ignored regarding the test.
 * Stores errors during checking to a MachineCheckResults object given as a
 * parameter.
 *
 * @param mach Machine to be checked for registers resources.
 * @param results MachineCheckResults where possible errors are added.
 * @param ignoreRFs A sorted list of RFs to be ignored while checking the
 *        needed registers.
 * @return True if no problems were found during testing, false otherwise.
 */
bool 
RegisterQuantityCheck::checkWithIgnore(
    const TTAMachine::Machine& mach, 
    MachineCheckResults& results, 
    const std::set<std::string>& ignoreRFs) const {
 
    std::set<Register> guardRegs;
 
    // find all registers that can be used for guards
    findGuardRegisters(mach, guardRegs, ignoreRFs);
 
    // check if enough predicate registers
    checkPredRegs(guardRegs.size(), &results);
 
    // count all integer registers
    unsigned int intRegs = countIntRegisters(mach, guardRegs, ignoreRFs);
 
    // check if enough integer registers
    missingIntRegs(intRegs, &results, fullyConCheck_.check(mach));
 
    return results.errorCount() == 0;
}
 
 
/**
 * Check only if enough integer registers. 
 *
 * @param mach Machine to be checked for int registers.
 * @return True if enough integer registers found.
 */
bool 
RegisterQuantityCheck::checkIntRegs(const TTAMachine::Machine& mach) const {
    // find all registers that can be used for guards
    std::set<Register> guardRegs;
    const std::set<std::string> ignoreRFs; //empty, no ignore
    findGuardRegisters(mach, guardRegs, ignoreRFs);
 
    // count all integer registers
    unsigned int intRegs = countIntRegisters(mach, guardRegs, ignoreRFs);
 
    // check if enough integer registers
    if (missingIntRegs(intRegs, NULL, fullyConCheck_.check(mach))) {
        return false;
    }
    return true;
}
 
 
/**
 * Checks register quantities with an option to ignore some RFs.
 *
 * Can be passed a list of RFs names that are ignored regarding the test.
 *
 * @param mach Machine to be checked for registers resources.
 * @param guardRegs Counts registers that can be used as guards in the
 *        given machine.
 * @param ignoreRFs A sorted list of RFs to be ignored while checking the
 *        needed registers.
 * @return True if no problems were found during testing, false otherwise.
 */
void
RegisterQuantityCheck::findGuardRegisters(
    const TTAMachine::Machine& mach, 
    std::set<Register>& guardRegs,
    const std::set<std::string>& ignoreRFs) const {
    
    // find all registers that can be used for guards
    TTAMachine::Machine::BusNavigator busNav = mach.busNavigator();
    for (int i = 0; i < busNav.count(); i++) {
        TTAMachine::Bus* bus = busNav.item(i);
        for (int j = 0; j < bus->guardCount(); j++) {
            const TTAMachine::RegisterGuard* regGuard =
                dynamic_cast<TTAMachine::RegisterGuard*>(bus->guard(j));
            if (regGuard != NULL) {
                if(ignoreRFs.find(regGuard->registerFile()->name()) ==
                        ignoreRFs.end()) {
                    guardRegs.insert(
                        Register(
                            regGuard->registerFile(), regGuard->registerIndex()));
                }
            }
        }
    }
}
 
 
/**
 * Counts integer registers int the given machine.
 *
 * Doesn't count guard registers given as sorted list of pairs.
 * Can be passed a list of RFs names that are ignored regarding the test.
 *
 * @param mach Machine where integer registers are counted.
 * @param guardRegs A sorted list of register file, index pairs.
 * @param ignoreRFs A sorted list of RFs to be ignored while counting the
 *        registers.
 * @return The number of counted integer registers in them machine.
 */
unsigned int
RegisterQuantityCheck::countIntRegisters(
    const TTAMachine::Machine& mach, 
    const std::set<Register>& guardRegs,
    const std::set<std::string>& ignoreRFs) const {
 
    TTAMachine::Machine::RegisterFileNavigator regNav =
        mach.registerFileNavigator();
 
    unsigned int intRegs = 0;
    for (int i = 0; i < regNav.count(); i++) {
        const TTAMachine::RegisterFile* rf = regNav.item(i);
        if (rf->width() == 32 && 
                ignoreRFs.find(rf->name()) == ignoreRFs.end()) {
            for (int j = 0; j < rf->size(); j++) {
                if (!AssocTools::containsKey(guardRegs, Register(rf,j))) {
                    intRegs++;
                }
            }
        }
    }
    return intRegs;
}
 
 
/**
 * Checks that there are enough predicate registers.
 *
 * Outputs errors in MachineCheckResults object if given as a pointer.
 *
 * @param regCount The number of predicate registers.
 * @param results MachineCheckResults where possible errors are added.
 * @return True if the number of predicate registers given was high enough.
 */
bool
RegisterQuantityCheck::checkPredRegs(
    const unsigned int& regCount,
    MachineCheckResults* results) const {
    
    if (regCount < 2) {
        if (results != NULL) {
            std::string msg = "too few predicate registers, 2 needed, ";
            msg += Conversion::toString(regCount);
            msg += " found";
            results->addError(*this, msg);
        }
        return false;
    }
   return true;
}
 
 
/**
 * Checks that there are enough integer registers.
 *
 * Outputs errors in MachineCheckResults object if given as a pointer.
 *
 * @param regCount The number of integer registers.
 * @param results MachineCheckResults where possible errors are added.
 * @return number of missing registers, 0 if none missing.
 */
unsigned int
RegisterQuantityCheck::missingIntRegs(
    const unsigned int& regCount,
    MachineCheckResults* results,
    bool isFullyConnected) const {
 
    unsigned int neededIntRegs = isFullyConnected ? 5 : 6;
    unsigned int missingRegisters = 0;
     
    if (regCount < neededIntRegs) {
        missingRegisters = neededIntRegs - regCount;
        if (results != NULL) {
            results->addError(*this, "too few integer registers");
        }
    }
   return missingRegisters;
}
 
 
/**
 * Adds integer registers to an int rf so that requirements are met.
 *
 * @param machine Machine where integer registers are to be added if needed.
 * @return True if something was done to the machine, false otherwise.
 */
bool
RegisterQuantityCheck::fixIntRegs(TTAMachine::Machine& mach) const {
    // find all guard registers, which are ignored
    std::set<Register> guardRegs;
    const std::set<std::string> ignoreRFs; //empty, no ignore
    findGuardRegisters(mach, guardRegs, ignoreRFs);
 
    // count all integer registers
    unsigned int intRegs = countIntRegisters(mach, guardRegs, ignoreRFs);
   
    unsigned int missingRegs = 
        missingIntRegs(intRegs, NULL, fullyConCheck_.check(mach));
 
    if (!missingRegs) {
        return true;
    }
 
    TTAMachine::Machine::RegisterFileNavigator regNav =
        mach.registerFileNavigator();
 
    // find an int rf to add registers
    for (int i = 0; i < regNav.count(); i++) {
        TTAMachine::RegisterFile* rf = regNav.item(i);
        if (rf->width() == 32) {
            rf->setNumberOfRegisters(rf->size() + missingRegs);
            return true;
        }
    }
 
    // no int rf found
    return false;
}
 
 
/**
 * Returns true if an int register file found, meaning int registers can be
 * added.
 *
 * @return True, if int rf found.
 */
bool
RegisterQuantityCheck::canFixIntRegs(const TTAMachine::Machine& mach) const {
    TTAMachine::Machine::RegisterFileNavigator regNav =
        mach.registerFileNavigator();
 
    // return true if an int register file was found
    for (int i = 0; i < regNav.count(); i++) {
        TTAMachine::RegisterFile* rf = regNav.item(i);
        if (rf->width() == 32) {
            return true;
        }
    }
    return false;
}