Commit 02a5354d authored by Alkis Evlogimenos's avatar Alkis Evlogimenos
Browse files

Make the set of fixed (preallocated) intervals be a fixed superset of 

unhandled + handled. So unhandled is now including all fixed intervals
and fixed intervals never changes when processing a function.

llvm-svn: 12462
parent a3783a57

llvm/lib/CodeGen/RegAllocLinearScan.cpp

+10 −29
Original line number Diff line number Diff line
@@ -135,9 +135,9 @@ namespace { 
void RA::releaseMemory()

{

    unhandled_.clear();

    fixed_.clear();

    active_.clear();

    inactive_.clear();

    fixed_.clear();

    handled_.clear();

}
@@ -171,25 +171,10 @@ void RA::linearScan() 
    DEBUG(printIntervals("active", active_.begin(), active_.end()));

    DEBUG(printIntervals("inactive", inactive_.begin(), inactive_.end()));



    while (!unhandled_.empty() || !fixed_.empty()) {

    while (!unhandled_.empty()) {

        // pick the interval with the earliest start point

        IntervalPtrs::value_type cur;

        if (fixed_.empty()) {

            cur = unhandled_.front();

            unhandled_.pop_front();

        }

        else if (unhandled_.empty()) {

            cur = fixed_.front();

            fixed_.pop_front();

        }

        else if (unhandled_.front()->start() < fixed_.front()->start()) {

            cur = unhandled_.front();

        IntervalPtrs::value_type cur = unhandled_.front();

        unhandled_.pop_front();

        }

        else {

            cur = fixed_.front();

            fixed_.pop_front();

        }



        DEBUG(std::cerr << "\n*** CURRENT ***: " << *cur << '\n');
@@ -234,10 +219,9 @@ void RA::initIntervalSets(LiveIntervals::Intervals& li) 


    for (LiveIntervals::Intervals::iterator i = li.begin(), e = li.end();

         i != e; ++i) {

        unhandled_.push_back(&*i);

        if (MRegisterInfo::isPhysicalRegister(i->reg))

            fixed_.push_back(&*i);

        else

            unhandled_.push_back(&*i);

    }

}
@@ -444,7 +428,7 @@ void RA::assignRegOrStackSlotAtInterval(IntervalPtrs::value_type cur) 


    DEBUG(std::cerr << "\t\trolling back to: " << earliestStart << '\n');

    // scan handled in reverse order and undo each one, restoring the

    // state of unhandled and fixed

    // state of unhandled

    while (!handled_.empty()) {

        IntervalPtrs::value_type i = handled_.back();

        // if this interval starts before t we are done
@@ -456,8 +440,8 @@ void RA::assignRegOrStackSlotAtInterval(IntervalPtrs::value_type cur) 
        if ((it = find(active_.begin(), active_.end(), i)) != active_.end()) {

            active_.erase(it);

            if (MRegisterInfo::isPhysicalRegister(i->reg)) {

                fixed_.push_front(i);

                prt_->delRegUse(i->reg);

                unhandled_.push_front(i);

            }

            else {

                prt_->delRegUse(vrm_->getPhys(i->reg));
@@ -479,7 +463,7 @@ void RA::assignRegOrStackSlotAtInterval(IntervalPtrs::value_type cur) 
        else if ((it = find(inactive_.begin(), inactive_.end(), i)) != inactive_.end()) {

            inactive_.erase(it);

            if (MRegisterInfo::isPhysicalRegister(i->reg))

                fixed_.push_front(i);

                unhandled_.push_front(i);

            else {

                vrm_->clearVirt(i->reg);

                if (i->spilled()) {
@@ -496,14 +480,11 @@ void RA::assignRegOrStackSlotAtInterval(IntervalPtrs::value_type cur) 
            }

        }

        else {

            if (MRegisterInfo::isPhysicalRegister(i->reg))

                fixed_.push_front(i);

            else {

            if (MRegisterInfo::isVirtualRegister(i->reg))

                vrm_->clearVirt(i->reg);

            unhandled_.push_front(i);

        }

    }

    }



    // scan the rest and undo each interval that expired after t and

    // insert it in active (the next iteration of the algorithm will