[llvm-commits] CVS: llvm/lib/CodeGen/RegAllocLinearScan.cpp RegAllocIterativeScan.cpp
Alkis Evlogimenos
alkis at cs.uiuc.edu
Wed Aug 4 02:46:37 PDT 2004
Changes in directory llvm/lib/CodeGen:
RegAllocLinearScan.cpp updated: 1.86 -> 1.87
RegAllocIterativeScan.cpp updated: 1.10 -> 1.11
---
Log message:
Convert indentation to 2 spaces.
---
Diffs of the changes: (+818 -818)
Index: llvm/lib/CodeGen/RegAllocLinearScan.cpp
diff -u llvm/lib/CodeGen/RegAllocLinearScan.cpp:1.86 llvm/lib/CodeGen/RegAllocLinearScan.cpp:1.87
--- llvm/lib/CodeGen/RegAllocLinearScan.cpp:1.86 Sun Jul 25 03:10:33 2004
+++ llvm/lib/CodeGen/RegAllocLinearScan.cpp Wed Aug 4 04:46:26 2004
@@ -35,502 +35,502 @@
namespace {
- Statistic<double> efficiency
- ("regalloc", "Ratio of intervals processed over total intervals");
+ Statistic<double> efficiency
+ ("regalloc", "Ratio of intervals processed over total intervals");
- static unsigned numIterations = 0;
- static unsigned numIntervals = 0;
+ static unsigned numIterations = 0;
+ static unsigned numIntervals = 0;
- class RA : public MachineFunctionPass {
- private:
- MachineFunction* mf_;
- const TargetMachine* tm_;
- const MRegisterInfo* mri_;
- LiveIntervals* li_;
- typedef std::vector<LiveInterval*> IntervalPtrs;
- IntervalPtrs handled_, fixed_, active_, inactive_;
- typedef std::priority_queue<LiveInterval*,
- IntervalPtrs,
- greater_ptr<LiveInterval> > IntervalHeap;
- IntervalHeap unhandled_;
- std::auto_ptr<PhysRegTracker> prt_;
- std::auto_ptr<VirtRegMap> vrm_;
- std::auto_ptr<Spiller> spiller_;
-
- typedef std::vector<float> SpillWeights;
- SpillWeights spillWeights_;
-
- public:
- virtual const char* getPassName() const {
- return "Linear Scan Register Allocator";
- }
-
- virtual void getAnalysisUsage(AnalysisUsage &AU) const {
- AU.addRequired<LiveVariables>();
- AU.addRequired<LiveIntervals>();
- MachineFunctionPass::getAnalysisUsage(AU);
- }
-
- /// runOnMachineFunction - register allocate the whole function
- bool runOnMachineFunction(MachineFunction&);
-
- void releaseMemory();
-
- private:
- /// linearScan - the linear scan algorithm
- void linearScan();
-
- /// initIntervalSets - initializa the four interval sets:
- /// unhandled, fixed, active and inactive
- void initIntervalSets();
-
- /// processActiveIntervals - expire old intervals and move
- /// non-overlapping ones to the incative list
- void processActiveIntervals(LiveInterval* cur);
-
- /// processInactiveIntervals - expire old intervals and move
- /// overlapping ones to the active list
- void processInactiveIntervals(LiveInterval* cur);
-
- /// updateSpillWeights - updates the spill weights of the
- /// specifed physical register and its weight
- void updateSpillWeights(unsigned reg, SpillWeights::value_type weight);
-
- /// assignRegOrStackSlotAtInterval - assign a register if one
- /// is available, or spill.
- void assignRegOrStackSlotAtInterval(LiveInterval* cur);
-
- ///
- /// register handling helpers
- ///
-
- /// getFreePhysReg - return a free physical register for this
- /// virtual register interval if we have one, otherwise return
- /// 0
- unsigned getFreePhysReg(LiveInterval* cur);
-
- /// assignVirt2StackSlot - assigns this virtual register to a
- /// stack slot. returns the stack slot
- int assignVirt2StackSlot(unsigned virtReg);
-
- template <typename ItTy>
- void printIntervals(const char* const str, ItTy i, ItTy e) const {
- if (str) std::cerr << str << " intervals:\n";
- for (; i != e; ++i) {
- std::cerr << "\t" << **i << " -> ";
- unsigned reg = (*i)->reg;
- if (MRegisterInfo::isVirtualRegister(reg)) {
- reg = vrm_->getPhys(reg);
- }
- std::cerr << mri_->getName(reg) << '\n';
- }
+ class RA : public MachineFunctionPass {
+ private:
+ MachineFunction* mf_;
+ const TargetMachine* tm_;
+ const MRegisterInfo* mri_;
+ LiveIntervals* li_;
+ typedef std::vector<LiveInterval*> IntervalPtrs;
+ IntervalPtrs handled_, fixed_, active_, inactive_;
+ typedef std::priority_queue<LiveInterval*,
+ IntervalPtrs,
+ greater_ptr<LiveInterval> > IntervalHeap;
+ IntervalHeap unhandled_;
+ std::auto_ptr<PhysRegTracker> prt_;
+ std::auto_ptr<VirtRegMap> vrm_;
+ std::auto_ptr<Spiller> spiller_;
+
+ typedef std::vector<float> SpillWeights;
+ SpillWeights spillWeights_;
+
+ public:
+ virtual const char* getPassName() const {
+ return "Linear Scan Register Allocator";
+ }
+
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.addRequired<LiveVariables>();
+ AU.addRequired<LiveIntervals>();
+ MachineFunctionPass::getAnalysisUsage(AU);
+ }
+
+ /// runOnMachineFunction - register allocate the whole function
+ bool runOnMachineFunction(MachineFunction&);
+
+ void releaseMemory();
+
+ private:
+ /// linearScan - the linear scan algorithm
+ void linearScan();
+
+ /// initIntervalSets - initializa the four interval sets:
+ /// unhandled, fixed, active and inactive
+ void initIntervalSets();
+
+ /// processActiveIntervals - expire old intervals and move
+ /// non-overlapping ones to the incative list
+ void processActiveIntervals(LiveInterval* cur);
+
+ /// processInactiveIntervals - expire old intervals and move
+ /// overlapping ones to the active list
+ void processInactiveIntervals(LiveInterval* cur);
+
+ /// updateSpillWeights - updates the spill weights of the
+ /// specifed physical register and its weight
+ void updateSpillWeights(unsigned reg, SpillWeights::value_type weight);
+
+ /// assignRegOrStackSlotAtInterval - assign a register if one
+ /// is available, or spill.
+ void assignRegOrStackSlotAtInterval(LiveInterval* cur);
+
+ ///
+ /// register handling helpers
+ ///
+
+ /// getFreePhysReg - return a free physical register for this
+ /// virtual register interval if we have one, otherwise return
+ /// 0
+ unsigned getFreePhysReg(LiveInterval* cur);
+
+ /// assignVirt2StackSlot - assigns this virtual register to a
+ /// stack slot. returns the stack slot
+ int assignVirt2StackSlot(unsigned virtReg);
+
+ template <typename ItTy>
+ void printIntervals(const char* const str, ItTy i, ItTy e) const {
+ if (str) std::cerr << str << " intervals:\n";
+ for (; i != e; ++i) {
+ std::cerr << "\t" << **i << " -> ";
+ unsigned reg = (*i)->reg;
+ if (MRegisterInfo::isVirtualRegister(reg)) {
+ reg = vrm_->getPhys(reg);
}
- };
+ std::cerr << mri_->getName(reg) << '\n';
+ }
+ }
+ };
}
void RA::releaseMemory()
{
- while (!unhandled_.empty()) unhandled_.pop();
- fixed_.clear();
- active_.clear();
- inactive_.clear();
- handled_.clear();
+ while (!unhandled_.empty()) unhandled_.pop();
+ fixed_.clear();
+ active_.clear();
+ inactive_.clear();
+ handled_.clear();
}
bool RA::runOnMachineFunction(MachineFunction &fn) {
- mf_ = &fn;
- tm_ = &fn.getTarget();
- mri_ = tm_->getRegisterInfo();
- li_ = &getAnalysis<LiveIntervals>();
- if (!prt_.get()) prt_.reset(new PhysRegTracker(*mri_));
- vrm_.reset(new VirtRegMap(*mf_));
- if (!spiller_.get()) spiller_.reset(createSpiller());
+ mf_ = &fn;
+ tm_ = &fn.getTarget();
+ mri_ = tm_->getRegisterInfo();
+ li_ = &getAnalysis<LiveIntervals>();
+ if (!prt_.get()) prt_.reset(new PhysRegTracker(*mri_));
+ vrm_.reset(new VirtRegMap(*mf_));
+ if (!spiller_.get()) spiller_.reset(createSpiller());
- initIntervalSets();
+ initIntervalSets();
- linearScan();
+ linearScan();
- spiller_->runOnMachineFunction(*mf_, *vrm_);
+ spiller_->runOnMachineFunction(*mf_, *vrm_);
- return true;
+ return true;
}
void RA::linearScan()
{
- // linear scan algorithm
- DEBUG(std::cerr << "********** LINEAR SCAN **********\n");
- DEBUG(std::cerr << "********** Function: "
- << mf_->getFunction()->getName() << '\n');
+ // linear scan algorithm
+ DEBUG(std::cerr << "********** LINEAR SCAN **********\n");
+ DEBUG(std::cerr << "********** Function: "
+ << mf_->getFunction()->getName() << '\n');
+
+ // DEBUG(printIntervals("unhandled", unhandled_.begin(), unhandled_.end()));
+ DEBUG(printIntervals("fixed", fixed_.begin(), fixed_.end()));
+ DEBUG(printIntervals("active", active_.begin(), active_.end()));
+ DEBUG(printIntervals("inactive", inactive_.begin(), inactive_.end()));
+
+ while (!unhandled_.empty()) {
+ // pick the interval with the earliest start point
+ LiveInterval* cur = unhandled_.top();
+ unhandled_.pop();
+ ++numIterations;
+ DEBUG(std::cerr << "\n*** CURRENT ***: " << *cur << '\n');
+
+ processActiveIntervals(cur);
+ processInactiveIntervals(cur);
+
+ // if this register is fixed we are done
+ if (MRegisterInfo::isPhysicalRegister(cur->reg)) {
+ prt_->addRegUse(cur->reg);
+ active_.push_back(cur);
+ handled_.push_back(cur);
+ }
+ // otherwise we are allocating a virtual register. try to find
+ // a free physical register or spill an interval in order to
+ // assign it one (we could spill the current though).
+ else {
+ assignRegOrStackSlotAtInterval(cur);
+ }
- // DEBUG(printIntervals("unhandled", unhandled_.begin(), unhandled_.end()));
- DEBUG(printIntervals("fixed", fixed_.begin(), fixed_.end()));
DEBUG(printIntervals("active", active_.begin(), active_.end()));
DEBUG(printIntervals("inactive", inactive_.begin(), inactive_.end()));
+ }
+ numIntervals += li_->getNumIntervals();
+ efficiency = double(numIterations) / double(numIntervals);
+
+ // expire any remaining active intervals
+ for (IntervalPtrs::reverse_iterator
+ i = active_.rbegin(); i != active_.rend(); ) {
+ unsigned reg = (*i)->reg;
+ DEBUG(std::cerr << "\tinterval " << **i << " expired\n");
+ if (MRegisterInfo::isVirtualRegister(reg))
+ reg = vrm_->getPhys(reg);
+ prt_->delRegUse(reg);
+ i = IntervalPtrs::reverse_iterator(active_.erase(i.base()-1));
+ }
+
+ // expire any remaining inactive intervals
+ for (IntervalPtrs::reverse_iterator
+ i = inactive_.rbegin(); i != inactive_.rend(); ) {
+ DEBUG(std::cerr << "\tinterval " << **i << " expired\n");
+ i = IntervalPtrs::reverse_iterator(inactive_.erase(i.base()-1));
+ }
- while (!unhandled_.empty()) {
- // pick the interval with the earliest start point
- LiveInterval* cur = unhandled_.top();
- unhandled_.pop();
- ++numIterations;
- DEBUG(std::cerr << "\n*** CURRENT ***: " << *cur << '\n');
-
- processActiveIntervals(cur);
- processInactiveIntervals(cur);
-
- // if this register is fixed we are done
- if (MRegisterInfo::isPhysicalRegister(cur->reg)) {
- prt_->addRegUse(cur->reg);
- active_.push_back(cur);
- handled_.push_back(cur);
- }
- // otherwise we are allocating a virtual register. try to find
- // a free physical register or spill an interval in order to
- // assign it one (we could spill the current though).
- else {
- assignRegOrStackSlotAtInterval(cur);
- }
-
- DEBUG(printIntervals("active", active_.begin(), active_.end()));
- DEBUG(printIntervals("inactive", inactive_.begin(), inactive_.end()));
- }
- numIntervals += li_->getNumIntervals();
- efficiency = double(numIterations) / double(numIntervals);
-
- // expire any remaining active intervals
- for (IntervalPtrs::reverse_iterator
- i = active_.rbegin(); i != active_.rend(); ) {
- unsigned reg = (*i)->reg;
- DEBUG(std::cerr << "\tinterval " << **i << " expired\n");
- if (MRegisterInfo::isVirtualRegister(reg))
- reg = vrm_->getPhys(reg);
- prt_->delRegUse(reg);
- i = IntervalPtrs::reverse_iterator(active_.erase(i.base()-1));
- }
-
- // expire any remaining inactive intervals
- for (IntervalPtrs::reverse_iterator
- i = inactive_.rbegin(); i != inactive_.rend(); ) {
- DEBUG(std::cerr << "\tinterval " << **i << " expired\n");
- i = IntervalPtrs::reverse_iterator(inactive_.erase(i.base()-1));
- }
-
- DEBUG(std::cerr << *vrm_);
+ DEBUG(std::cerr << *vrm_);
}
void RA::initIntervalSets()
{
- assert(unhandled_.empty() && fixed_.empty() &&
- active_.empty() && inactive_.empty() &&
- "interval sets should be empty on initialization");
-
- for (LiveIntervals::iterator i = li_->begin(), e = li_->end(); i != e; ++i){
- unhandled_.push(&i->second);
- if (MRegisterInfo::isPhysicalRegister(i->second.reg))
- fixed_.push_back(&i->second);
- }
+ assert(unhandled_.empty() && fixed_.empty() &&
+ active_.empty() && inactive_.empty() &&
+ "interval sets should be empty on initialization");
+
+ for (LiveIntervals::iterator i = li_->begin(), e = li_->end(); i != e; ++i){
+ unhandled_.push(&i->second);
+ if (MRegisterInfo::isPhysicalRegister(i->second.reg))
+ fixed_.push_back(&i->second);
+ }
}
void RA::processActiveIntervals(IntervalPtrs::value_type cur)
{
- DEBUG(std::cerr << "\tprocessing active intervals:\n");
- for (IntervalPtrs::reverse_iterator
- i = active_.rbegin(); i != active_.rend();) {
- unsigned reg = (*i)->reg;
- // remove expired intervals
- if ((*i)->expiredAt(cur->start())) {
- DEBUG(std::cerr << "\t\tinterval " << **i << " expired\n");
- if (MRegisterInfo::isVirtualRegister(reg))
- reg = vrm_->getPhys(reg);
- prt_->delRegUse(reg);
- // remove from active
- i = IntervalPtrs::reverse_iterator(active_.erase(i.base()-1));
- }
- // move inactive intervals to inactive list
- else if (!(*i)->liveAt(cur->start())) {
- DEBUG(std::cerr << "\t\tinterval " << **i << " inactive\n");
- if (MRegisterInfo::isVirtualRegister(reg))
- reg = vrm_->getPhys(reg);
- prt_->delRegUse(reg);
- // add to inactive
- inactive_.push_back(*i);
- // remove from active
- i = IntervalPtrs::reverse_iterator(active_.erase(i.base()-1));
- }
- else {
- ++i;
- }
+ DEBUG(std::cerr << "\tprocessing active intervals:\n");
+ for (IntervalPtrs::reverse_iterator
+ i = active_.rbegin(); i != active_.rend();) {
+ unsigned reg = (*i)->reg;
+ // remove expired intervals
+ if ((*i)->expiredAt(cur->start())) {
+ DEBUG(std::cerr << "\t\tinterval " << **i << " expired\n");
+ if (MRegisterInfo::isVirtualRegister(reg))
+ reg = vrm_->getPhys(reg);
+ prt_->delRegUse(reg);
+ // remove from active
+ i = IntervalPtrs::reverse_iterator(active_.erase(i.base()-1));
+ }
+ // move inactive intervals to inactive list
+ else if (!(*i)->liveAt(cur->start())) {
+ DEBUG(std::cerr << "\t\tinterval " << **i << " inactive\n");
+ if (MRegisterInfo::isVirtualRegister(reg))
+ reg = vrm_->getPhys(reg);
+ prt_->delRegUse(reg);
+ // add to inactive
+ inactive_.push_back(*i);
+ // remove from active
+ i = IntervalPtrs::reverse_iterator(active_.erase(i.base()-1));
+ }
+ else {
+ ++i;
}
+ }
}
void RA::processInactiveIntervals(IntervalPtrs::value_type cur)
{
- DEBUG(std::cerr << "\tprocessing inactive intervals:\n");
- for (IntervalPtrs::reverse_iterator
- i = inactive_.rbegin(); i != inactive_.rend();) {
- unsigned reg = (*i)->reg;
-
- // remove expired intervals
- if ((*i)->expiredAt(cur->start())) {
- DEBUG(std::cerr << "\t\tinterval " << **i << " expired\n");
- // remove from inactive
- i = IntervalPtrs::reverse_iterator(inactive_.erase(i.base()-1));
- }
- // move re-activated intervals in active list
- else if ((*i)->liveAt(cur->start())) {
- DEBUG(std::cerr << "\t\tinterval " << **i << " active\n");
- if (MRegisterInfo::isVirtualRegister(reg))
- reg = vrm_->getPhys(reg);
- prt_->addRegUse(reg);
- // add to active
- active_.push_back(*i);
- // remove from inactive
- i = IntervalPtrs::reverse_iterator(inactive_.erase(i.base()-1));
- }
- else {
- ++i;
- }
+ DEBUG(std::cerr << "\tprocessing inactive intervals:\n");
+ for (IntervalPtrs::reverse_iterator
+ i = inactive_.rbegin(); i != inactive_.rend();) {
+ unsigned reg = (*i)->reg;
+
+ // remove expired intervals
+ if ((*i)->expiredAt(cur->start())) {
+ DEBUG(std::cerr << "\t\tinterval " << **i << " expired\n");
+ // remove from inactive
+ i = IntervalPtrs::reverse_iterator(inactive_.erase(i.base()-1));
+ }
+ // move re-activated intervals in active list
+ else if ((*i)->liveAt(cur->start())) {
+ DEBUG(std::cerr << "\t\tinterval " << **i << " active\n");
+ if (MRegisterInfo::isVirtualRegister(reg))
+ reg = vrm_->getPhys(reg);
+ prt_->addRegUse(reg);
+ // add to active
+ active_.push_back(*i);
+ // remove from inactive
+ i = IntervalPtrs::reverse_iterator(inactive_.erase(i.base()-1));
}
+ else {
+ ++i;
+ }
+ }
}
void RA::updateSpillWeights(unsigned reg, SpillWeights::value_type weight)
{
- spillWeights_[reg] += weight;
- for (const unsigned* as = mri_->getAliasSet(reg); *as; ++as)
- spillWeights_[*as] += weight;
+ spillWeights_[reg] += weight;
+ for (const unsigned* as = mri_->getAliasSet(reg); *as; ++as)
+ spillWeights_[*as] += weight;
}
void RA::assignRegOrStackSlotAtInterval(LiveInterval* cur)
{
- DEBUG(std::cerr << "\tallocating current interval: ");
-
- PhysRegTracker backupPrt = *prt_;
+ DEBUG(std::cerr << "\tallocating current interval: ");
- spillWeights_.assign(mri_->getNumRegs(), 0.0);
-
- // for each interval in active update spill weights
- for (IntervalPtrs::const_iterator i = active_.begin(), e = active_.end();
- i != e; ++i) {
- unsigned reg = (*i)->reg;
- if (MRegisterInfo::isVirtualRegister(reg))
- reg = vrm_->getPhys(reg);
- updateSpillWeights(reg, (*i)->weight);
- }
+ PhysRegTracker backupPrt = *prt_;
- // for every interval in inactive we overlap with, mark the
- // register as not free and update spill weights
- for (IntervalPtrs::const_iterator i = inactive_.begin(),
- e = inactive_.end(); i != e; ++i) {
- if (cur->overlaps(**i)) {
- unsigned reg = (*i)->reg;
- if (MRegisterInfo::isVirtualRegister(reg))
- reg = vrm_->getPhys(reg);
- prt_->addRegUse(reg);
- updateSpillWeights(reg, (*i)->weight);
- }
- }
+ spillWeights_.assign(mri_->getNumRegs(), 0.0);
- // for every interval in fixed we overlap with,
- // mark the register as not free and update spill weights
- for (IntervalPtrs::const_iterator i = fixed_.begin(),
- e = fixed_.end(); i != e; ++i) {
- if (cur->overlaps(**i)) {
- unsigned reg = (*i)->reg;
- prt_->addRegUse(reg);
- updateSpillWeights(reg, (*i)->weight);
- }
- }
-
- unsigned physReg = getFreePhysReg(cur);
- // restore the physical register tracker
- *prt_ = backupPrt;
- // if we find a free register, we are done: assign this virtual to
- // the free physical register and add this interval to the active
- // list.
- if (physReg) {
- DEBUG(std::cerr << mri_->getName(physReg) << '\n');
- vrm_->assignVirt2Phys(cur->reg, physReg);
- prt_->addRegUse(physReg);
- active_.push_back(cur);
- handled_.push_back(cur);
- return;
- }
- DEBUG(std::cerr << "no free registers\n");
-
- DEBUG(std::cerr << "\tassigning stack slot at interval "<< *cur << ":\n");
-
- float minWeight = HUGE_VAL;
- unsigned minReg = 0;
- const TargetRegisterClass* rc = mf_->getSSARegMap()->getRegClass(cur->reg);
- for (TargetRegisterClass::iterator i = rc->allocation_order_begin(*mf_);
- i != rc->allocation_order_end(*mf_); ++i) {
- unsigned reg = *i;
- if (minWeight > spillWeights_[reg]) {
- minWeight = spillWeights_[reg];
- minReg = reg;
- }
- }
- DEBUG(std::cerr << "\t\tregister with min weight: "
- << mri_->getName(minReg) << " (" << minWeight << ")\n");
-
- // if the current has the minimum weight, we need to spill it and
- // add any added intervals back to unhandled, and restart
- // linearscan.
- if (cur->weight <= minWeight) {
- DEBUG(std::cerr << "\t\t\tspilling(c): " << *cur << '\n';);
- int slot = vrm_->assignVirt2StackSlot(cur->reg);
- std::vector<LiveInterval*> added =
- li_->addIntervalsForSpills(*cur, *vrm_, slot);
- if (added.empty())
- return; // Early exit if all spills were folded.
-
- // Merge added with unhandled. Note that we know that
- // addIntervalsForSpills returns intervals sorted by their starting
- // point.
- for (unsigned i = 0, e = added.size(); i != e; ++i)
- unhandled_.push(added[i]);
- return;
- }
-
- // push the current interval back to unhandled since we are going
- // to re-run at least this iteration. Since we didn't modify it it
- // should go back right in the front of the list
- unhandled_.push(cur);
-
- // otherwise we spill all intervals aliasing the register with
- // minimum weight, rollback to the interval with the earliest
- // start point and let the linear scan algorithm run again
- std::vector<LiveInterval*> added;
- assert(MRegisterInfo::isPhysicalRegister(minReg) &&
- "did not choose a register to spill?");
- std::vector<bool> toSpill(mri_->getNumRegs(), false);
- // we are going to spill minReg and all its aliases
- toSpill[minReg] = true;
- for (const unsigned* as = mri_->getAliasSet(minReg); *as; ++as)
- toSpill[*as] = true;
-
- // the earliest start of a spilled interval indicates up to where
- // in handled we need to roll back
- unsigned earliestStart = cur->start();
-
- // set of spilled vregs (used later to rollback properly)
- std::set<unsigned> spilled;
-
- // spill live intervals of virtual regs mapped to the physical
- // register we want to clear (and its aliases). we only spill
- // those that overlap with the current interval as the rest do not
- // affect its allocation. we also keep track of the earliest start
- // of all spilled live intervals since this will mark our rollback
- // point
- for (IntervalPtrs::iterator
- i = active_.begin(); i != active_.end(); ++i) {
- unsigned reg = (*i)->reg;
- if (MRegisterInfo::isVirtualRegister(reg) &&
- toSpill[vrm_->getPhys(reg)] &&
- cur->overlaps(**i)) {
- DEBUG(std::cerr << "\t\t\tspilling(a): " << **i << '\n');
- earliestStart = std::min(earliestStart, (*i)->start());
- int slot = vrm_->assignVirt2StackSlot((*i)->reg);
- std::vector<LiveInterval*> newIs =
- li_->addIntervalsForSpills(**i, *vrm_, slot);
- std::copy(newIs.begin(), newIs.end(), std::back_inserter(added));
- spilled.insert(reg);
- }
- }
- for (IntervalPtrs::iterator
- i = inactive_.begin(); i != inactive_.end(); ++i) {
- unsigned reg = (*i)->reg;
- if (MRegisterInfo::isVirtualRegister(reg) &&
- toSpill[vrm_->getPhys(reg)] &&
- cur->overlaps(**i)) {
- DEBUG(std::cerr << "\t\t\tspilling(i): " << **i << '\n');
- earliestStart = std::min(earliestStart, (*i)->start());
- int slot = vrm_->assignVirt2StackSlot((*i)->reg);
- std::vector<LiveInterval*> newIs =
- li_->addIntervalsForSpills(**i, *vrm_, slot);
- std::copy(newIs.begin(), newIs.end(), std::back_inserter(added));
- spilled.insert(reg);
- }
- }
-
- DEBUG(std::cerr << "\t\trolling back to: " << earliestStart << '\n');
- // scan handled in reverse order up to the earliaset start of a
- // spilled live interval and undo each one, restoring the state of
- // unhandled
- while (!handled_.empty()) {
- LiveInterval* i = handled_.back();
- // if this interval starts before t we are done
- if (i->start() < earliestStart)
- break;
- DEBUG(std::cerr << "\t\t\tundo changes for: " << *i << '\n');
- handled_.pop_back();
- // when undoing a live interval allocation we must know if it
- // is active or inactive to properly update the PhysRegTracker
- // and the VirtRegMap
- IntervalPtrs::iterator it;
- if ((it = find(active_.begin(), active_.end(), i)) != active_.end()) {
- active_.erase(it);
- if (MRegisterInfo::isPhysicalRegister(i->reg)) {
- prt_->delRegUse(i->reg);
- unhandled_.push(i);
- }
- else {
- if (!spilled.count(i->reg))
- unhandled_.push(i);
- prt_->delRegUse(vrm_->getPhys(i->reg));
- vrm_->clearVirt(i->reg);
- }
- }
- else if ((it = find(inactive_.begin(), inactive_.end(), i)) != inactive_.end()) {
- inactive_.erase(it);
- if (MRegisterInfo::isPhysicalRegister(i->reg))
- unhandled_.push(i);
- else {
- if (!spilled.count(i->reg))
- unhandled_.push(i);
- vrm_->clearVirt(i->reg);
- }
- }
- else {
- if (MRegisterInfo::isVirtualRegister(i->reg))
- vrm_->clearVirt(i->reg);
- unhandled_.push(i);
- }
- }
-
- // scan the rest and undo each interval that expired after t and
- // insert it in active (the next iteration of the algorithm will
- // put it in inactive if required)
- IntervalPtrs::iterator i = handled_.begin(), e = handled_.end();
- for (; i != e; ++i) {
- if (!(*i)->expiredAt(earliestStart) && (*i)->expiredAt(cur->start())) {
- DEBUG(std::cerr << "\t\t\tundo changes for: " << **i << '\n');
- active_.push_back(*i);
- if (MRegisterInfo::isPhysicalRegister((*i)->reg))
- prt_->addRegUse((*i)->reg);
- else
- prt_->addRegUse(vrm_->getPhys((*i)->reg));
- }
- }
-
- std::sort(added.begin(), added.end(), less_ptr<LiveInterval>());
- // merge added with unhandled
+ // for each interval in active update spill weights
+ for (IntervalPtrs::const_iterator i = active_.begin(), e = active_.end();
+ i != e; ++i) {
+ unsigned reg = (*i)->reg;
+ if (MRegisterInfo::isVirtualRegister(reg))
+ reg = vrm_->getPhys(reg);
+ updateSpillWeights(reg, (*i)->weight);
+ }
+
+ // for every interval in inactive we overlap with, mark the
+ // register as not free and update spill weights
+ for (IntervalPtrs::const_iterator i = inactive_.begin(),
+ e = inactive_.end(); i != e; ++i) {
+ if (cur->overlaps(**i)) {
+ unsigned reg = (*i)->reg;
+ if (MRegisterInfo::isVirtualRegister(reg))
+ reg = vrm_->getPhys(reg);
+ prt_->addRegUse(reg);
+ updateSpillWeights(reg, (*i)->weight);
+ }
+ }
+
+ // for every interval in fixed we overlap with,
+ // mark the register as not free and update spill weights
+ for (IntervalPtrs::const_iterator i = fixed_.begin(),
+ e = fixed_.end(); i != e; ++i) {
+ if (cur->overlaps(**i)) {
+ unsigned reg = (*i)->reg;
+ prt_->addRegUse(reg);
+ updateSpillWeights(reg, (*i)->weight);
+ }
+ }
+
+ unsigned physReg = getFreePhysReg(cur);
+ // restore the physical register tracker
+ *prt_ = backupPrt;
+ // if we find a free register, we are done: assign this virtual to
+ // the free physical register and add this interval to the active
+ // list.
+ if (physReg) {
+ DEBUG(std::cerr << mri_->getName(physReg) << '\n');
+ vrm_->assignVirt2Phys(cur->reg, physReg);
+ prt_->addRegUse(physReg);
+ active_.push_back(cur);
+ handled_.push_back(cur);
+ return;
+ }
+ DEBUG(std::cerr << "no free registers\n");
+
+ DEBUG(std::cerr << "\tassigning stack slot at interval "<< *cur << ":\n");
+
+ float minWeight = HUGE_VAL;
+ unsigned minReg = 0;
+ const TargetRegisterClass* rc = mf_->getSSARegMap()->getRegClass(cur->reg);
+ for (TargetRegisterClass::iterator i = rc->allocation_order_begin(*mf_);
+ i != rc->allocation_order_end(*mf_); ++i) {
+ unsigned reg = *i;
+ if (minWeight > spillWeights_[reg]) {
+ minWeight = spillWeights_[reg];
+ minReg = reg;
+ }
+ }
+ DEBUG(std::cerr << "\t\tregister with min weight: "
+ << mri_->getName(minReg) << " (" << minWeight << ")\n");
+
+ // if the current has the minimum weight, we need to spill it and
+ // add any added intervals back to unhandled, and restart
+ // linearscan.
+ if (cur->weight <= minWeight) {
+ DEBUG(std::cerr << "\t\t\tspilling(c): " << *cur << '\n';);
+ int slot = vrm_->assignVirt2StackSlot(cur->reg);
+ std::vector<LiveInterval*> added =
+ li_->addIntervalsForSpills(*cur, *vrm_, slot);
+ if (added.empty())
+ return; // Early exit if all spills were folded.
+
+ // Merge added with unhandled. Note that we know that
+ // addIntervalsForSpills returns intervals sorted by their starting
+ // point.
for (unsigned i = 0, e = added.size(); i != e; ++i)
- unhandled_.push(added[i]);
+ unhandled_.push(added[i]);
+ return;
+ }
+
+ // push the current interval back to unhandled since we are going
+ // to re-run at least this iteration. Since we didn't modify it it
+ // should go back right in the front of the list
+ unhandled_.push(cur);
+
+ // otherwise we spill all intervals aliasing the register with
+ // minimum weight, rollback to the interval with the earliest
+ // start point and let the linear scan algorithm run again
+ std::vector<LiveInterval*> added;
+ assert(MRegisterInfo::isPhysicalRegister(minReg) &&
+ "did not choose a register to spill?");
+ std::vector<bool> toSpill(mri_->getNumRegs(), false);
+ // we are going to spill minReg and all its aliases
+ toSpill[minReg] = true;
+ for (const unsigned* as = mri_->getAliasSet(minReg); *as; ++as)
+ toSpill[*as] = true;
+
+ // the earliest start of a spilled interval indicates up to where
+ // in handled we need to roll back
+ unsigned earliestStart = cur->start();
+
+ // set of spilled vregs (used later to rollback properly)
+ std::set<unsigned> spilled;
+
+ // spill live intervals of virtual regs mapped to the physical
+ // register we want to clear (and its aliases). we only spill
+ // those that overlap with the current interval as the rest do not
+ // affect its allocation. we also keep track of the earliest start
+ // of all spilled live intervals since this will mark our rollback
+ // point
+ for (IntervalPtrs::iterator
+ i = active_.begin(); i != active_.end(); ++i) {
+ unsigned reg = (*i)->reg;
+ if (MRegisterInfo::isVirtualRegister(reg) &&
+ toSpill[vrm_->getPhys(reg)] &&
+ cur->overlaps(**i)) {
+ DEBUG(std::cerr << "\t\t\tspilling(a): " << **i << '\n');
+ earliestStart = std::min(earliestStart, (*i)->start());
+ int slot = vrm_->assignVirt2StackSlot((*i)->reg);
+ std::vector<LiveInterval*> newIs =
+ li_->addIntervalsForSpills(**i, *vrm_, slot);
+ std::copy(newIs.begin(), newIs.end(), std::back_inserter(added));
+ spilled.insert(reg);
+ }
+ }
+ for (IntervalPtrs::iterator
+ i = inactive_.begin(); i != inactive_.end(); ++i) {
+ unsigned reg = (*i)->reg;
+ if (MRegisterInfo::isVirtualRegister(reg) &&
+ toSpill[vrm_->getPhys(reg)] &&
+ cur->overlaps(**i)) {
+ DEBUG(std::cerr << "\t\t\tspilling(i): " << **i << '\n');
+ earliestStart = std::min(earliestStart, (*i)->start());
+ int slot = vrm_->assignVirt2StackSlot((*i)->reg);
+ std::vector<LiveInterval*> newIs =
+ li_->addIntervalsForSpills(**i, *vrm_, slot);
+ std::copy(newIs.begin(), newIs.end(), std::back_inserter(added));
+ spilled.insert(reg);
+ }
+ }
+
+ DEBUG(std::cerr << "\t\trolling back to: " << earliestStart << '\n');
+ // scan handled in reverse order up to the earliaset start of a
+ // spilled live interval and undo each one, restoring the state of
+ // unhandled
+ while (!handled_.empty()) {
+ LiveInterval* i = handled_.back();
+ // if this interval starts before t we are done
+ if (i->start() < earliestStart)
+ break;
+ DEBUG(std::cerr << "\t\t\tundo changes for: " << *i << '\n');
+ handled_.pop_back();
+ // when undoing a live interval allocation we must know if it
+ // is active or inactive to properly update the PhysRegTracker
+ // and the VirtRegMap
+ IntervalPtrs::iterator it;
+ if ((it = find(active_.begin(), active_.end(), i)) != active_.end()) {
+ active_.erase(it);
+ if (MRegisterInfo::isPhysicalRegister(i->reg)) {
+ prt_->delRegUse(i->reg);
+ unhandled_.push(i);
+ }
+ else {
+ if (!spilled.count(i->reg))
+ unhandled_.push(i);
+ prt_->delRegUse(vrm_->getPhys(i->reg));
+ vrm_->clearVirt(i->reg);
+ }
+ }
+ else if ((it = find(inactive_.begin(), inactive_.end(), i)) != inactive_.end()) {
+ inactive_.erase(it);
+ if (MRegisterInfo::isPhysicalRegister(i->reg))
+ unhandled_.push(i);
+ else {
+ if (!spilled.count(i->reg))
+ unhandled_.push(i);
+ vrm_->clearVirt(i->reg);
+ }
+ }
+ else {
+ if (MRegisterInfo::isVirtualRegister(i->reg))
+ vrm_->clearVirt(i->reg);
+ unhandled_.push(i);
+ }
+ }
+
+ // scan the rest and undo each interval that expired after t and
+ // insert it in active (the next iteration of the algorithm will
+ // put it in inactive if required)
+ IntervalPtrs::iterator i = handled_.begin(), e = handled_.end();
+ for (; i != e; ++i) {
+ if (!(*i)->expiredAt(earliestStart) && (*i)->expiredAt(cur->start())) {
+ DEBUG(std::cerr << "\t\t\tundo changes for: " << **i << '\n');
+ active_.push_back(*i);
+ if (MRegisterInfo::isPhysicalRegister((*i)->reg))
+ prt_->addRegUse((*i)->reg);
+ else
+ prt_->addRegUse(vrm_->getPhys((*i)->reg));
+ }
+ }
+
+ std::sort(added.begin(), added.end(), less_ptr<LiveInterval>());
+ // merge added with unhandled
+ for (unsigned i = 0, e = added.size(); i != e; ++i)
+ unhandled_.push(added[i]);
}
unsigned RA::getFreePhysReg(LiveInterval* cur)
{
- const TargetRegisterClass* rc = mf_->getSSARegMap()->getRegClass(cur->reg);
+ const TargetRegisterClass* rc = mf_->getSSARegMap()->getRegClass(cur->reg);
- for (TargetRegisterClass::iterator i = rc->allocation_order_begin(*mf_);
- i != rc->allocation_order_end(*mf_); ++i) {
- unsigned reg = *i;
- if (prt_->isRegAvail(reg))
- return reg;
- }
- return 0;
+ for (TargetRegisterClass::iterator i = rc->allocation_order_begin(*mf_);
+ i != rc->allocation_order_end(*mf_); ++i) {
+ unsigned reg = *i;
+ if (prt_->isRegAvail(reg))
+ return reg;
+ }
+ return 0;
}
FunctionPass* llvm::createLinearScanRegisterAllocator() {
- return new RA();
+ return new RA();
}
Index: llvm/lib/CodeGen/RegAllocIterativeScan.cpp
diff -u llvm/lib/CodeGen/RegAllocIterativeScan.cpp:1.10 llvm/lib/CodeGen/RegAllocIterativeScan.cpp:1.11
--- llvm/lib/CodeGen/RegAllocIterativeScan.cpp:1.10 Sat Jul 24 06:44:15 2004
+++ llvm/lib/CodeGen/RegAllocIterativeScan.cpp Wed Aug 4 04:46:26 2004
@@ -40,439 +40,439 @@
namespace {
- Statistic<double> efficiency
- ("regalloc", "Ratio of intervals processed over total intervals");
+ Statistic<double> efficiency
+ ("regalloc", "Ratio of intervals processed over total intervals");
- static unsigned numIterations = 0;
- static unsigned numIntervals = 0;
+ static unsigned numIterations = 0;
+ static unsigned numIntervals = 0;
- class RA : public MachineFunctionPass {
- private:
- MachineFunction* mf_;
- const TargetMachine* tm_;
- const MRegisterInfo* mri_;
- LiveIntervals* li_;
- typedef std::vector<LiveInterval*> IntervalPtrs;
- IntervalPtrs unhandled_, fixed_, active_, inactive_, handled_, spilled_;
-
- std::auto_ptr<PhysRegTracker> prt_;
- std::auto_ptr<VirtRegMap> vrm_;
- std::auto_ptr<Spiller> spiller_;
-
- typedef std::vector<float> SpillWeights;
- SpillWeights spillWeights_;
-
- public:
- virtual const char* getPassName() const {
- return "Iterative Scan Register Allocator";
- }
-
- virtual void getAnalysisUsage(AnalysisUsage &AU) const {
- AU.addRequired<LiveVariables>();
- AU.addRequired<LiveIntervals>();
- MachineFunctionPass::getAnalysisUsage(AU);
- }
-
- /// runOnMachineFunction - register allocate the whole function
- bool runOnMachineFunction(MachineFunction&);
-
- void releaseMemory();
-
- private:
- /// linearScan - the linear scan algorithm. Returns a boolean
- /// indicating if there were any spills
- bool linearScan();
-
- /// initIntervalSets - initializes the four interval sets:
- /// unhandled, fixed, active and inactive
- void initIntervalSets();
-
- /// processActiveIntervals - expire old intervals and move
- /// non-overlapping ones to the incative list
- void processActiveIntervals(IntervalPtrs::value_type cur);
-
- /// processInactiveIntervals - expire old intervals and move
- /// overlapping ones to the active list
- void processInactiveIntervals(IntervalPtrs::value_type cur);
-
- /// updateSpillWeights - updates the spill weights of the
- /// specifed physical register and its weight
- void updateSpillWeights(unsigned reg, SpillWeights::value_type weight);
-
- /// assignRegOrStackSlotAtInterval - assign a register if one
- /// is available, or spill.
- void assignRegOrSpillAtInterval(IntervalPtrs::value_type cur);
-
- ///
- /// register handling helpers
- ///
-
- /// getFreePhysReg - return a free physical register for this
- /// virtual register interval if we have one, otherwise return
- /// 0
- unsigned getFreePhysReg(IntervalPtrs::value_type cur);
-
- /// assignVirt2StackSlot - assigns this virtual register to a
- /// stack slot. returns the stack slot
- int assignVirt2StackSlot(unsigned virtReg);
-
- void printIntervals(const char* const str,
- RA::IntervalPtrs::const_iterator i,
- RA::IntervalPtrs::const_iterator e) const {
- if (str) std::cerr << str << " intervals:\n";
- for (; i != e; ++i) {
- std::cerr << "\t" << **i << " -> ";
- unsigned reg = (*i)->reg;
- if (MRegisterInfo::isVirtualRegister(reg)) {
- reg = vrm_->getPhys(reg);
- }
- std::cerr << mri_->getName(reg) << '\n';
- }
+ class RA : public MachineFunctionPass {
+ private:
+ MachineFunction* mf_;
+ const TargetMachine* tm_;
+ const MRegisterInfo* mri_;
+ LiveIntervals* li_;
+ typedef std::vector<LiveInterval*> IntervalPtrs;
+ IntervalPtrs unhandled_, fixed_, active_, inactive_, handled_, spilled_;
+
+ std::auto_ptr<PhysRegTracker> prt_;
+ std::auto_ptr<VirtRegMap> vrm_;
+ std::auto_ptr<Spiller> spiller_;
+
+ typedef std::vector<float> SpillWeights;
+ SpillWeights spillWeights_;
+
+ public:
+ virtual const char* getPassName() const {
+ return "Iterative Scan Register Allocator";
+ }
+
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.addRequired<LiveVariables>();
+ AU.addRequired<LiveIntervals>();
+ MachineFunctionPass::getAnalysisUsage(AU);
+ }
+
+ /// runOnMachineFunction - register allocate the whole function
+ bool runOnMachineFunction(MachineFunction&);
+
+ void releaseMemory();
+
+ private:
+ /// linearScan - the linear scan algorithm. Returns a boolean
+ /// indicating if there were any spills
+ bool linearScan();
+
+ /// initIntervalSets - initializes the four interval sets:
+ /// unhandled, fixed, active and inactive
+ void initIntervalSets();
+
+ /// processActiveIntervals - expire old intervals and move
+ /// non-overlapping ones to the incative list
+ void processActiveIntervals(IntervalPtrs::value_type cur);
+
+ /// processInactiveIntervals - expire old intervals and move
+ /// overlapping ones to the active list
+ void processInactiveIntervals(IntervalPtrs::value_type cur);
+
+ /// updateSpillWeights - updates the spill weights of the
+ /// specifed physical register and its weight
+ void updateSpillWeights(unsigned reg, SpillWeights::value_type weight);
+
+ /// assignRegOrStackSlotAtInterval - assign a register if one
+ /// is available, or spill.
+ void assignRegOrSpillAtInterval(IntervalPtrs::value_type cur);
+
+ ///
+ /// register handling helpers
+ ///
+
+ /// getFreePhysReg - return a free physical register for this
+ /// virtual register interval if we have one, otherwise return
+ /// 0
+ unsigned getFreePhysReg(IntervalPtrs::value_type cur);
+
+ /// assignVirt2StackSlot - assigns this virtual register to a
+ /// stack slot. returns the stack slot
+ int assignVirt2StackSlot(unsigned virtReg);
+
+ void printIntervals(const char* const str,
+ RA::IntervalPtrs::const_iterator i,
+ RA::IntervalPtrs::const_iterator e) const {
+ if (str) std::cerr << str << " intervals:\n";
+ for (; i != e; ++i) {
+ std::cerr << "\t" << **i << " -> ";
+ unsigned reg = (*i)->reg;
+ if (MRegisterInfo::isVirtualRegister(reg)) {
+ reg = vrm_->getPhys(reg);
}
- };
+ std::cerr << mri_->getName(reg) << '\n';
+ }
+ }
+ };
}
void RA::releaseMemory()
{
- unhandled_.clear();
- fixed_.clear();
- active_.clear();
- inactive_.clear();
- handled_.clear();
- spilled_.clear();
+ unhandled_.clear();
+ fixed_.clear();
+ active_.clear();
+ inactive_.clear();
+ handled_.clear();
+ spilled_.clear();
}
bool RA::runOnMachineFunction(MachineFunction &fn) {
- mf_ = &fn;
- tm_ = &fn.getTarget();
- mri_ = tm_->getRegisterInfo();
- li_ = &getAnalysis<LiveIntervals>();
- if (!prt_.get()) prt_.reset(new PhysRegTracker(*mri_));
- vrm_.reset(new VirtRegMap(*mf_));
- if (!spiller_.get()) spiller_.reset(createSpiller());
-
- initIntervalSets();
-
- numIntervals += li_->getNumIntervals();
-
- while (linearScan()) {
- // we spilled some registers, so we need to add intervals for
- // the spill code and restart the algorithm
- std::set<unsigned> spilledRegs;
- for (IntervalPtrs::iterator
- i = spilled_.begin(); i != spilled_.end(); ++i) {
- int slot = vrm_->assignVirt2StackSlot((*i)->reg);
- std::vector<LiveInterval*> added =
- li_->addIntervalsForSpills(**i, *vrm_, slot);
- std::copy(added.begin(), added.end(), std::back_inserter(handled_));
- spilledRegs.insert((*i)->reg);
- }
- spilled_.clear();
- for (IntervalPtrs::iterator
- i = handled_.begin(); i != handled_.end(); )
- if (spilledRegs.count((*i)->reg))
- i = handled_.erase(i);
- else
- ++i;
- handled_.swap(unhandled_);
- vrm_->clearAllVirt();
+ mf_ = &fn;
+ tm_ = &fn.getTarget();
+ mri_ = tm_->getRegisterInfo();
+ li_ = &getAnalysis<LiveIntervals>();
+ if (!prt_.get()) prt_.reset(new PhysRegTracker(*mri_));
+ vrm_.reset(new VirtRegMap(*mf_));
+ if (!spiller_.get()) spiller_.reset(createSpiller());
+
+ initIntervalSets();
+
+ numIntervals += li_->getNumIntervals();
+
+ while (linearScan()) {
+ // we spilled some registers, so we need to add intervals for
+ // the spill code and restart the algorithm
+ std::set<unsigned> spilledRegs;
+ for (IntervalPtrs::iterator
+ i = spilled_.begin(); i != spilled_.end(); ++i) {
+ int slot = vrm_->assignVirt2StackSlot((*i)->reg);
+ std::vector<LiveInterval*> added =
+ li_->addIntervalsForSpills(**i, *vrm_, slot);
+ std::copy(added.begin(), added.end(), std::back_inserter(handled_));
+ spilledRegs.insert((*i)->reg);
}
+ spilled_.clear();
+ for (IntervalPtrs::iterator
+ i = handled_.begin(); i != handled_.end(); )
+ if (spilledRegs.count((*i)->reg))
+ i = handled_.erase(i);
+ else
+ ++i;
+ handled_.swap(unhandled_);
+ vrm_->clearAllVirt();
+ }
- efficiency = double(numIterations) / double(numIntervals);
+ efficiency = double(numIterations) / double(numIntervals);
- DEBUG(std::cerr << *vrm_);
+ DEBUG(std::cerr << *vrm_);
- spiller_->runOnMachineFunction(*mf_, *vrm_);
+ spiller_->runOnMachineFunction(*mf_, *vrm_);
- return true;
+ return true;
}
bool RA::linearScan()
{
- // linear scan algorithm
- DEBUG(std::cerr << "********** LINEAR SCAN **********\n");
- DEBUG(std::cerr << "********** Function: "
- << mf_->getFunction()->getName() << '\n');
-
+ // linear scan algorithm
+ DEBUG(std::cerr << "********** LINEAR SCAN **********\n");
+ DEBUG(std::cerr << "********** Function: "
+ << mf_->getFunction()->getName() << '\n');
+
+
+ std::sort(unhandled_.begin(), unhandled_.end(),
+ greater_ptr<LiveInterval>());
+ DEBUG(printIntervals("unhandled", unhandled_.begin(), unhandled_.end()));
+ DEBUG(printIntervals("fixed", fixed_.begin(), fixed_.end()));
+ DEBUG(printIntervals("active", active_.begin(), active_.end()));
+ DEBUG(printIntervals("inactive", inactive_.begin(), inactive_.end()));
+
+ while (!unhandled_.empty()) {
+ // pick the interval with the earliest start point
+ IntervalPtrs::value_type cur = unhandled_.back();
+ unhandled_.pop_back();
+ ++numIterations;
+ DEBUG(std::cerr << "\n*** CURRENT ***: " << *cur << '\n');
+
+ processActiveIntervals(cur);
+ processInactiveIntervals(cur);
+
+ // if this register is fixed we are done
+ if (MRegisterInfo::isPhysicalRegister(cur->reg)) {
+ prt_->addRegUse(cur->reg);
+ active_.push_back(cur);
+ handled_.push_back(cur);
+ }
+ // otherwise we are allocating a virtual register. try to find
+ // a free physical register or spill an interval in order to
+ // assign it one (we could spill the current though).
+ else {
+ assignRegOrSpillAtInterval(cur);
+ }
- std::sort(unhandled_.begin(), unhandled_.end(),
- greater_ptr<LiveInterval>());
- DEBUG(printIntervals("unhandled", unhandled_.begin(), unhandled_.end()));
- DEBUG(printIntervals("fixed", fixed_.begin(), fixed_.end()));
DEBUG(printIntervals("active", active_.begin(), active_.end()));
DEBUG(printIntervals("inactive", inactive_.begin(), inactive_.end()));
+ }
- while (!unhandled_.empty()) {
- // pick the interval with the earliest start point
- IntervalPtrs::value_type cur = unhandled_.back();
- unhandled_.pop_back();
- ++numIterations;
- DEBUG(std::cerr << "\n*** CURRENT ***: " << *cur << '\n');
-
- processActiveIntervals(cur);
- processInactiveIntervals(cur);
-
- // if this register is fixed we are done
- if (MRegisterInfo::isPhysicalRegister(cur->reg)) {
- prt_->addRegUse(cur->reg);
- active_.push_back(cur);
- handled_.push_back(cur);
- }
- // otherwise we are allocating a virtual register. try to find
- // a free physical register or spill an interval in order to
- // assign it one (we could spill the current though).
- else {
- assignRegOrSpillAtInterval(cur);
- }
+ // expire any remaining active intervals
+ for (IntervalPtrs::reverse_iterator
+ i = active_.rbegin(); i != active_.rend(); ) {
+ unsigned reg = (*i)->reg;
+ DEBUG(std::cerr << "\tinterval " << **i << " expired\n");
+ if (MRegisterInfo::isVirtualRegister(reg))
+ reg = vrm_->getPhys(reg);
+ prt_->delRegUse(reg);
+ i = IntervalPtrs::reverse_iterator(active_.erase(i.base()-1));
+ }
+
+ // expire any remaining inactive intervals
+ for (IntervalPtrs::reverse_iterator
+ i = inactive_.rbegin(); i != inactive_.rend(); ) {
+ DEBUG(std::cerr << "\tinterval " << **i << " expired\n");
+ i = IntervalPtrs::reverse_iterator(inactive_.erase(i.base()-1));
+ }
- DEBUG(printIntervals("active", active_.begin(), active_.end()));
- DEBUG(printIntervals("inactive", inactive_.begin(), inactive_.end()));
- }
-
- // expire any remaining active intervals
- for (IntervalPtrs::reverse_iterator
- i = active_.rbegin(); i != active_.rend(); ) {
- unsigned reg = (*i)->reg;
- DEBUG(std::cerr << "\tinterval " << **i << " expired\n");
- if (MRegisterInfo::isVirtualRegister(reg))
- reg = vrm_->getPhys(reg);
- prt_->delRegUse(reg);
- i = IntervalPtrs::reverse_iterator(active_.erase(i.base()-1));
- }
-
- // expire any remaining inactive intervals
- for (IntervalPtrs::reverse_iterator
- i = inactive_.rbegin(); i != inactive_.rend(); ) {
- DEBUG(std::cerr << "\tinterval " << **i << " expired\n");
- i = IntervalPtrs::reverse_iterator(inactive_.erase(i.base()-1));
- }
-
- // return true if we spilled anything
- return !spilled_.empty();
+ // return true if we spilled anything
+ return !spilled_.empty();
}
void RA::initIntervalSets() {
- assert(unhandled_.empty() && fixed_.empty() &&
- active_.empty() && inactive_.empty() &&
- "interval sets should be empty on initialization");
-
- for (LiveIntervals::iterator i = li_->begin(), e = li_->end(); i != e; ++i){
- unhandled_.push_back(&i->second);
- if (MRegisterInfo::isPhysicalRegister(i->second.reg))
- fixed_.push_back(&i->second);
- }
+ assert(unhandled_.empty() && fixed_.empty() &&
+ active_.empty() && inactive_.empty() &&
+ "interval sets should be empty on initialization");
+
+ for (LiveIntervals::iterator i = li_->begin(), e = li_->end(); i != e; ++i){
+ unhandled_.push_back(&i->second);
+ if (MRegisterInfo::isPhysicalRegister(i->second.reg))
+ fixed_.push_back(&i->second);
+ }
}
void RA::processActiveIntervals(IntervalPtrs::value_type cur)
{
- DEBUG(std::cerr << "\tprocessing active intervals:\n");
- for (IntervalPtrs::reverse_iterator
- i = active_.rbegin(); i != active_.rend();) {
- unsigned reg = (*i)->reg;
- // remove expired intervals
- if ((*i)->expiredAt(cur->start())) {
- DEBUG(std::cerr << "\t\tinterval " << **i << " expired\n");
- if (MRegisterInfo::isVirtualRegister(reg))
- reg = vrm_->getPhys(reg);
- prt_->delRegUse(reg);
- // remove from active
- i = IntervalPtrs::reverse_iterator(active_.erase(i.base()-1));
- }
- // move inactive intervals to inactive list
- else if (!(*i)->liveAt(cur->start())) {
- DEBUG(std::cerr << "\t\tinterval " << **i << " inactive\n");
- if (MRegisterInfo::isVirtualRegister(reg))
- reg = vrm_->getPhys(reg);
- prt_->delRegUse(reg);
- // add to inactive
- inactive_.push_back(*i);
- // remove from active
- i = IntervalPtrs::reverse_iterator(active_.erase(i.base()-1));
- }
- else {
- ++i;
- }
+ DEBUG(std::cerr << "\tprocessing active intervals:\n");
+ for (IntervalPtrs::reverse_iterator
+ i = active_.rbegin(); i != active_.rend();) {
+ unsigned reg = (*i)->reg;
+ // remove expired intervals
+ if ((*i)->expiredAt(cur->start())) {
+ DEBUG(std::cerr << "\t\tinterval " << **i << " expired\n");
+ if (MRegisterInfo::isVirtualRegister(reg))
+ reg = vrm_->getPhys(reg);
+ prt_->delRegUse(reg);
+ // remove from active
+ i = IntervalPtrs::reverse_iterator(active_.erase(i.base()-1));
+ }
+ // move inactive intervals to inactive list
+ else if (!(*i)->liveAt(cur->start())) {
+ DEBUG(std::cerr << "\t\tinterval " << **i << " inactive\n");
+ if (MRegisterInfo::isVirtualRegister(reg))
+ reg = vrm_->getPhys(reg);
+ prt_->delRegUse(reg);
+ // add to inactive
+ inactive_.push_back(*i);
+ // remove from active
+ i = IntervalPtrs::reverse_iterator(active_.erase(i.base()-1));
}
+ else {
+ ++i;
+ }
+ }
}
void RA::processInactiveIntervals(IntervalPtrs::value_type cur)
{
- DEBUG(std::cerr << "\tprocessing inactive intervals:\n");
- for (IntervalPtrs::reverse_iterator
- i = inactive_.rbegin(); i != inactive_.rend();) {
- unsigned reg = (*i)->reg;
-
- // remove expired intervals
- if ((*i)->expiredAt(cur->start())) {
- DEBUG(std::cerr << "\t\tinterval " << **i << " expired\n");
- // remove from inactive
- i = IntervalPtrs::reverse_iterator(inactive_.erase(i.base()-1));
- }
- // move re-activated intervals in active list
- else if ((*i)->liveAt(cur->start())) {
- DEBUG(std::cerr << "\t\tinterval " << **i << " active\n");
- if (MRegisterInfo::isVirtualRegister(reg))
- reg = vrm_->getPhys(reg);
- prt_->addRegUse(reg);
- // add to active
- active_.push_back(*i);
- // remove from inactive
- i = IntervalPtrs::reverse_iterator(inactive_.erase(i.base()-1));
- }
- else {
- ++i;
- }
+ DEBUG(std::cerr << "\tprocessing inactive intervals:\n");
+ for (IntervalPtrs::reverse_iterator
+ i = inactive_.rbegin(); i != inactive_.rend();) {
+ unsigned reg = (*i)->reg;
+
+ // remove expired intervals
+ if ((*i)->expiredAt(cur->start())) {
+ DEBUG(std::cerr << "\t\tinterval " << **i << " expired\n");
+ // remove from inactive
+ i = IntervalPtrs::reverse_iterator(inactive_.erase(i.base()-1));
+ }
+ // move re-activated intervals in active list
+ else if ((*i)->liveAt(cur->start())) {
+ DEBUG(std::cerr << "\t\tinterval " << **i << " active\n");
+ if (MRegisterInfo::isVirtualRegister(reg))
+ reg = vrm_->getPhys(reg);
+ prt_->addRegUse(reg);
+ // add to active
+ active_.push_back(*i);
+ // remove from inactive
+ i = IntervalPtrs::reverse_iterator(inactive_.erase(i.base()-1));
+ }
+ else {
+ ++i;
}
+ }
}
void RA::updateSpillWeights(unsigned reg, SpillWeights::value_type weight)
{
- spillWeights_[reg] += weight;
- for (const unsigned* as = mri_->getAliasSet(reg); *as; ++as)
- spillWeights_[*as] += weight;
+ spillWeights_[reg] += weight;
+ for (const unsigned* as = mri_->getAliasSet(reg); *as; ++as)
+ spillWeights_[*as] += weight;
}
void RA::assignRegOrSpillAtInterval(IntervalPtrs::value_type cur)
{
- DEBUG(std::cerr << "\tallocating current interval: ");
-
- PhysRegTracker backupPrt = *prt_;
-
- spillWeights_.assign(mri_->getNumRegs(), 0.0);
-
- // for each interval in active update spill weights
- for (IntervalPtrs::const_iterator i = active_.begin(), e = active_.end();
- i != e; ++i) {
- unsigned reg = (*i)->reg;
- if (MRegisterInfo::isVirtualRegister(reg))
- reg = vrm_->getPhys(reg);
- updateSpillWeights(reg, (*i)->weight);
- }
-
- // for every interval in inactive we overlap with, mark the
- // register as not free and update spill weights
- for (IntervalPtrs::const_iterator i = inactive_.begin(),
- e = inactive_.end(); i != e; ++i) {
- if (cur->overlaps(**i)) {
- unsigned reg = (*i)->reg;
- if (MRegisterInfo::isVirtualRegister(reg))
- reg = vrm_->getPhys(reg);
- prt_->addRegUse(reg);
- updateSpillWeights(reg, (*i)->weight);
- }
- }
-
- // for every interval in fixed we overlap with,
- // mark the register as not free and update spill weights
- for (IntervalPtrs::const_iterator i = fixed_.begin(),
- e = fixed_.end(); i != e; ++i) {
- if (cur->overlaps(**i)) {
- unsigned reg = (*i)->reg;
- prt_->addRegUse(reg);
- updateSpillWeights(reg, (*i)->weight);
- }
- }
+ DEBUG(std::cerr << "\tallocating current interval: ");
- unsigned physReg = getFreePhysReg(cur);
- // restore the physical register tracker
- *prt_ = backupPrt;
- // if we find a free register, we are done: assign this virtual to
- // the free physical register and add this interval to the active
- // list.
- if (physReg) {
- DEBUG(std::cerr << mri_->getName(physReg) << '\n');
- vrm_->assignVirt2Phys(cur->reg, physReg);
- prt_->addRegUse(physReg);
- active_.push_back(cur);
- handled_.push_back(cur);
- return;
- }
- DEBUG(std::cerr << "no free registers\n");
-
- DEBUG(std::cerr << "\tassigning stack slot at interval "<< *cur << ":\n");
-
- float minWeight = HUGE_VAL;
- unsigned minReg = 0;
- const TargetRegisterClass* rc = mf_->getSSARegMap()->getRegClass(cur->reg);
- for (TargetRegisterClass::iterator i = rc->allocation_order_begin(*mf_);
- i != rc->allocation_order_end(*mf_); ++i) {
- unsigned reg = *i;
- if (minWeight > spillWeights_[reg]) {
- minWeight = spillWeights_[reg];
- minReg = reg;
- }
- }
- DEBUG(std::cerr << "\t\tregister with min weight: "
- << mri_->getName(minReg) << " (" << minWeight << ")\n");
+ PhysRegTracker backupPrt = *prt_;
- // if the current has the minimum weight, we spill it and move on
- if (cur->weight <= minWeight) {
- DEBUG(std::cerr << "\t\t\tspilling(c): " << *cur << '\n');
- spilled_.push_back(cur);
- return;
- }
-
- // otherwise we spill all intervals aliasing the register with
- // minimum weight, assigned the newly cleared register to the
- // current interval and continue
- assert(MRegisterInfo::isPhysicalRegister(minReg) &&
- "did not choose a register to spill?");
- std::vector<bool> toSpill(mri_->getNumRegs(), false);
- toSpill[minReg] = true;
- for (const unsigned* as = mri_->getAliasSet(minReg); *as; ++as)
- toSpill[*as] = true;
- unsigned earliestStart = cur->start();
+ spillWeights_.assign(mri_->getNumRegs(), 0.0);
- std::set<unsigned> spilled;
-
- for (IntervalPtrs::iterator i = active_.begin(); i != active_.end(); ) {
- unsigned reg = (*i)->reg;
- if (MRegisterInfo::isVirtualRegister(reg) &&
- toSpill[vrm_->getPhys(reg)] &&
- cur->overlaps(**i)) {
- DEBUG(std::cerr << "\t\t\tspilling(a): " << **i << '\n');
- spilled_.push_back(*i);
- prt_->delRegUse(vrm_->getPhys(reg));
- vrm_->clearVirt(reg);
- i = active_.erase(i);
- }
- else
- ++i;
- }
- for (IntervalPtrs::iterator i = inactive_.begin(); i != inactive_.end(); ) {
- unsigned reg = (*i)->reg;
- if (MRegisterInfo::isVirtualRegister(reg) &&
- toSpill[vrm_->getPhys(reg)] &&
- cur->overlaps(**i)) {
- DEBUG(std::cerr << "\t\t\tspilling(i): " << **i << '\n');
- spilled_.push_back(*i);
- vrm_->clearVirt(reg);
- i = inactive_.erase(i);
- }
- else
- ++i;
- }
-
- vrm_->assignVirt2Phys(cur->reg, minReg);
- prt_->addRegUse(minReg);
+ // for each interval in active update spill weights
+ for (IntervalPtrs::const_iterator i = active_.begin(), e = active_.end();
+ i != e; ++i) {
+ unsigned reg = (*i)->reg;
+ if (MRegisterInfo::isVirtualRegister(reg))
+ reg = vrm_->getPhys(reg);
+ updateSpillWeights(reg, (*i)->weight);
+ }
+
+ // for every interval in inactive we overlap with, mark the
+ // register as not free and update spill weights
+ for (IntervalPtrs::const_iterator i = inactive_.begin(),
+ e = inactive_.end(); i != e; ++i) {
+ if (cur->overlaps(**i)) {
+ unsigned reg = (*i)->reg;
+ if (MRegisterInfo::isVirtualRegister(reg))
+ reg = vrm_->getPhys(reg);
+ prt_->addRegUse(reg);
+ updateSpillWeights(reg, (*i)->weight);
+ }
+ }
+
+ // for every interval in fixed we overlap with,
+ // mark the register as not free and update spill weights
+ for (IntervalPtrs::const_iterator i = fixed_.begin(),
+ e = fixed_.end(); i != e; ++i) {
+ if (cur->overlaps(**i)) {
+ unsigned reg = (*i)->reg;
+ prt_->addRegUse(reg);
+ updateSpillWeights(reg, (*i)->weight);
+ }
+ }
+
+ unsigned physReg = getFreePhysReg(cur);
+ // restore the physical register tracker
+ *prt_ = backupPrt;
+ // if we find a free register, we are done: assign this virtual to
+ // the free physical register and add this interval to the active
+ // list.
+ if (physReg) {
+ DEBUG(std::cerr << mri_->getName(physReg) << '\n');
+ vrm_->assignVirt2Phys(cur->reg, physReg);
+ prt_->addRegUse(physReg);
active_.push_back(cur);
handled_.push_back(cur);
+ return;
+ }
+ DEBUG(std::cerr << "no free registers\n");
+
+ DEBUG(std::cerr << "\tassigning stack slot at interval "<< *cur << ":\n");
+
+ float minWeight = HUGE_VAL;
+ unsigned minReg = 0;
+ const TargetRegisterClass* rc = mf_->getSSARegMap()->getRegClass(cur->reg);
+ for (TargetRegisterClass::iterator i = rc->allocation_order_begin(*mf_);
+ i != rc->allocation_order_end(*mf_); ++i) {
+ unsigned reg = *i;
+ if (minWeight > spillWeights_[reg]) {
+ minWeight = spillWeights_[reg];
+ minReg = reg;
+ }
+ }
+ DEBUG(std::cerr << "\t\tregister with min weight: "
+ << mri_->getName(minReg) << " (" << minWeight << ")\n");
+
+ // if the current has the minimum weight, we spill it and move on
+ if (cur->weight <= minWeight) {
+ DEBUG(std::cerr << "\t\t\tspilling(c): " << *cur << '\n');
+ spilled_.push_back(cur);
+ return;
+ }
+
+ // otherwise we spill all intervals aliasing the register with
+ // minimum weight, assigned the newly cleared register to the
+ // current interval and continue
+ assert(MRegisterInfo::isPhysicalRegister(minReg) &&
+ "did not choose a register to spill?");
+ std::vector<bool> toSpill(mri_->getNumRegs(), false);
+ toSpill[minReg] = true;
+ for (const unsigned* as = mri_->getAliasSet(minReg); *as; ++as)
+ toSpill[*as] = true;
+ unsigned earliestStart = cur->start();
+
+ std::set<unsigned> spilled;
+
+ for (IntervalPtrs::iterator i = active_.begin(); i != active_.end(); ) {
+ unsigned reg = (*i)->reg;
+ if (MRegisterInfo::isVirtualRegister(reg) &&
+ toSpill[vrm_->getPhys(reg)] &&
+ cur->overlaps(**i)) {
+ DEBUG(std::cerr << "\t\t\tspilling(a): " << **i << '\n');
+ spilled_.push_back(*i);
+ prt_->delRegUse(vrm_->getPhys(reg));
+ vrm_->clearVirt(reg);
+ i = active_.erase(i);
+ }
+ else
+ ++i;
+ }
+ for (IntervalPtrs::iterator i = inactive_.begin(); i != inactive_.end(); ) {
+ unsigned reg = (*i)->reg;
+ if (MRegisterInfo::isVirtualRegister(reg) &&
+ toSpill[vrm_->getPhys(reg)] &&
+ cur->overlaps(**i)) {
+ DEBUG(std::cerr << "\t\t\tspilling(i): " << **i << '\n');
+ spilled_.push_back(*i);
+ vrm_->clearVirt(reg);
+ i = inactive_.erase(i);
+ }
+ else
+ ++i;
+ }
+
+ vrm_->assignVirt2Phys(cur->reg, minReg);
+ prt_->addRegUse(minReg);
+ active_.push_back(cur);
+ handled_.push_back(cur);
}
unsigned RA::getFreePhysReg(IntervalPtrs::value_type cur)
{
- const TargetRegisterClass* rc = mf_->getSSARegMap()->getRegClass(cur->reg);
+ const TargetRegisterClass* rc = mf_->getSSARegMap()->getRegClass(cur->reg);
- for (TargetRegisterClass::iterator i = rc->allocation_order_begin(*mf_);
- i != rc->allocation_order_end(*mf_); ++i) {
- unsigned reg = *i;
- if (prt_->isRegAvail(reg))
- return reg;
- }
- return 0;
+ for (TargetRegisterClass::iterator i = rc->allocation_order_begin(*mf_);
+ i != rc->allocation_order_end(*mf_); ++i) {
+ unsigned reg = *i;
+ if (prt_->isRegAvail(reg))
+ return reg;
+ }
+ return 0;
}
FunctionPass* llvm::createIterativeScanRegisterAllocator() {
- return new RA();
+ return new RA();
}
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