* There is no reason for SpillWeights to be an instance var

* Do not put fixed registers into the unhandled set.  This means they will
  never find their way into the inactive, active, or handled sets, so we
  can simplify a bunch of code.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@17945 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2004-11-18 06:01:45 +00:00
parent 9fddc12c9b
commit c8b9f33ac0

View File

@ -73,9 +73,6 @@ namespace {
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";
@ -105,10 +102,6 @@ namespace {
/// ones to the active list.
void processInactiveIntervals(unsigned CurPoint);
/// 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);
@ -168,6 +161,22 @@ bool RA::runOnMachineFunction(MachineFunction &fn) {
return true;
}
/// initIntervalSets - initialize the interval sets.
///
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) {
if (MRegisterInfo::isPhysicalRegister(i->second.reg))
fixed_.push_back(std::make_pair(&i->second, i->second.begin()));
else
unhandled_.push(&i->second);
}
}
void RA::linearScan()
{
// linear scan algorithm
@ -190,17 +199,13 @@ void RA::linearScan()
processActiveIntervals(cur->beginNumber());
processInactiveIntervals(cur->beginNumber());
// if this register is fixed we are done
if (MRegisterInfo::isPhysicalRegister(cur->reg)) {
prt_->addRegUse(cur->reg);
active_.push_back(std::make_pair(cur, cur->begin()));
handled_.push_back(cur);
} else {
// otherwise we are allocating a virtual register. try to find a free
// physical register or spill an interval (possibly this one) in order to
// assign it one.
assignRegOrStackSlotAtInterval(cur);
}
assert(MRegisterInfo::isVirtualRegister(cur->reg) &&
"Can only allocate virtual registers!");
// Allocating a virtual register. try to find a free
// physical register or spill an interval (possibly this one) in order to
// assign it one.
assignRegOrStackSlotAtInterval(cur);
DEBUG(printIntervals("active", active_.begin(), active_.end()));
DEBUG(printIntervals("inactive", inactive_.begin(), inactive_.end()));
@ -213,8 +218,9 @@ void RA::linearScan()
i = active_.rbegin(); i != active_.rend(); ) {
unsigned reg = i->first->reg;
DEBUG(std::cerr << "\tinterval " << *i->first << " expired\n");
if (MRegisterInfo::isVirtualRegister(reg))
reg = vrm_->getPhys(reg);
assert(MRegisterInfo::isVirtualRegister(reg) &&
"Can only allocate virtual registers!");
reg = vrm_->getPhys(reg);
prt_->delRegUse(reg);
i = IntervalPtrs::reverse_iterator(active_.erase(i.base()-1));
}
@ -229,21 +235,6 @@ void RA::linearScan()
DEBUG(std::cerr << *vrm_);
}
/// initIntervalSets - initialize the interval sets.
///
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(std::make_pair(&i->second, i->second.begin()));
}
}
/// processActiveIntervals - expire old intervals and move non-overlapping ones
/// to the inactive list.
void RA::processActiveIntervals(unsigned CurPoint)
@ -259,8 +250,9 @@ void RA::processActiveIntervals(unsigned CurPoint)
if (IntervalPos == Interval->end()) { // Remove expired intervals.
DEBUG(std::cerr << "\t\tinterval " << *Interval << " expired\n");
if (MRegisterInfo::isVirtualRegister(reg))
reg = vrm_->getPhys(reg);
assert(MRegisterInfo::isVirtualRegister(reg) &&
"Can only allocate virtual registers!");
reg = vrm_->getPhys(reg);
prt_->delRegUse(reg);
// Pop off the end of the list.
@ -271,8 +263,9 @@ void RA::processActiveIntervals(unsigned CurPoint)
} else if (IntervalPos->start > CurPoint) {
// Move inactive intervals to inactive list.
DEBUG(std::cerr << "\t\tinterval " << *Interval << " inactive\n");
if (MRegisterInfo::isVirtualRegister(reg))
reg = vrm_->getPhys(reg);
assert(MRegisterInfo::isVirtualRegister(reg) &&
"Can only allocate virtual registers!");
reg = vrm_->getPhys(reg);
prt_->delRegUse(reg);
// add to inactive.
inactive_.push_back(std::make_pair(Interval, IntervalPos));
@ -311,8 +304,9 @@ void RA::processInactiveIntervals(unsigned CurPoint)
} else if (IntervalPos->start <= CurPoint) {
// move re-activated intervals in active list
DEBUG(std::cerr << "\t\tinterval " << *Interval << " active\n");
if (MRegisterInfo::isVirtualRegister(reg))
reg = vrm_->getPhys(reg);
assert(MRegisterInfo::isVirtualRegister(reg) &&
"Can only allocate virtual registers!");
reg = vrm_->getPhys(reg);
prt_->addRegUse(reg);
// add to active
active_.push_back(std::make_pair(Interval, IntervalPos));
@ -330,11 +324,12 @@ void RA::processInactiveIntervals(unsigned CurPoint)
/// updateSpillWeights - updates the spill weights of the specifed physical
/// register and its weight.
void RA::updateSpillWeights(unsigned reg, SpillWeights::value_type weight)
{
spillWeights_[reg] += weight;
for (const unsigned* as = mri_->getAliasSet(reg); *as; ++as)
spillWeights_[*as] += weight;
static void updateSpillWeights(std::vector<float> &Weights,
unsigned reg, float weight,
const MRegisterInfo *MRI) {
Weights[reg] += weight;
for (const unsigned* as = MRI->getAliasSet(reg); *as; ++as)
Weights[*as] += weight;
}
static RA::IntervalPtrs::iterator FindIntervalInVector(RA::IntervalPtrs &IP,
@ -363,17 +358,19 @@ void RA::assignRegOrStackSlotAtInterval(LiveInterval* cur)
PhysRegTracker backupPrt = *prt_;
spillWeights_.assign(mri_->getNumRegs(), 0.0);
std::vector<float> SpillWeights;
SpillWeights.assign(mri_->getNumRegs(), 0.0);
unsigned StartPosition = cur->beginNumber();
// for each interval in active update spill weights
// for each interval in active, update spill weights.
for (IntervalPtrs::const_iterator i = active_.begin(), e = active_.end();
i != e; ++i) {
unsigned reg = i->first->reg;
if (MRegisterInfo::isVirtualRegister(reg))
reg = vrm_->getPhys(reg);
updateSpillWeights(reg, i->first->weight);
assert(MRegisterInfo::isVirtualRegister(reg) &&
"Can only allocate virtual registers!");
reg = vrm_->getPhys(reg);
updateSpillWeights(SpillWeights, reg, i->first->weight, mri_);
}
// for every interval in inactive we overlap with, mark the
@ -382,10 +379,11 @@ void RA::assignRegOrStackSlotAtInterval(LiveInterval* cur)
e = inactive_.end(); i != e; ++i) {
if (cur->overlapsFrom(*i->first, i->second-1)) {
unsigned reg = i->first->reg;
if (MRegisterInfo::isVirtualRegister(reg))
reg = vrm_->getPhys(reg);
assert(MRegisterInfo::isVirtualRegister(reg) &&
"Can only allocate virtual registers!");
reg = vrm_->getPhys(reg);
prt_->addRegUse(reg);
updateSpillWeights(reg, i->first->weight);
updateSpillWeights(SpillWeights, reg, i->first->weight, mri_);
}
}
@ -402,7 +400,7 @@ void RA::assignRegOrStackSlotAtInterval(LiveInterval* cur)
if (cur->overlapsFrom(*I, II)) {
unsigned reg = I->reg;
prt_->addRegUse(reg);
updateSpillWeights(reg, I->weight);
updateSpillWeights(SpillWeights, reg, I->weight, mri_);
}
}
}
@ -431,8 +429,8 @@ void RA::assignRegOrStackSlotAtInterval(LiveInterval* cur)
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];
if (minWeight > SpillWeights[reg]) {
minWeight = SpillWeights[reg];
minReg = reg;
}
}
@ -492,7 +490,7 @@ void RA::assignRegOrStackSlotAtInterval(LiveInterval* cur)
// mark our rollback point.
for (IntervalPtrs::iterator i = active_.begin(); i != active_.end(); ++i) {
unsigned reg = i->first->reg;
if (MRegisterInfo::isVirtualRegister(reg) &&
if (//MRegisterInfo::isVirtualRegister(reg) &&
toSpill[vrm_->getPhys(reg)] &&
cur->overlapsFrom(*i->first, i->second)) {
DEBUG(std::cerr << "\t\t\tspilling(a): " << *i->first << '\n');
@ -506,7 +504,7 @@ void RA::assignRegOrStackSlotAtInterval(LiveInterval* cur)
}
for (IntervalPtrs::iterator i = inactive_.begin(); i != inactive_.end(); ++i){
unsigned reg = i->first->reg;
if (MRegisterInfo::isVirtualRegister(reg) &&
if (//MRegisterInfo::isVirtualRegister(reg) &&
toSpill[vrm_->getPhys(reg)] &&
cur->overlapsFrom(*i->first, i->second-1)) {
DEBUG(std::cerr << "\t\t\tspilling(i): " << *i->first << '\n');
@ -538,6 +536,7 @@ void RA::assignRegOrStackSlotAtInterval(LiveInterval* cur)
if ((it = FindIntervalInVector(active_, i)) != active_.end()) {
active_.erase(it);
if (MRegisterInfo::isPhysicalRegister(i->reg)) {
assert(0 && "daksjlfd");
prt_->delRegUse(i->reg);
unhandled_.push(i);
} else {
@ -548,17 +547,18 @@ void RA::assignRegOrStackSlotAtInterval(LiveInterval* cur)
}
} else if ((it = FindIntervalInVector(inactive_, i)) != inactive_.end()) {
inactive_.erase(it);
if (MRegisterInfo::isPhysicalRegister(i->reg))
if (MRegisterInfo::isPhysicalRegister(i->reg)) {
assert(0 && "daksjlfd");
unhandled_.push(i);
else {
} else {
if (!spilled.count(i->reg))
unhandled_.push(i);
vrm_->clearVirt(i->reg);
}
}
else {
if (MRegisterInfo::isVirtualRegister(i->reg))
vrm_->clearVirt(i->reg);
} else {
assert(MRegisterInfo::isVirtualRegister(i->reg) &&
"Can only allocate virtual registers!");
vrm_->clearVirt(i->reg);
unhandled_.push(i);
}
}
@ -578,9 +578,10 @@ void RA::assignRegOrStackSlotAtInterval(LiveInterval* cur)
HI->expiredAt(cur->beginNumber())) {
DEBUG(std::cerr << "\t\t\tundo changes for: " << *HI << '\n');
active_.push_back(std::make_pair(HI, HI->begin()));
if (MRegisterInfo::isPhysicalRegister(HI->reg))
if (MRegisterInfo::isPhysicalRegister(HI->reg)) {
assert(0 &&"sdflkajsdf");
prt_->addRegUse(HI->reg);
else
} else
prt_->addRegUse(vrm_->getPhys(HI->reg));
}
}
@ -598,8 +599,9 @@ unsigned RA::getFreePhysReg(LiveInterval* cur)
for (IntervalPtrs::iterator i = inactive_.begin(), e = inactive_.end();
i != e; ++i) {
unsigned reg = i->first->reg;
if (MRegisterInfo::isVirtualRegister(reg))
reg = vrm_->getPhys(reg);
assert(MRegisterInfo::isVirtualRegister(reg) &&
"Can only allocate virtual registers!");
reg = vrm_->getPhys(reg);
++inactiveCounts[reg];
}