static unsigned numIterations = 0;
static unsigned numIntervals = 0;
- struct VISIBILITY_HIDDEN RA : public MachineFunctionPass {
+ struct VISIBILITY_HIDDEN RALinScan : public MachineFunctionPass {
+ static char ID;
+ RALinScan() : MachineFunctionPass((intptr_t)&ID) {}
+
typedef std::pair<LiveInterval*, LiveInterval::iterator> IntervalPtr;
typedef std::vector<IntervalPtr> IntervalPtrs;
private:
const TargetMachine* tm_;
const MRegisterInfo* mri_;
LiveIntervals* li_;
- bool *PhysRegsUsed;
/// handled_ - Intervals are added to the handled_ set in the order of their
/// start value. This is uses for backtracking.
}
}
};
+ char RALinScan::ID = 0;
}
-void RA::ComputeRelatedRegClasses() {
+void RALinScan::ComputeRelatedRegClasses() {
const MRegisterInfo &MRI = *mri_;
// First pass, add all reg classes to the union, and determine at least one
RelatedRegClasses.unionSets(I->second, OneClassForEachPhysReg[*AS]);
}
-bool RA::runOnMachineFunction(MachineFunction &fn) {
+bool RALinScan::runOnMachineFunction(MachineFunction &fn) {
mf_ = &fn;
tm_ = &fn.getTarget();
mri_ = tm_->getRegisterInfo();
if (RelatedRegClasses.empty())
ComputeRelatedRegClasses();
- PhysRegsUsed = new bool[mri_->getNumRegs()];
- std::fill(PhysRegsUsed, PhysRegsUsed+mri_->getNumRegs(), false);
- fn.setUsedPhysRegs(PhysRegsUsed);
-
if (!prt_.get()) prt_.reset(new PhysRegTracker(*mri_));
vrm_.reset(new VirtRegMap(*mf_));
if (!spiller_.get()) spiller_.reset(createSpiller());
/// initIntervalSets - initialize the interval sets.
///
-void RA::initIntervalSets()
+void RALinScan::initIntervalSets()
{
assert(unhandled_.empty() && fixed_.empty() &&
active_.empty() && inactive_.empty() &&
for (LiveIntervals::iterator i = li_->begin(), e = li_->end(); i != e; ++i) {
if (MRegisterInfo::isPhysicalRegister(i->second.reg)) {
- PhysRegsUsed[i->second.reg] = true;
+ mf_->setPhysRegUsed(i->second.reg);
fixed_.push_back(std::make_pair(&i->second, i->second.begin()));
} else
unhandled_.push(&i->second);
}
}
-void RA::linearScan()
+void RALinScan::linearScan()
{
// linear scan algorithm
DOUT << "********** LINEAR SCAN **********\n";
/// processActiveIntervals - expire old intervals and move non-overlapping ones
/// to the inactive list.
-void RA::processActiveIntervals(unsigned CurPoint)
+void RALinScan::processActiveIntervals(unsigned CurPoint)
{
DOUT << "\tprocessing active intervals:\n";
/// processInactiveIntervals - expire old intervals and move overlapping
/// ones to the active list.
-void RA::processInactiveIntervals(unsigned CurPoint)
+void RALinScan::processInactiveIntervals(unsigned CurPoint)
{
DOUT << "\tprocessing inactive intervals:\n";
Weights[*as] += weight;
}
-static RA::IntervalPtrs::iterator FindIntervalInVector(RA::IntervalPtrs &IP,
- LiveInterval *LI) {
- for (RA::IntervalPtrs::iterator I = IP.begin(), E = IP.end(); I != E; ++I)
+static
+RALinScan::IntervalPtrs::iterator
+FindIntervalInVector(RALinScan::IntervalPtrs &IP, LiveInterval *LI) {
+ for (RALinScan::IntervalPtrs::iterator I = IP.begin(), E = IP.end();
+ I != E; ++I)
if (I->first == LI) return I;
return IP.end();
}
-static void RevertVectorIteratorsTo(RA::IntervalPtrs &V, unsigned Point) {
+static void RevertVectorIteratorsTo(RALinScan::IntervalPtrs &V, unsigned Point){
for (unsigned i = 0, e = V.size(); i != e; ++i) {
- RA::IntervalPtr &IP = V[i];
+ RALinScan::IntervalPtr &IP = V[i];
LiveInterval::iterator I = std::upper_bound(IP.first->begin(),
IP.second, Point);
if (I != IP.first->begin()) --I;
/// assignRegOrStackSlotAtInterval - assign a register if one is available, or
/// spill.
-void RA::assignRegOrStackSlotAtInterval(LiveInterval* cur)
+void RALinScan::assignRegOrStackSlotAtInterval(LiveInterval* cur)
{
DOUT << "\tallocating current interval: ";
// Find a register to spill.
float minWeight = HUGE_VALF;
- unsigned minReg = 0;
- for (TargetRegisterClass::iterator i = RC->allocation_order_begin(*mf_),
- e = RC->allocation_order_end(*mf_); i != e; ++i) {
- unsigned reg = *i;
- if (minWeight > SpillWeights[reg]) {
- minWeight = SpillWeights[reg];
- minReg = reg;
+ unsigned minReg = cur->preference; // Try the preferred register first.
+
+ if (!minReg || SpillWeights[minReg] == HUGE_VALF)
+ for (TargetRegisterClass::iterator i = RC->allocation_order_begin(*mf_),
+ e = RC->allocation_order_end(*mf_); i != e; ++i) {
+ unsigned reg = *i;
+ if (minWeight > SpillWeights[reg]) {
+ minWeight = SpillWeights[reg];
+ minReg = reg;
+ }
}
- }
// If we didn't find a register that is spillable, try aliases?
if (!minReg) {
/// getFreePhysReg - return a free physical register for this virtual register
/// interval if we have one, otherwise return 0.
-unsigned RA::getFreePhysReg(LiveInterval *cur) {
+unsigned RALinScan::getFreePhysReg(LiveInterval *cur) {
std::vector<unsigned> inactiveCounts(mri_->getNumRegs(), 0);
unsigned MaxInactiveCount = 0;
}
}
- const TargetRegisterClass* rc = mf_->getSSARegMap()->getRegClass(cur->reg);
-
unsigned FreeReg = 0;
unsigned FreeRegInactiveCount = 0;
-
+
+ // If copy coalescer has assigned a "preferred" register, check if it's
+ // available first.
+ if (cur->preference)
+ if (prt_->isRegAvail(cur->preference)) {
+ DOUT << "\t\tassigned the preferred register: "
+ << mri_->getName(cur->preference) << "\n";
+ return cur->preference;
+ } else
+ DOUT << "\t\tunable to assign the preferred register: "
+ << mri_->getName(cur->preference) << "\n";
+
// Scan for the first available register.
- TargetRegisterClass::iterator I = rc->allocation_order_begin(*mf_);
- TargetRegisterClass::iterator E = rc->allocation_order_end(*mf_);
+ TargetRegisterClass::iterator I = RC->allocation_order_begin(*mf_);
+ TargetRegisterClass::iterator E = RC->allocation_order_end(*mf_);
for (; I != E; ++I)
if (prt_->isRegAvail(*I)) {
FreeReg = *I;
}
FunctionPass* llvm::createLinearScanRegisterAllocator() {
- return new RA();
+ return new RALinScan();
}
projects / oota-llvm.git / blobdiff