// This file implements a linear scan register allocator.
//
//===----------------------------------------------------------------------===//
+
#define DEBUG_TYPE "regalloc"
#include "llvm/Function.h"
#include "llvm/CodeGen/LiveVariables.h"
-#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/SSARegMap.h"
#include "llvm/Target/MRegisterInfo.h"
-#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetMachine.h"
-#include "llvm/Support/CFG.h"
#include "Support/Debug.h"
-#include "Support/DepthFirstIterator.h"
-#include "Support/Statistic.h"
#include "Support/STLExtras.h"
#include "LiveIntervals.h"
#include "PhysRegTracker.h"
+#include "VirtRegMap.h"
#include <algorithm>
+#include <cmath>
+#include <iostream>
+#include <set>
+
using namespace llvm;
namespace {
- Statistic<> numStores("ra-linearscan", "Number of stores added");
- Statistic<> numLoads ("ra-linearscan", "Number of loads added");
- Statistic<> numSpills("ra-linearscan", "Number of register spills");
-
class RA : public MachineFunctionPass {
private:
MachineFunction* mf_;
const TargetMachine* tm_;
- const TargetInstrInfo* tii_;
const MRegisterInfo* mri_;
LiveIntervals* li_;
- typedef std::list<LiveIntervals::Interval*> IntervalPtrs;
+ typedef std::list<LiveInterval*> IntervalPtrs;
IntervalPtrs unhandled_, fixed_, active_, inactive_, handled_;
std::auto_ptr<PhysRegTracker> prt_;
-
- typedef std::map<unsigned, unsigned> Virt2PhysMap;
- Virt2PhysMap v2pMap_;
-
- typedef std::map<unsigned, int> Virt2StackSlotMap;
- Virt2StackSlotMap v2ssMap_;
-
- int instrAdded_;
+ std::auto_ptr<VirtRegMap> vrm_;
+ std::auto_ptr<Spiller> spiller_;
typedef std::vector<float> SpillWeights;
SpillWeights spillWeights_;
void releaseMemory();
private:
+ /// linearScan - the linear scan algorithm
+ void linearScan();
+
/// initIntervalSets - initializa the four interval sets:
/// unhandled, fixed, active and inactive
void initIntervalSets(LiveIntervals::Intervals& li);
/// is available, or spill.
void assignRegOrStackSlotAtInterval(IntervalPtrs::value_type cur);
- /// addSpillCode - adds spill code for interval. The interval
- /// must be modified by LiveIntervals::updateIntervalForSpill.
- void addSpillCode(IntervalPtrs::value_type li, int slot);
-
///
/// register handling helpers
///
/// 0
unsigned getFreePhysReg(IntervalPtrs::value_type cur);
- /// assignVirt2PhysReg - assigns the free physical register to
- /// the virtual register passed as arguments
- Virt2PhysMap::iterator
- assignVirt2PhysReg(unsigned virtReg, unsigned physReg);
-
- /// clearVirtReg - free the physical register associated with this
- /// virtual register and disassociate virtual->physical and
- /// physical->virtual mappings
- void clearVirtReg(Virt2PhysMap::iterator it);
-
/// assignVirt2StackSlot - assigns this virtual register to a
/// stack slot. returns the stack slot
int assignVirt2StackSlot(unsigned virtReg);
- /// getStackSlot - returns the offset of the specified
- /// register on the stack
- int getStackSlot(unsigned virtReg);
-
- void printVirtRegAssignment() const {
- std::cerr << "register assignment:\n";
-
- for (Virt2PhysMap::const_iterator
- i = v2pMap_.begin(), e = v2pMap_.end(); i != e; ++i) {
- assert(i->second != 0);
- std::cerr << "[reg" << i->first << " -> "
- << mri_->getName(i->second) << "]\n";
- }
- for (Virt2StackSlotMap::const_iterator
- i = v2ssMap_.begin(), e = v2ssMap_.end(); i != e; ++i) {
- std::cerr << '[' << i->first << " -> ss#" << i->second << "]\n";
- }
- std::cerr << '\n';
- }
-
void printIntervals(const char* const str,
RA::IntervalPtrs::const_iterator i,
RA::IntervalPtrs::const_iterator e) const {
std::cerr << "\t" << **i << " -> ";
unsigned reg = (*i)->reg;
if (MRegisterInfo::isVirtualRegister(reg)) {
- Virt2PhysMap::const_iterator it = v2pMap_.find(reg);
- reg = (it == v2pMap_.end() ? 0 : it->second);
+ reg = vrm_->getPhys(reg);
}
std::cerr << mri_->getName(reg) << '\n';
}
}
- void verifyAssignment() const {
- for (Virt2PhysMap::const_iterator i = v2pMap_.begin(),
- e = v2pMap_.end(); i != e; ++i)
- for (Virt2PhysMap::const_iterator i2 = next(i); i2 != e; ++i2)
- if (MRegisterInfo::isVirtualRegister(i->second) &&
- (i->second == i2->second ||
- mri_->areAliases(i->second, i2->second))) {
- const LiveIntervals::Interval
- &in = li_->getInterval(i->second),
- &in2 = li_->getInterval(i2->second);
- if (in.overlaps(in2)) {
- std::cerr << in << " overlaps " << in2 << '\n';
- assert(0);
- }
- }
- }
+// void verifyAssignment() const {
+// for (Virt2PhysMap::const_iterator i = v2pMap_.begin(),
+// e = v2pMap_.end(); i != e; ++i)
+// for (Virt2PhysMap::const_iterator i2 = next(i); i2 != e; ++i2)
+// if (MRegisterInfo::isVirtualRegister(i->second) &&
+// (i->second == i2->second ||
+// mri_->areAliases(i->second, i2->second))) {
+// const Interval
+// &in = li_->getInterval(i->second),
+// &in2 = li_->getInterval(i2->second);
+// if (in.overlaps(in2)) {
+// std::cerr << in << " overlaps " << in2 << '\n';
+// assert(0);
+// }
+// }
+// }
};
}
void RA::releaseMemory()
{
- v2pMap_.clear();
- v2ssMap_.clear();
unhandled_.clear();
+ fixed_.clear();
active_.clear();
inactive_.clear();
- fixed_.clear();
handled_.clear();
}
bool RA::runOnMachineFunction(MachineFunction &fn) {
mf_ = &fn;
tm_ = &fn.getTarget();
- tii_ = &tm_->getInstrInfo();
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(li_->getIntervals());
+ linearScan();
+
+ spiller_->runOnMachineFunction(*mf_, *vrm_);
+
+ return true;
+}
+
+void RA::linearScan()
+{
// linear scan algorithm
DEBUG(std::cerr << "********** LINEAR SCAN **********\n");
DEBUG(std::cerr << "********** Function: "
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();
- unhandled_.pop_front();
- }
- else {
- cur = fixed_.front();
- fixed_.pop_front();
- }
+ IntervalPtrs::value_type cur = unhandled_.front();
+ unhandled_.pop_front();
DEBUG(std::cerr << "\n*** CURRENT ***: " << *cur << '\n');
for (IntervalPtrs::iterator i = active_.begin(); i != active_.end(); ++i) {
unsigned reg = (*i)->reg;
DEBUG(std::cerr << "\tinterval " << **i << " expired\n");
- if (MRegisterInfo::isVirtualRegister(reg)) {
- reg = v2pMap_[reg];
- }
+ if (MRegisterInfo::isVirtualRegister(reg))
+ reg = vrm_->getPhys(reg);
prt_->delRegUse(reg);
}
- DEBUG(printVirtRegAssignment());
-
- DEBUG(std::cerr << "********** REWRITE MACHINE CODE **********\n");
- DEBUG(std::cerr << "********** Function: "
- << mf_->getFunction()->getName() << '\n');
-
- for (MachineFunction::iterator mbbi = mf_->begin(), mbbe = mf_->end();
- mbbi != mbbe; ++mbbi) {
- instrAdded_ = 0;
-
- for (MachineBasicBlock::iterator mii = mbbi->begin(), mie = mbbi->end();
- mii != mie; ++mii) {
- DEBUG(
- std::cerr << '[';
- unsigned index = li_->getInstructionIndex(mii);
- if (index == std::numeric_limits<unsigned>::max())
- std::cerr << '*';
- else
- std::cerr << index;
- std::cerr << "]\t";
- mii->print(std::cerr, *tm_));
-
- // use our current mapping and actually replace every
- // virtual register with its allocated physical registers
- DEBUG(std::cerr << "\t");
- for (unsigned i = 0, e = mii->getNumOperands();
- i != e; ++i) {
- MachineOperand& op = mii->getOperand(i);
- if (op.isRegister() &&
- MRegisterInfo::isVirtualRegister(op.getReg())) {
- unsigned virtReg = op.getReg();
- Virt2PhysMap::iterator it = v2pMap_.find(virtReg);
- assert(it != v2pMap_.end() &&
- "all virtual registers must be allocated");
- unsigned physReg = it->second;
- assert(MRegisterInfo::isPhysicalRegister(physReg));
- DEBUG(std::cerr << "\t[reg" << virtReg
- << " -> " << mri_->getName(physReg) << ']');
- mii->SetMachineOperandReg(i, physReg);
- }
- }
- DEBUG(std::cerr << '\n');
- }
- }
-
- DEBUG(std::cerr << "********** MACHINEINSTRS **********\n");
- DEBUG(
- for (MachineFunction::iterator mbbi = mf_->begin(), mbbe = mf_->end();
- mbbi != mbbe; ++mbbi) {
- std::cerr << mbbi->getBasicBlock()->getName() << ":\n";
- for (MachineBasicBlock::iterator mii = mbbi->begin(),
- mie = mbbi->end(); mii != mie; ++mii) {
- unsigned index = li_->getInstructionIndex(mii);
- if (index == std::numeric_limits<unsigned>::max())
- std::cerr << "*\t";
- else
- std::cerr << index << '\t';
- mii->print(std::cerr, *tm_);
- }
- });
-
- return true;
+ DEBUG(std::cerr << *vrm_);
}
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);
}
}
// remove expired intervals
if ((*i)->expiredAt(cur->start())) {
DEBUG(std::cerr << "\t\tinterval " << **i << " expired\n");
- if (MRegisterInfo::isVirtualRegister(reg)) {
- reg = v2pMap_[reg];
- }
+ if (MRegisterInfo::isVirtualRegister(reg))
+ reg = vrm_->getPhys(reg);
prt_->delRegUse(reg);
// remove from active
i = active_.erase(i);
// 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 = v2pMap_[reg];
- }
+ if (MRegisterInfo::isVirtualRegister(reg))
+ reg = vrm_->getPhys(reg);
prt_->delRegUse(reg);
// add to inactive
inactive_.push_back(*i);
// 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 = v2pMap_[reg];
- }
+ if (MRegisterInfo::isVirtualRegister(reg))
+ reg = vrm_->getPhys(reg);
prt_->addRegUse(reg);
// add to active
active_.push_back(*i);
i != e; ++i) {
unsigned reg = (*i)->reg;
if (MRegisterInfo::isVirtualRegister(reg))
- reg = v2pMap_[reg];
+ reg = vrm_->getPhys(reg);
updateSpillWeights(reg, (*i)->weight);
}
if (cur->overlaps(**i)) {
unsigned reg = (*i)->reg;
if (MRegisterInfo::isVirtualRegister(reg))
- reg = v2pMap_[reg];
+ reg = vrm_->getPhys(reg);
prt_->addRegUse(reg);
updateSpillWeights(reg, (*i)->weight);
}
// list.
if (physReg) {
DEBUG(std::cerr << mri_->getName(physReg) << '\n');
- assignVirt2PhysReg(cur->reg, physReg);
+ vrm_->assignVirt2Phys(cur->reg, physReg);
+ prt_->addRegUse(physReg);
active_.push_back(cur);
handled_.push_back(cur);
return;
DEBUG(std::cerr << "\tassigning stack slot at interval "<< *cur << ":\n");
- float minWeight = std::numeric_limits<float>::infinity();
+ float minWeight = HUGE_VAL;
unsigned minReg = 0;
const TargetRegisterClass* rc = mf_->getSSARegMap()->getRegClass(cur->reg);
for (TargetRegisterClass::iterator i = rc->allocation_order_begin(*mf_);
DEBUG(std::cerr << "\t\tregister with min weight: "
<< mri_->getName(minReg) << " (" << minWeight << ")\n");
- // if the current has the minimum weight, we need to modify it,
- // push it back in unhandled and let the linear scan algorithm run
- // again
+ // 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 = assignVirt2StackSlot(cur->reg);
- li_->updateSpilledInterval(*cur, slot);
-
- // if we didn't eliminate the interval find where to add it
- // back to unhandled. We need to scan since unhandled are
- // sorted on earliest start point and we may have changed our
- // start point.
- if (!cur->empty()) {
- addSpillCode(cur, slot);
- IntervalPtrs::iterator it = unhandled_.begin();
- while (it != unhandled_.end() && (*it)->start() < cur->start())
- ++it;
- unhandled_.insert(it, cur);
+ int slot = vrm_->assignVirt2StackSlot(cur->reg);
+ std::vector<LiveInterval*> added =
+ li_->addIntervalsForSpills(*cur, *vrm_, slot);
+
+ // merge added with unhandled
+ std::vector<LiveInterval*>::iterator addedIt = added.begin();
+ std::vector<LiveInterval*>::iterator addedItEnd = added.end();
+ for (IntervalPtrs::iterator i = unhandled_.begin(), e = unhandled_.end();
+ i != e && addedIt != addedItEnd; ++i) {
+ if ((*i)->start() > (*addedIt)->start())
+ i = unhandled_.insert(i, *(addedIt++));
}
+ while (addedIt != addedItEnd)
+ unhandled_.push_back(*(addedIt++));
+
return;
}
// 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);
toSpill[*as] = true;
unsigned earliestStart = cur->start();
+ std::set<unsigned> spilled;
+
for (IntervalPtrs::iterator i = active_.begin(); i != active_.end(); ++i) {
unsigned reg = (*i)->reg;
if (MRegisterInfo::isVirtualRegister(reg) &&
- toSpill[v2pMap_[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 = assignVirt2StackSlot((*i)->reg);
- li_->updateSpilledInterval(**i, slot);
- addSpillCode(*i, slot);
+ 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[v2pMap_[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 = assignVirt2StackSlot((*i)->reg);
- li_->updateSpilledInterval(**i, slot);
- addSpillCode(*i, slot);
+ 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 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
- if (!i->empty() && i->start() < earliestStart)
+ if (i->start() < earliestStart)
break;
DEBUG(std::cerr << "\t\t\tundo changes for: " << *i << '\n');
handled_.pop_back();
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 {
- Virt2PhysMap::iterator v2pIt = v2pMap_.find(i->reg);
- clearVirtReg(v2pIt);
- prt_->delRegUse(v2pIt->second);
- if (i->spilled()) {
- if (!i->empty()) {
- IntervalPtrs::iterator it = unhandled_.begin();
- while (it != unhandled_.end() &&
- (*it)->start() < i->start())
- ++it;
- unhandled_.insert(it, i);
- }
- }
- else
+ if (!spilled.count(i->reg))
unhandled_.push_front(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))
- fixed_.push_front(i);
+ unhandled_.push_front(i);
else {
- Virt2PhysMap::iterator v2pIt = v2pMap_.find(i->reg);
- clearVirtReg(v2pIt);
- if (i->spilled()) {
- if (!i->empty()) {
- IntervalPtrs::iterator it = unhandled_.begin();
- while (it != unhandled_.end() &&
- (*it)->start() < i->start())
- ++it;
- unhandled_.insert(it, i);
- }
- }
- else
+ if (!spilled.count(i->reg))
unhandled_.push_front(i);
+ vrm_->clearVirt(i->reg);
}
}
else {
- if (MRegisterInfo::isPhysicalRegister(i->reg))
- fixed_.push_front(i);
- else {
- Virt2PhysMap::iterator v2pIt = v2pMap_.find(i->reg);
- clearVirtReg(v2pIt);
- unhandled_.push_front(i);
- }
+ if (MRegisterInfo::isVirtualRegister(i->reg))
+ vrm_->clearVirt(i->reg);
+ unhandled_.push_front(i);
}
}
active_.push_back(*i);
if (MRegisterInfo::isPhysicalRegister((*i)->reg))
prt_->addRegUse((*i)->reg);
- else {
- assert(v2pMap_.count((*i)->reg));
- prt_->addRegUse(v2pMap_.find((*i)->reg)->second);
- }
+ else
+ prt_->addRegUse(vrm_->getPhys((*i)->reg));
}
}
-}
-void RA::addSpillCode(IntervalPtrs::value_type li, int slot)
-{
- // We scan the instructions corresponding to each range. We load
- // when we have a use and spill at end of basic blocks or end of
- // ranges only if the register was modified.
- const TargetRegisterClass* rc = mf_->getSSARegMap()->getRegClass(li->reg);
-
- for (LiveIntervals::Interval::Ranges::iterator i = li->ranges.begin(),
- e = li->ranges.end(); i != e; ++i) {
- unsigned index = i->first;
- unsigned end = i->second;
-
- bool loaded = false;
-
- // skip deleted instructions. getInstructionFromIndex returns
- // null if the instruction was deleted (because of coalescing
- // for example)
- while (!li_->getInstructionFromIndex(index))
- index += LiveIntervals::InstrSlots::NUM;
- MachineBasicBlock::iterator mi = li_->getInstructionFromIndex(index);
- MachineBasicBlock* mbb = mi->getParent();
- assert(mbb && "machine instruction not bound to basic block");
-
- for (; index < end; index += LiveIntervals::InstrSlots::NUM) {
- // ignore deleted instructions
- while (!li_->getInstructionFromIndex(index)) index += 2;
- mi = li_->getInstructionFromIndex(index);
- DEBUG(std::cerr << "\t\t\t\texamining: \t\t\t\t\t"
- << LiveIntervals::getBaseIndex(index) << '\t';
- mi->print(std::cerr, *tm_));
-
- // if it is used in this instruction load it
- for (unsigned i = 0; i < mi->getNumOperands(); ++i) {
- MachineOperand& mop = mi->getOperand(i);
- if (mop.isRegister() && mop.getReg() == li->reg &&
- mop.isUse() && !loaded) {
- loaded = true;
- mri_->loadRegFromStackSlot(*mbb, mi, li->reg, slot, rc);
- ++numLoads;
- DEBUG(std::cerr << "\t\t\t\tadded load for reg" << li->reg
- << " from ss#" << slot << " before: \t"
- << LiveIntervals::getBaseIndex(index) << '\t';
- mi->print(std::cerr, *tm_));
- }
- }
-
- // if it is defined in this instruction mark as dirty
- for (unsigned i = 0; i < mi->getNumOperands(); ++i) {
- MachineOperand& mop = mi->getOperand(i);
- if (mop.isRegister() && mop.getReg() == li->reg &&
- mop.isDef()) {
- loaded = true;
-
- mri_->storeRegToStackSlot(*mbb, next(mi), li->reg, slot,rc);
- ++numStores;
- DEBUG(std::cerr << "\t\t\t\tadded store for reg" << li->reg
- << " to ss#" << slot << " after: \t\t"
- << LiveIntervals::getBaseIndex(index) << " \t";
- mi->print(std::cerr, *tm_));
- }
- }
- }
+ std::sort(added.begin(), added.end(), less_ptr<LiveInterval>());
+ // merge added with unhandled
+ std::vector<LiveInterval*>::iterator addedIt = added.begin();
+ std::vector<LiveInterval*>::iterator addedItEnd = added.end();
+ for (IntervalPtrs::iterator i = unhandled_.begin(), e = unhandled_.end();
+ i != e && addedIt != addedItEnd; ++i) {
+ if ((*i)->start() > (*addedIt)->start())
+ i = unhandled_.insert(i, *(addedIt++));
}
+ while (addedIt != addedItEnd)
+ unhandled_.push_back(*(addedIt++));
+
}
unsigned RA::getFreePhysReg(IntervalPtrs::value_type cur)
return 0;
}
-RA::Virt2PhysMap::iterator
-RA::assignVirt2PhysReg(unsigned virtReg, unsigned physReg)
-{
- bool inserted;
- Virt2PhysMap::iterator it;
- tie(it, inserted) = v2pMap_.insert(std::make_pair(virtReg, physReg));
- assert(inserted && "attempting to assign a virt->phys mapping to an "
- "already mapped register");
- prt_->addRegUse(physReg);
- return it;
-}
-
-void RA::clearVirtReg(Virt2PhysMap::iterator it)
-{
- assert(it != v2pMap_.end() &&
- "attempting to clear a not allocated virtual register");
- unsigned physReg = it->second;
- v2pMap_.erase(it);
- DEBUG(std::cerr << "\t\t\tcleared register " << mri_->getName(physReg)
- << "\n");
-}
-
-
-int RA::assignVirt2StackSlot(unsigned virtReg)
-{
- const TargetRegisterClass* rc = mf_->getSSARegMap()->getRegClass(virtReg);
- int frameIndex = mf_->getFrameInfo()->CreateStackObject(rc);
-
- bool inserted = v2ssMap_.insert(std::make_pair(virtReg, frameIndex)).second;
- assert(inserted && "attempt to assign stack slot to spilled register!");
- ++numSpills;
- return frameIndex;
-}
-
-int RA::getStackSlot(unsigned virtReg)
-{
- assert(v2ssMap_.count(virtReg) &&
- "attempt to get stack slot for a non spilled register");
- return v2ssMap_.find(virtReg)->second;
-}
-
FunctionPass* llvm::createLinearScanRegisterAllocator() {
return new RA();
}
projects / oota-llvm.git / blobdiff