#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 "Support/STLExtras.h"
#include "LiveIntervals.h"
#include "PhysRegTracker.h"
+#include "VirtRegMap.h"
#include <algorithm>
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:
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_;
+ std::auto_ptr<VirtRegMap> vrm_;
int instrAdded_;
/// 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_->getPhys4Virt(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 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 RA::releaseMemory()
{
- v2pMap_.clear();
- v2ssMap_.clear();
unhandled_.clear();
active_.clear();
inactive_.clear();
mri_ = tm_->getRegisterInfo();
li_ = &getAnalysis<LiveIntervals>();
if (!prt_.get()) prt_.reset(new PhysRegTracker(*mri_));
+ vrm_.reset(new VirtRegMap(*mf_));
initIntervalSets(li_->getIntervals());
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_->getPhys4Virt(reg);
prt_->delRegUse(reg);
}
- DEBUG(printVirtRegAssignment());
+ DEBUG(std::cerr << *vrm_);
DEBUG(std::cerr << "********** REWRITE MACHINE CODE **********\n");
DEBUG(std::cerr << "********** Function: "
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));
+ unsigned physReg = vrm_->getPhys4Virt(virtReg);
DEBUG(std::cerr << "\t[reg" << virtReg
<< " -> " << mri_->getName(physReg) << ']');
mii->SetMachineOperandReg(i, physReg);
// 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_->getPhys4Virt(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_->getPhys4Virt(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_->getPhys4Virt(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_->getPhys4Virt(reg);
updateSpillWeights(reg, (*i)->weight);
}
if (cur->overlaps(**i)) {
unsigned reg = (*i)->reg;
if (MRegisterInfo::isVirtualRegister(reg))
- reg = v2pMap_[reg];
+ reg = vrm_->getPhys4Virt(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;
// again
if (cur->weight <= minWeight) {
DEBUG(std::cerr << "\t\t\tspilling(c): " << *cur << '\n';);
- int slot = assignVirt2StackSlot(cur->reg);
+ int slot = vrm_->assignVirt2StackSlot(cur->reg);
li_->updateSpilledInterval(*cur, slot);
// if we didn't eliminate the interval find where to add it
for (IntervalPtrs::iterator i = active_.begin(); i != active_.end(); ++i) {
unsigned reg = (*i)->reg;
if (MRegisterInfo::isVirtualRegister(reg) &&
- toSpill[v2pMap_[reg]] &&
+ toSpill[vrm_->getPhys4Virt(reg)] &&
cur->overlaps(**i)) {
DEBUG(std::cerr << "\t\t\tspilling(a): " << **i << '\n');
earliestStart = std::min(earliestStart, (*i)->start());
- int slot = assignVirt2StackSlot((*i)->reg);
+ int slot = vrm_->assignVirt2StackSlot((*i)->reg);
li_->updateSpilledInterval(**i, slot);
addSpillCode(*i, slot);
}
i != inactive_.end(); ++i) {
unsigned reg = (*i)->reg;
if (MRegisterInfo::isVirtualRegister(reg) &&
- toSpill[v2pMap_[reg]] &&
+ toSpill[vrm_->getPhys4Virt(reg)] &&
cur->overlaps(**i)) {
DEBUG(std::cerr << "\t\t\tspilling(i): " << **i << '\n');
earliestStart = std::min(earliestStart, (*i)->start());
- int slot = assignVirt2StackSlot((*i)->reg);
+ int slot = vrm_->assignVirt2StackSlot((*i)->reg);
li_->updateSpilledInterval(**i, slot);
addSpillCode(*i, slot);
}
prt_->delRegUse(i->reg);
}
else {
- Virt2PhysMap::iterator v2pIt = v2pMap_.find(i->reg);
- clearVirtReg(v2pIt);
- prt_->delRegUse(v2pIt->second);
+ prt_->delRegUse(vrm_->getPhys4Virt(i->reg));
+ vrm_->clearVirtReg(i->reg);
if (i->spilled()) {
if (!i->empty()) {
IntervalPtrs::iterator it = unhandled_.begin();
if (MRegisterInfo::isPhysicalRegister(i->reg))
fixed_.push_front(i);
else {
- Virt2PhysMap::iterator v2pIt = v2pMap_.find(i->reg);
- clearVirtReg(v2pIt);
+ vrm_->clearVirtReg(i->reg);
if (i->spilled()) {
if (!i->empty()) {
IntervalPtrs::iterator it = unhandled_.begin();
if (MRegisterInfo::isPhysicalRegister(i->reg))
fixed_.push_front(i);
else {
- Virt2PhysMap::iterator v2pIt = v2pMap_.find(i->reg);
- clearVirtReg(v2pIt);
+ vrm_->clearVirtReg(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_->getPhys4Virt((*i)->reg));
}
}
}
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();
}
--- /dev/null
+//===-- llvm/CodeGen/VirtRegMap.h - Virtual Register Map -*- C++ -*--------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements a virtual register map. This maps virtual
+// registers to physical registers and virtual registers to stack
+// slots. It is created and updated by a register allocator and then
+// used by a machine code rewriter that adds spill code and rewrites
+// virtual into physical register references.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CODEGEN_VIRTREGMAP_H
+#define LLVM_CODEGEN_VIRTREGMAP_H
+
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/SSARegMap.h"
+#include <climits>
+
+namespace llvm {
+
+ class VirtRegMap {
+ public:
+ typedef std::vector<unsigned> Virt2PhysMap;
+ typedef std::vector<int> Virt2StackSlotMap;
+
+ enum {
+ NO_PHYS_REG = 0,
+ NO_STACK_SLOT = INT_MAX
+ };
+
+ private:
+ MachineFunction* mf_;
+ Virt2PhysMap v2pMap_;
+ Virt2StackSlotMap v2ssMap_;
+
+ // do not implement
+ VirtRegMap(const VirtRegMap& rhs);
+ const VirtRegMap& operator=(const VirtRegMap& rhs);
+
+ static unsigned toIndex(unsigned virtReg) {
+ return virtReg - MRegisterInfo::FirstVirtualRegister;
+ }
+ static unsigned fromIndex(unsigned index) {
+ return index + MRegisterInfo::FirstVirtualRegister;
+ }
+
+ public:
+ VirtRegMap(MachineFunction& mf)
+ : mf_(&mf),
+ v2pMap_(mf.getSSARegMap()->getNumVirtualRegs(), NO_PHYS_REG),
+ v2ssMap_(mf.getSSARegMap()->getNumVirtualRegs(), NO_STACK_SLOT) {
+ }
+
+ unsigned getPhys4Virt(unsigned virtReg) const {
+ assert(MRegisterInfo::isVirtualRegister(virtReg));
+ return v2pMap_[toIndex(virtReg)];
+ }
+
+ void assignVirt2Phys(unsigned virtReg, unsigned physReg) {
+ assert(MRegisterInfo::isVirtualRegister(virtReg) &&
+ MRegisterInfo::isPhysicalRegister(physReg));
+ assert(v2pMap_[toIndex(virtReg)] == NO_PHYS_REG &&
+ "attempt to assign physical register to already mapped "
+ "virtual register");
+ v2pMap_[toIndex(virtReg)] = physReg;
+ }
+
+ void clearVirtReg(unsigned virtReg) {
+ assert(MRegisterInfo::isVirtualRegister(virtReg));
+ assert(v2pMap_[toIndex(virtReg)] != NO_PHYS_REG &&
+ "attempt to clear a not assigned virtual register");
+ v2pMap_[toIndex(virtReg)] = NO_PHYS_REG;
+ }
+
+ int getStackSlot4Virt(unsigned virtReg) const {
+ assert(MRegisterInfo::isVirtualRegister(virtReg));
+ return v2ssMap_[toIndex(virtReg)];
+ }
+
+ int assignVirt2StackSlot(unsigned virtReg);
+
+ friend std::ostream& operator<<(std::ostream& os, const VirtRegMap& li);
+ };
+
+ std::ostream& operator<<(std::ostream& os, const VirtRegMap& li);
+
+} // End llvm namespace
+
+#endif
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