#include "llvm/ADT/IndexedMap.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/SparseSet.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/STLExtras.h"
#include <algorithm>
public:
static char ID;
RAFast() : MachineFunctionPass(ID), StackSlotForVirtReg(-1),
- isBulkSpilling(false) {
- initializePHIEliminationPass(*PassRegistry::getPassRegistry());
- initializeTwoAddressInstructionPassPass(*PassRegistry::getPassRegistry());
- }
+ isBulkSpilling(false) {}
private:
const TargetMachine *TM;
MachineFunction *MF;
// Everything we know about a live virtual register.
struct LiveReg {
MachineInstr *LastUse; // Last instr to use reg.
+ unsigned VirtReg; // Virtual register number.
unsigned PhysReg; // Currently held here.
unsigned short LastOpNum; // OpNum on LastUse.
bool Dirty; // Register needs spill.
- LiveReg(unsigned p=0) : LastUse(0), PhysReg(p), LastOpNum(0),
- Dirty(false) {}
+ explicit LiveReg(unsigned v)
+ : LastUse(0), VirtReg(v), PhysReg(0), LastOpNum(0), Dirty(false) {}
+
+ unsigned getSparseSetKey() const {
+ return TargetRegisterInfo::virtReg2Index(VirtReg);
+ }
};
- typedef DenseMap<unsigned, LiveReg> LiveRegMap;
- typedef LiveRegMap::value_type LiveRegEntry;
+ typedef SparseSet<LiveReg> LiveRegMap;
// LiveVirtRegs - This map contains entries for each virtual register
// that is currently available in a physical register.
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesCFG();
- AU.addRequiredID(PHIEliminationID);
- AU.addRequiredID(TwoAddressInstructionPassID);
MachineFunctionPass::getAnalysisUsage(AU);
}
void usePhysReg(MachineOperand&);
void definePhysReg(MachineInstr *MI, unsigned PhysReg, RegState NewState);
unsigned calcSpillCost(unsigned PhysReg) const;
- void assignVirtToPhysReg(LiveRegEntry &LRE, unsigned PhysReg);
- void allocVirtReg(MachineInstr *MI, LiveRegEntry &LRE, unsigned Hint);
+ void assignVirtToPhysReg(LiveReg&, unsigned PhysReg);
+ LiveRegMap::iterator findLiveVirtReg(unsigned VirtReg) {
+ return LiveVirtRegs.find(TargetRegisterInfo::virtReg2Index(VirtReg));
+ }
+ LiveRegMap::const_iterator findLiveVirtReg(unsigned VirtReg) const {
+ return LiveVirtRegs.find(TargetRegisterInfo::virtReg2Index(VirtReg));
+ }
+ LiveRegMap::iterator assignVirtToPhysReg(unsigned VReg, unsigned PhysReg);
+ LiveRegMap::iterator allocVirtReg(MachineInstr *MI, LiveRegMap::iterator,
+ unsigned Hint);
LiveRegMap::iterator defineVirtReg(MachineInstr *MI, unsigned OpNum,
unsigned VirtReg, unsigned Hint);
LiveRegMap::iterator reloadVirtReg(MachineInstr *MI, unsigned OpNum,
/// killVirtReg - Mark virtreg as no longer available.
void RAFast::killVirtReg(LiveRegMap::iterator LRI) {
- addKillFlag(LRI->second);
- const LiveReg &LR = LRI->second;
- assert(PhysRegState[LR.PhysReg] == LRI->first && "Broken RegState mapping");
- PhysRegState[LR.PhysReg] = regFree;
+ addKillFlag(*LRI);
+ assert(PhysRegState[LRI->PhysReg] == LRI->VirtReg &&
+ "Broken RegState mapping");
+ PhysRegState[LRI->PhysReg] = regFree;
// Erase from LiveVirtRegs unless we're spilling in bulk.
if (!isBulkSpilling)
LiveVirtRegs.erase(LRI);
void RAFast::killVirtReg(unsigned VirtReg) {
assert(TargetRegisterInfo::isVirtualRegister(VirtReg) &&
"killVirtReg needs a virtual register");
- LiveRegMap::iterator LRI = LiveVirtRegs.find(VirtReg);
+ LiveRegMap::iterator LRI = findLiveVirtReg(VirtReg);
if (LRI != LiveVirtRegs.end())
killVirtReg(LRI);
}
void RAFast::spillVirtReg(MachineBasicBlock::iterator MI, unsigned VirtReg) {
assert(TargetRegisterInfo::isVirtualRegister(VirtReg) &&
"Spilling a physical register is illegal!");
- LiveRegMap::iterator LRI = LiveVirtRegs.find(VirtReg);
+ LiveRegMap::iterator LRI = findLiveVirtReg(VirtReg);
assert(LRI != LiveVirtRegs.end() && "Spilling unmapped virtual register");
spillVirtReg(MI, LRI);
}
/// spillVirtReg - Do the actual work of spilling.
void RAFast::spillVirtReg(MachineBasicBlock::iterator MI,
LiveRegMap::iterator LRI) {
- LiveReg &LR = LRI->second;
- assert(PhysRegState[LR.PhysReg] == LRI->first && "Broken RegState mapping");
+ LiveReg &LR = *LRI;
+ assert(PhysRegState[LR.PhysReg] == LRI->VirtReg && "Broken RegState mapping");
if (LR.Dirty) {
// If this physreg is used by the instruction, we want to kill it on the
// instruction, not on the spill.
bool SpillKill = LR.LastUse != MI;
LR.Dirty = false;
- DEBUG(dbgs() << "Spilling " << PrintReg(LRI->first, TRI)
+ DEBUG(dbgs() << "Spilling " << PrintReg(LRI->VirtReg, TRI)
<< " in " << PrintReg(LR.PhysReg, TRI));
- const TargetRegisterClass *RC = MRI->getRegClass(LRI->first);
- int FI = getStackSpaceFor(LRI->first, RC);
+ const TargetRegisterClass *RC = MRI->getRegClass(LRI->VirtReg);
+ int FI = getStackSpaceFor(LRI->VirtReg, RC);
DEBUG(dbgs() << " to stack slot #" << FI << "\n");
TII->storeRegToStackSlot(*MBB, MI, LR.PhysReg, SpillKill, FI, RC, TRI);
++NumStores; // Update statistics
// If this register is used by DBG_VALUE then insert new DBG_VALUE to
// identify spilled location as the place to find corresponding variable's
// value.
- SmallVector<MachineInstr *, 4> &LRIDbgValues = LiveDbgValueMap[LRI->first];
+ SmallVector<MachineInstr *, 4> &LRIDbgValues =
+ LiveDbgValueMap[LRI->VirtReg];
for (unsigned li = 0, le = LRIDbgValues.size(); li != le; ++li) {
MachineInstr *DBG = LRIDbgValues[li];
const MDNode *MDPtr =
DEBUG(dbgs() << "Inserting debug info due to spill:" << "\n" << *NewDV);
}
}
- // Now this register is spilled there is should not be any DBG_VALUE pointing
- // to this register because they are all pointing to spilled value now.
+ // Now this register is spilled there is should not be any DBG_VALUE
+ // pointing to this register because they are all pointing to spilled value
+ // now.
LRIDbgValues.clear();
if (SpillKill)
LR.LastUse = 0; // Don't kill register again
}
// Maybe a superregister is reserved?
- for (const unsigned *AS = TRI->getAliasSet(PhysReg);
+ for (const uint16_t *AS = TRI->getAliasSet(PhysReg);
unsigned Alias = *AS; ++AS) {
switch (PhysRegState[Alias]) {
case regDisabled:
// This is a disabled register, disable all aliases.
PhysRegState[PhysReg] = NewState;
- for (const unsigned *AS = TRI->getAliasSet(PhysReg);
+ for (const uint16_t *AS = TRI->getAliasSet(PhysReg);
unsigned Alias = *AS; ++AS) {
switch (unsigned VirtReg = PhysRegState[Alias]) {
case regDisabled:
DEBUG(dbgs() << PrintReg(VirtReg, TRI) << " corresponding "
<< PrintReg(PhysReg, TRI) << " is reserved already.\n");
return spillImpossible;
- default:
- return LiveVirtRegs.lookup(VirtReg).Dirty ? spillDirty : spillClean;
+ default: {
+ LiveRegMap::const_iterator I = findLiveVirtReg(VirtReg);
+ assert(I != LiveVirtRegs.end() && "Missing VirtReg entry");
+ return I->Dirty ? spillDirty : spillClean;
+ }
}
// This is a disabled register, add up cost of aliases.
DEBUG(dbgs() << PrintReg(PhysReg, TRI) << " is disabled.\n");
unsigned Cost = 0;
- for (const unsigned *AS = TRI->getAliasSet(PhysReg);
+ for (const uint16_t *AS = TRI->getAliasSet(PhysReg);
unsigned Alias = *AS; ++AS) {
if (UsedInInstr.test(Alias))
return spillImpossible;
break;
case regReserved:
return spillImpossible;
- default:
- Cost += LiveVirtRegs.lookup(VirtReg).Dirty ? spillDirty : spillClean;
+ default: {
+ LiveRegMap::const_iterator I = findLiveVirtReg(VirtReg);
+ assert(I != LiveVirtRegs.end() && "Missing VirtReg entry");
+ Cost += I->Dirty ? spillDirty : spillClean;
break;
}
+ }
}
return Cost;
}
/// that PhysReg is the proper container for VirtReg now. The physical
/// register must not be used for anything else when this is called.
///
-void RAFast::assignVirtToPhysReg(LiveRegEntry &LRE, unsigned PhysReg) {
- DEBUG(dbgs() << "Assigning " << PrintReg(LRE.first, TRI) << " to "
+void RAFast::assignVirtToPhysReg(LiveReg &LR, unsigned PhysReg) {
+ DEBUG(dbgs() << "Assigning " << PrintReg(LR.VirtReg, TRI) << " to "
<< PrintReg(PhysReg, TRI) << "\n");
- PhysRegState[PhysReg] = LRE.first;
- assert(!LRE.second.PhysReg && "Already assigned a physreg");
- LRE.second.PhysReg = PhysReg;
+ PhysRegState[PhysReg] = LR.VirtReg;
+ assert(!LR.PhysReg && "Already assigned a physreg");
+ LR.PhysReg = PhysReg;
+}
+
+RAFast::LiveRegMap::iterator
+RAFast::assignVirtToPhysReg(unsigned VirtReg, unsigned PhysReg) {
+ LiveRegMap::iterator LRI = findLiveVirtReg(VirtReg);
+ assert(LRI != LiveVirtRegs.end() && "VirtReg disappeared");
+ assignVirtToPhysReg(*LRI, PhysReg);
+ return LRI;
}
/// allocVirtReg - Allocate a physical register for VirtReg.
-void RAFast::allocVirtReg(MachineInstr *MI, LiveRegEntry &LRE, unsigned Hint) {
- const unsigned VirtReg = LRE.first;
+RAFast::LiveRegMap::iterator RAFast::allocVirtReg(MachineInstr *MI,
+ LiveRegMap::iterator LRI,
+ unsigned Hint) {
+ const unsigned VirtReg = LRI->VirtReg;
assert(TargetRegisterInfo::isVirtualRegister(VirtReg) &&
"Can only allocate virtual registers");
if (Cost < spillDirty) {
if (Cost)
definePhysReg(MI, Hint, regFree);
- return assignVirtToPhysReg(LRE, Hint);
+ // definePhysReg may kill virtual registers and modify LiveVirtRegs.
+ // That invalidates LRI, so run a new lookup for VirtReg.
+ return assignVirtToPhysReg(VirtReg, Hint);
}
}
// First try to find a completely free register.
for (ArrayRef<unsigned>::iterator I = AO.begin(), E = AO.end(); I != E; ++I) {
unsigned PhysReg = *I;
- if (PhysRegState[PhysReg] == regFree && !UsedInInstr.test(PhysReg))
- return assignVirtToPhysReg(LRE, PhysReg);
+ if (PhysRegState[PhysReg] == regFree && !UsedInInstr.test(PhysReg)) {
+ assignVirtToPhysReg(*LRI, PhysReg);
+ return LRI;
+ }
}
DEBUG(dbgs() << "Allocating " << PrintReg(VirtReg) << " from "
DEBUG(dbgs() << "\tCost: " << Cost << "\n");
DEBUG(dbgs() << "\tBestCost: " << BestCost << "\n");
// Cost is 0 when all aliases are already disabled.
- if (Cost == 0)
- return assignVirtToPhysReg(LRE, *I);
+ if (Cost == 0) {
+ assignVirtToPhysReg(*LRI, *I);
+ return LRI;
+ }
if (Cost < BestCost)
BestReg = *I, BestCost = Cost;
}
if (BestReg) {
definePhysReg(MI, BestReg, regFree);
- return assignVirtToPhysReg(LRE, BestReg);
+ // definePhysReg may kill virtual registers and modify LiveVirtRegs.
+ // That invalidates LRI, so run a new lookup for VirtReg.
+ return assignVirtToPhysReg(VirtReg, BestReg);
}
// Nothing we can do. Report an error and keep going with a bad allocation.
MI->emitError("ran out of registers during register allocation");
definePhysReg(MI, *AO.begin(), regFree);
- assignVirtToPhysReg(LRE, *AO.begin());
+ return assignVirtToPhysReg(VirtReg, *AO.begin());
}
/// defineVirtReg - Allocate a register for VirtReg and mark it as dirty.
"Not a virtual register");
LiveRegMap::iterator LRI;
bool New;
- tie(LRI, New) = LiveVirtRegs.insert(std::make_pair(VirtReg, LiveReg()));
- LiveReg &LR = LRI->second;
+ tie(LRI, New) = LiveVirtRegs.insert(LiveReg(VirtReg));
if (New) {
// If there is no hint, peek at the only use of this register.
if ((!Hint || !TargetRegisterInfo::isPhysicalRegister(Hint)) &&
if (UseMI.isCopyLike())
Hint = UseMI.getOperand(0).getReg();
}
- allocVirtReg(MI, *LRI, Hint);
- } else if (LR.LastUse) {
+ LRI = allocVirtReg(MI, LRI, Hint);
+ } else if (LRI->LastUse) {
// Redefining a live register - kill at the last use, unless it is this
// instruction defining VirtReg multiple times.
- if (LR.LastUse != MI || LR.LastUse->getOperand(LR.LastOpNum).isUse())
- addKillFlag(LR);
+ if (LRI->LastUse != MI || LRI->LastUse->getOperand(LRI->LastOpNum).isUse())
+ addKillFlag(*LRI);
}
- assert(LR.PhysReg && "Register not assigned");
- LR.LastUse = MI;
- LR.LastOpNum = OpNum;
- LR.Dirty = true;
- UsedInInstr.set(LR.PhysReg);
+ assert(LRI->PhysReg && "Register not assigned");
+ LRI->LastUse = MI;
+ LRI->LastOpNum = OpNum;
+ LRI->Dirty = true;
+ UsedInInstr.set(LRI->PhysReg);
return LRI;
}
"Not a virtual register");
LiveRegMap::iterator LRI;
bool New;
- tie(LRI, New) = LiveVirtRegs.insert(std::make_pair(VirtReg, LiveReg()));
- LiveReg &LR = LRI->second;
+ tie(LRI, New) = LiveVirtRegs.insert(LiveReg(VirtReg));
MachineOperand &MO = MI->getOperand(OpNum);
if (New) {
- allocVirtReg(MI, *LRI, Hint);
+ LRI = allocVirtReg(MI, LRI, Hint);
const TargetRegisterClass *RC = MRI->getRegClass(VirtReg);
int FrameIndex = getStackSpaceFor(VirtReg, RC);
DEBUG(dbgs() << "Reloading " << PrintReg(VirtReg, TRI) << " into "
- << PrintReg(LR.PhysReg, TRI) << "\n");
- TII->loadRegFromStackSlot(*MBB, MI, LR.PhysReg, FrameIndex, RC, TRI);
+ << PrintReg(LRI->PhysReg, TRI) << "\n");
+ TII->loadRegFromStackSlot(*MBB, MI, LRI->PhysReg, FrameIndex, RC, TRI);
++NumLoads;
- } else if (LR.Dirty) {
+ } else if (LRI->Dirty) {
if (isLastUseOfLocalReg(MO)) {
DEBUG(dbgs() << "Killing last use: " << MO << "\n");
if (MO.isUse())
DEBUG(dbgs() << "Clearing clean dead: " << MO << "\n");
MO.setIsDead(false);
}
- assert(LR.PhysReg && "Register not assigned");
- LR.LastUse = MI;
- LR.LastOpNum = OpNum;
- UsedInInstr.set(LR.PhysReg);
+ assert(LRI->PhysReg && "Register not assigned");
+ LRI->LastUse = MI;
+ LRI->LastOpNum = OpNum;
+ UsedInInstr.set(LRI->PhysReg);
return LRI;
}
UsedInInstr.set(Reg);
if (ThroughRegs.count(PhysRegState[Reg]))
definePhysReg(MI, Reg, regFree);
- for (const unsigned *AS = TRI->getAliasSet(Reg); *AS; ++AS) {
+ for (const uint16_t *AS = TRI->getAliasSet(Reg); *AS; ++AS) {
UsedInInstr.set(*AS);
if (ThroughRegs.count(PhysRegState[*AS]))
definePhysReg(MI, *AS, regFree);
DEBUG(dbgs() << "Operand " << i << "("<< MO << ") is tied to operand "
<< DefIdx << ".\n");
LiveRegMap::iterator LRI = reloadVirtReg(MI, i, Reg, 0);
- unsigned PhysReg = LRI->second.PhysReg;
+ unsigned PhysReg = LRI->PhysReg;
setPhysReg(MI, i, PhysReg);
// Note: we don't update the def operand yet. That would cause the normal
// def-scan to attempt spilling.
// Reload the register, but don't assign to the operand just yet.
// That would confuse the later phys-def processing pass.
LiveRegMap::iterator LRI = reloadVirtReg(MI, i, Reg, 0);
- PartialDefs.push_back(LRI->second.PhysReg);
+ PartialDefs.push_back(LRI->PhysReg);
}
}
continue;
// Note: defineVirtReg may invalidate MO.
LiveRegMap::iterator LRI = defineVirtReg(MI, i, Reg, 0);
- unsigned PhysReg = LRI->second.PhysReg;
+ unsigned PhysReg = LRI->PhysReg;
if (setPhysReg(MI, i, PhysReg))
VirtDead.push_back(Reg);
}
continue;
unsigned OperReg = MO.getReg();
- for (const unsigned *AS = TRI->getOverlaps(Reg); *AS; ++AS) {
- if (OperReg != *AS)
- continue;
- if (OperReg == Reg || TRI->isSuperRegister(OperReg, Reg)) {
- // If the ret already has an operand for this physreg or a superset,
- // don't duplicate it. Set the kill flag if the value is defined.
- if (hasDef && !MO.isKill())
- MO.setIsKill();
- Found = true;
- break;
- }
+ if (!TargetRegisterInfo::isPhysicalRegister(OperReg))
+ continue;
+
+ if (OperReg == Reg || TRI->isSuperRegister(OperReg, Reg)) {
+ // If the ret already has an operand for this physreg or a superset,
+ // don't duplicate it. Set the kill flag if the value is defined.
+ if (hasDef && !MO.isKill())
+ MO.setIsKill();
+ Found = true;
+ break;
}
}
if (!Found)
DEBUG(dbgs() << "\nAllocating " << *MBB);
PhysRegState.assign(TRI->getNumRegs(), regDisabled);
- assert(LiveVirtRegs.empty() && "Mapping not cleared form last block?");
+ assert(LiveVirtRegs.empty() && "Mapping not cleared from last block?");
MachineBasicBlock::iterator MII = MBB->begin();
case regReserved:
dbgs() << "*";
break;
- default:
+ default: {
dbgs() << '=' << PrintReg(PhysRegState[Reg]);
- if (LiveVirtRegs[PhysRegState[Reg]].Dirty)
+ LiveRegMap::iterator I = findLiveVirtReg(PhysRegState[Reg]);
+ assert(I != LiveVirtRegs.end() && "Missing VirtReg entry");
+ if (I->Dirty)
dbgs() << "*";
- assert(LiveVirtRegs[PhysRegState[Reg]].PhysReg == Reg &&
- "Bad inverse map");
+ assert(I->PhysReg == Reg && "Bad inverse map");
break;
}
+ }
}
dbgs() << '\n';
// Check that LiveVirtRegs is the inverse.
for (LiveRegMap::iterator i = LiveVirtRegs.begin(),
e = LiveVirtRegs.end(); i != e; ++i) {
- assert(TargetRegisterInfo::isVirtualRegister(i->first) &&
+ assert(TargetRegisterInfo::isVirtualRegister(i->VirtReg) &&
"Bad map key");
- assert(TargetRegisterInfo::isPhysicalRegister(i->second.PhysReg) &&
+ assert(TargetRegisterInfo::isPhysicalRegister(i->PhysReg) &&
"Bad map value");
- assert(PhysRegState[i->second.PhysReg] == i->first &&
- "Bad inverse map");
+ assert(PhysRegState[i->PhysReg] == i->VirtReg && "Bad inverse map");
}
});
if (!MO.isReg()) continue;
unsigned Reg = MO.getReg();
if (!TargetRegisterInfo::isVirtualRegister(Reg)) continue;
- LiveRegMap::iterator LRI = LiveVirtRegs.find(Reg);
+ LiveRegMap::iterator LRI = findLiveVirtReg(Reg);
if (LRI != LiveVirtRegs.end())
- setPhysReg(MI, i, LRI->second.PhysReg);
+ setPhysReg(MI, i, LRI->PhysReg);
else {
int SS = StackSlotForVirtReg[Reg];
if (SS == -1) {
if (!TargetRegisterInfo::isVirtualRegister(Reg)) continue;
if (MO.isUse()) {
LiveRegMap::iterator LRI = reloadVirtReg(MI, i, Reg, CopyDst);
- unsigned PhysReg = LRI->second.PhysReg;
+ unsigned PhysReg = LRI->PhysReg;
CopySrc = (CopySrc == Reg || CopySrc == PhysReg) ? PhysReg : 0;
if (setPhysReg(MI, i, PhysReg))
killVirtReg(LRI);
// Look for physreg defs and tied uses.
if (!MO.isDef() && !MI->isRegTiedToDefOperand(i)) continue;
UsedInInstr.set(Reg);
- for (const unsigned *AS = TRI->getAliasSet(Reg); *AS; ++AS)
+ for (const uint16_t *AS = TRI->getAliasSet(Reg); *AS; ++AS)
UsedInInstr.set(*AS);
}
}
continue;
}
LiveRegMap::iterator LRI = defineVirtReg(MI, i, Reg, CopySrc);
- unsigned PhysReg = LRI->second.PhysReg;
+ unsigned PhysReg = LRI->PhysReg;
if (setPhysReg(MI, i, PhysReg)) {
VirtDead.push_back(Reg);
CopyDst = 0; // cancel coalescing;
RegClassInfo.runOnMachineFunction(Fn);
UsedInInstr.resize(TRI->getNumRegs());
+ assert(!MRI->isSSA() && "regalloc requires leaving SSA");
+
// initialize the virtual->physical register map to have a 'null'
// mapping for all virtual registers
StackSlotForVirtReg.resize(MRI->getNumVirtRegs());
+ LiveVirtRegs.setUniverse(MRI->getNumVirtRegs());
// Loop over all of the basic blocks, eliminating virtual register references
for (MachineFunction::iterator MBBi = Fn.begin(), MBBe = Fn.end();
AllocateBasicBlock();
}
- // Make sure the set of used physregs is closed under subreg operations.
- MRI->closePhysRegsUsed(*TRI);
-
// Add the clobber lists for all the instructions we skipped earlier.
for (SmallPtrSet<const MCInstrDesc*, 4>::const_iterator
I = SkippedInstrs.begin(), E = SkippedInstrs.end(); I != E; ++I)
- if (const unsigned *Defs = (*I)->getImplicitDefs())
+ if (const uint16_t *Defs = (*I)->getImplicitDefs())
while (*Defs)
MRI->setPhysRegUsed(*Defs++);
+ // All machine operands and other references to virtual registers have been
+ // replaced. Remove the virtual registers.
+ MRI->clearVirtRegs();
+
SkippedInstrs.clear();
StackSlotForVirtReg.clear();
LiveDbgValueMap.clear();