#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/Debug.h"
+#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/Compiler.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <set>
#include <queue>
}
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.setPreservesCFG();
AU.addRequired<LiveIntervals>();
if (StrongPHIElim)
AU.addRequiredID(StrongPHIEliminationID);
}
}
if (Error)
- abort();
+ llvm_unreachable(0);
#endif
regUse_.clear();
regUseBackUp_.clear();
/// getFreePhysReg - return a free physical register for this virtual
/// register interval if we have one, otherwise return 0.
unsigned getFreePhysReg(LiveInterval* cur);
- unsigned getFreePhysReg(const TargetRegisterClass *RC,
+ unsigned getFreePhysReg(LiveInterval* cur,
+ const TargetRegisterClass *RC,
unsigned MaxInactiveCount,
SmallVector<unsigned, 256> &inactiveCounts,
bool SkipDGRegs);
/// different register classes or because the coalescer was overly
/// conservative.
unsigned RALinScan::attemptTrivialCoalescing(LiveInterval &cur, unsigned Reg) {
- if ((cur.preference && cur.preference == Reg) || !cur.containsOneValue())
+ unsigned Preference = vrm_->getRegAllocPref(cur.reg);
+ if ((Preference && Preference == Reg) || !cur.containsOneValue())
return Reg;
VNInfo *vni = cur.begin()->valno;
- if (!vni->def || vni->def == ~1U || vni->def == ~0U)
+ if (!vni->def || vni->isUnused() || !vni->isDefAccurate())
return Reg;
MachineInstr *CopyMI = li_->getInstructionFromIndex(vni->def);
unsigned SrcReg, DstReg, SrcSubReg, DstSubReg, PhysReg;
{
// linear scan algorithm
DOUT << "********** LINEAR SCAN **********\n";
- DOUT << "********** Function: " << mf_->getFunction()->getName() << '\n';
+ DEBUG(errs() << "********** Function: "
+ << mf_->getFunction()->getName() << '\n');
DEBUG(printIntervals("fixed", fixed_.begin(), fixed_.end()));
if (!isPhys && vrm_->getPreSplitReg(cur.reg))
continue;
- // A register defined by an implicit_def can be liveout the def BB and livein
- // to a use BB. Add it to the livein set of the use BB's.
- if (!isPhys && cur.empty()) {
- if (MachineInstr *DefMI = mri_->getVRegDef(cur.reg)) {
- assert(DefMI->getOpcode() == TargetInstrInfo::IMPLICIT_DEF);
- MachineBasicBlock *DefMBB = DefMI->getParent();
- SmallPtrSet<MachineBasicBlock*, 4> Seen;
- Seen.insert(DefMBB);
- for (MachineRegisterInfo::reg_iterator ri = mri_->reg_begin(cur.reg),
- re = mri_->reg_end(); ri != re; ++ri) {
- MachineInstr *UseMI = &*ri;
- MachineBasicBlock *UseMBB = UseMI->getParent();
- if (Seen.insert(UseMBB)) {
- assert(TargetRegisterInfo::isPhysicalRegister(Reg) &&
- "Adding a virtual register to livein set?");
- UseMBB->addLiveIn(Reg);
- }
- }
- }
- }
for (LiveInterval::Ranges::const_iterator I = cur.begin(), E = cur.end();
I != E; ++I) {
const LiveRange &LR = *I;
// register allocator had to spill other registers in its register class.
if (ls_->getNumIntervals() == 0)
return;
- if (!vrm_->FindUnusedRegisters(tri_, li_))
+ if (!vrm_->FindUnusedRegisters(li_))
return;
}
if (SI.hasAtLeastOneValue())
VNI = SI.getValNumInfo(0);
else
- VNI = SI.getNextValue(~0U, 0, ls_->getVNInfoAllocator());
+ VNI = SI.getNextValue(0, 0, false, ls_->getVNInfoAllocator());
LiveInterval &RI = li_->getInterval(cur->reg);
// FIXME: This may be overly conservative.
// This is an implicitly defined live interval, just assign any register.
const TargetRegisterClass *RC = mri_->getRegClass(cur->reg);
if (cur->empty()) {
- unsigned physReg = cur->preference;
+ unsigned physReg = vrm_->getRegAllocPref(cur->reg);
if (!physReg)
physReg = *RC->allocation_order_begin(*mf_);
DOUT << tri_->getName(physReg) << '\n';
// register class, then we should try to assign it the same register.
// This can happen when the move is from a larger register class to a smaller
// one, e.g. X86::mov32to32_. These move instructions are not coalescable.
- if (!cur->preference && cur->hasAtLeastOneValue()) {
+ if (!vrm_->getRegAllocPref(cur->reg) && cur->hasAtLeastOneValue()) {
VNInfo *vni = cur->begin()->valno;
- if (vni->def && vni->def != ~1U && vni->def != ~0U) {
+ if (vni->def && !vni->isUnused() && vni->isDefAccurate()) {
MachineInstr *CopyMI = li_->getInstructionFromIndex(vni->def);
unsigned SrcReg, DstReg, SrcSubReg, DstSubReg;
if (CopyMI &&
if (DstSubReg)
Reg = tri_->getMatchingSuperReg(Reg, DstSubReg, RC);
if (Reg && allocatableRegs_[Reg] && RC->contains(Reg))
- cur->preference = Reg;
+ mri_->setRegAllocationHint(cur->reg, 0, Reg);
}
}
}
if (LiveInterval *NextReloadLI = hasNextReloadInterval(cur)) {
// "Downgrade" physReg to try to keep physReg from being allocated until
// the next reload from the same SS is allocated.
- NextReloadLI->preference = physReg;
+ mri_->setRegAllocationHint(NextReloadLI->reg, 0, physReg);
DowngradeRegister(cur, physReg);
}
return;
// Find a register to spill.
float minWeight = HUGE_VALF;
- unsigned minReg = 0; /*cur->preference*/; // Try the pref register first.
+ unsigned minReg = 0;
bool Found = false;
std::vector<std::pair<unsigned,float> > RegsWeights;
DowngradedRegs.clear();
assignRegOrStackSlotAtInterval(cur);
} else {
- cerr << "Ran out of registers during register allocation!\n";
- exit(1);
+ llvm_report_error("Ran out of registers during register allocation!");
}
return;
}
// mark our rollback point.
std::vector<LiveInterval*> added;
while (!spillIs.empty()) {
- bool epicFail = false;
LiveInterval *sli = spillIs.back();
spillIs.pop_back();
DOUT << "\t\t\tspilling(a): " << *sli << '\n';
addStackInterval(sli, ls_, li_, mri_, *vrm_);
std::copy(newIs.begin(), newIs.end(), std::back_inserter(added));
spilled.insert(sli->reg);
-
- if (epicFail) {
- //abort();
- }
}
unsigned earliestStart = earliestStartInterval->beginNumber();
// It interval has a preference, it must be defined by a copy. Clear the
// preference now since the source interval allocation may have been
// undone as well.
- i->preference = 0;
+ mri_->setRegAllocationHint(i->reg, 0, 0);
else {
UpgradeRegister(ii->second);
}
}
}
-unsigned RALinScan::getFreePhysReg(const TargetRegisterClass *RC,
+unsigned RALinScan::getFreePhysReg(LiveInterval* cur,
+ const TargetRegisterClass *RC,
unsigned MaxInactiveCount,
SmallVector<unsigned, 256> &inactiveCounts,
bool SkipDGRegs) {
unsigned FreeReg = 0;
unsigned FreeRegInactiveCount = 0;
- TargetRegisterClass::iterator I = RC->allocation_order_begin(*mf_);
- TargetRegisterClass::iterator E = RC->allocation_order_end(*mf_);
+ std::pair<unsigned, unsigned> Hint = mri_->getRegAllocationHint(cur->reg);
+ // Resolve second part of the hint (if possible) given the current allocation.
+ unsigned physReg = Hint.second;
+ if (physReg &&
+ TargetRegisterInfo::isVirtualRegister(physReg) && vrm_->hasPhys(physReg))
+ physReg = vrm_->getPhys(physReg);
+
+ TargetRegisterClass::iterator I, E;
+ tie(I, E) = tri_->getAllocationOrder(RC, Hint.first, physReg, *mf_);
assert(I != E && "No allocatable register in this register class!");
// Scan for the first available register.
// return this register.
if (FreeReg == 0 || FreeRegInactiveCount == MaxInactiveCount)
return FreeReg;
-
+
// Continue scanning the registers, looking for the one with the highest
// inactive count. Alkis found that this reduced register pressure very
// slightly on X86 (in rev 1.94 of this file), though this should probably be
// If copy coalescer has assigned a "preferred" register, check if it's
// available first.
- if (cur->preference) {
- DOUT << "(preferred: " << tri_->getName(cur->preference) << ") ";
- if (isRegAvail(cur->preference) &&
- RC->contains(cur->preference))
- return cur->preference;
+ unsigned Preference = vrm_->getRegAllocPref(cur->reg);
+ if (Preference) {
+ DOUT << "(preferred: " << tri_->getName(Preference) << ") ";
+ if (isRegAvail(Preference) &&
+ RC->contains(Preference))
+ return Preference;
}
if (!DowngradedRegs.empty()) {
- unsigned FreeReg = getFreePhysReg(RC, MaxInactiveCount, inactiveCounts,
+ unsigned FreeReg = getFreePhysReg(cur, RC, MaxInactiveCount, inactiveCounts,
true);
if (FreeReg)
return FreeReg;
}
- return getFreePhysReg(RC, MaxInactiveCount, inactiveCounts, false);
+ return getFreePhysReg(cur, RC, MaxInactiveCount, inactiveCounts, false);
}
FunctionPass* llvm::createLinearScanRegisterAllocator() {
projects / oota-llvm.git / blobdiff