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-rw-r--r--include/llvm/CodeGen/LiveIntervalAnalysis.h4
-rw-r--r--lib/CodeGen/LiveInterval.cpp2
-rw-r--r--lib/CodeGen/LiveIntervalAnalysis.cpp4
-rw-r--r--lib/CodeGen/RegAllocLinearScan.cpp15
-rw-r--r--lib/CodeGen/Spiller.cpp336
-rw-r--r--lib/CodeGen/Spiller.h4
6 files changed, 343 insertions, 22 deletions
diff --git a/include/llvm/CodeGen/LiveIntervalAnalysis.h b/include/llvm/CodeGen/LiveIntervalAnalysis.h
index 7a02d0fe99..a06e310c29 100644
--- a/include/llvm/CodeGen/LiveIntervalAnalysis.h
+++ b/include/llvm/CodeGen/LiveIntervalAnalysis.h
@@ -186,6 +186,10 @@ namespace llvm {
return indexes_->getMBBFromIndex(index);
}
+ SlotIndex getMBBTerminatorGap(const MachineBasicBlock *mbb) {
+ return indexes_->getTerminatorGap(mbb);
+ }
+
SlotIndex InsertMachineInstrInMaps(MachineInstr *MI) {
return indexes_->insertMachineInstrInMaps(MI);
}
diff --git a/lib/CodeGen/LiveInterval.cpp b/lib/CodeGen/LiveInterval.cpp
index 8d632cb5ca..cc286aa13d 100644
--- a/lib/CodeGen/LiveInterval.cpp
+++ b/lib/CodeGen/LiveInterval.cpp
@@ -847,7 +847,7 @@ void LiveInterval::print(raw_ostream &OS, const TargetRegisterInfo *TRI) const {
if (vni->isUnused()) {
OS << "x";
} else {
- if (!vni->isDefAccurate())
+ if (!vni->isDefAccurate() && !vni->isPHIDef())
OS << "?";
else
OS << vni->def;
diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index 35337efd50..c16ddc57ca 100644
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -401,7 +401,7 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock *mbb,
interval.removeRange(Start, End);
assert(interval.ranges.size() == 1 &&
"Newly discovered PHI interval has >1 ranges.");
- MachineBasicBlock *killMBB = getMBBFromIndex(interval.endIndex());
+ MachineBasicBlock *killMBB = getMBBFromIndex(VNI->def);
VNI->addKill(indexes_->getTerminatorGap(killMBB));
VNI->setHasPHIKill(true);
DEBUG({
@@ -412,7 +412,7 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock *mbb,
// Replace the interval with one of a NEW value number. Note that this
// value number isn't actually defined by an instruction, weird huh? :)
LiveRange LR(Start, End,
- interval.getNextValue(SlotIndex(getMBBStartIdx(mbb), true),
+ interval.getNextValue(SlotIndex(getMBBStartIdx(Killer->getParent()), true),
0, false, VNInfoAllocator));
LR.valno->setIsPHIDef(true);
DEBUG(errs() << " replace range with " << LR);
diff --git a/lib/CodeGen/RegAllocLinearScan.cpp b/lib/CodeGen/RegAllocLinearScan.cpp
index 4ff512932f..c1f587567e 100644
--- a/lib/CodeGen/RegAllocLinearScan.cpp
+++ b/lib/CodeGen/RegAllocLinearScan.cpp
@@ -1261,9 +1261,9 @@ void RALinScan::assignRegOrStackSlotAtInterval(LiveInterval* cur) {
// The earliest start of a Spilled interval indicates up to where
// in handled we need to roll back
+ assert(!spillIs.empty() && "No spill intervals?");
+ SlotIndex earliestStart = spillIs[0]->beginIndex();
- LiveInterval *earliestStartInterval = cur;
-
// Spill live intervals of virtual regs mapped to the physical register we
// want to clear (and its aliases). We only spill those that overlap with the
// current interval as the rest do not affect its allocation. we also keep
@@ -1274,19 +1274,16 @@ void RALinScan::assignRegOrStackSlotAtInterval(LiveInterval* cur) {
LiveInterval *sli = spillIs.back();
spillIs.pop_back();
DEBUG(errs() << "\t\t\tspilling(a): " << *sli << '\n');
- earliestStartInterval =
- (earliestStartInterval->beginIndex() < sli->beginIndex()) ?
- earliestStartInterval : sli;
+ if (sli->beginIndex() < earliestStart)
+ earliestStart = sli->beginIndex();
std::vector<LiveInterval*> newIs;
- newIs = spiller_->spill(sli, spillIs);
+ newIs = spiller_->spill(sli, spillIs, &earliestStart);
addStackInterval(sli, ls_, li_, mri_, *vrm_);
std::copy(newIs.begin(), newIs.end(), std::back_inserter(added));
spilled.insert(sli->reg);
}
- SlotIndex earliestStart = earliestStartInterval->beginIndex();
-
DEBUG(errs() << "\t\trolling back to: " << earliestStart << '\n');
// Scan handled in reverse order up to the earliest start of a
@@ -1295,7 +1292,7 @@ void RALinScan::assignRegOrStackSlotAtInterval(LiveInterval* cur) {
while (!handled_.empty()) {
LiveInterval* i = handled_.back();
// If this interval starts before t we are done.
- if (i->beginIndex() < earliestStart)
+ if (!i->empty() && i->beginIndex() < earliestStart)
break;
DEBUG(errs() << "\t\t\tundo changes for: " << *i << '\n');
handled_.pop_back();
diff --git a/lib/CodeGen/Spiller.cpp b/lib/CodeGen/Spiller.cpp
index 7466215565..bc246c14b7 100644
--- a/lib/CodeGen/Spiller.cpp
+++ b/lib/CodeGen/Spiller.cpp
@@ -20,22 +20,25 @@
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
+#include <set>
using namespace llvm;
namespace {
- enum SpillerName { trivial, standard };
+ enum SpillerName { trivial, standard, splitting };
}
static cl::opt<SpillerName>
spillerOpt("spiller",
cl::desc("Spiller to use: (default: standard)"),
cl::Prefix,
- cl::values(clEnumVal(trivial, "trivial spiller"),
- clEnumVal(standard, "default spiller"),
+ cl::values(clEnumVal(trivial, "trivial spiller"),
+ clEnumVal(standard, "default spiller"),
+ clEnumVal(splitting, "splitting spiller"),
clEnumValEnd),
cl::init(standard));
+// Spiller virtual destructor implementation.
Spiller::~Spiller() {}
namespace {
@@ -170,7 +173,8 @@ public:
: SpillerBase(mf, lis, vrm) {}
std::vector<LiveInterval*> spill(LiveInterval *li,
- SmallVectorImpl<LiveInterval*> &spillIs) {
+ SmallVectorImpl<LiveInterval*> &spillIs,
+ SlotIndex*) {
// Ignore spillIs - we don't use it.
return trivialSpillEverywhere(li);
}
@@ -179,23 +183,336 @@ public:
/// Falls back on LiveIntervals::addIntervalsForSpills.
class StandardSpiller : public Spiller {
-private:
+protected:
LiveIntervals *lis;
const MachineLoopInfo *loopInfo;
VirtRegMap *vrm;
public:
- StandardSpiller(MachineFunction *mf, LiveIntervals *lis,
- const MachineLoopInfo *loopInfo, VirtRegMap *vrm)
+ StandardSpiller(LiveIntervals *lis, const MachineLoopInfo *loopInfo,
+ VirtRegMap *vrm)
: lis(lis), loopInfo(loopInfo), vrm(vrm) {}
/// Falls back on LiveIntervals::addIntervalsForSpills.
std::vector<LiveInterval*> spill(LiveInterval *li,
- SmallVectorImpl<LiveInterval*> &spillIs) {
+ SmallVectorImpl<LiveInterval*> &spillIs,
+ SlotIndex*) {
return lis->addIntervalsForSpills(*li, spillIs, loopInfo, *vrm);
}
};
+/// When a call to spill is placed this spiller will first try to break the
+/// interval up into its component values (one new interval per value).
+/// If this fails, or if a call is placed to spill a previously split interval
+/// then the spiller falls back on the standard spilling mechanism.
+class SplittingSpiller : public StandardSpiller {
+public:
+ SplittingSpiller(MachineFunction *mf, LiveIntervals *lis,
+ const MachineLoopInfo *loopInfo, VirtRegMap *vrm)
+ : StandardSpiller(lis, loopInfo, vrm) {
+
+ mri = &mf->getRegInfo();
+ tii = mf->getTarget().getInstrInfo();
+ tri = mf->getTarget().getRegisterInfo();
+ }
+
+ std::vector<LiveInterval*> spill(LiveInterval *li,
+ SmallVectorImpl<LiveInterval*> &spillIs,
+ SlotIndex *earliestStart) {
+
+ if (worthTryingToSplit(li)) {
+ return tryVNISplit(li, earliestStart);
+ }
+ // else
+ return StandardSpiller::spill(li, spillIs, earliestStart);
+ }
+
+private:
+
+ MachineRegisterInfo *mri;
+ const TargetInstrInfo *tii;
+ const TargetRegisterInfo *tri;
+ DenseSet<LiveInterval*> alreadySplit;
+
+ bool worthTryingToSplit(LiveInterval *li) const {
+ return (!alreadySplit.count(li) && li->getNumValNums() > 1);
+ }
+
+ /// Try to break a LiveInterval into its component values.
+ std::vector<LiveInterval*> tryVNISplit(LiveInterval *li,
+ SlotIndex *earliestStart) {
+
+ DEBUG(errs() << "Trying VNI split of %reg" << *li << "\n");
+
+ std::vector<LiveInterval*> added;
+ SmallVector<VNInfo*, 4> vnis;
+
+ std::copy(li->vni_begin(), li->vni_end(), std::back_inserter(vnis));
+
+ for (SmallVectorImpl<VNInfo*>::iterator vniItr = vnis.begin(),
+ vniEnd = vnis.end(); vniItr != vniEnd; ++vniItr) {
+ VNInfo *vni = *vniItr;
+
+ // Skip unused VNIs, or VNIs with no kills.
+ if (vni->isUnused() || vni->kills.empty())
+ continue;
+
+ DEBUG(errs() << " Extracted Val #" << vni->id << " as ");
+ LiveInterval *splitInterval = extractVNI(li, vni);
+
+ if (splitInterval != 0) {
+ DEBUG(errs() << *splitInterval << "\n");
+ added.push_back(splitInterval);
+ alreadySplit.insert(splitInterval);
+ if (earliestStart != 0) {
+ if (splitInterval->beginIndex() < *earliestStart)
+ *earliestStart = splitInterval->beginIndex();
+ }
+ } else {
+ DEBUG(errs() << "0\n");
+ }
+ }
+
+ DEBUG(errs() << "Original LI: " << *li << "\n");
+
+ // If there original interval still contains some live ranges
+ // add it to added and alreadySplit.
+ if (!li->empty()) {
+ added.push_back(li);
+ alreadySplit.insert(li);
+ if (earliestStart != 0) {
+ if (li->beginIndex() < *earliestStart)
+ *earliestStart = li->beginIndex();
+ }
+ }
+
+ return added;
+ }
+
+ /// Extract the given value number from the interval.
+ LiveInterval* extractVNI(LiveInterval *li, VNInfo *vni) const {
+ assert(vni->isDefAccurate() || vni->isPHIDef());
+ assert(!vni->kills.empty());
+
+ // Create a new vreg and live interval, copy VNI kills & ranges over.
+ const TargetRegisterClass *trc = mri->getRegClass(li->reg);
+ unsigned newVReg = mri->createVirtualRegister(trc);
+ vrm->grow();
+ LiveInterval *newLI = &lis->getOrCreateInterval(newVReg);
+ VNInfo *newVNI = newLI->createValueCopy(vni, lis->getVNInfoAllocator());
+
+ // Start by copying all live ranges in the VN to the new interval.
+ for (LiveInterval::iterator rItr = li->begin(), rEnd = li->end();
+ rItr != rEnd; ++rItr) {
+ if (rItr->valno == vni) {
+ newLI->addRange(LiveRange(rItr->start, rItr->end, newVNI));
+ }
+ }
+
+ // Erase the old VNI & ranges.
+ li->removeValNo(vni);
+
+ // Collect all current uses of the register belonging to the given VNI.
+ // We'll use this to rename the register after we've dealt with the def.
+ std::set<MachineInstr*> uses;
+ for (MachineRegisterInfo::use_iterator
+ useItr = mri->use_begin(li->reg), useEnd = mri->use_end();
+ useItr != useEnd; ++useItr) {
+ uses.insert(&*useItr);
+ }
+
+ // Process the def instruction for this VNI.
+ if (newVNI->isPHIDef()) {
+ // Insert a copy at the start of the MBB. The range proceeding the
+ // copy will be attached to the original LiveInterval.
+ MachineBasicBlock *defMBB = lis->getMBBFromIndex(newVNI->def);
+ tii->copyRegToReg(*defMBB, defMBB->begin(), newVReg, li->reg, trc, trc);
+ MachineInstr *copyMI = defMBB->begin();
+ copyMI->addRegisterKilled(li->reg, tri);
+ SlotIndex copyIdx = lis->InsertMachineInstrInMaps(copyMI);
+ VNInfo *phiDefVNI = li->getNextValue(lis->getMBBStartIdx(defMBB),
+ 0, false, lis->getVNInfoAllocator());
+ phiDefVNI->setIsPHIDef(true);
+ phiDefVNI->addKill(copyIdx.getDefIndex());
+ li->addRange(LiveRange(phiDefVNI->def, copyIdx.getDefIndex(), phiDefVNI));
+ LiveRange *oldPHIDefRange =
+ newLI->getLiveRangeContaining(lis->getMBBStartIdx(defMBB));
+
+ // If the old phi def starts in the middle of the range chop it up.
+ if (oldPHIDefRange->start < lis->getMBBStartIdx(defMBB)) {
+ LiveRange oldPHIDefRange2(copyIdx.getDefIndex(), oldPHIDefRange->end,
+ oldPHIDefRange->valno);
+ oldPHIDefRange->end = lis->getMBBStartIdx(defMBB);
+ newLI->addRange(oldPHIDefRange2);
+ } else if (oldPHIDefRange->start == lis->getMBBStartIdx(defMBB)) {
+ // Otherwise if it's at the start of the range just trim it.
+ oldPHIDefRange->start = copyIdx.getDefIndex();
+ } else {
+ assert(false && "PHI def range doesn't cover PHI def?");
+ }
+
+ newVNI->def = copyIdx.getDefIndex();
+ newVNI->setCopy(copyMI);
+ newVNI->setIsPHIDef(false); // not a PHI def anymore.
+ newVNI->setIsDefAccurate(true);
+ } else {
+ // non-PHI def. Rename the def. If it's two-addr that means renaming the use
+ // and inserting a new copy too.
+ MachineInstr *defInst = lis->getInstructionFromIndex(newVNI->def);
+ // We'll rename this now, so we can remove it from uses.
+ uses.erase(defInst);
+ unsigned defOpIdx = defInst->findRegisterDefOperandIdx(li->reg);
+ bool isTwoAddr = defInst->isRegTiedToUseOperand(defOpIdx),
+ twoAddrUseIsUndef = false;
+
+ for (unsigned i = 0; i < defInst->getNumOperands(); ++i) {
+ MachineOperand &mo = defInst->getOperand(i);
+ if (mo.isReg() && (mo.isDef() || isTwoAddr) && (mo.getReg()==li->reg)) {
+ mo.setReg(newVReg);
+ if (isTwoAddr && mo.isUse() && mo.isUndef())
+ twoAddrUseIsUndef = true;
+ }
+ }
+
+ SlotIndex defIdx = lis->getInstructionIndex(defInst);
+ newVNI->def = defIdx.getDefIndex();
+
+ if (isTwoAddr && !twoAddrUseIsUndef) {
+ MachineBasicBlock *defMBB = defInst->getParent();
+ tii->copyRegToReg(*defMBB, defInst, newVReg, li->reg, trc, trc);
+ MachineInstr *copyMI = prior(MachineBasicBlock::iterator(defInst));
+ SlotIndex copyIdx = lis->InsertMachineInstrInMaps(copyMI);
+ copyMI->addRegisterKilled(li->reg, tri);
+ LiveRange *origUseRange =
+ li->getLiveRangeContaining(newVNI->def.getUseIndex());
+ VNInfo *origUseVNI = origUseRange->valno;
+ origUseRange->end = copyIdx.getDefIndex();
+ bool updatedKills = false;
+ for (unsigned k = 0; k < origUseVNI->kills.size(); ++k) {
+ if (origUseVNI->kills[k] == defIdx.getDefIndex()) {
+ origUseVNI->kills[k] = copyIdx.getDefIndex();
+ updatedKills = true;
+ break;
+ }
+ }
+ assert(updatedKills && "Failed to update VNI kill list.");
+ VNInfo *copyVNI = newLI->getNextValue(copyIdx.getDefIndex(), copyMI,
+ true, lis->getVNInfoAllocator());
+ copyVNI->addKill(defIdx.getDefIndex());
+ LiveRange copyRange(copyIdx.getDefIndex(),defIdx.getDefIndex(),copyVNI);
+ newLI->addRange(copyRange);
+ }
+ }
+
+ for (std::set<MachineInstr*>::iterator
+ usesItr = uses.begin(), usesEnd = uses.end();
+ usesItr != usesEnd; ++usesItr) {
+ MachineInstr *useInst = *usesItr;
+ SlotIndex useIdx = lis->getInstructionIndex(useInst);
+ LiveRange *useRange =
+ newLI->getLiveRangeContaining(useIdx.getUseIndex());
+
+ // If this use doesn't belong to the new interval skip it.
+ if (useRange == 0)
+ continue;
+
+ // This use doesn't belong to the VNI, skip it.
+ if (useRange->valno != newVNI)
+ continue;
+
+ // Check if this instr is two address.
+ unsigned useOpIdx = useInst->findRegisterUseOperandIdx(li->reg);
+ bool isTwoAddress = useInst->isRegTiedToDefOperand(useOpIdx);
+
+ // Rename uses (and defs for two-address instrs).
+ for (unsigned i = 0; i < useInst->getNumOperands(); ++i) {
+ MachineOperand &mo = useInst->getOperand(i);
+ if (mo.isReg() && (mo.isUse() || isTwoAddress) &&
+ (mo.getReg() == li->reg)) {
+ mo.setReg(newVReg);
+ }
+ }
+
+ // If this is a two address instruction we've got some extra work to do.
+ if (isTwoAddress) {
+ // We modified the def operand, so we need to copy back to the original
+ // reg.
+ MachineBasicBlock *useMBB = useInst->getParent();
+ MachineBasicBlock::iterator useItr(useInst);
+ tii->copyRegToReg(*useMBB, next(useItr), li->reg, newVReg, trc, trc);
+ MachineInstr *copyMI = next(useItr);
+ copyMI->addRegisterKilled(newVReg, tri);
+ SlotIndex copyIdx = lis->InsertMachineInstrInMaps(copyMI);
+
+ // Change the old two-address defined range & vni to start at
+ // (and be defined by) the copy.
+ LiveRange *origDefRange =
+ li->getLiveRangeContaining(useIdx.getDefIndex());
+ origDefRange->start = copyIdx.getDefIndex();
+ origDefRange->valno->def = copyIdx.getDefIndex();
+ origDefRange->valno->setCopy(copyMI);
+
+ // Insert a new range & vni for the two-address-to-copy value. This
+ // will be attached to the new live interval.
+ VNInfo *copyVNI =
+ newLI->getNextValue(useIdx.getDefIndex(), 0, true,
+ lis->getVNInfoAllocator());
+ copyVNI->addKill(copyIdx.getDefIndex());
+ LiveRange copyRange(useIdx.getDefIndex(),copyIdx.getDefIndex(),copyVNI);
+ newLI->addRange(copyRange);
+ }
+ }
+
+ // Iterate over any PHI kills - we'll need to insert new copies for them.
+ for (VNInfo::KillSet::iterator
+ killItr = newVNI->kills.begin(), killEnd = newVNI->kills.end();
+ killItr != killEnd; ++killItr) {
+ SlotIndex killIdx(*killItr);
+ if (killItr->isPHI()) {
+ MachineBasicBlock *killMBB = lis->getMBBFromIndex(killIdx);
+ LiveRange *oldKillRange =
+ newLI->getLiveRangeContaining(killIdx);
+
+ assert(oldKillRange != 0 && "No kill range?");
+
+ tii->copyRegToReg(*killMBB, killMBB->getFirstTerminator(),
+ li->reg, newVReg, trc, trc);
+ MachineInstr *copyMI = prior(killMBB->getFirstTerminator());
+ copyMI->addRegisterKilled(newVReg, tri);
+ SlotIndex copyIdx = lis->InsertMachineInstrInMaps(copyMI);
+
+ // Save the current end. We may need it to add a new range if the
+ // current range runs of the end of the MBB.
+ SlotIndex newKillRangeEnd = oldKillRange->end;
+ oldKillRange->end = copyIdx.getDefIndex();
+
+ if (newKillRangeEnd != lis->getMBBEndIdx(killMBB).getNextSlot()) {
+ assert(newKillRangeEnd > lis->getMBBEndIdx(killMBB).getNextSlot() &&
+ "PHI kill range doesn't reach kill-block end. Not sane.");
+ newLI->addRange(LiveRange(lis->getMBBEndIdx(killMBB).getNextSlot(),
+ newKillRangeEnd, newVNI));
+ }
+
+ *killItr = oldKillRange->end;
+ VNInfo *newKillVNI = li->getNextValue(copyIdx.getDefIndex(),
+ copyMI, true,
+ lis->getVNInfoAllocator());
+ newKillVNI->addKill(lis->getMBBTerminatorGap(killMBB));
+ newKillVNI->setHasPHIKill(true);
+ li->addRange(LiveRange(copyIdx.getDefIndex(),
+ lis->getMBBEndIdx(killMBB).getNextSlot(),
+ newKillVNI));
+ }
+
+ }
+
+ newVNI->setHasPHIKill(false);
+
+ return newLI;
+ }
+
+};
+
}
llvm::Spiller* llvm::createSpiller(MachineFunction *mf, LiveIntervals *lis,
@@ -203,7 +520,8 @@ llvm::Spiller* llvm::createSpiller(MachineFunction *mf, LiveIntervals *lis,
VirtRegMap *vrm) {
switch (spillerOpt) {
case trivial: return new TrivialSpiller(mf, lis, vrm); break;
- case standard: return new StandardSpiller(mf, lis, loopInfo, vrm); break;
+ case standard: return new StandardSpiller(lis, loopInfo, vrm); break;
+ case splitting: return new SplittingSpiller(mf, lis, loopInfo, vrm); break;
default: llvm_unreachable("Unreachable!"); break;
}
}
diff --git a/lib/CodeGen/Spiller.h b/lib/CodeGen/Spiller.h
index c6bd9857db..dda52e871f 100644
--- a/lib/CodeGen/Spiller.h
+++ b/lib/CodeGen/Spiller.h
@@ -21,6 +21,7 @@ namespace llvm {
class MachineFunction;
class MachineInstr;
class MachineLoopInfo;
+ class SlotIndex;
class VirtRegMap;
class VNInfo;
@@ -35,7 +36,8 @@ namespace llvm {
/// Spill the given live range. The method used will depend on the Spiller
/// implementation selected.
virtual std::vector<LiveInterval*> spill(LiveInterval *li,
- SmallVectorImpl<LiveInterval*> &spillIs) = 0;
+ SmallVectorImpl<LiveInterval*> &spillIs,
+ SlotIndex *earliestIndex = 0) = 0;
};
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2025-06-24 15:29:03 +0000