diff --git a/lib/CodeGen/InlineSpiller.cpp b/lib/CodeGen/InlineSpiller.cpp
index 1492566cfe5..5ac66105d89 100644
--- a/lib/CodeGen/InlineSpiller.cpp
+++ b/lib/CodeGen/InlineSpiller.cpp
@@ -113,9 +113,10 @@ bool InlineSpiller::split() {
splitAnalysis_.analyze(li_);
if (const MachineLoop *loop = splitAnalysis_.getBestSplitLoop()) {
- SplitEditor(splitAnalysis_, lis_, vrm_, *newIntervals_)
- .splitAroundLoop(loop);
- return true;
+ // We can split, but li_ may be left intact with fewer uses.
+ if (SplitEditor(splitAnalysis_, lis_, vrm_, *newIntervals_)
+ .splitAroundLoop(loop))
+ return true;
}
return false;
}
diff --git a/lib/CodeGen/SplitKit.cpp b/lib/CodeGen/SplitKit.cpp
index 9b0d73a4f23..e6a7b70c7d6 100644
--- a/lib/CodeGen/SplitKit.cpp
+++ b/lib/CodeGen/SplitKit.cpp
@@ -289,22 +289,18 @@ SplitEditor::SplitEditor(SplitAnalysis &sa, LiveIntervals &lis, VirtRegMap &vrm,
: sa_(sa), lis_(lis), vrm_(vrm),
mri_(vrm.getMachineFunction().getRegInfo()),
tii_(*vrm.getMachineFunction().getTarget().getInstrInfo()),
+ curli_(sa_.getCurLI()),
dupli_(0), openli_(0),
intervals_(intervals),
firstInterval(intervals_.size())
{
- const LiveInterval *curli = sa_.getCurLI();
- assert(curli && "SplitEditor created from empty SplitAnalysis");
+ assert(curli_ && "SplitEditor created from empty SplitAnalysis");
- // Make sure curli is assigned a stack slot, so all our intervals get the
- // same slot as curli.
- if (vrm_.getStackSlot(curli->reg) == VirtRegMap::NO_STACK_SLOT)
- vrm_.assignVirt2StackSlot(curli->reg);
+ // Make sure curli_ is assigned a stack slot, so all our intervals get the
+ // same slot as curli_.
+ if (vrm_.getStackSlot(curli_->reg) == VirtRegMap::NO_STACK_SLOT)
+ vrm_.assignVirt2StackSlot(curli_->reg);
- // Create an interval for dupli that is a copy of curli.
- dupli_ = createInterval();
- dupli_->Copy(*curli, &mri_, lis_.getVNInfoAllocator());
- DEBUG(dbgs() << "SplitEditor DupLI: " << *dupli_ << '\n');
}
LiveInterval *SplitEditor::createInterval() {
@@ -316,10 +312,20 @@ LiveInterval *SplitEditor::createInterval() {
return &Intv;
}
-VNInfo *SplitEditor::mapValue(VNInfo *dupliVNI) {
- VNInfo *&VNI = valueMap_[dupliVNI];
+LiveInterval *SplitEditor::getDupLI() {
+ if (!dupli_) {
+ // Create an interval for dupli that is a copy of curli.
+ dupli_ = createInterval();
+ dupli_->Copy(*curli_, &mri_, lis_.getVNInfoAllocator());
+ DEBUG(dbgs() << "SplitEditor DupLI: " << *dupli_ << '\n');
+ }
+ return dupli_;
+}
+
+VNInfo *SplitEditor::mapValue(const VNInfo *curliVNI) {
+ VNInfo *&VNI = valueMap_[curliVNI];
if (!VNI)
- VNI = openli_->createValueCopy(dupliVNI, lis_.getVNInfoAllocator());
+ VNI = openli_->createValueCopy(curliVNI, lis_.getVNInfoAllocator());
return VNI;
}
@@ -330,9 +336,8 @@ VNInfo *SplitEditor::mapValue(VNInfo *dupliVNI) {
VNInfo *SplitEditor::insertCopy(LiveInterval &LI,
MachineBasicBlock &MBB,
MachineBasicBlock::iterator I) {
- unsigned curli = sa_.getCurLI()->reg;
MachineInstr *MI = BuildMI(MBB, I, DebugLoc(), tii_.get(TargetOpcode::COPY),
- LI.reg).addReg(curli);
+ LI.reg).addReg(curli_->reg);
SlotIndex DefIdx = lis_.InsertMachineInstrInMaps(MI).getDefIndex();
return LI.getNextValue(DefIdx, MI, true, lis_.getVNInfoAllocator());
}
@@ -352,9 +357,9 @@ void SplitEditor::enterIntvAtEnd(MachineBasicBlock &A, MachineBasicBlock &B) {
assert(openli_ && "openIntv not called before enterIntvAtEnd");
SlotIndex EndA = lis_.getMBBEndIdx(&A);
- VNInfo *DupVNIA = dupli_->getVNInfoAt(EndA.getPrevIndex());
- if (!DupVNIA) {
- DEBUG(dbgs() << " ignoring enterIntvAtEnd, dupli not live out of BB#"
+ VNInfo *CurVNIA = curli_->getVNInfoAt(EndA.getPrevIndex());
+ if (!CurVNIA) {
+ DEBUG(dbgs() << " ignoring enterIntvAtEnd, curli not live out of BB#"
<< A.getNumber() << ".\n");
return;
}
@@ -370,9 +375,9 @@ void SplitEditor::enterIntvAtEnd(MachineBasicBlock &A, MachineBasicBlock &B) {
// Now look at the start of B.
SlotIndex StartB = lis_.getMBBStartIdx(&B);
SlotIndex EndB = lis_.getMBBEndIdx(&B);
- LiveRange *DupB = dupli_->getLiveRangeContaining(StartB);
- if (!DupB) {
- DEBUG(dbgs() << " enterIntvAtEnd: dupli not live in to BB#"
+ const LiveRange *CurB = curli_->getLiveRangeContaining(StartB);
+ if (!CurB) {
+ DEBUG(dbgs() << " enterIntvAtEnd: curli not live in to BB#"
<< B.getNumber() << ".\n");
return;
}
@@ -384,9 +389,9 @@ void SplitEditor::enterIntvAtEnd(MachineBasicBlock &A, MachineBasicBlock &B) {
lis_.getVNInfoAllocator());
VNIB->setIsPHIDef(true);
// Add a minimal range for the new value.
- openli_->addRange(LiveRange(VNIB->def, std::min(EndB, DupB->end), VNIB));
+ openli_->addRange(LiveRange(VNIB->def, std::min(EndB, CurB->end), VNIB));
- VNInfo *&mapVNI = valueMap_[DupB->valno];
+ VNInfo *&mapVNI = valueMap_[CurB->valno];
if (mapVNI) {
// Multiple copies - must create PHI value.
abort();
@@ -408,8 +413,8 @@ void SplitEditor::useIntv(const MachineBasicBlock &MBB) {
void SplitEditor::useIntv(SlotIndex Start, SlotIndex End) {
assert(openli_ && "openIntv not called before useIntv");
- // Map the dupli values from the interval into openli_
- LiveInterval::const_iterator B = dupli_->begin(), E = dupli_->end();
+ // Map the curli values from the interval into openli_
+ LiveInterval::const_iterator B = curli_->begin(), E = curli_->end();
LiveInterval::const_iterator I = std::lower_bound(B, E, Start);
if (I != B) {
@@ -435,27 +440,31 @@ void SplitEditor::leaveIntvAtTop(MachineBasicBlock &MBB) {
assert(openli_ && "openIntv not called before leaveIntvAtTop");
SlotIndex Start = lis_.getMBBStartIdx(&MBB);
- LiveRange *DupLR = dupli_->getLiveRangeContaining(Start);
+ const LiveRange *CurLR = curli_->getLiveRangeContaining(Start);
- // Is dupli even live-in to MBB?
- if (!DupLR) {
+ // Is curli even live-in to MBB?
+ if (!CurLR) {
DEBUG(dbgs() << " leaveIntvAtTop at " << Start << ": not live\n");
return;
}
- // Is dupli defined by PHI at the beginning of MBB?
- bool isPHIDef = DupLR->valno->isPHIDef() &&
- DupLR->valno->def.getBaseIndex() == Start;
+ // Is curli defined by PHI at the beginning of MBB?
+ bool isPHIDef = CurLR->valno->isPHIDef() &&
+ CurLR->valno->def.getBaseIndex() == Start;
- // If MBB is using a value of dupli that was defined outside the openli range,
+ // If MBB is using a value of curli that was defined outside the openli range,
// we don't want to copy it back here.
- if (!isPHIDef && !openli_->liveAt(DupLR->valno->def)) {
+ if (!isPHIDef && !openli_->liveAt(CurLR->valno->def)) {
DEBUG(dbgs() << " leaveIntvAtTop at " << Start
<< ": using external value\n");
liveThrough_ = true;
return;
}
+ // We are going to insert a back copy, so we must have a dupli_.
+ LiveRange *DupLR = getDupLI()->getLiveRangeContaining(Start);
+ assert(DupLR && "dupli not live into black, but curli is?");
+
// Insert the COPY instruction.
MachineInstr *MI = BuildMI(MBB, MBB.begin(), DebugLoc(),
tii_.get(TargetOpcode::COPY), dupli_->reg)
@@ -501,8 +510,6 @@ void SplitEditor::closeIntv() {
assert(openli_ && "openIntv not called before closeIntv");
DEBUG(dbgs() << " closeIntv cleaning up\n");
-
- DEBUG(dbgs() << " dup " << *dupli_ << '\n');
DEBUG(dbgs() << " open " << *openli_ << '\n');
if (liveThrough_) {
@@ -510,6 +517,7 @@ void SplitEditor::closeIntv() {
} else {
// live out with copies inserted, or killed by region. Either way we need to
// remove the overlapping region from dupli.
+ getDupLI();
for (LiveInterval::iterator I = openli_->begin(), E = openli_->end();
I != E; ++I) {
dupli_->removeRange(I->start, I->end);
@@ -567,7 +575,7 @@ void SplitEditor::rewrite() {
// Loop Splitting
//===----------------------------------------------------------------------===//
-void SplitEditor::splitAroundLoop(const MachineLoop *Loop) {
+bool SplitEditor::splitAroundLoop(const MachineLoop *Loop) {
SplitAnalysis::LoopBlocks Blocks;
sa_.getLoopBlocks(Loop, Blocks);
@@ -601,5 +609,6 @@ void SplitEditor::splitAroundLoop(const MachineLoop *Loop) {
// Done.
closeIntv();
rewrite();
+ return dupli_;
}
diff --git a/lib/CodeGen/SplitKit.h b/lib/CodeGen/SplitKit.h
index 6ded4f464c0..d5136877de6 100644
--- a/lib/CodeGen/SplitKit.h
+++ b/lib/CodeGen/SplitKit.h
@@ -121,8 +121,7 @@ public:
/// SplitEditor - Edit machine code and LiveIntervals for live range
/// splitting.
///
-/// - Create a SplitEditor from a SplitAnalysis. This will create a new
-/// LiveInterval, dupli, that is identical to SA.curli.
+/// - Create a SplitEditor from a SplitAnalysis.
/// - Start a new live interval with openIntv.
/// - Mark the places where the new interval is entered using enterIntv*
/// - Mark the ranges where the new interval is used with useIntv*
@@ -137,8 +136,12 @@ class SplitEditor {
MachineRegisterInfo &mri_;
const TargetInstrInfo &tii_;
- /// dupli_ - Created as a copy of sa_.curli_, ranges are carved out as new
- /// intervals get added through openIntv / closeIntv.
+ /// curli_ - The immutable interval we are currently splitting.
+ const LiveInterval *const curli_;
+
+ /// dupli_ - Created as a copy of curli_, ranges are carved out as new
+ /// intervals get added through openIntv / closeIntv. This is used to avoid
+ /// editing curli_.
LiveInterval *dupli_;
/// Currently open LiveInterval.
@@ -148,13 +151,16 @@ class SplitEditor {
/// register class and spill slot as curli.
LiveInterval *createInterval();
- /// valueMap_ - Map values in dupli to values in openIntv. These are direct 1-1
- /// mappings, and do not include values created by inserted copies.
- DenseMap<VNInfo*,VNInfo*> valueMap_;
+ /// getDupLI - Ensure dupli is created and return it.
+ LiveInterval *getDupLI();
- /// mapValue - Return the openIntv value that corresponds to the given dupli
- /// value.
- VNInfo *mapValue(VNInfo *dupliVNI);
+ /// valueMap_ - Map values in dupli to values in openIntv. These are direct 1-1
+ /// mappings, and do not include values created by inserted copies.
+ DenseMap<const VNInfo*, VNInfo*> valueMap_;
+
+ /// mapValue - Return the openIntv value that corresponds to the given curli
+ /// value.
+ VNInfo *mapValue(const VNInfo *curliVNI);
/// A dupli value is live through openIntv.
bool liveThrough_;
@@ -178,8 +184,8 @@ public:
SplitEditor(SplitAnalysis &SA, LiveIntervals&, VirtRegMap&,
std::vector<LiveInterval*> &newIntervals);
- /// getAnalysis - Get the corresponding analysis.
- SplitAnalysis &getAnalysis() { return sa_; }
+ /// getAnalysis - Get the corresponding analysis.
+ SplitAnalysis &getAnalysis() { return sa_; }
/// Create a new virtual register and live interval.
void openIntv();
@@ -210,8 +216,9 @@ public:
// ===--- High level methods ---===
/// splitAroundLoop - Split curli into a separate live interval inside
- /// the loop.
- void splitAroundLoop(const MachineLoop*);
+ /// the loop. Return true if curli has been completely replaced, false if
+ /// curli is still intact, and needs to be spilled or split further.
+ bool splitAroundLoop(const MachineLoop*);
};