Refine stack slot interval weight computation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52040 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index 053e4d2..37e3895 100644
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -972,7 +972,9 @@
const MachineLoopInfo *loopInfo,
unsigned &NewVReg, unsigned ImpUse, bool &HasDef, bool &HasUse,
std::map<unsigned,unsigned> &MBBVRegsMap,
- std::vector<LiveInterval*> &NewLIs) {
+ std::vector<LiveInterval*> &NewLIs, float &SSWeight) {
+ MachineBasicBlock *MBB = MI->getParent();
+ unsigned loopDepth = loopInfo->getLoopDepth(MBB);
bool CanFold = false;
RestartInstruction:
for (unsigned i = 0; i != MI->getNumOperands(); ++i) {
@@ -1041,7 +1043,14 @@
}
}
- if (TryFold) {
+ // Update stack slot spill weight if we are splitting.
+ float Weight = getSpillWeight(HasDef, HasUse, loopDepth);
+ if (!TrySplit)
+ SSWeight += Weight;
+
+ if (!TryFold)
+ CanFold = false;
+ else {
// Do not fold load / store here if we are splitting. We'll find an
// optimal point to insert a load / store later.
if (!TrySplit) {
@@ -1052,15 +1061,17 @@
HasUse = false;
HasDef = false;
CanFold = false;
- if (isRemoved(MI))
+ if (isRemoved(MI)) {
+ SSWeight -= Weight;
break;
+ }
goto RestartInstruction;
}
} else {
+ // We'll try to fold it later if it's profitable.
CanFold = canFoldMemoryOperand(MI, Ops, DefIsReMat);
}
- } else
- CanFold = false;
+ }
// Create a new virtual register for the spill interval.
bool CreatedNewVReg = false;
@@ -1195,7 +1206,7 @@
BitVector &RestoreMBBs,
std::map<unsigned, std::vector<SRInfo> > &RestoreIdxes,
std::map<unsigned,unsigned> &MBBVRegsMap,
- std::vector<LiveInterval*> &NewLIs) {
+ std::vector<LiveInterval*> &NewLIs, float &SSWeight) {
bool AllCanFold = true;
unsigned NewVReg = 0;
unsigned start = getBaseIndex(I->start);
@@ -1283,10 +1294,10 @@
bool HasDef = false;
bool HasUse = false;
bool CanFold = rewriteInstructionForSpills(li, I->valno, TrySplit,
- index, end, MI, ReMatOrigDefMI, ReMatDefMI,
- Slot, LdSlot, isLoad, isLoadSS, DefIsReMat,
- CanDelete, vrm, rc, ReMatIds, loopInfo, NewVReg,
- ImpUse, HasDef, HasUse, MBBVRegsMap, NewLIs);
+ index, end, MI, ReMatOrigDefMI, ReMatDefMI,
+ Slot, LdSlot, isLoad, isLoadSS, DefIsReMat,
+ CanDelete, vrm, rc, ReMatIds, loopInfo, NewVReg,
+ ImpUse, HasDef, HasUse, MBBVRegsMap, NewLIs, SSWeight);
if (!HasDef && !HasUse)
continue;
@@ -1445,7 +1456,8 @@
std::vector<LiveInterval*> LiveIntervals::
addIntervalsForSpills(const LiveInterval &li,
- const MachineLoopInfo *loopInfo, VirtRegMap &vrm) {
+ const MachineLoopInfo *loopInfo, VirtRegMap &vrm,
+ float &SSWeight) {
// Since this is called after the analysis is done we don't know if
// LiveVariables is available
lv_ = getAnalysisToUpdate<LiveVariables>();
@@ -1457,6 +1469,9 @@
li.print(DOUT, tri_);
DOUT << '\n';
+ // Spill slot weight.
+ SSWeight = 0.0f;
+
// Each bit specify whether it a spill is required in the MBB.
BitVector SpillMBBs(mf_->getNumBlockIDs());
std::map<unsigned, std::vector<SRInfo> > SpillIdxes;
@@ -1511,17 +1526,18 @@
Slot, LdSlot, isLoad, isLoadSS, DefIsReMat,
false, vrm, rc, ReMatIds, loopInfo,
SpillMBBs, SpillIdxes, RestoreMBBs, RestoreIdxes,
- MBBVRegsMap, NewLIs);
+ MBBVRegsMap, NewLIs, SSWeight);
} else {
rewriteInstructionsForSpills(li, false, I, NULL, 0,
Slot, 0, false, false, false,
false, vrm, rc, ReMatIds, loopInfo,
SpillMBBs, SpillIdxes, RestoreMBBs, RestoreIdxes,
- MBBVRegsMap, NewLIs);
+ MBBVRegsMap, NewLIs, SSWeight);
}
IsFirstRange = false;
}
+ SSWeight = 0.0f; // Already accounted for when split.
handleSpilledImpDefs(li, vrm, rc, NewLIs);
return NewLIs;
}
@@ -1587,7 +1603,7 @@
Slot, LdSlot, isLoad, isLoadSS, DefIsReMat,
CanDelete, vrm, rc, ReMatIds, loopInfo,
SpillMBBs, SpillIdxes, RestoreMBBs, RestoreIdxes,
- MBBVRegsMap, NewLIs);
+ MBBVRegsMap, NewLIs, SSWeight);
}
// Insert spills / restores if we are splitting.
@@ -1601,6 +1617,8 @@
if (NeedStackSlot) {
int Id = SpillMBBs.find_first();
while (Id != -1) {
+ MachineBasicBlock *MBB = mf_->getBlockNumbered(Id);
+ unsigned loopDepth = loopInfo->getLoopDepth(MBB);
std::vector<SRInfo> &spills = SpillIdxes[Id];
for (unsigned i = 0, e = spills.size(); i != e; ++i) {
int index = spills[i].index;
@@ -1657,6 +1675,10 @@
if (isKill)
AddedKill.insert(&nI);
}
+
+ // Update spill slot weight.
+ if (!isReMat)
+ SSWeight += getSpillWeight(true, false, loopDepth);
}
Id = SpillMBBs.find_next(Id);
}
@@ -1664,6 +1686,9 @@
int Id = RestoreMBBs.find_first();
while (Id != -1) {
+ MachineBasicBlock *MBB = mf_->getBlockNumbered(Id);
+ unsigned loopDepth = loopInfo->getLoopDepth(MBB);
+
std::vector<SRInfo> &restores = RestoreIdxes[Id];
for (unsigned i = 0, e = restores.size(); i != e; ++i) {
int index = restores[i].index;
@@ -1671,6 +1696,7 @@
continue;
unsigned VReg = restores[i].vreg;
LiveInterval &nI = getOrCreateInterval(VReg);
+ bool isReMat = vrm.isReMaterialized(VReg);
MachineInstr *MI = getInstructionFromIndex(index);
bool CanFold = false;
Ops.clear();
@@ -1694,7 +1720,7 @@
// Fold the load into the use if possible.
bool Folded = false;
if (CanFold && !Ops.empty()) {
- if (!vrm.isReMaterialized(VReg))
+ if (!isReMat)
Folded = tryFoldMemoryOperand(MI, vrm, NULL,index,Ops,true,Slot,VReg);
else {
MachineInstr *ReMatDefMI = vrm.getReMaterializedMI(VReg);
@@ -1722,6 +1748,10 @@
nI.removeRange(getLoadIndex(index), getUseIndex(index)+1);
else
vrm.addRestorePoint(VReg, MI);
+
+ // Update spill slot weight.
+ if (!isReMat)
+ SSWeight += getSpillWeight(false, true, loopDepth);
}
Id = RestoreMBBs.find_next(Id);
}
diff --git a/lib/CodeGen/RegAllocLinearScan.cpp b/lib/CodeGen/RegAllocLinearScan.cpp
index 8bfa868..d29f6da 100644
--- a/lib/CodeGen/RegAllocLinearScan.cpp
+++ b/lib/CodeGen/RegAllocLinearScan.cpp
@@ -515,11 +515,14 @@
/// addStackInterval - Create a LiveInterval for stack if the specified live
/// interval has been spilled.
static void addStackInterval(LiveInterval *cur, LiveStacks *ls_,
- LiveIntervals *li_, VirtRegMap &vrm_) {
+ LiveIntervals *li_, float &Weight,
+ VirtRegMap &vrm_) {
int SS = vrm_.getStackSlot(cur->reg);
if (SS == VirtRegMap::NO_STACK_SLOT)
return;
LiveInterval &SI = ls_->getOrCreateInterval(SS);
+ SI.weight += Weight;
+
VNInfo *VNI;
if (SI.getNumValNums())
VNI = SI.getValNumInfo(0);
@@ -529,7 +532,6 @@
LiveInterval &RI = li_->getInterval(cur->reg);
// FIXME: This may be overly conservative.
SI.MergeRangesInAsValue(RI, VNI);
- SI.weight += RI.weight;
}
/// assignRegOrStackSlotAtInterval - assign a register if one is available, or
@@ -743,9 +745,10 @@
// linearscan.
if (cur->weight != HUGE_VALF && cur->weight <= minWeight) {
DOUT << "\t\t\tspilling(c): " << *cur << '\n';
+ float SSWeight;
std::vector<LiveInterval*> added =
- li_->addIntervalsForSpills(*cur, loopInfo, *vrm_);
- addStackInterval(cur, ls_, li_, *vrm_);
+ li_->addIntervalsForSpills(*cur, loopInfo, *vrm_, SSWeight);
+ addStackInterval(cur, ls_, li_, SSWeight, *vrm_);
if (added.empty())
return; // Early exit if all spills were folded.
@@ -796,9 +799,10 @@
cur->overlapsFrom(*i->first, i->second)) {
DOUT << "\t\t\tspilling(a): " << *i->first << '\n';
earliestStart = std::min(earliestStart, i->first->beginNumber());
+ float SSWeight;
std::vector<LiveInterval*> newIs =
- li_->addIntervalsForSpills(*i->first, loopInfo, *vrm_);
- addStackInterval(i->first, ls_, li_, *vrm_);
+ li_->addIntervalsForSpills(*i->first, loopInfo, *vrm_, SSWeight);
+ addStackInterval(i->first, ls_, li_, SSWeight, *vrm_);
std::copy(newIs.begin(), newIs.end(), std::back_inserter(added));
spilled.insert(reg);
}
@@ -810,9 +814,10 @@
cur->overlapsFrom(*i->first, i->second-1)) {
DOUT << "\t\t\tspilling(i): " << *i->first << '\n';
earliestStart = std::min(earliestStart, i->first->beginNumber());
+ float SSWeight;
std::vector<LiveInterval*> newIs =
- li_->addIntervalsForSpills(*i->first, loopInfo, *vrm_);
- addStackInterval(i->first, ls_, li_, *vrm_);
+ li_->addIntervalsForSpills(*i->first, loopInfo, *vrm_, SSWeight);
+ addStackInterval(i->first, ls_, li_, SSWeight, *vrm_);
std::copy(newIs.begin(), newIs.end(), std::back_inserter(added));
spilled.insert(reg);
}