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-rw-r--r--lib/CodeGen/InterferenceCache.h12
-rw-r--r--lib/CodeGen/RegAllocGreedy.cpp55
2 files changed, 39 insertions, 28 deletions
diff --git a/lib/CodeGen/InterferenceCache.h b/lib/CodeGen/InterferenceCache.h
index 6c36fa4021..6434b3a788 100644
--- a/lib/CodeGen/InterferenceCache.h
+++ b/lib/CodeGen/InterferenceCache.h
@@ -127,10 +127,14 @@ public:
Entry *CacheEntry;
BlockInterference *Current;
public:
- /// Cursor - Create a cursor for the interference allocated to PhysReg and
- /// all its aliases.
- Cursor(InterferenceCache &Cache, unsigned PhysReg)
- : CacheEntry(Cache.get(PhysReg)), Current(0) {}
+ /// Cursor - Create a dangling cursor.
+ Cursor() : CacheEntry(0), Current(0) {}
+
+ /// setPhysReg - Point this cursor to PhysReg's interference.
+ void setPhysReg(InterferenceCache &Cache, unsigned PhysReg) {
+ CacheEntry = Cache.get(PhysReg);
+ Current = 0;
+ }
/// moveTo - Move cursor to basic block MBBNum.
void moveToBlock(unsigned MBBNum) {
diff --git a/lib/CodeGen/RegAllocGreedy.cpp b/lib/CodeGen/RegAllocGreedy.cpp
index d79573c205..4728a050b1 100644
--- a/lib/CodeGen/RegAllocGreedy.cpp
+++ b/lib/CodeGen/RegAllocGreedy.cpp
@@ -160,11 +160,13 @@ class RAGreedy : public MachineFunctionPass,
/// Global live range splitting candidate info.
struct GlobalSplitCandidate {
unsigned PhysReg;
+ InterferenceCache::Cursor Intf;
BitVector LiveBundles;
SmallVector<unsigned, 8> ActiveBlocks;
- void reset(unsigned Reg) {
+ void reset(InterferenceCache &Cache, unsigned Reg) {
PhysReg = Reg;
+ Intf.setPhysReg(Cache, Reg);
LiveBundles.clear();
ActiveBlocks.clear();
}
@@ -206,8 +208,8 @@ private:
float calcSpillCost();
bool addSplitConstraints(InterferenceCache::Cursor, float&);
void addThroughConstraints(InterferenceCache::Cursor, ArrayRef<unsigned>);
- void growRegion(GlobalSplitCandidate &Cand, InterferenceCache::Cursor);
- float calcGlobalSplitCost(GlobalSplitCandidate&, InterferenceCache::Cursor);
+ void growRegion(GlobalSplitCandidate &Cand);
+ float calcGlobalSplitCost(GlobalSplitCandidate&);
void splitAroundRegion(LiveInterval&, GlobalSplitCandidate&,
SmallVectorImpl<LiveInterval*>&);
void calcGapWeights(unsigned, SmallVectorImpl<float>&);
@@ -720,8 +722,7 @@ void RAGreedy::addThroughConstraints(InterferenceCache::Cursor Intf,
SpillPlacer->addLinks(ArrayRef<unsigned>(TBS, T));
}
-void RAGreedy::growRegion(GlobalSplitCandidate &Cand,
- InterferenceCache::Cursor Intf) {
+void RAGreedy::growRegion(GlobalSplitCandidate &Cand) {
// Keep track of through blocks that have not been added to SpillPlacer.
BitVector Todo = SA->getThroughBlocks();
SmallVectorImpl<unsigned> &ActiveBlocks = Cand.ActiveBlocks;
@@ -753,7 +754,7 @@ void RAGreedy::growRegion(GlobalSplitCandidate &Cand,
// Any new blocks to add?
if (ActiveBlocks.size() == AddedTo)
break;
- addThroughConstraints(Intf,
+ addThroughConstraints(Cand.Intf,
ArrayRef<unsigned>(ActiveBlocks).slice(AddedTo));
AddedTo = ActiveBlocks.size();
@@ -794,8 +795,7 @@ float RAGreedy::calcSpillCost() {
/// pattern in LiveBundles. This cost should be added to the local cost of the
/// interference pattern in SplitConstraints.
///
-float RAGreedy::calcGlobalSplitCost(GlobalSplitCandidate &Cand,
- InterferenceCache::Cursor Intf) {
+float RAGreedy::calcGlobalSplitCost(GlobalSplitCandidate &Cand) {
float GlobalCost = 0;
const BitVector &LiveBundles = Cand.LiveBundles;
ArrayRef<SplitAnalysis::BlockInfo> UseBlocks = SA->getUseBlocks();
@@ -822,8 +822,8 @@ float RAGreedy::calcGlobalSplitCost(GlobalSplitCandidate &Cand,
continue;
if (RegIn && RegOut) {
// We need double spill code if this block has interference.
- Intf.moveToBlock(Number);
- if (Intf.hasInterference())
+ Cand.Intf.moveToBlock(Number);
+ if (Cand.Intf.hasInterference())
GlobalCost += 2*SpillPlacer->getBlockFrequency(Number);
continue;
}
@@ -853,7 +853,12 @@ void RAGreedy::splitAroundRegion(LiveInterval &VirtReg,
dbgs() << ".\n";
});
- InterferenceCache::Cursor Intf(IntfCache, Cand.PhysReg);
+ InterferenceCache::Cursor &Intf = Cand.Intf;
+
+ // FIXME: We need cache reference counts to guarantee that Intf hasn't been
+ // clobbered.
+ Intf.setPhysReg(IntfCache, Cand.PhysReg);
+
LiveRangeEdit LREdit(VirtReg, NewVRegs, this);
SE->reset(LREdit);
@@ -1243,17 +1248,18 @@ unsigned RAGreedy::tryRegionSplit(LiveInterval &VirtReg, AllocationOrder &Order,
DEBUG(dbgs() << "Cost of isolating all blocks = " << BestCost << '\n');
const unsigned NoCand = ~0u;
unsigned BestCand = NoCand;
+ unsigned NumCands = 0;
Order.rewind();
- for (unsigned Cand = 0; unsigned PhysReg = Order.next(); ++Cand) {
- if (GlobalCand.size() <= Cand)
- GlobalCand.resize(Cand+1);
- GlobalCand[Cand].reset(PhysReg);
+ while (unsigned PhysReg = Order.next()) {
+ if (GlobalCand.size() <= NumCands)
+ GlobalCand.resize(NumCands+1);
+ GlobalSplitCandidate &Cand = GlobalCand[NumCands];
+ Cand.reset(IntfCache, PhysReg);
- SpillPlacer->prepare(GlobalCand[Cand].LiveBundles);
+ SpillPlacer->prepare(Cand.LiveBundles);
float Cost;
- InterferenceCache::Cursor Intf(IntfCache, PhysReg);
- if (!addSplitConstraints(Intf, Cost)) {
+ if (!addSplitConstraints(Cand.Intf, Cost)) {
DEBUG(dbgs() << PrintReg(PhysReg, TRI) << "\tno positive bundles\n");
continue;
}
@@ -1268,28 +1274,29 @@ unsigned RAGreedy::tryRegionSplit(LiveInterval &VirtReg, AllocationOrder &Order,
});
continue;
}
- growRegion(GlobalCand[Cand], Intf);
+ growRegion(Cand);
SpillPlacer->finish();
// No live bundles, defer to splitSingleBlocks().
- if (!GlobalCand[Cand].LiveBundles.any()) {
+ if (!Cand.LiveBundles.any()) {
DEBUG(dbgs() << " no bundles.\n");
continue;
}
- Cost += calcGlobalSplitCost(GlobalCand[Cand], Intf);
+ Cost += calcGlobalSplitCost(Cand);
DEBUG({
dbgs() << ", total = " << Cost << " with bundles";
- for (int i = GlobalCand[Cand].LiveBundles.find_first(); i>=0;
- i = GlobalCand[Cand].LiveBundles.find_next(i))
+ for (int i = Cand.LiveBundles.find_first(); i>=0;
+ i = Cand.LiveBundles.find_next(i))
dbgs() << " EB#" << i;
dbgs() << ".\n";
});
if (Cost < BestCost) {
- BestCand = Cand;
+ BestCand = NumCands;
BestCost = Hysteresis * Cost; // Prevent rounding effects.
}
+ ++NumCands;
}
if (BestCand == NoCand)
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2025-04-28 16:07:15 +0000