Also account for the spill code that would be inserted in live-through blocks with interference.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129030 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/RegAllocGreedy.cpp b/lib/CodeGen/RegAllocGreedy.cpp
index 66ef62b..7564c1d 100644
--- a/lib/CodeGen/RegAllocGreedy.cpp
+++ b/lib/CodeGen/RegAllocGreedy.cpp
@@ -170,7 +170,7 @@
void LRE_DidCloneVirtReg(unsigned, unsigned);
bool addSplitConstraints(unsigned, float&);
- float calcGlobalSplitCost(const BitVector&);
+ float calcGlobalSplitCost(unsigned, const BitVector&);
void splitAroundRegion(LiveInterval&, unsigned, const BitVector&,
SmallVectorImpl<LiveInterval*>&);
void calcGapWeights(unsigned, SmallVectorImpl<float>&);
@@ -520,7 +520,8 @@
/// pattern in LiveBundles. This cost should be added to the local cost of the
/// interference pattern in SplitConstraints.
///
-float RAGreedy::calcGlobalSplitCost(const BitVector &LiveBundles) {
+float RAGreedy::calcGlobalSplitCost(unsigned PhysReg,
+ const BitVector &LiveBundles) {
float GlobalCost = 0;
ArrayRef<SplitAnalysis::BlockInfo> UseBlocks = SA->getUseBlocks();
for (unsigned i = 0; i != UseBlocks.size(); ++i) {
@@ -538,14 +539,24 @@
GlobalCost += Ins * SpillPlacer->getBlockFrequency(BC.Number);
}
+ InterferenceCache::Cursor Intf(IntfCache, PhysReg);
ArrayRef<unsigned> ThroughBlocks = SA->getThroughBlocks();
SplitConstraints.resize(UseBlocks.size() + ThroughBlocks.size());
for (unsigned i = 0; i != ThroughBlocks.size(); ++i) {
unsigned Number = ThroughBlocks[i];
bool RegIn = LiveBundles[Bundles->getBundle(Number, 0)];
bool RegOut = LiveBundles[Bundles->getBundle(Number, 1)];
- if (RegIn != RegOut)
- GlobalCost += SpillPlacer->getBlockFrequency(Number);
+ if (!RegIn && !RegOut)
+ continue;
+ if (RegIn && RegOut) {
+ // We need double spill code if this block has interference.
+ Intf.moveToBlock(Number);
+ if (Intf.hasInterference())
+ GlobalCost += 2*SpillPlacer->getBlockFrequency(Number);
+ continue;
+ }
+ // live-in / stack-out or stack-in live-out.
+ GlobalCost += SpillPlacer->getBlockFrequency(Number);
}
return GlobalCost;
}
@@ -811,7 +822,7 @@
continue;
}
- Cost += calcGlobalSplitCost(LiveBundles);
+ Cost += calcGlobalSplitCost(PhysReg, LiveBundles);
DEBUG({
dbgs() << ", total = " << Cost << " with bundles";
for (int i = LiveBundles.find_first(); i>=0; i = LiveBundles.find_next(i))