replica
/
hanchenye-llvm-project
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Only keep the global split candidates that work out. 

Some pysical registers create split solutions that would spill anywhere.
They should not even be considered in future multi-way global splits.

This does not affect code generation (yet).

llvm-svn: 135080
This commit is contained in:
Jakob Stoklund Olesen 2011-07-13 20:49:46 +00:00
parent ef67e7d623
commit 5fba5b8eb9
1 changed files with 15 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
llvm/lib/CodeGen/RegAllocGreedy.cpp
View File

@ -1243,16 +1243,18 @@ 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(IntfCache, 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;
if (!addSplitConstraints(GlobalCand[Cand].Intf, Cost)) {
if (!addSplitConstraints(Cand.Intf, Cost)) {
DEBUG(dbgs() << PrintReg(PhysReg, TRI) << "\tno positive bundles\n");
continue;
}
@ -1267,28 +1269,29 @@ unsigned RAGreedy::tryRegionSplit(LiveInterval &VirtReg, AllocationOrder &Order,
});
continue;
}
growRegion(GlobalCand[Cand]);
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]);
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)