Register Allocator: refactoring (no functionality change).

Factor out two functions calculateRegionSplitCost and doRegionSplit
from tryRegionSplit. These two functions will be used in coming patches.

rdar://16162005


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204684 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Manman Ren 2014-03-24 23:23:42 +00:00
parent 0f53443d82
commit 66124f9e89

View File

@ -306,6 +306,15 @@ private:
SmallVectorImpl<unsigned>&, unsigned = ~0u);
unsigned tryRegionSplit(LiveInterval&, AllocationOrder&,
SmallVectorImpl<unsigned>&);
/// Calculate cost of region splitting.
unsigned calculateRegionSplitCost(LiveInterval &VirtReg,
AllocationOrder &Order,
BlockFrequency &BestCost,
unsigned &NumCands);
/// Perform region splitting.
unsigned doRegionSplit(LiveInterval &VirtReg, unsigned BestCand,
bool HasCompact,
SmallVectorImpl<unsigned> &NewVRegs);
unsigned tryBlockSplit(LiveInterval&, AllocationOrder&,
SmallVectorImpl<unsigned>&);
unsigned tryInstructionSplit(LiveInterval&, AllocationOrder&,
@ -1231,9 +1240,7 @@ void RAGreedy::splitAroundRegion(LiveRangeEdit &LREdit,
unsigned RAGreedy::tryRegionSplit(LiveInterval &VirtReg, AllocationOrder &Order,
SmallVectorImpl<unsigned> &NewVRegs) {
unsigned NumCands = 0;
unsigned BestCand = NoCand;
BlockFrequency BestCost;
SmallVector<unsigned, 8> UsedCands;
// Check if we can split this live range around a compact region.
bool HasCompact = calcCompactRegion(GlobalCand.front());
@ -1249,6 +1256,21 @@ unsigned RAGreedy::tryRegionSplit(LiveInterval &VirtReg, AllocationOrder &Order,
MBFI->printBlockFreq(dbgs(), BestCost) << '\n');
}
unsigned BestCand =
calculateRegionSplitCost(VirtReg, Order, BestCost, NumCands);
// No solutions found, fall back to single block splitting.
if (!HasCompact && BestCand == NoCand)
return 0;
return doRegionSplit(VirtReg, BestCand, HasCompact, NewVRegs);
}
unsigned RAGreedy::calculateRegionSplitCost(LiveInterval &VirtReg,
AllocationOrder &Order,
BlockFrequency &BestCost,
unsigned &NumCands) {
unsigned BestCand = NoCand;
Order.rewind();
while (unsigned PhysReg = Order.next()) {
// Discard bad candidates before we run out of interference cache cursors.
@ -1317,11 +1339,13 @@ unsigned RAGreedy::tryRegionSplit(LiveInterval &VirtReg, AllocationOrder &Order,
}
++NumCands;
}
return BestCand;
}
// No solutions found, fall back to single block splitting.
if (!HasCompact && BestCand == NoCand)
return 0;
unsigned RAGreedy::doRegionSplit(LiveInterval &VirtReg, unsigned BestCand,
bool HasCompact,
SmallVectorImpl<unsigned> &NewVRegs) {
SmallVector<unsigned, 8> UsedCands;
// Prepare split editor.
LiveRangeEdit LREdit(&VirtReg, NewVRegs, *MF, *LIS, VRM, this);
SE->reset(LREdit, SplitSpillMode);