Build the Hopfield network incrementally when splitting global live ranges.
It is common for large live ranges to have few basic blocks with register uses
and many live-through blocks without any uses. This approach grows the Hopfield
network incrementally around the use blocks, completely avoiding checking
interference for some through blocks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129188 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SplitKit.h b/lib/CodeGen/SplitKit.h
index 20ac8a1..f1ff501 100644
--- a/lib/CodeGen/SplitKit.h
+++ b/lib/CodeGen/SplitKit.h
@@ -89,7 +89,10 @@
SmallVector<BlockInfo, 8> UseBlocks;
/// ThroughBlocks - Block numbers where CurLI is live through without uses.
- SmallVector<unsigned, 8> ThroughBlocks;
+ BitVector ThroughBlocks;
+
+ /// NumThroughBlocks - Number of live-through blocks.
+ unsigned NumThroughBlocks;
SlotIndex computeLastSplitPoint(unsigned Num);
@@ -135,9 +138,11 @@
/// where CurLI has uses.
ArrayRef<BlockInfo> getUseBlocks() { return UseBlocks; }
- /// getThroughBlocks - Return an array of block numbers where CurLI is live
- /// through without uses.
- ArrayRef<unsigned> getThroughBlocks() { return ThroughBlocks; }
+ /// getNumThroughBlocks - Return the number of through blocks.
+ unsigned getNumThroughBlocks() const { return NumThroughBlocks; }
+
+ /// isThroughBlock - Return true if CurLI is live through MBB without uses.
+ bool isThroughBlock(unsigned MBB) const { return ThroughBlocks.test(MBB); }
typedef SmallPtrSet<const MachineBasicBlock*, 16> BlockPtrSet;