Extract parts of RAGreedy::splitAroundRegion as SplitKit methods.

This gets rid of some of the gory splitting details in RAGreedy and
makes them available to future SplitKit clients.

Slightly generalize the functionality to support multi-way splitting.
Specifically, SplitEditor::splitLiveThroughBlock() supports switching
between different register intervals in a block.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135307 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 36 insertions, 0 deletions

diff --git a/lib/CodeGen/SplitKit.h b/lib/CodeGen/SplitKit.h
index a9ccf40be2..7948b725f8 100644
--- a/lib/CodeGen/SplitKit.h
+++ b/lib/CodeGen/SplitKit.h
@@ -426,6 +426,42 @@ public:
   /// splitSingleBlocks - Split CurLI into a separate live interval inside each
   /// basic block in Blocks.
   void splitSingleBlocks(const SplitAnalysis::BlockPtrSet &Blocks);
+
+  /// splitLiveThroughBlock - Split CurLI in the given block such that it
+  /// enters the block in IntvIn and leaves it in IntvOut. There may be uses in
+  /// the block, but they will be ignored when placing split points.
+  ///
+  /// @param MBBNum      Block number.
+  /// @param IntvIn      Interval index entering the block.
+  /// @param LeaveBefore When set, leave IntvIn before this point.
+  /// @param IntvOut     Interval index leaving the block.
+  /// @param EnterAfter  When set, enter IntvOut after this point.
+  void splitLiveThroughBlock(unsigned MBBNum,
+                             unsigned IntvIn, SlotIndex LeaveBefore,
+                             unsigned IntvOut, SlotIndex EnterAfter);
+
+  /// splitRegInBlock - Split CurLI in the given block such that it enters the
+  /// block in IntvIn and leaves it on the stack (or not at all). Split points
+  /// are placed in a way that avoids putting uses in the stack interval. This
+  /// may require creating a local interval when there is interference.
+  ///
+  /// @param BI          Block descriptor.
+  /// @param IntvIn      Interval index entering the block. Not 0.
+  /// @param LeaveBefore When set, leave IntvIn before this point.
+  void splitRegInBlock(const SplitAnalysis::BlockInfo &BI,
+                       unsigned IntvIn, SlotIndex LeaveBefore);
+
+  /// splitRegOutBlock - Split CurLI in the given block such that it enters the
+  /// block on the stack (or isn't live-in at all) and leaves it in IntvOut.
+  /// Split points are placed to avoid interference and such that the uses are
+  /// not in the stack interval. This may require creating a local interval
+  /// when there is interference.
+  ///
+  /// @param BI          Block descriptor.
+  /// @param IntvOut     Interval index leaving the block.
+  /// @param EnterAfter  When set, enter IntvOut after this point.
+  void splitRegOutBlock(const SplitAnalysis::BlockInfo &BI,
+                        unsigned IntvOut, SlotIndex EnterAfter);
 };
 
 }