Move extendRange() into SplitEditor and delete the LiveRangeMap class.

Extract the updateSSA() method from the too long extendRange().

LiveOutCache can be shared among all the new intervals since there is at most
one of the new ranges live out from each basic block.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126818 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 32 insertions, 60 deletions

diff --git a/lib/CodeGen/SplitKit.h b/lib/CodeGen/SplitKit.h
index 6d0e6367d5..a0d935de1d 100644
--- a/lib/CodeGen/SplitKit.h
+++ b/lib/CodeGen/SplitKit.h
@@ -144,63 +144,6 @@ public:
 };
 
 
-/// LiveIntervalMap - Map values from a large LiveInterval into a small
-/// interval that is a subset. Insert phi-def values as needed. This class is
-/// used by SplitEditor to create new smaller LiveIntervals.
-///
-/// ParentLI is the larger interval, LI is the subset interval. Every value
-/// in LI corresponds to exactly one value in ParentLI, and the live range
-/// of the value is contained within the live range of the ParentLI value.
-/// Values in ParentLI may map to any number of OpenLI values, including 0.
-class LiveIntervalMap {
-  LiveIntervals &LIS;
-  MachineDominatorTree &MDT;
-
-  // The parent interval is never changed.
-  const LiveInterval &ParentLI;
-
-  // The child interval's values are fully contained inside ParentLI values.
-  LiveInterval *LI;
-
-  typedef std::pair<VNInfo*, MachineDomTreeNode*> LiveOutPair;
-  typedef DenseMap<MachineBasicBlock*,LiveOutPair> LiveOutMap;
-
-  // LiveOutCache - Map each basic block where LI is live out to the live-out
-  // value and its defining block. One of these conditions shall be true:
-  //
-  //  1. !LiveOutCache.count(MBB)
-  //  2. LiveOutCache[MBB].second.getNode() == MBB
-  //  3. forall P in preds(MBB): LiveOutCache[P] == LiveOutCache[MBB]
-  //
-  // This is only a cache, the values can be computed as:
-  //
-  //  VNI = LI->getVNInfoAt(LIS.getMBBEndIdx(MBB))
-  //  Node = mbt_[LIS.getMBBFromIndex(VNI->def)]
-  //
-  // The cache is also used as a visiteed set by mapValue().
-  LiveOutMap LiveOutCache;
-
-  // Dump the live-out cache to dbgs().
-  void dumpCache();
-
-public:
-  LiveIntervalMap(LiveIntervals &lis,
-                  MachineDominatorTree &mdt,
-                  const LiveInterval &parentli)
-    : LIS(lis), MDT(mdt), ParentLI(parentli), LI(0) {}
-
-  /// reset - clear all data structures and start a new live interval.
-  void reset(LiveInterval *);
-
-  /// getLI - return the current live interval.
-  LiveInterval *getLI() const { return LI; }
-
-  /// extendRange - Extend the live range of LI so it reaches Idx.
-  /// Insert PHIDefs as needed to preserve SSA form.
-  void extendRange(SlotIndex Idx);
-};
-
-
 /// SplitEditor - Edit machine code and LiveIntervals for live range
 /// splitting.
 ///
@@ -240,9 +183,6 @@ class SplitEditor {
   /// Idx.
   RegAssignMap RegAssign;
 
-  /// LIMappers - One LiveIntervalMap or each interval in Edit.
-  SmallVector<LiveIntervalMap, 4> LIMappers;
-
   typedef DenseMap<std::pair<unsigned, unsigned>, VNInfo*> ValueMap;
 
   /// Values - keep track of the mapping from parent values to values in the new
@@ -255,6 +195,26 @@ class SplitEditor {
   ///    The new value has no live ranges anywhere.
   ValueMap Values;
 
+  typedef std::pair<VNInfo*, MachineDomTreeNode*> LiveOutPair;
+  typedef DenseMap<MachineBasicBlock*,LiveOutPair> LiveOutMap;
+
+  // LiveOutCache - Map each basic block where a new register is live out to the
+  // live-out value and its defining block.
+  // One of these conditions shall be true:
+  //
+  //  1. !LiveOutCache.count(MBB)
+  //  2. LiveOutCache[MBB].second.getNode() == MBB
+  //  3. forall P in preds(MBB): LiveOutCache[P] == LiveOutCache[MBB]
+  //
+  // This is only a cache, the values can be computed as:
+  //
+  //  VNI = Edit.get(RegIdx)->getVNInfoAt(LIS.getMBBEndIdx(MBB))
+  //  Node = mbt_[LIS.getMBBFromIndex(VNI->def)]
+  //
+  // The cache is also used as a visited set by extendRange(). It can be shared
+  // by all the new registers because at most one is live out of each block.
+  LiveOutMap LiveOutCache;
+
   /// defValue - define a value in RegIdx from ParentVNI at Idx.
   /// Idx does not have to be ParentVNI->def, but it must be contained within
   /// ParentVNI's live range in ParentLI. The new value is added to the value
@@ -274,6 +234,18 @@ class SplitEditor {
                         MachineBasicBlock &MBB,
                         MachineBasicBlock::iterator I);
 
+  /// extendRange - Extend the live range of Edit.get(RegIdx) so it reaches Idx.
+  /// Insert PHIDefs as needed to preserve SSA form.
+  void extendRange(unsigned RegIdx, SlotIndex Idx);
+
+  /// updateSSA - Insert PHIDefs as necessary and update LiveOutCache such that
+  /// Edit.get(RegIdx) is live-in to all the blocks in LiveIn.
+  /// Return the value that is eventually live-in to IdxMBB.
+  VNInfo *updateSSA(unsigned RegIdx,
+                    SmallVectorImpl<MachineDomTreeNode*> &LiveIn,
+                    SlotIndex Idx,
+                    const MachineBasicBlock *IdxMBB);
+
   /// rewriteAssigned - Rewrite all uses of Edit.getReg() to assigned registers.
   void rewriteAssigned();