Exclusively use SplitAnalysis::getLastSplitPoint().

Delete the alternative implementation in LiveIntervalAnalysis.

These functions computed the same thing, but SplitAnalysis caches the
result.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147911 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/LiveIntervalAnalysis.h

@@ -269,12 +269,6 @@ namespace llvm {
     /// within a single basic block.
     bool intervalIsInOneMBB(const LiveInterval &li) const;
 
-    /// getLastSplitPoint - Return the last possible insertion point in mbb for
-    /// spilling and splitting code. This is the first terminator, or the call
-    /// instruction if li is live into a landing pad successor.
-    MachineBasicBlock::iterator getLastSplitPoint(const LiveInterval &li,
-                                                  MachineBasicBlock *mbb) const;
-
     /// addKillFlags - Add kill flags to any instruction that kills a virtual
     /// register.
     void addKillFlags();

lib/CodeGen/LiveIntervalAnalysis.cpp

@@ -779,28 +779,6 @@ bool LiveIntervals::shrinkToUses(LiveInterval *li,
 // Register allocator hooks.
 //
 
-MachineBasicBlock::iterator
-LiveIntervals::getLastSplitPoint(const LiveInterval &li,
-                                 MachineBasicBlock *mbb) const {
-  const MachineBasicBlock *lpad = mbb->getLandingPadSuccessor();
-
-  // If li is not live into a landing pad, we can insert spill code before the
-  // first terminator.
-  if (!lpad || !isLiveInToMBB(li, lpad))
-    return mbb->getFirstTerminator();
-
-  // When there is a landing pad, spill code must go before the call instruction
-  // that can throw.
-  MachineBasicBlock::iterator I = mbb->end(), B = mbb->begin();
-  while (I != B) {
-    --I;
-    if (I->isCall())
-      return I;
-  }
-  // The block contains no calls that can throw, so use the first terminator.
-  return mbb->getFirstTerminator();
-}
-
 void LiveIntervals::addKillFlags() {
   for (iterator I = begin(), E = end(); I != E; ++I) {
     unsigned Reg = I->first;

lib/CodeGen/SplitKit.cpp

@@ -95,6 +95,14 @@ SlotIndex SplitAnalysis::computeLastSplitPoint(unsigned Num) {
     return LSP.first;
 }
 
+MachineBasicBlock::iterator
+SplitAnalysis::getLastSplitPointIter(MachineBasicBlock *MBB) {
+  SlotIndex LSP = getLastSplitPoint(MBB->getNumber());
+  if (LSP == LIS.getMBBEndIdx(MBB))
+    return MBB->end();
+  return LIS.getInstructionFromIndex(LSP);
+}
+
 /// analyzeUses - Count instructions, basic blocks, and loops using CurLI.
 void SplitAnalysis::analyzeUses() {
   assert(UseSlots.empty() && "Call clear first");
@@ -497,7 +505,7 @@ SlotIndex SplitEditor::enterIntvAtEnd(MachineBasicBlock &MBB) {
   }
   DEBUG(dbgs() << ": valno " << ParentVNI->id);
   VNInfo *VNI = defFromParent(OpenIdx, ParentVNI, Last, MBB,
-                              LIS.getLastSplitPoint(Edit->getParent(), &MBB));
+                              SA.getLastSplitPointIter(&MBB));
   RegAssign.insert(VNI->def, End, OpenIdx);
   DEBUG(dump());
   return VNI->def;
@@ -780,7 +788,7 @@ void SplitEditor::hoistCopiesForSize() {
     SlotIndex Last = LIS.getMBBEndIdx(Dom.first).getPrevSlot();
     Dom.second =
       defFromParent(0, ParentVNI, Last, *Dom.first,
-                    LIS.getLastSplitPoint(Edit->getParent(), Dom.first))->def;
+                    SA.getLastSplitPointIter(Dom.first))->def;
   }
 
   // Remove redundant back-copies that are now known to be dominated by another

lib/CodeGen/SplitKit.h

@@ -135,7 +135,7 @@ public:
   /// getParent - Return the last analyzed interval.
   const LiveInterval &getParent() const { return *CurLI; }
 
-  /// getLastSplitPoint - Return that base index of the last valid split point
+  /// getLastSplitPoint - Return the base index of the last valid split point
   /// in the basic block numbered Num.
   SlotIndex getLastSplitPoint(unsigned Num) {
     // Inline the common simple case.
@@ -145,6 +145,9 @@ public:
     return computeLastSplitPoint(Num);
   }
 
+  /// getLastSplitPointIter - Returns the last split point as an iterator.
+  MachineBasicBlock::iterator getLastSplitPointIter(MachineBasicBlock*);
+
   /// isOriginalEndpoint - Return true if the original live range was killed or
   /// (re-)defined at Idx. Idx should be the 'def' slot for a normal kill/def,
   /// and 'use' for an early-clobber def.