Switch extendInBlock() to take a kill slot instead of the last use slot.

Three out of four clients prefer this interface which is consistent with
extendIntervalEndTo() and LiveRangeCalc::extend().

llvm-svn: 139604

llvm/include/llvm/CodeGen/LiveInterval.h

@@ -452,10 +452,10 @@ namespace llvm {
       addRangeFrom(LR, ranges.begin());
     }
 
-    /// extendInBlock - If this interval is live before UseIdx in the basic
-    /// block that starts at StartIdx, extend it to be live at UseIdx and return
-    /// the value. If there is no live range before UseIdx, return NULL.
-    VNInfo *extendInBlock(SlotIndex StartIdx, SlotIndex UseIdx);
+    /// extendInBlock - If this interval is live before Kill in the basic block
+    /// that starts at StartIdx, extend it to be live up to Kill, and return
+    /// the value. If there is no live range before Kill, return NULL.
+    VNInfo *extendInBlock(SlotIndex StartIdx, SlotIndex Kill);
 
     /// join - Join two live intervals (this, and other) together.  This applies
     /// mappings to the value numbers in the LHS/RHS intervals as specified.  If

llvm/lib/CodeGen/LiveInterval.cpp

@@ -294,20 +294,20 @@ LiveInterval::addRangeFrom(LiveRange LR, iterator From) {
   return ranges.insert(it, LR);
 }
 
-/// extendInBlock - If this interval is live before UseIdx in the basic
-/// block that starts at StartIdx, extend it to be live at UseIdx and return
-/// the value. If there is no live range before UseIdx, return NULL.
-VNInfo *LiveInterval::extendInBlock(SlotIndex StartIdx, SlotIndex UseIdx) {
+/// extendInBlock - If this interval is live before Kill in the basic
+/// block that starts at StartIdx, extend it to be live up to Kill and return
+/// the value. If there is no live range before Kill, return NULL.
+VNInfo *LiveInterval::extendInBlock(SlotIndex StartIdx, SlotIndex Kill) {
   if (empty())
     return 0;
-  iterator I = std::upper_bound(begin(), end(), UseIdx);
+  iterator I = std::upper_bound(begin(), end(), Kill.getPrevSlot());
   if (I == begin())
     return 0;
   --I;
   if (I->end <= StartIdx)
     return 0;
-  if (I->end <= UseIdx)
-    extendIntervalEndTo(I, UseIdx.getNextSlot());
+  if (I->end < Kill)
+    extendIntervalEndTo(I, Kill);
   return I->valno;
 }
 

llvm/lib/CodeGen/LiveIntervalAnalysis.cpp

@@ -804,7 +804,7 @@ bool LiveIntervals::shrinkToUses(LiveInterval *li,
     SlotIndex BlockStart = getMBBStartIdx(MBB);
 
     // Extend the live range for VNI to be live at Idx.
-    if (VNInfo *ExtVNI = NewLI.extendInBlock(BlockStart, Idx)) {
+    if (VNInfo *ExtVNI = NewLI.extendInBlock(BlockStart, Idx.getNextSlot())) {
       (void)ExtVNI;
       assert(ExtVNI == VNI && "Unexpected existing value number");
       // Is this a PHIDef we haven't seen before?

llvm/lib/CodeGen/LiveRangeCalc.cpp

@@ -63,13 +63,12 @@ void LiveRangeCalc::extend(LiveInterval *LI,
   assert(Kill.isValid() && "Invalid SlotIndex");
   assert(Indexes && "Missing SlotIndexes");
   assert(DomTree && "Missing dominator tree");
-  SlotIndex LastUse = Kill.getPrevSlot();
 
-  MachineBasicBlock *KillMBB = Indexes->getMBBFromIndex(LastUse);
+  MachineBasicBlock *KillMBB = Indexes->getMBBFromIndex(Kill.getPrevSlot());
   assert(Kill && "No MBB at Kill");
 
   // Is there a def in the same MBB we can extend?
-  if (LI->extendInBlock(Indexes->getMBBStartIdx(KillMBB), LastUse))
+  if (LI->extendInBlock(Indexes->getMBBStartIdx(KillMBB), Kill))
     return;
 
   // Find the single reaching def, or determine if Kill is jointly dominated by
@@ -134,7 +133,7 @@ VNInfo *LiveRangeCalc::findReachingDefs(LiveInterval *LI,
 
        // First time we see Pred.  Try to determine the live-out value, but set
        // it as null if Pred is live-through with an unknown value.
-       VNInfo *VNI = LI->extendInBlock(Start, End.getPrevSlot());
+       VNInfo *VNI = LI->extendInBlock(Start, End);
        setLiveOutValue(Pred, VNI);
        if (VNI) {
          if (TheVNI && TheVNI != VNI)

llvm/lib/CodeGen/SplitKit.cpp

@@ -648,8 +648,7 @@ bool SplitEditor::transferValues() {
 
       // The first block may be live-in, or it may have its own def.
       if (Start != BlockStart) {
-        VNInfo *VNI = LI->extendInBlock(BlockStart,
-                                        std::min(BlockEnd, End).getPrevSlot());
+        VNInfo *VNI = LI->extendInBlock(BlockStart, std::min(BlockEnd, End));
         assert(VNI && "Missing def for complex mapped value");
         DEBUG(dbgs() << ':' << VNI->id << "*BB#" << MBB->getNumber());
         // MBB has its own def. Is it also live-out?
@@ -669,8 +668,7 @@ bool SplitEditor::transferValues() {
         if (BlockStart == ParentVNI->def) {
           // This block has the def of a parent PHI, so it isn't live-in.
           assert(ParentVNI->isPHIDef() && "Non-phi defined at block start?");
-          VNInfo *VNI = LI->extendInBlock(BlockStart,
-                                         std::min(BlockEnd, End).getPrevSlot());
+          VNInfo *VNI = LI->extendInBlock(BlockStart, std::min(BlockEnd, End));
           assert(VNI && "Missing def for complex mapped parent PHI");
           if (End >= BlockEnd)
             LRC.setLiveOutValue(MBB, VNI); // Live-out as well.