Special cases are needed in renumbering when dealing with renumbering after a PHI has been removed. The interval previously defined

by the PHI needs to be extended to the beginning of its basic block, and the intervals that were inputs need to be trimmed to the end 
of their basic blocks.

llvm-svn: 54070

lib/CodeGen/LiveIntervalAnalysis.cpp

@@ -126,6 +126,7 @@ void LiveIntervals::computeNumbering() {
     MBB2IdxMap[MBB->getNumber()] = std::make_pair(StartIdx, MIIndex - 1);
     Idx2MBBMap.push_back(std::make_pair(StartIdx, MBB));
   }
+  
   std::sort(Idx2MBBMap.begin(), Idx2MBBMap.end(), Idx2MBBCompare());
   
   if (!OldI2MI.empty())
@@ -139,7 +140,7 @@ void LiveIntervals::computeNumbering() {
         // instruction or its predecessor.
         unsigned index = LI->start / InstrSlots::NUM;
         unsigned offset = LI->start % InstrSlots::NUM;
-        if (offset == InstrSlots::LOAD) {
+        if (offset == InstrSlots::LOAD || LI->valno->def == ~0U) {
           std::vector<IdxMBBPair>::const_iterator I =
                   std::lower_bound(OldI2MBB.begin(), OldI2MBB.end(), LI->start);
           // Take the pair containing the index
@@ -157,7 +158,30 @@ void LiveIntervals::computeNumbering() {
         // following instruction.
         index = (LI->end - 1) / InstrSlots::NUM;
         offset  = LI->end % InstrSlots::NUM;
-        if (offset == InstrSlots::USE) {
+        if (LI->valno->hasPHIKill && !OldI2MI[index]) {
+          // Special handling for when this was previously killed by a PHI, but
+          // the PHI has now been removed.  We need to trim the live interval
+          // to die at the end of the preceding block.
+          std::vector<IdxMBBPair>::const_iterator I =
+                  std::lower_bound(OldI2MBB.begin(), OldI2MBB.end(), LI->end);
+          // Take the pair containing the index
+          std::vector<IdxMBBPair>::const_iterator J =
+                    ((I != OldI2MBB.end() && I->first > index) ||
+                    (I == OldI2MBB.end() && OldI2MBB.size()>0)) ? (I-1): I;
+          
+          MachineBasicBlock* StartMBB = J->second;
+          MachineBasicBlock* CurrMBB = J->second;
+          
+          while (CurrMBB == StartMBB) {
+            while (index > 0 && !OldI2MI[index]) --index;
+            CurrMBB = OldI2MI[index]->getParent();
+            if (!StartMBB) StartMBB = CurrMBB;
+            
+            --index;
+          }
+          
+          LI->end = getMBBEndIdx(CurrMBB) + 1;
+        } else if (offset == InstrSlots::USE) {
           std::vector<IdxMBBPair>::const_iterator I =
                   std::lower_bound(OldI2MBB.begin(), OldI2MBB.end(), LI->end);
           // Take the pair containing the index
@@ -179,11 +203,13 @@ void LiveIntervals::computeNumbering() {
         // Remap the VNInfo def index, which works the same as the
         // start indices above.
         VNInfo* vni = LI->valno;
+        if (vni->def != ~0U) {
           index = vni->def / InstrSlots::NUM;
           offset = vni->def % InstrSlots::NUM;
           if (offset == InstrSlots::LOAD) {
             std::vector<IdxMBBPair>::const_iterator I =
-                  std::lower_bound(OldI2MBB.begin(), OldI2MBB.end(), vni->def);
+                    std::lower_bound(OldI2MBB.begin(), OldI2MBB.end(), 
+                                     vni->def);
             // Take the pair containing the index
             std::vector<IdxMBBPair>::const_iterator J =
                       ((I != OldI2MBB.end() && I->first > index) ||
@@ -194,13 +220,38 @@ void LiveIntervals::computeNumbering() {
           } else {
             vni->def = mi2iMap_[OldI2MI[index]] + offset;
           }
+        }
         
         // Remap the VNInfo kill indices, which works the same as
         // the end indices above.
         for (size_t i = 0; i < vni->kills.size(); ++i) {
           index = (vni->kills[i]-1) / InstrSlots::NUM;
           offset = vni->kills[i] % InstrSlots::NUM;
-          if (offset == InstrSlots::USE) {
+          
+          if (LI->valno->hasPHIKill && !OldI2MI[index]) {
+            // Special handling for when this was previously killed by a PHI,
+            // but the PHI has now been removed.  We need to trim the live
+            // interval to die at the end of the preceding block.
+            std::vector<IdxMBBPair>::const_iterator I =
+                    std::lower_bound(OldI2MBB.begin(), OldI2MBB.end(), LI->end);
+            // Take the pair containing the index
+            std::vector<IdxMBBPair>::const_iterator J =
+                      ((I != OldI2MBB.end() && I->first > index) ||
+                      (I == OldI2MBB.end() && OldI2MBB.size()>0)) ? (I-1): I;
+
+            MachineBasicBlock* StartMBB = J->second;
+            MachineBasicBlock* CurrMBB = J->second;
+
+            while (CurrMBB == StartMBB) {
+              while (index > 0 && !OldI2MI[index]) --index;
+              CurrMBB = OldI2MI[index]->getParent();
+              if (!StartMBB) StartMBB = CurrMBB;
+
+              --index;
+            }
+
+            vni->kills[i] = getMBBEndIdx(CurrMBB) + 1;
+          } else if (offset == InstrSlots::USE) {
             std::vector<IdxMBBPair>::const_iterator I =
              std::lower_bound(OldI2MBB.begin(), OldI2MBB.end(), vni->kills[i]);
             // Take the pair containing the index