Fix an issue where LiveIntervals was trying to be smart about removing kill

markers, and ended up foiling the interval reconstruction.

This allows us to turn on reconstruction in the pre alloc splitter, which
fixes a number of miscompilations.

llvm-svn: 63025

1 files changed, 12 insertions, 34 deletions

diff --git a/llvm/lib/CodeGen/PreAllocSplitting.cpp b/llvm/lib/CodeGen/PreAllocSplitting.cpp
index 16a9e6d9b04..0325f7cd02b 100644
--- a/llvm/lib/CodeGen/PreAllocSplitting.cpp
+++ b/llvm/lib/CodeGen/PreAllocSplitting.cpp
@@ -748,12 +748,12 @@ VNInfo* PreAllocSplitting::PerformPHIConstruction(
     ret = PerformPHIConstruction(walker, MBB, LI, Visited, Defs, Uses,
                                  NewVNs, LiveOut, Phis, false, true);
     
+    LI->addRange(LiveRange(UseIndex, EndIndex+1, ret));
+    
     // FIXME: Need to set kills properly for inter-block stuff.
     if (LI->isKill(ret, UseIndex)) LI->removeKill(ret, UseIndex);
     if (intrablock)
       LI->addKill(ret, EndIndex);
-    
-    LI->addRange(LiveRange(UseIndex, EndIndex+1, ret));
   } else if (ContainsDefs && ContainsUses){
     SmallPtrSet<MachineInstr*, 2>& BlockDefs = Defs[MBB];
     SmallPtrSet<MachineInstr*, 2>& BlockUses = Uses[MBB];
@@ -805,13 +805,13 @@ VNInfo* PreAllocSplitting::PerformPHIConstruction(
       ret = PerformPHIConstruction(walker, MBB, LI, Visited, Defs, Uses,
                                    NewVNs, LiveOut, Phis, false, true);
 
+    LI->addRange(LiveRange(StartIndex, EndIndex+1, ret));
+    
     if (foundUse && LI->isKill(ret, StartIndex))
       LI->removeKill(ret, StartIndex);
     if (intrablock) {
       LI->addKill(ret, EndIndex);
     }
-
-    LI->addRange(LiveRange(StartIndex, EndIndex+1, ret));
   }
   
   // Memoize results so we don't have to recompute them.
@@ -1131,18 +1131,10 @@ bool PreAllocSplitting::Rematerialize(unsigned vreg, VNInfo* ValNo,
   TII->reMaterialize(MBB, RestorePt, vreg, DefMI);
   LIs->InsertMachineInstrInMaps(prior(RestorePt), RestoreIdx);
   
-  if (KillPt->getParent() == BarrierMBB) {
-    VNInfo* After = UpdateRegisterInterval(ValNo, LIs->getUseIndex(KillIdx)+1,
-                           LIs->getDefIndex(RestoreIdx));
-    
-    RenumberValno(After);
-
-    ++NumSplits;
-    ++NumRemats;
-    return true;
-  }
-
-  RepairLiveInterval(CurrLI, ValNo, DefMI, RestoreIdx);
+  ReconstructLiveInterval(CurrLI);
+  unsigned RematIdx = LIs->getInstructionIndex(prior(RestorePt));
+  RematIdx = LiveIntervals::getDefIndex(RematIdx);
+  RenumberValno(CurrLI->findDefinedVNInfo(RematIdx));
   
   ++NumSplits;
   ++NumRemats;
@@ -1315,28 +1307,14 @@ bool PreAllocSplitting::SplitRegLiveInterval(LiveInterval *LI) {
   MachineInstr *LoadMI = prior(RestorePt);
   LIs->InsertMachineInstrInMaps(LoadMI, RestoreIndex);
 
-  // If live interval is spilled in the same block as the barrier, just
-  // create a hole in the interval.
-  if (!DefMBB ||
-      (SpillMI && SpillMI->getParent() == BarrierMBB)) {
-    // Update spill stack slot live interval.
-    UpdateSpillSlotInterval(ValNo, LIs->getUseIndex(SpillIndex)+1,
-                            LIs->getDefIndex(RestoreIndex));
-
-    VNInfo* After = UpdateRegisterInterval(ValNo,
-                           LIs->getUseIndex(SpillIndex)+1,
-                           LIs->getDefIndex(RestoreIndex));
-    RenumberValno(After);
-   
-    ++NumSplits;
-    return true;
-  }
-
   // Update spill stack slot live interval.
   UpdateSpillSlotInterval(ValNo, LIs->getUseIndex(SpillIndex)+1,
                           LIs->getDefIndex(RestoreIndex));
 
-  RepairLiveInterval(CurrLI, ValNo, DefMI, RestoreIndex);
+  ReconstructLiveInterval(CurrLI);
+  unsigned RestoreIdx = LIs->getInstructionIndex(prior(RestorePt));
+  RestoreIdx = LiveIntervals::getDefIndex(RestoreIdx);
+  RenumberValno(CurrLI->findDefinedVNInfo(RestoreIdx));
   
   ++NumSplits;
   return true;