LiveIntervalAnalysis: Add subregister aware variants pruneValue().

llvm-svn: 223886

2 files changed, 22 insertions, 12 deletions

diff --git a/llvm/lib/CodeGen/LiveIntervalAnalysis.cpp b/llvm/lib/CodeGen/LiveIntervalAnalysis.cpp
index 77e7149c713..dde55f9dd48 100644
--- a/llvm/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/llvm/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -542,26 +542,25 @@ void LiveIntervals::extendToIndices(LiveRange &LR,
     LRCalc->extend(LR, Indices[i]);
 }
 
-void LiveIntervals::pruneValue(LiveInterval *LI, SlotIndex Kill,
+void LiveIntervals::pruneValue(LiveRange &LR, SlotIndex Kill,
                                SmallVectorImpl<SlotIndex> *EndPoints) {
-  LiveQueryResult LRQ = LI->Query(Kill);
-  VNInfo *VNI = LRQ.valueOut();
+  LiveQueryResult LRQ = LR.Query(Kill);
+  VNInfo *VNI = LRQ.valueOutOrDead();
   if (!VNI)
     return;
 
   MachineBasicBlock *KillMBB = Indexes->getMBBFromIndex(Kill);
-  SlotIndex MBBStart, MBBEnd;
-  std::tie(MBBStart, MBBEnd) = Indexes->getMBBRange(KillMBB);
+  SlotIndex MBBEnd = Indexes->getMBBEndIdx(KillMBB);
 
   // If VNI isn't live out from KillMBB, the value is trivially pruned.
   if (LRQ.endPoint() < MBBEnd) {
-    LI->removeSegment(Kill, LRQ.endPoint());
+    LR.removeSegment(Kill, LRQ.endPoint());
     if (EndPoints) EndPoints->push_back(LRQ.endPoint());
     return;
   }
 
   // VNI is live out of KillMBB.
-  LI->removeSegment(Kill, MBBEnd);
+  LR.removeSegment(Kill, MBBEnd);
   if (EndPoints) EndPoints->push_back(MBBEnd);
 
   // Find all blocks that are reachable from KillMBB without leaving VNI's live
@@ -578,8 +577,9 @@ void LiveIntervals::pruneValue(LiveInterval *LI, SlotIndex Kill,
       MachineBasicBlock *MBB = *I;
 
       // Check if VNI is live in to MBB.
+      SlotIndex MBBStart, MBBEnd;
       std::tie(MBBStart, MBBEnd) = Indexes->getMBBRange(MBB);
-      LiveQueryResult LRQ = LI->Query(MBBStart);
+      LiveQueryResult LRQ = LR.Query(MBBStart);
       if (LRQ.valueIn() != VNI) {
         // This block isn't part of the VNI segment. Prune the search.
         I.skipChildren();
@@ -588,20 +588,30 @@ void LiveIntervals::pruneValue(LiveInterval *LI, SlotIndex Kill,
 
       // Prune the search if VNI is killed in MBB.
       if (LRQ.endPoint() < MBBEnd) {
-        LI->removeSegment(MBBStart, LRQ.endPoint());
+        LR.removeSegment(MBBStart, LRQ.endPoint());
         if (EndPoints) EndPoints->push_back(LRQ.endPoint());
         I.skipChildren();
         continue;
       }
 
       // VNI is live through MBB.
-      LI->removeSegment(MBBStart, MBBEnd);
+      LR.removeSegment(MBBStart, MBBEnd);
       if (EndPoints) EndPoints->push_back(MBBEnd);
       ++I;
     }
   }
 }
 
+void LiveIntervals::pruneValue(LiveInterval &LI, SlotIndex Kill,
+                               SmallVectorImpl<SlotIndex> *EndPoints) {
+  pruneValue((LiveRange&)LI, Kill, EndPoints);
+
+  for (LiveInterval::subrange_iterator SR = LI.subrange_begin(),
+       SE = LI.subrange_end(); SR != SE; ++SR) {
+    pruneValue(*SR, Kill, nullptr);
+  }
+}
+
 //===----------------------------------------------------------------------===//
 // Register allocator hooks.
 //
diff --git a/llvm/lib/CodeGen/RegisterCoalescer.cpp b/llvm/lib/CodeGen/RegisterCoalescer.cpp
index ec40656e4f0..12f4978de24 100644
--- a/llvm/lib/CodeGen/RegisterCoalescer.cpp
+++ b/llvm/lib/CodeGen/RegisterCoalescer.cpp
@@ -1917,7 +1917,7 @@ void JoinVals::pruneValues(JoinVals &Other,
       break;
     case CR_Replace: {
       // This value takes precedence over the value in Other.LI.
-      LIS->pruneValue(&Other.LI, Def, &EndPoints);
+      LIS->pruneValue(Other.LI, Def, &EndPoints);
       // Check if we're replacing an IMPLICIT_DEF value. The IMPLICIT_DEF
       // instructions are only inserted to provide a live-out value for PHI
       // predecessors, so the instruction should simply go away once its value
@@ -1951,7 +1951,7 @@ void JoinVals::pruneValues(JoinVals &Other,
         // We can no longer trust the value mapping computed by
         // computeAssignment(), the value that was originally copied could have
         // been replaced.
-        LIS->pruneValue(&LI, Def, &EndPoints);
+        LIS->pruneValue(LI, Def, &EndPoints);
         DEBUG(dbgs() << "\t\tpruned all of " << PrintReg(LI.reg) << " at "
                      << Def << ": " << LI << '\n');
       }