Use the newly created helper on LiveIntervals.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52013 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 21 insertions, 116 deletions

diff --git a/lib/CodeGen/StrongPHIElimination.cpp b/lib/CodeGen/StrongPHIElimination.cpp
index 5abab30576..57958ca056 100644
--- a/lib/CodeGen/StrongPHIElimination.cpp
+++ b/lib/CodeGen/StrongPHIElimination.cpp
@@ -52,8 +52,9 @@ namespace {
     // used as operands to another another PHI node
     std::set<unsigned> UsedByAnother;
     
-    // RenameSets are the sets of operands (and their VNInfo IDs) to a PHI
-    // (the defining instruction of the key) that can be renamed without copies.
+    // RenameSets are the is a map from a PHI-defined register
+    // to the input registers to be coalesced along with the index
+    // of the input registers.
     std::map<unsigned, std::map<unsigned, unsigned> > RenameSets;
     
     // PhiValueNumber holds the ID numbers of the VNs for each phi that we're
@@ -466,15 +467,11 @@ void StrongPHIElimination::processBlock(MachineBasicBlock* MBB) {
         UsedByAnother.insert(SrcReg);
       } else {
         // Otherwise, add it to the renaming set
-        LiveInterval& I = LI.getOrCreateInterval(SrcReg);
         // We need to subtract one from the index because live ranges are open
         // at the end.
         unsigned idx = LI.getMBBEndIdx(P->getOperand(i).getMBB()) - 1;
-        VNInfo* VN = I.getLiveRangeContaining(idx)->valno;
         
-        assert(VN && "No VNInfo for register?");
-        
-        PHIUnion.insert(std::make_pair(SrcReg, VN->id));
+        PHIUnion.insert(std::make_pair(SrcReg, idx));
         UnionedBlocks.insert(MRI.getVRegDef(SrcReg)->getParent());
       }
     }
@@ -744,22 +741,9 @@ void StrongPHIElimination::ScheduleCopies(MachineBasicBlock* MBB,
   // PHI, we don't create multiple overlapping live intervals.
   std::set<unsigned> RegHandled;
   for (SmallVector<std::pair<unsigned, MachineInstr*>, 4>::iterator I =
-       InsertedPHIDests.begin(), E = InsertedPHIDests.end(); I != E; ++I) {
-    if (!RegHandled.count(I->first)) {
-      LiveInterval& Interval = LI.getOrCreateInterval(I->first);
-      VNInfo* VN = Interval.getNextValue(
-          LI.getInstructionIndex(I->second) + LiveIntervals::InstrSlots::DEF,
-                                         I->second, LI.getVNInfoAllocator());
-      VN->hasPHIKill = true;
-      VN->kills.push_back(LI.getMBBEndIdx(I->second->getParent()));
-      LiveRange LR(LI.getInstructionIndex(I->second) +
-                      LiveIntervals::InstrSlots::DEF,
-                   LI.getMBBEndIdx(I->second->getParent()) + 1, VN);
-      Interval.addRange(LR);
-      
-      RegHandled.insert(I->first);
-    }
-  }
+       InsertedPHIDests.begin(), E = InsertedPHIDests.end(); I != E; ++I)
+    if (!RegHandled.count(I->first))
+      LI.addLiveRangeToEndOfBlock(I->first, I->second);
 }
 
 /// InsertCopies - insert copies into MBB and all of its successors
@@ -794,111 +778,30 @@ void StrongPHIElimination::InsertCopies(MachineBasicBlock* MBB,
     Stacks[*I].pop_back();
 }
 
-/// ComputeUltimateVN - Assuming we are going to join two live intervals,
-/// compute what the resultant value numbers for each value in the input two
-/// ranges will be.  This is complicated by copies between the two which can
-/// and will commonly cause multiple value numbers to be merged into one.
-///
-/// VN is the value number that we're trying to resolve.  InstDefiningValue
-/// keeps track of the new InstDefiningValue assignment for the result
-/// LiveInterval.  ThisFromOther/OtherFromThis are sets that keep track of
-/// whether a value in this or other is a copy from the opposite set.
-/// ThisValNoAssignments/OtherValNoAssignments keep track of value #'s that have
-/// already been assigned.
-///
-/// ThisFromOther[x] - If x is defined as a copy from the other interval, this
-/// contains the value number the copy is from.
-///
-static unsigned ComputeUltimateVN(VNInfo *VNI,
-                                  SmallVector<VNInfo*, 16> &NewVNInfo,
-                                  DenseMap<VNInfo*, VNInfo*> &ThisFromOther,
-                                  DenseMap<VNInfo*, VNInfo*> &OtherFromThis,
-                                  SmallVector<int, 16> &ThisValNoAssignments,
-                                  SmallVector<int, 16> &OtherValNoAssignments) {
-  unsigned VN = VNI->id;
-
-  // If the VN has already been computed, just return it.
-  if (ThisValNoAssignments[VN] >= 0)
-    return ThisValNoAssignments[VN];
-//  assert(ThisValNoAssignments[VN] != -2 && "Cyclic case?");
-
-  // If this val is not a copy from the other val, then it must be a new value
-  // number in the destination.
-  DenseMap<VNInfo*, VNInfo*>::iterator I = ThisFromOther.find(VNI);
-  if (I == ThisFromOther.end()) {
-    NewVNInfo.push_back(VNI);
-    return ThisValNoAssignments[VN] = NewVNInfo.size()-1;
-  }
-  VNInfo *OtherValNo = I->second;
-
-  // Otherwise, this *is* a copy from the RHS.  If the other side has already
-  // been computed, return it.
-  if (OtherValNoAssignments[OtherValNo->id] >= 0)
-    return ThisValNoAssignments[VN] = OtherValNoAssignments[OtherValNo->id];
-  
-  // Mark this value number as currently being computed, then ask what the
-  // ultimate value # of the other value is.
-  ThisValNoAssignments[VN] = -2;
-  unsigned UltimateVN =
-    ComputeUltimateVN(OtherValNo, NewVNInfo, OtherFromThis, ThisFromOther,
-                      OtherValNoAssignments, ThisValNoAssignments);
-  return ThisValNoAssignments[VN] = UltimateVN;
-}
-
 void StrongPHIElimination::mergeLiveIntervals(unsigned primary,
                                               unsigned secondary,
-                                              unsigned secondaryVN) {
+                                              unsigned secondaryIdx) {
   
   LiveIntervals& LI = getAnalysis<LiveIntervals>();
   LiveInterval& LHS = LI.getOrCreateInterval(primary);
   LiveInterval& RHS = LI.getOrCreateInterval(secondary);
   
-  // Compute the final value assignment, assuming that the live ranges can be
-  // coalesced.
-  SmallVector<int, 16> LHSValNoAssignments;
-  SmallVector<int, 16> RHSValNoAssignments;
-  SmallVector<VNInfo*, 16> NewVNInfo;
-  
-  LHSValNoAssignments.resize(LHS.getNumValNums(), -1);
-  RHSValNoAssignments.resize(RHS.getNumValNums(), -1);
-  NewVNInfo.reserve(LHS.getNumValNums() + RHS.getNumValNums());
-  
-  for (LiveInterval::vni_iterator I = LHS.vni_begin(), E = LHS.vni_end();
-       I != E; ++I) {
-    VNInfo *VNI = *I;
-    unsigned VN = VNI->id;
-    if (LHSValNoAssignments[VN] >= 0 || VNI->def == ~1U) 
-      continue;
-    
-    NewVNInfo.push_back(VNI);
-    LHSValNoAssignments[VN] = NewVNInfo.size()-1;
-  }
-  
-  for (LiveInterval::vni_iterator I = RHS.vni_begin(), E = RHS.vni_end();
-       I != E; ++I) {
-    VNInfo *VNI = *I;
-    unsigned VN = VNI->id;
-    if (RHSValNoAssignments[VN] >= 0 || VNI->def == ~1U)
-      continue;
-      
-    NewVNInfo.push_back(VNI);
-    RHSValNoAssignments[VN] = NewVNInfo.size()-1;
-  }
-
-  // If we get here, we know that we can coalesce the live ranges.  Ask the
-  // intervals to coalesce themselves now.
-
-  LHS.join(RHS, &LHSValNoAssignments[0], &RHSValNoAssignments[0], NewVNInfo);
-  LI.removeInterval(secondary);
+  LI.computeNumbering();
   
-  // The valno that was previously the input to the PHI node
-  // now has a PHIKill.
-  LHS.getValNumInfo(RHSValNoAssignments[secondaryVN])->hasPHIKill = true;
+  const LiveRange* RangeMergingIn = RHS.getLiveRangeContaining(secondaryIdx);
+  VNInfo* NewVN = LHS.getNextValue(secondaryIdx, RangeMergingIn->valno->copy,
+                  LI.getVNInfoAllocator());
+  NewVN->hasPHIKill = true;
+  LiveRange NewRange(RangeMergingIn->start, RangeMergingIn->end, NewVN);
+  LHS.addRange(NewRange);
+  RHS.removeRange(RangeMergingIn->start, RangeMergingIn->end, true);
 }
 
 bool StrongPHIElimination::runOnMachineFunction(MachineFunction &Fn) {
   LiveIntervals& LI = getAnalysis<LiveIntervals>();
   
+  LI.dump();
+  
   // Compute DFS numbers of each block
   computeDFS(Fn);
   
@@ -909,7 +812,7 @@ bool StrongPHIElimination::runOnMachineFunction(MachineFunction &Fn) {
       processBlock(I);
   
   // Insert copies
-  // FIXME: This process should probably preserve LiveVariables
+  // FIXME: This process should probably preserve LiveIntervals
   SmallPtrSet<MachineBasicBlock*, 16> visited;
   InsertCopies(Fn.begin(), visited);
   
@@ -961,5 +864,7 @@ bool StrongPHIElimination::runOnMachineFunction(MachineFunction &Fn) {
   
   LI.computeNumbering();
   
+  LI.dump();
+  
   return true;
 }