When checking whether a def of an aliased register is dead, ask the

[oota-llvm.git] / lib / CodeGen / StrongPHIElimination.cpp

diff --git a/lib/CodeGen/StrongPHIElimination.cpp b/lib/CodeGen/StrongPHIElimination.cpp
index 8bda41db3fa29a7d39988d0451e63a2a53f9c461..5658a65abc879733123c66d0a1beca040e6f0dcd 100644 (file)
--- a/lib/CodeGen/StrongPHIElimination.cpp
+++ b/lib/CodeGen/StrongPHIElimination.cpp
@@ -32,19 +32,18 @@
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/ADT/DepthFirstIterator.h"
 #include "llvm/ADT/Statistic.h"
-#include "llvm/Support/Compiler.h"
 #include "llvm/Support/Debug.h"
 using namespace llvm;
 
 namespace {
-  struct VISIBILITY_HIDDEN StrongPHIElimination : public MachineFunctionPass {
+  struct StrongPHIElimination : public MachineFunctionPass {
     static char ID; // Pass identification, replacement for typeid
     StrongPHIElimination() : MachineFunctionPass(&ID) {}
 
     // Waiting stores, for each MBB, the set of copies that need to
     // be inserted into that MBB
     DenseMap<MachineBasicBlock*,
-             std::map<unsigned, unsigned> > Waiting;
+             std::multimap<unsigned, unsigned> > Waiting;
     
     // Stacks holds the renaming stack for each register
     std::map<unsigned, std::vector<unsigned> > Stacks;
@@ -71,6 +70,7 @@ namespace {
     bool runOnMachineFunction(MachineFunction &Fn);
     
     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+      AU.setPreservesCFG();
       AU.addRequired<MachineDominatorTree>();
       AU.addRequired<LiveIntervals>();
       
@@ -294,8 +294,8 @@ StrongPHIElimination::computeDomForest(
 static bool isLiveIn(unsigned r, MachineBasicBlock* MBB,
                      LiveIntervals& LI) {
   LiveInterval& I = LI.getOrCreateInterval(r);
-  unsigned idx = LI.getMBBStartIdx(MBB);
-  return I.liveBeforeAndAt(idx);
+  LiveIndex idx = LI.getMBBStartIdx(MBB);
+  return I.liveAt(idx);
 }
 
 /// isLiveOut - help method that determines, from a regno, if a register is
@@ -419,7 +419,6 @@ void StrongPHIElimination::processBlock(MachineBasicBlock* MBB) {
   MachineBasicBlock::iterator P = MBB->begin();
   while (P != MBB->end() && P->getOpcode() == TargetInstrInfo::PHI) {
     unsigned DestReg = P->getOperand(0).getReg();
-
     
     // Don't both doing PHI elimination for dead PHI's.
     if (P->registerDefIsDead(DestReg)) {
@@ -428,7 +427,7 @@ void StrongPHIElimination::processBlock(MachineBasicBlock* MBB) {
     }
 
     LiveInterval& PI = LI.getOrCreateInterval(DestReg);
-    unsigned pIdx = LI.getDefIndex(LI.getInstructionIndex(P));
+    LiveIndex pIdx = LI.getDefIndex(LI.getInstructionIndex(P));
     VNInfo* PVN = PI.getLiveRangeContaining(pIdx)->valno;
     PhiValueNumber.insert(std::make_pair(DestReg, PVN->id));
 
@@ -448,6 +447,11 @@ void StrongPHIElimination::processBlock(MachineBasicBlock* MBB) {
         ProcessedNames.insert(SrcReg);
         continue;
       }
+      
+      // We don't need to insert copies for implicit_defs.
+      MachineInstr* DefMI = MRI.getVRegDef(SrcReg);
+      if (DefMI->getOpcode() == TargetInstrInfo::IMPLICIT_DEF)
+        ProcessedNames.insert(SrcReg);
     
       // Check for trivial interferences via liveness information, allowing us
       // to avoid extra work later.  Any registers that interfere cannot both
@@ -549,8 +553,8 @@ void StrongPHIElimination::processBlock(MachineBasicBlock* MBB) {
     // Add the renaming set for this PHI node to our overall renaming information
     for (std::map<unsigned, MachineBasicBlock*>::iterator QI = PHIUnion.begin(),
          QE = PHIUnion.end(); QI != QE; ++QI) {
-      DOUT << "Adding Renaming: " << QI->first << " -> "
-           << P->getOperand(0).getReg() << "\n";
+      DEBUG(errs() << "Adding Renaming: " << QI->first << " -> "
+                   << P->getOperand(0).getReg() << "\n");
     }
     
     RenameSets.insert(std::make_pair(P->getOperand(0).getReg(), PHIUnion));
@@ -643,13 +647,13 @@ void StrongPHIElimination::processPHIUnion(MachineInstr* Inst,
 void StrongPHIElimination::ScheduleCopies(MachineBasicBlock* MBB,
                                           std::set<unsigned>& pushed) {
   // FIXME: This function needs to update LiveIntervals
-  std::map<unsigned, unsigned>& copy_set= Waiting[MBB];
+  std::multimap<unsigned, unsigned>& copy_set= Waiting[MBB];
   
-  std::map<unsigned, unsigned> worklist;
+  std::multimap<unsigned, unsigned> worklist;
   std::map<unsigned, unsigned> map;
   
   // Setup worklist of initial copies
-  for (std::map<unsigned, unsigned>::iterator I = copy_set.begin(),
+  for (std::multimap<unsigned, unsigned>::iterator I = copy_set.begin(),
        E = copy_set.end(); I != E; ) {
     map.insert(std::make_pair(I->first, I->first));
     map.insert(std::make_pair(I->second, I->second));
@@ -658,9 +662,9 @@ void StrongPHIElimination::ScheduleCopies(MachineBasicBlock* MBB,
       worklist.insert(*I);
       
       // Avoid iterator invalidation
-      unsigned first = I->first;
+      std::multimap<unsigned, unsigned>::iterator OI = I;
       ++I;
-      copy_set.erase(first);
+      copy_set.erase(OI);
     } else {
       ++I;
     }
@@ -676,8 +680,9 @@ void StrongPHIElimination::ScheduleCopies(MachineBasicBlock* MBB,
   // Iterate over the worklist, inserting copies
   while (!worklist.empty() || !copy_set.empty()) {
     while (!worklist.empty()) {
-      std::pair<unsigned, unsigned> curr = *worklist.begin();
-      worklist.erase(curr.first);
+      std::multimap<unsigned, unsigned>::iterator WI = worklist.begin();
+      std::pair<unsigned, unsigned> curr = *WI;
+      worklist.erase(WI);
       
       const TargetRegisterClass *RC = MF->getRegInfo().getRegClass(curr.first);
       
@@ -691,6 +696,9 @@ void StrongPHIElimination::ScheduleCopies(MachineBasicBlock* MBB,
         TII->copyRegToReg(*PI->getParent(), PI, t,
                           curr.second, RC, RC);
         
+        DEBUG(errs() << "Inserted copy from " << curr.second << " to " << t
+                     << "\n");
+        
         // Push temporary on Stacks
         Stacks[curr.second].push_back(t);
         
@@ -705,6 +713,8 @@ void StrongPHIElimination::ScheduleCopies(MachineBasicBlock* MBB,
       TII->copyRegToReg(*MBB, MBB->getFirstTerminator(), curr.second,
                         map[curr.first], RC, RC);
       map[curr.first] = curr.second;
+      DEBUG(errs() << "Inserted copy from " << curr.first << " to "
+                   << curr.second << "\n");
       
       // Push this copy onto InsertedPHICopies so we can
       // update LiveIntervals with it.
@@ -712,15 +722,16 @@ void StrongPHIElimination::ScheduleCopies(MachineBasicBlock* MBB,
       InsertedPHIDests.push_back(std::make_pair(curr.second, --MI));
       
       // If curr.first is a destination in copy_set...
-      for (std::map<unsigned, unsigned>::iterator I = copy_set.begin(),
+      for (std::multimap<unsigned, unsigned>::iterator I = copy_set.begin(),
            E = copy_set.end(); I != E; )
         if (curr.first == I->second) {
           std::pair<unsigned, unsigned> temp = *I;
+          worklist.insert(temp);
           
           // Avoid iterator invalidation
+          std::multimap<unsigned, unsigned>::iterator OI = I;
           ++I;
-          copy_set.erase(temp.first);
-          worklist.insert(temp);
+          copy_set.erase(OI);
           
           break;
         } else {
@@ -729,13 +740,14 @@ void StrongPHIElimination::ScheduleCopies(MachineBasicBlock* MBB,
     }
     
     if (!copy_set.empty()) {
-      std::pair<unsigned, unsigned> curr = *copy_set.begin();
-      copy_set.erase(curr.first);
+      std::multimap<unsigned, unsigned>::iterator CI = copy_set.begin();
+      std::pair<unsigned, unsigned> curr = *CI;
       worklist.insert(curr);
+      copy_set.erase(CI);
       
       LiveInterval& I = LI.getInterval(curr.second);
       MachineBasicBlock::iterator term = MBB->getFirstTerminator();
-      unsigned endIdx = 0;
+      LiveIndex endIdx = LiveIndex();
       if (term != MBB->end())
         endIdx = LI.getInstructionIndex(term);
       else
@@ -771,16 +783,15 @@ void StrongPHIElimination::ScheduleCopies(MachineBasicBlock* MBB,
        InsertedPHIDests.begin(), E = InsertedPHIDests.end(); I != E; ++I) {
     if (RegHandled.insert(I->first).second) {
       LiveInterval& Int = LI.getOrCreateInterval(I->first);
-      unsigned instrIdx = LI.getInstructionIndex(I->second);
-      if (Int.liveAt(LiveIntervals::getDefIndex(instrIdx)))
-        Int.removeRange(LiveIntervals::getDefIndex(instrIdx),
-                        LI.getMBBEndIdx(I->second->getParent())+1,
+      LiveIndex instrIdx = LI.getInstructionIndex(I->second);
+      if (Int.liveAt(LI.getDefIndex(instrIdx)))
+        Int.removeRange(LI.getDefIndex(instrIdx),
+                        LI.getNextSlot(LI.getMBBEndIdx(I->second->getParent())),
                         true);
       
       LiveRange R = LI.addLiveRangeToEndOfBlock(I->first, I->second);
-      R.valno->copy = I->second;
-      R.valno->def =
-                  LiveIntervals::getDefIndex(LI.getInstructionIndex(I->second));
+      R.valno->setCopy(I->second);
+      R.valno->def = LI.getDefIndex(LI.getInstructionIndex(I->second));
     }
   }
 }
@@ -801,12 +812,12 @@ void StrongPHIElimination::InsertCopies(MachineDomTreeNode* MDTN,
       continue;
     
     for (unsigned i = 0; i < I->getNumOperands(); ++i)
-      if (I->getOperand(i).isRegister() &&
+      if (I->getOperand(i).isReg() &&
           Stacks[I->getOperand(i).getReg()].size()) {
         // Remove the live range for the old vreg.
         LiveInterval& OldInt = LI.getInterval(I->getOperand(i).getReg());
         LiveInterval::iterator OldLR = OldInt.FindLiveRangeContaining(
-                  LiveIntervals::getUseIndex(LI.getInstructionIndex(I)));
+                  LI.getUseIndex(LI.getInstructionIndex(I)));
         if (OldLR != OldInt.end())
           OldInt.removeRange(*OldLR, true);
         
@@ -816,13 +827,13 @@ void StrongPHIElimination::InsertCopies(MachineDomTreeNode* MDTN,
         // Add a live range for the new vreg
         LiveInterval& Int = LI.getInterval(I->getOperand(i).getReg());
         VNInfo* FirstVN = *Int.vni_begin();
-        FirstVN->hasPHIKill = false;
+        FirstVN->setHasPHIKill(false);
         if (I->getOperand(i).isKill())
-          FirstVN->kills.push_back(
-                         LiveIntervals::getUseIndex(LI.getInstructionIndex(I)));
+          FirstVN->addKill(
+                 LI.getUseIndex(LI.getInstructionIndex(I)));
         
         LiveRange LR (LI.getMBBStartIdx(I->getParent()),
-                      LiveIntervals::getUseIndex(LI.getInstructionIndex(I)),
+                      LI.getNextSlot(LI.getUseIndex(LI.getInstructionIndex(I))),
                       FirstVN);
         
         Int.addRange(LR);
@@ -857,8 +868,8 @@ bool StrongPHIElimination::mergeLiveIntervals(unsigned primary,
   for (LiveInterval::iterator I = RHS.begin(), E = RHS.end(); I != E; ++I) {
     LiveRange R = *I;
  
-    unsigned Start = R.start;
-    unsigned End = R.end;
+    LiveIndex Start = R.start;
+    LiveIndex End = R.end;
     if (LHS.getLiveRangeContaining(Start))
       return false;
     
@@ -875,10 +886,7 @@ bool StrongPHIElimination::mergeLiveIntervals(unsigned primary,
     VNInfo* OldVN = R.valno;
     VNInfo*& NewVN = VNMap[OldVN];
     if (!NewVN) {
-      NewVN = LHS.getNextValue(OldVN->def,
-                               OldVN->copy,
-                               LI.getVNInfoAllocator());
-      NewVN->kills = OldVN->kills;
+      NewVN = LHS.createValueCopy(OldVN, LI.getVNInfoAllocator());
     }
     
     LiveRange LR (R.start, R.end, NewVN);
@@ -919,7 +927,8 @@ bool StrongPHIElimination::runOnMachineFunction(MachineFunction &Fn) {
         unsigned reg = OI->first;
         ++OI;
         I->second.erase(reg);
-        DOUT << "Removing Renaming: " << reg << " -> " << I->first << "\n";
+        DEBUG(errs() << "Removing Renaming: " << reg << " -> " << I->first
+                     << "\n");
       }
     }
   }
@@ -936,7 +945,7 @@ bool StrongPHIElimination::runOnMachineFunction(MachineFunction &Fn) {
     while (I->second.size()) {
       std::map<unsigned, MachineBasicBlock*>::iterator SI = I->second.begin();
       
-      DOUT << "Renaming: " << SI->first << " -> " << I->first << "\n";
+      DEBUG(errs() << "Renaming: " << SI->first << " -> " << I->first << "\n");
       
       if (SI->first != I->first) {
         if (mergeLiveIntervals(I->first, SI->first)) {
@@ -957,22 +966,27 @@ bool StrongPHIElimination::runOnMachineFunction(MachineFunction &Fn) {
           LI.computeNumbering();
           
           LiveInterval& Int = LI.getOrCreateInterval(I->first);
-          unsigned instrIdx =
+          LiveIndex instrIdx =
                      LI.getInstructionIndex(--SI->second->getFirstTerminator());
-          if (Int.liveAt(LiveIntervals::getDefIndex(instrIdx)))
-            Int.removeRange(LiveIntervals::getDefIndex(instrIdx),
-                            LI.getMBBEndIdx(SI->second)+1, true);
+          if (Int.liveAt(LI.getDefIndex(instrIdx)))
+            Int.removeRange(LI.getDefIndex(instrIdx),
+                            LI.getNextSlot(LI.getMBBEndIdx(SI->second)), true);
 
           LiveRange R = LI.addLiveRangeToEndOfBlock(I->first,
                                             --SI->second->getFirstTerminator());
-          R.valno->copy = --SI->second->getFirstTerminator();
-          R.valno->def = LiveIntervals::getDefIndex(instrIdx);
+          R.valno->setCopy(--SI->second->getFirstTerminator());
+          R.valno->def = LI.getDefIndex(instrIdx);
           
-          DOUT << "Renaming failed: " << SI->first << " -> "
-               << I->first << "\n";
+          DEBUG(errs() << "Renaming failed: " << SI->first << " -> "
+                       << I->first << "\n");
         }
       }
       
+      LiveInterval& Int = LI.getOrCreateInterval(I->first);
+      const LiveRange* LR =
+                       Int.getLiveRangeContaining(LI.getMBBEndIdx(SI->second));
+      LR->valno->setHasPHIKill(true);
+      
       I->second.erase(SI->first);
     }
   
@@ -996,7 +1010,7 @@ bool StrongPHIElimination::runOnMachineFunction(MachineFunction &Fn) {
       if (PI.containsOneValue()) {
         LI.removeInterval(DestReg);
       } else {
-        unsigned idx = LI.getDefIndex(LI.getInstructionIndex(PInstr));
+        LiveIndex idx = LI.getDefIndex(LI.getInstructionIndex(PInstr));
         PI.removeRange(*PI.getLiveRangeContaining(idx), true);
       }
     } else {
@@ -1010,8 +1024,7 @@ bool StrongPHIElimination::runOnMachineFunction(MachineFunction &Fn) {
         LiveInterval& InputI = LI.getInterval(reg);
         if (MBB != PInstr->getParent() &&
             InputI.liveAt(LI.getMBBStartIdx(PInstr->getParent())) &&
-            InputI.expiredAt(LI.getInstructionIndex(PInstr) + 
-                             LiveIntervals::InstrSlots::NUM))
+            InputI.expiredAt(LI.getNextIndex(LI.getInstructionIndex(PInstr))))
           InputI.removeRange(LI.getMBBStartIdx(PInstr->getParent()),
                              LI.getInstructionIndex(PInstr),
                              true);
@@ -1019,9 +1032,9 @@ bool StrongPHIElimination::runOnMachineFunction(MachineFunction &Fn) {
       
       // If the PHI is not dead, then the valno defined by the PHI
       // now has an unknown def.
-      unsigned idx = LI.getDefIndex(LI.getInstructionIndex(PInstr));
+      LiveIndex idx = LI.getDefIndex(LI.getInstructionIndex(PInstr));
       const LiveRange* PLR = PI.getLiveRangeContaining(idx);
-      PLR->valno->def = ~0U;
+      PLR->valno->setIsPHIDef(true);
       LiveRange R (LI.getMBBStartIdx(PInstr->getParent()),
                    PLR->start, PLR->valno);
       PI.addRange(R);