X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FSimpleRegisterCoalescing.cpp;h=a60939c301057c2d0f0498c316c866cb949eec6c;hb=a29c13086a3add78a3a79f744573fe09eaa9dc88;hp=bb860d293e5554dd0d7760a247b5c77aa9397a1c;hpb=99cbdff66c6a1f35e83f8103bf444ddab61fcb59;p=oota-llvm.git

diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp
index bb860d293e5..a60939c3010 100644
--- a/lib/CodeGen/SimpleRegisterCoalescing.cpp
+++ b/lib/CodeGen/SimpleRegisterCoalescing.cpp
@@ -460,9 +460,20 @@ bool SimpleRegisterCoalescing::ReMaterializeTrivialDef(LiveInterval &SrcInt,
   unsigned DefIdx = li_->getDefIndex(CopyIdx);
   const LiveRange *DLR= li_->getInterval(DstReg).getLiveRangeContaining(DefIdx);
   DLR->valno->copy = NULL;
+  // Don't forget to update sub-register intervals.
+  if (TargetRegisterInfo::isPhysicalRegister(DstReg)) {
+    for (const unsigned* SR = tri_->getSubRegisters(DstReg); *SR; ++SR) {
+      if (!li_->hasInterval(*SR))
+        continue;
+      DLR = li_->getInterval(*SR).getLiveRangeContaining(DefIdx);
+      if (DLR && DLR->valno->copy == CopyMI)
+        DLR->valno->copy = NULL;
+    }
+  }
 
-  MachineBasicBlock::iterator MII = CopyMI;
   MachineBasicBlock *MBB = CopyMI->getParent();
+  MachineBasicBlock::iterator MII = next(MachineBasicBlock::iterator(CopyMI));
+  CopyMI->removeFromParent();
   tii_->reMaterialize(*MBB, MII, DstReg, DefMI);
   MachineInstr *NewMI = prior(MII);
   // CopyMI may have implicit operands, transfer them over to the newly
@@ -481,7 +492,7 @@ bool SimpleRegisterCoalescing::ReMaterializeTrivialDef(LiveInterval &SrcInt,
   }
 
   li_->ReplaceMachineInstrInMaps(CopyMI, NewMI);
-  CopyMI->eraseFromParent();
+  MBB->getParent()->DeleteMachineInstr(CopyMI);
   ReMatCopies.insert(CopyMI);
   ReMatDefs.insert(DefMI);
   ++NumReMats;
@@ -696,6 +707,18 @@ bool SimpleRegisterCoalescing::ShortenDeadCopyLiveRange(LiveInterval &li,
   return false;
 }
 
+/// RemoveDeadDef - If a def of a live interval is now determined dead, remove
+/// the val# it defines. If the live interval becomes empty, remove it as well.
+bool SimpleRegisterCoalescing::RemoveDeadDef(LiveInterval &li,
+                                             MachineInstr *DefMI) {
+  unsigned DefIdx = li_->getDefIndex(li_->getInstructionIndex(DefMI));
+  LiveInterval::iterator MLR = li.FindLiveRangeContaining(DefIdx);
+  if (DefIdx != MLR->valno->def)
+    return false;
+  li.removeValNo(MLR->valno);
+  return removeIntervalIfEmpty(li, li_, tri_);
+}
+
 /// PropagateDeadness - Propagate the dead marker to the instruction which
 /// defines the val#.
 static void PropagateDeadness(LiveInterval &li, MachineInstr *CopyMI,
@@ -2269,6 +2292,7 @@ bool SimpleRegisterCoalescing::runOnMachineFunction(MachineFunction &fn) {
 
   // Perform a final pass over the instructions and compute spill weights
   // and remove identity moves.
+  SmallVector<unsigned, 4> DeadDefs;
   for (MachineFunction::iterator mbbi = mf_->begin(), mbbe = mf_->end();
        mbbi != mbbe; ++mbbi) {
     MachineBasicBlock* mbb = mbbi;
@@ -2302,9 +2326,13 @@ bool SimpleRegisterCoalescing::runOnMachineFunction(MachineFunction &fn) {
         bool isDead = true;
         for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
           const MachineOperand &MO = MI->getOperand(i);
-          if (!MO.isReg() || MO.isDead())
+          if (!MO.isReg())
             continue;
           unsigned Reg = MO.getReg();
+          if (TargetRegisterInfo::isVirtualRegister(Reg))
+            DeadDefs.push_back(Reg);
+          if (MO.isDead())
+            continue;
           if (TargetRegisterInfo::isPhysicalRegister(Reg) ||
               !mri_->use_empty(Reg)) {
             isDead = false;
@@ -2312,10 +2340,16 @@ bool SimpleRegisterCoalescing::runOnMachineFunction(MachineFunction &fn) {
           }
         }
         if (isDead) {
+          while (!DeadDefs.empty()) {
+            unsigned DeadDef = DeadDefs.back();
+            DeadDefs.pop_back();
+            RemoveDeadDef(li_->getInterval(DeadDef), MI);
+          }
           li_->RemoveMachineInstrFromMaps(mii);
           mii = mbbi->erase(mii);
           continue;
-        }
+        } else
+          DeadDefs.clear();
       }
 
       // If the move will be an identity move delete it