1 files changed, 21 insertions, 45 deletions

diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp
index 543278b467..f14dacae12 100644
--- a/lib/CodeGen/SimpleRegisterCoalescing.cpp
+++ b/lib/CodeGen/SimpleRegisterCoalescing.cpp
@@ -236,7 +236,7 @@ bool SimpleRegisterCoalescing::AdjustCopiesBackFrom(LiveInterval &IntA,
   // If the copy instruction was killing the destination register before the
   // merge, find the last use and trim the live range. That will also add the
   // isKill marker.
-  if (CopyMI->killsRegister(IntA.reg))
+  if (ALR->valno->isKill(CopyIdx))
     TrimLiveIntervalToLastUse(CopyUseIdx, CopyMI->getParent(), IntA, ALR);
 
   ++numExtends;
@@ -709,7 +709,7 @@ bool SimpleRegisterCoalescing::ReMaterializeTrivialDef(LiveInterval &SrcInt,
   // kill.
   bool checkForDeadDef = false;
   MachineBasicBlock *MBB = CopyMI->getParent();
-  if (CopyMI->killsRegister(SrcInt.reg))
+  if (SrcLR->valno->isKill(DefIdx))
     if (!TrimLiveIntervalToLastUse(CopyIdx, MBB, SrcInt, SrcLR)) {
       checkForDeadDef = true;
     }
@@ -837,9 +837,6 @@ SimpleRegisterCoalescing::UpdateRegDefsUses(unsigned SrcReg, unsigned DstReg,
       assert(OldSubIdx < SubIdx && "Conflicting sub-register index!");
     else if (SubIdx)
       O.setSubReg(SubIdx);
-    // Remove would-be duplicated kill marker.
-    if (O.isKill() && UseMI->killsRegister(DstReg))
-      O.setIsKill(false);
     O.setReg(DstReg);
 
     // After updating the operand, check if the machine instruction has
@@ -866,38 +863,6 @@ SimpleRegisterCoalescing::UpdateRegDefsUses(unsigned SrcReg, unsigned DstReg,
   }
 }
 
-/// RemoveUnnecessaryKills - Remove kill markers that are no longer accurate
-/// due to live range lengthening as the result of coalescing.
-void SimpleRegisterCoalescing::RemoveUnnecessaryKills(unsigned Reg,
-                                                      LiveInterval &LI) {
-  for (MachineRegisterInfo::use_iterator UI = mri_->use_begin(Reg),
-         UE = mri_->use_end(); UI != UE; ++UI) {
-    MachineOperand &UseMO = UI.getOperand();
-    if (!UseMO.isKill())
-      continue;
-    MachineInstr *UseMI = UseMO.getParent();
-    SlotIndex UseIdx =
-      li_->getInstructionIndex(UseMI).getUseIndex();
-    const LiveRange *LR = LI.getLiveRangeContaining(UseIdx);
-    if (!LR ||
-        (!LR->valno->isKill(UseIdx.getDefIndex()) &&
-         LR->valno->def != UseIdx.getDefIndex())) {
-      // Interesting problem. After coalescing reg1027's def and kill are both
-      // at the same point:  %reg1027,0.000000e+00 = [56,814:0)  0@70-(814)
-      //
-      // bb5:
-      // 60   %reg1027<def> = t2MOVr %reg1027, 14, %reg0, %reg0
-      // 68   %reg1027<def> = t2LDRi12 %reg1027<kill>, 8, 14, %reg0
-      // 76   t2CMPzri %reg1038<kill,undef>, 0, 14, %reg0, %CPSR<imp-def>
-      // 84   %reg1027<def> = t2MOVr %reg1027, 14, %reg0, %reg0
-      // 96   t2Bcc mbb<bb5,0x2030910>, 1, %CPSR<kill>
-      //
-      // Do not remove the kill marker on t2LDRi12.
-      UseMO.setIsKill(false);
-    }
-  }
-}
-
 /// removeIntervalIfEmpty - Check if the live interval of a physical register
 /// is empty, if so remove it and also remove the empty intervals of its
 /// sub-registers. Return true if live interval is removed.
@@ -1811,12 +1776,6 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) {
   // Remember to delete the copy instruction.
   JoinedCopies.insert(CopyMI);
 
-  // Some live range has been lengthened due to colaescing, eliminate the
-  // unnecessary kills.
-  RemoveUnnecessaryKills(SrcReg, *ResDstInt);
-  if (TargetRegisterInfo::isVirtualRegister(DstReg))
-    RemoveUnnecessaryKills(DstReg, *ResDstInt);
-
   UpdateRegDefsUses(SrcReg, DstReg, SubIdx);
 
   // If we have extended the live range of a physical register, make sure we
@@ -2825,8 +2784,25 @@ bool SimpleRegisterCoalescing::runOnMachineFunction(MachineFunction &fn) {
         li_->RemoveMachineInstrFromMaps(MI);
         mii = mbbi->erase(mii);
         ++numPeep;
-      } else {
-        ++mii;
+        continue;
+      }
+
+      ++mii;
+
+      // Check for now unnecessary kill flags.
+      if (li_->isNotInMIMap(MI)) continue;
+      SlotIndex UseIdx = li_->getInstructionIndex(MI).getUseIndex();
+      for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+        MachineOperand &MO = MI->getOperand(i);
+        if (!MO.isReg() || !MO.isKill()) continue;
+        unsigned reg = MO.getReg();
+        if (!reg || !li_->hasInterval(reg)) continue;
+        LiveInterval &LI = li_->getInterval(reg);
+        const LiveRange *LR = LI.getLiveRangeContaining(UseIdx);
+        if (!LR ||
+            (!LR->valno->isKill(UseIdx.getDefIndex()) &&
+             LR->valno->def != UseIdx.getDefIndex()))
+          MO.setIsKill(false);
       }
     }
   }