[llvm-commits] [llvm] r47749 - in /llvm/trunk/lib/CodeGen: SimpleRegisterCoalescing.cpp SimpleRegisterCoalescing.h

[Evan Cheng]

Author: evancheng
Date: Thu Feb 28 20:50:03 2008
New Revision: 47749

URL: http://llvm.org/viewvc/llvm-project?rev=47749&view=rev
Log:
No need for coalescer to update kills. Only copies are coalesced and those instructions will be deleted. Doh.

Modified:
    llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp
    llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.h

Modified: llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp?rev=47749&r1=47748&r2=47749&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp (original)
+++ llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp Thu Feb 28 20:50:03 2008
@@ -385,26 +385,6 @@
   return true;
 }
 
-/// 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()) {
-      MachineInstr *UseMI = UseMO.getParent();
-      unsigned UseIdx = li_->getUseIndex(li_->getInstructionIndex(UseMI));
-      if (JoinedCopies.count(UseMI))
-        continue;
-      LiveInterval::const_iterator UI = LI.FindLiveRangeContaining(UseIdx);
-      assert(UI != LI.end());
-      if (!LI.isKill(UI->valno, UseIdx+1))
-        UseMO.setIsKill(false);
-    }
-  }
-}
-
 /// isBackEdgeCopy - Returns true if CopyMI is a back edge copy.
 ///
 bool SimpleRegisterCoalescing::isBackEdgeCopy(MachineInstr *CopyMI,
@@ -734,13 +714,6 @@
   // we have to update any aliased register's live ranges to indicate that they
   // have clobbered values for this range.
   if (TargetRegisterInfo::isPhysicalRegister(DstReg)) {
-    // Unset unnecessary kills.
-    if (!ResDstInt->containsOneValue()) {
-      for (LiveInterval::Ranges::const_iterator I = ResSrcInt->begin(),
-             E = ResSrcInt->end(); I != E; ++I)
-        unsetRegisterKills(I->start, I->end, DstReg);
-    }
-
     // If this is a extract_subreg where dst is a physical register, e.g.
     // cl = EXTRACT_SUBREG reg1024, 1
     // then create and update the actual physical register allocated to RHS.
@@ -810,12 +783,6 @@
   // 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);
-
   // SrcReg is guarateed to be the register whose live interval that is
   // being merged.
   li_->removeInterval(SrcReg);
@@ -1496,6 +1463,7 @@
 
 /// findDefOperand - Returns the MachineOperand that is a def of the specific
 /// register. It returns NULL if the def is not found.
+/// FIXME: Move to MachineInstr.
 MachineOperand *SimpleRegisterCoalescing::findDefOperand(MachineInstr *MI,
                                                          unsigned Reg) const {
   for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
@@ -1507,34 +1475,8 @@
   return NULL;
 }
 
-/// unsetRegisterKills - Unset IsKill property of all uses of specific register
-/// between cycles Start and End.
-void SimpleRegisterCoalescing::unsetRegisterKills(unsigned Start, unsigned End,
-                                                  unsigned Reg) {
-  int e = (End-1) / InstrSlots::NUM * InstrSlots::NUM;
-  int s = Start;
-  while (e >= s) {
-    // Skip deleted instructions
-    MachineInstr *MI = li_->getInstructionFromIndex(e);
-    while ((e - InstrSlots::NUM) >= s && !MI) {
-      e -= InstrSlots::NUM;
-      MI = li_->getInstructionFromIndex(e);
-    }
-    if (e < s || MI == NULL)
-      return;
-
-    for (unsigned i = 0, NumOps = MI->getNumOperands(); i != NumOps; ++i) {
-      MachineOperand &MO = MI->getOperand(i);
-      if (MO.isRegister() && MO.isKill() && MO.getReg() &&
-          tri_->regsOverlap(MO.getReg(), Reg)) {
-        MO.setIsKill(false);
-      }
-    }
-
-    e -= InstrSlots::NUM;
-  }
-}
-
+/// RemoveUnnecessaryKills - Remove kill markers that are no longer accurate
+/// due to live range lengthening as the result of coalescing.
 void SimpleRegisterCoalescing::printRegName(unsigned reg) const {
   if (TargetRegisterInfo::isPhysicalRegister(reg))
     cerr << tri_->getName(reg);

Modified: llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.h?rev=47749&r1=47748&r2=47749&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.h (original)
+++ llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.h Thu Feb 28 20:50:03 2008
@@ -190,10 +190,6 @@
     bool RemoveCopyByCommutingDef(LiveInterval &IntA, LiveInterval &IntB,
                                   MachineInstr *CopyMI);
 
-    /// RemoveUnnecessaryKills - Remove kill markers that are no longer accurate
-    /// due to live range lengthening as the result of coalescing.
-    void RemoveUnnecessaryKills(unsigned Reg, LiveInterval &LI);
-
     /// isBackEdgeCopy - Returns true if CopyMI is a back edge copy.
     ///
     bool isBackEdgeCopy(MachineInstr *CopyMI, unsigned DstReg);
@@ -214,10 +210,6 @@
     /// register. It returns NULL if the def is not found.
     MachineOperand *findDefOperand(MachineInstr *MI, unsigned Reg) const;
 
-    /// unsetRegisterKills - Unset IsKill property of all uses of specific register
-    /// between cycles Start and End.
-    void unsetRegisterKills(unsigned Start, unsigned End, unsigned Reg);
-
     void printRegName(unsigned reg) const;
   };