[llvm-commits] [llvm] r134228 - /llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp

[Rafael Espindola]

Author: rafael
Date: Thu Jun 30 21:35:06 2011
New Revision: 134228

URL: http://llvm.org/viewvc/llvm-project?rev=134228&view=rev
Log:
Check the liveinterval, not the kill flag.

Modified:
    llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp

Modified: llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp?rev=134228&r1=134227&r2=134228&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp (original)
+++ llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp Thu Jun 30 21:35:06 2011
@@ -1197,7 +1197,8 @@
 // which allows us to coalesce A and B.
 // MI is the definition of B. LR is the life range of A that includes
 // the slot just before B. If we return true, we add "B = X" to DupCopies.
-static bool RegistersDefinedFromSameValue(const TargetRegisterInfo &tri,
+static bool RegistersDefinedFromSameValue(LiveIntervals &li,
+                                          const TargetRegisterInfo &tri,
                                           CoalescerPair &CP, MachineInstr *MI,
                                           LiveRange *LR,
                                      SmallVector<MachineInstr*, 8> &DupCopies) {
@@ -1207,14 +1208,16 @@
   if (!MI->isFullCopy() || CP.isPartial() || CP.isPhys())
     return false;
 
+  unsigned Dst = MI->getOperand(0).getReg();
+  unsigned Src = MI->getOperand(1).getReg();
+
   // FIXME: If "B = X" kills X, we have to move the kill back to its
   // previous use. For now we just avoid the optimization in that case.
-  if (MI->getOperand(1).isKill())
+  SlotIndex CopyIdx = li.getInstructionIndex(MI).getNextIndex().getDefIndex();
+  LiveInterval &SrcInt = li.getInterval(Src);
+  if (SrcInt.killedAt(CopyIdx))
     return false;
 
-  unsigned Dst = MI->getOperand(0).getReg();
-  unsigned Src = MI->getOperand(1).getReg();
-
   if (!TargetRegisterInfo::isVirtualRegister(Src) ||
       !TargetRegisterInfo::isVirtualRegister(Dst))
     return false;
@@ -1332,7 +1335,7 @@
     // from the RHS interval, we can use its value #.
     MachineInstr *MI = VNI->getCopy();
     if (!CP.isCoalescable(MI) &&
-        !RegistersDefinedFromSameValue(*tri_, CP, MI, lr, DupCopies))
+        !RegistersDefinedFromSameValue(*li_, *tri_, CP, MI, lr, DupCopies))
       continue;
 
     LHSValsDefinedFromRHS[VNI] = lr->valno;
@@ -1359,7 +1362,7 @@
     // from the LHS interval, we can use its value #.
     MachineInstr *MI = VNI->getCopy();
     if (!CP.isCoalescable(MI) &&
-        !RegistersDefinedFromSameValue(*tri_, CP, MI, lr, DupCopies))
+        !RegistersDefinedFromSameValue(*li_, *tri_, CP, MI, lr, DupCopies))
         continue;
 
     RHSValsDefinedFromLHS[VNI] = lr->valno;