Clear kill flags while computing live ranges.

Kill flags are difficult to maintain, and liveness queries are better
handled by live intervals.

Kill flags are reinserted after register allocation by addKillFlags().

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163334 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/LiveRangeCalc.cpp b/lib/CodeGen/LiveRangeCalc.cpp
index d828f25932e72e69e6f186f18b22284e49dc8c41..c3ff4f1b6d2eb6708cdd5c0f3ca31da28b7f402c 100644 (file)
--- a/lib/CodeGen/LiveRangeCalc.cpp
+++ b/lib/CodeGen/LiveRangeCalc.cpp
@@ -65,7 +65,11 @@ void LiveRangeCalc::extendToUses(LiveInterval *LI, unsigned Reg) {
   // Visit all operands that read Reg. This may include partial defs.
   for (MachineRegisterInfo::reg_nodbg_iterator I = MRI->reg_nodbg_begin(Reg),
        E = MRI->reg_nodbg_end(); I != E; ++I) {
-    const MachineOperand &MO = I.getOperand();
+    MachineOperand &MO = I.getOperand();
+    // Clear all kill flags. They will be reinserted after register allocation
+    // by LiveIntervalAnalysis::addKillFlags().
+    if (MO.isUse())
+      MO.setIsKill(false);
     if (!MO.readsReg())
       continue;
     // MI is reading Reg. We may have visited MI before if it happens to be