Teach MachineLICM and MachineSink how to clear kill flags conservatively
when they move instructions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@103737 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineInstr.cpp b/lib/CodeGen/MachineInstr.cpp
index 99b5beb..d909fb0 100644
--- a/lib/CodeGen/MachineInstr.cpp
+++ b/lib/CodeGen/MachineInstr.cpp
@@ -938,6 +938,16 @@
   return true;
 }
 
+/// clearKillInfo - Clears kill flags on all operands.
+///
+void MachineInstr::clearKillInfo() {
+  for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
+    MachineOperand &MO = getOperand(i);
+    if (MO.isReg() && MO.isUse())
+      MO.setIsKill(false);
+  }
+}
+
 /// copyKillDeadInfo - Copies kill / dead operand properties from MI.
 ///
 void MachineInstr::copyKillDeadInfo(const MachineInstr *MI) {