+/// isSafeToDelete - If the specified instruction does not produce any side
+/// effects and all of its defs are dead, then it's safe to delete.
+static bool isSafeToDelete(MachineInstr *MI, const TargetInstrInfo *TII) {
+ const TargetInstrDesc &TID = MI->getDesc();
+ if (TID.mayStore() || TID.isCall())
+ return false;
+ if (TID.isTerminator() || TID.hasUnmodeledSideEffects())
+ return false;
+
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ MachineOperand &MO = MI->getOperand(i);
+ if (!MO.isReg() || !MO.isDef())
+ continue;
+ if (!MO.isDead())
+ return false;
+ }
+
+ return true;
+}
+