[TargetSchedule] Use 'isOutOfOrder' as possible to avoid magic number. NFC.

[flyingforyou]

Summary

Using isOutOfOrder makes the code more clear.

[hfinkel]

LGTM

[flyingforyou]

Thanks for review Hal.!

Committed in r273255.

lib/CodeGen/TargetSchedule.cpp

if (SCDesc->isValid())
       return computeInstrLatency(*SCDesc);
   }
   return TII->defaultDefLatency(SchedModel, MI);
 }
 
 unsigned TargetSchedModel::
 computeOutputLatency(const MachineInstr *DefMI, unsigned DefOperIdx,
                      const MachineInstr *DepMI) const {
-  if (SchedModel.MicroOpBufferSize <= 1)
+  if (!SchedModel.isOutOfOrder())
     return 1;
 
-  // MicroOpBufferSize > 1 indicates an out-of-order processor that can dispatch
-  // WAW dependencies in the same cycle.
+  // Out-of-order processor can dispatch WAW dependencies in the same cycle.
 
   // Treat predication as a data dependency for out-of-order cpus. In-order
   // cpus do not need to treat predicated writes specially.
   //
   // TODO: The following hack exists because predication passes do not
   // correctly append imp-use operands, and readsReg() strangely returns false
   // for predicated defs.
   unsigned Reg = DefMI->getOperand(DefOperIdx).getReg();