590     // -RegB is not tied to a register and RegC is compatible with RegA.  in isProfitableToCommute()
591     // -RegB is tied to the wrong physical register, but RegC is.  in isProfitableToCommute()
592     // -RegB is tied to the wrong physical register, and RegC isn't tied.  in isProfitableToCommute()
596     // -RegC is not tied to a register and RegB is compatible with RegA.  in isProfitableToCommute()
597     // -RegC is tied to the wrong physical register, but RegB is.  in isProfitableToCommute()
598     // -RegC is tied to the wrong physical register, and RegB isn't tied.  in isProfitableToCommute()
1201 /// For the case where an instruction has a single pair of tied register
1202 /// operands, attempt some transformations that may either eliminate the tied
1399 // Collect tied operands of MI that need to be handled.
1401 // Return true if any tied operands where found, including the trivial ones.
1417     // Tied constraint already satisfied?  in collectTiedOperands()
1440 // Process a list of tied MI operands that all use the same source register.
1441 // The tied pairs are of the form (SrcIdx, DstIdx).
1471       // The register is tied to multiple destinations (or else we would  in processTiedPairs()
1473       // already matches the tied destination.  Leave it.  in processTiedPairs()
1503                "tied subregister must be a truncation");  in processTiedPairs()
1509                && "tied subregister must be a truncation");  in processTiedPairs()
1557       // Replace other (un-tied) uses of regB with LastCopiedReg.  in processTiedPairs()
1591     // Some tied uses of regB matched their destination registers, so  in processTiedPairs()
1593     // removed from a different tied use of regB, so now we need to add  in processTiedPairs()
1652       // First scan through all the tied register uses in this instruction  in runOnMachineFunction()
1653       // and record a list of pairs of tied operands for each register.  in runOnMachineFunction()
1663       // If the instruction has a single pair of tied operands, try some  in runOnMachineFunction()
1664       // transformations that may either eliminate the tied operands or  in runOnMachineFunction()
1676             // The tied operands have been eliminated or shifted further down  in runOnMachineFunction()
1706       // since most instructions do not have tied operands.  in runOnMachineFunction()