Introduce MO_LaneMask as new machine operand type. This can be used to hold liveness infomation at sub-register granularity for register-type operands. We also introduce a new COPY_LANEMASK instruction that uses MO_lanemask operand to perform partial copy from source register opernad. One such use case of MO_LaneMask can be seen in #151123, where it can be used to store live regUnits information corresponding to the source register of the COPY instructions, later can be used during CopyPhysReg expansion.
9.9 KiB
9.9 KiB