cd86b2ab32
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.
This directory contains tests for the MIR file format parser and printer. It was necessary to split the tests across different targets as no single target covers all features available in machine IR. Tests for codegen passes should NOT be here but in test/CodeGen/sometarget. As a rule of thumb this directory should only contain tests using 'llc -run-pass none'.