Instruction input.
Size: 1 dword.
Operands: :ref:`v<amdgpu_synid_v>`, :ref:`s<amdgpu_synid_s>`, :ref:`flat_scratch<amdgpu_synid_flat_scratch>`, :ref:`vcc<amdgpu_synid_vcc>`, :ref:`trap<amdgpu_synid_trap>`, :ref:`m0<amdgpu_synid_m0>`, :ref:`exec<amdgpu_synid_exec>`, :ref:`iconst<amdgpu_synid_iconst>`