Write val to low 128 bits of a ZMM register; upper bits are preserved.
(wx128 reg val x86) → x86
Function: wx128$inline
(defun wx128$inline (reg val x86) (declare (xargs :stobjs (x86))) (declare (type (unsigned-byte 4) reg) (type (unsigned-byte 128) val)) (wz128 reg val x86 :regtype 1))