https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65676
--- Comment #2 from Uroš Bizjak <ubizjak at gmail dot com> --- Looking at the definition of __mmask8 and __mmask16 in vx512fintrin.h: typedef unsigned char __mmask8; typedef unsigned short __mmask16; the masks should use: DEF_PRIMITIVE_TYPE (UQI, unsigned_intQI_type_node) DEF_PRIMITIVE_TYPE (UHI, unsigned_intHI_type_node)