@multitable @columnfractions .12 .17 .17 .54
@headitem Extension @tab Minimum Architecture @tab Enabled by default
@tab Description
+@item @code{compnum} @tab ARMv8.2-A @tab ARMv8.3-A or later
+ @tab Enable the complex number SIMD extensions. This implies
+ @code{fp16} and @code{simd}.
@item @code{crc} @tab ARMv8-A @tab ARMv8.1-A or later
@tab Enable CRC instructions.
@item @code{crypto} @tab ARMv8-A @tab No