Each SIMD vector type is named scalar-count, where scalar is a scalar C type and count is a vector dimension.

The following 128-bit vector types are defined in the math.vectors.simd vocabulary:
char-16 uchar-16 short-8 ushort-8 int-4 uint-4 longlong-2 ulonglong-2 float-4 double-2

Double-width 256-bit vector types are defined in the math.vectors.simd.cords vocabulary:
char-32 uchar-32 short-16 ushort-16 int-8 uint-8 longlong-4 ulonglong-4 float-8 double-4