AVX-512 and ARM SVE2 are Predicated SIMD ISAs.
**None of them provide Scalability to the Programmer**. SVE2 is **Silicon**
Scalable, not **Programmer** Scalable: the distinction is profoundly
-important (already causing problems).
+important (already
+[causing problems](https://gist.github.com/zingaburga/805669eb891c820bd220418ee3f0d6bd#file-sve2-md) ).
For Predicated SIMD, Programmers must emulate Cray-style scaling
through explicit predicate masking, which increases instruction count in
hot-loops.