destruction of LR during loops (particularly Vertical-First
ones).
* **VSb** In VLSET Mode, after testing,
- if VSb is set, VL is truncated if the branch succeeds. If VSb is clear,
- VL is truncated if the branch did **not** take place.
+ if VSb is set, VL is truncated if the test succeeds. If VSb is clear,
+ VL is truncated if a test *fails*. Masked-out (skipped)
+ bits are not considered
+ part of testing.
* **CTi** CTR inversion. CTR-test Mode normally decrements per element
tested. CTR inversion decrements if a test *fails*. Only relevant
in CTR-test Mode.