[Libre-soc-dev] [RFC] SVP64 Branches (contd)

[lkcl]

https://libre-soc.org/openpower/sv/branches/

after realising that CTR can be used to save instructions in tight Vector loops by not needing an explicit GPR subtraction, comparison, and etc etc, i also realised that there are even more possible modes that might be useful.

* only reduce CTR on predicated elements.  you know there's 50 elements somewhere in a list of length e.g. 5000, you want to process those but stop when the 50th has been done.

* only reduce CTR on condition tests that succeed

* only reduce CTR on condition tests that *fail*

there are plenty more options like this, what are they? what is actually useful?

l.