Section 5.7/8.5 clarification

[buxtonpaul]

In section 5.7 Disabling CHERI Registers the description points to Sections 3.3 and 8.5 for instructions that should generate exceptions. Whilst the text does say CHERI instructions, it is quite easy to read it as all instructions in table 8.5 would generate an exception.
Suggest either

1. Add column to the table in 8.5 to indicate clearly the instructions specified.
2. Reword the sentence to make it clear that not all the instructions in 8.5 are CHERI instructions. E.g.
   The instructions in Section 3.3 and the CHERI instructions in Section 8.5 cause illegal instruction exceptions.

[tariqkurd-repo]

it's certainly not very clear, it should be the instructions added (not modified) by the addition of Zcheripurecap and Zcherihybrid. I'm not sure such a list exists in the spec, as they often include the modified instructions such as in table 31 (section 8.3).

It should be a simple fix, when I get a chance.

[tomaird]

Additionally, should the instructions added by Zish4add and Zabhlrsc also generate exceptions? One would assume not since those extensions aren't mentioned, but then again they are added by the same spec so it might be worth a clarification too to make it explicit.

[tariqkurd-repo]

As it stands, these instructions are not disabled by CRE=0
All instructions which are disabled by CRE=0 have this text on the instruction page:

these instructions don't access any CHERI state, so don't need to be disabled.
The outlier is cram which is disabled by CRE even though it accesses CHERI state, but is useless in a non-CHERI system, unlike the others which could be useful.