Saving instruction encoding space in CHERI RISC-V #120
Description
In previous discussions, we concluded that there are some instructions in CHERI-RISC-V that could potentially be omitted without loosing performance if they are rare and/or could be easily emulated with other instructions. These instructions include:
- CSetEqualsExact: Could be emulated with cgethigh, cgettag, and address comparison
- CRepresentableAlignmentMask
- CTestSubset: Perhaps could be emulated with CBuildCap (except when the capability is sealed!)
It would be good to investigate this more carefully by looking at performance data.