Bug 1181 - ask the ISA WG to produce a list of which instructions are needed by SFS and SFFS in 64-bit mode
Summary: ask the ISA WG to produce a list of which instructions are needed by SFS and ...
Status: CONFIRMED
Alias: None
Product: Libre-SOC's first SoC
Classification: Unclassified
Component: Specification (show other bugs)
Version: unspecified
Hardware: PC Linux
: --- enhancement
Assignee: Luke Kenneth Casson Leighton
URL:
Depends on:
Blocks:
 
Reported: 2023-10-10 19:17 BST by Jacob Lifshay
Modified: 2023-10-10 19:17 BST (History)
1 user (show)

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Description Jacob Lifshay 2023-10-10 19:17:41 BST 
it isn't clear what instructions are needed by SFS and SFFS in 64-bit mode, I think we should submit a rfc or something to clarify that. e.g. are 128-bit atomics required by 64-bit mode? (it would be nice if they are since gcc/clang enable them by default on powerpc64le-linux-gnu; also since once cache line pinning is implemented, reading/writing 128-bits isn't too horribly difficult) what about bpermd or pdep/pext?

I also think BE-mode should be optional for 64-bit cpus.

imo the best option is to introduce new SFS64 and SFFS64 compliancy levels.