On 13/3/21 6:47 am, Eli Schwartz via arch-dev-public wrote:
On 3/4/21 6:33 AM, Allan McRae via arch-dev-public wrote:
On 3/3/21 10:54 am, Allan McRae via arch-dev-public wrote:
On 2/3/21 9:51 pm, Allan McRae wrote:
Hi all,
A new RFC has been opened here: https://gitlab.archlinux.org/archlinux/rfcs/-/merge_requests/2
Summary: Make -march=x86_64-v2 the default for our packages. This assumes the following instruction sets which are essentially available on all but the oldest AMD CPUs:
CMPXCHG16B, LAHF-SAHF, POPCNT, SSE3, SSE4.1, SSE4.2, SSSE3
Please visit the above link for discussion.
Lets put discussion on this RFC on hold for a while. Clearly there is a reasonable amount of objection to making x86-64-v2 the default. While this mostly appears to be objection based on personal circumstances and not on the basis of whether this change is good for the distro, I will work within these limits.
A lot of comments have suggested adding x86-64-v2 and -v3 as additional architectures instead. I will revamp the the proposal to take that approach. Though, to do this automated would require more work it may be the push we need for a signing enclave to be set up.
For the record -- the RFC has now been revamped. The new form of the proposal is to add a -v3 (skipping right over -v2) additional architecture.
``` Alternatives Considered -----------------------
Moving the baseline to x86-64-v2 was discussed, but the gains were not considered enough to justify removal of support for hardware without SSE4.2. ```
As an FYI - I'm still working on the RFC update. I forgot that pushing to my branch updated the merge request... I'll post a new RFC on the mailing list once it is ready for comment. People are of course free to comment as I work on it so it is in better shape once it is submitted. Allan