GCC-13 Branch with RISC-V Performance-Related Backports

[Jeff Law]

On 4/18/23 04:34, Kito Cheng wrote:
>>> Based on some discussions, it looks like a handful of vendors are
>>> planning on maintaining GCC-13 branches that include various
>>> performance-related backports (ie, patches not suitable for the standard
>>> GCC-13 release branch).
> 
> Did you consider also include necessary vectorizeor stuffs? I expect there would
> be some patch in middle end for enable auto vec, like this:
> 
> https://patchwork.ozlabs.org/project/gcc/patch/20230407014741.139387-1-juzhe.zhong@rivai.ai/
I think to some degree middle end patches are inevitable.  I think the 
same basic guidelines applies.  If it's on the trunk, then pulling it 
over to our branch is implicitly OK.

> 
>>>
>>> I don't think we'd actually agreed to a set of branch rules, but it
>>> seems like the following were where the discussion ended up:
>>>
>>> * Make a "riscv" vendor branch.  I don't think we came up with a name,
>>>    but "riscv/gcc-13-perf" seems fine to me.
>>> * Regularly rebase the branch on the GCC-13 release branch.
> 
> I would prefer merge rather than rebase since let us have a stable
> sha1 as some reference point.
I slightly prefer the rebase approach.  Its easier to see where we are 
relative to the current gcc-13 bits.  Doing an occasional forced update 
isn't that bad (I've worked with this kind of flow for shared topic 
branches in the past).  But if you feel strongly, I can live with a 
merge flow as well.

Jeff