RFR: 8346664: C2: Optimize mask check with constant offset [v3]

[Matthias Ernst]

On Mon, 27 Jan 2025 07:49:27 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

>> What's left to do here? Thanks!
>
> @mernst-github Thanks for the test update!
> 
> I see there is still discussion around this line:
> `  return zeros > 0 && ((((jlong)1) << zeros) > mask_t->hi_as_long() && mask_t->lo_as_long() >= 0);`
> 
> It is indeed difficult to read. Maybe even just some clever names of temporary variables could help. But I leave that up to you ;)
> 
> Ping me when you want me to run testing and review again :)

@eme64 I do think the new version is much clearer. I've committed it, and I think this PR is good to go.

-------------

PR Comment: https://git.openjdk.org/jdk/pull/22856#issuecomment-2615125714