RFR: 8282365: Consolidate and improve division by constant idealizations [v33]

[Kim Barrett]

On Mon, 27 Nov 2023 23:06:51 GMT, Kim Barrett <kbarrett at openjdk.org> wrote:

>> Quan Anh Mai has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 74 commits:
>> 
>>  - fix proof
>>  - Merge branch 'master' into unsignedDiv
>>  - fix assert macro, benchmarks
>>  - comment styles
>>  - disable test with Xcomp
>>  - remove verify
>>  - fix x86 test
>>  - more rigorous control
>>  - verify the effectiveness of test
>>  - require x64
>>  - ... and 64 more: https://git.openjdk.org/jdk/compare/5224e979...529bd0f9
>
> Not a review - mostly a comment for future development. I only became aware of
> this PR recently (I don't track compiler PRs that closely), so didn't notice
> the embedded separation of Java-semantics arithmetic from globalDefintions. I
> strongly approve of that separation, but wish it had been done in it's own PR.
> Kind of late for suggesting that now though. That change can (and hopefully
> will) be followed by changes to remove the need to #include javaArithmetic.hpp
> from globalDefinitons.hpp, since most code doesn't need javaArithmetic.hpp.
> That's likely to take a while to accomplish, but would be a nice goal to
> achieve. This goes along with the ongoing cleanup of replacing
> unnecessary/inappropriate uses of JNI integral types with "native" types.

> @kimbarrett Thanks for the suggestion, I will create a tracking issue right after the integration of this.

That's not what @stefank and I were suggesting.  Instead we'd like the extraction of javaArithmetic to be a separate
change that is integrated first, with the uses here coming after.  Alternatively, leave out that extraction from this
change (with corresponding adjustments of includes and some additions to (probably) globalDefinitions), and do
the extraction as a followup.  The point being that the two parts are largely independent.

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PR Comment: https://git.openjdk.org/jdk/pull/9947#issuecomment-1830624232