RFR: 8315066: Add unsigned bounds and known bits to TypeInt/Long [v7]

[Quan Anh Mai]

On Tue, 3 Sep 2024 13:49:05 GMT, Emanuel Peter <epeter 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 11 commits:
>> 
>>  - fix compile errors
>>  - Merge branch 'master' into unsignedbounds
>>  - add comments
>>  - Merge branch 'master' into unsignedbounds
>>  - fix release build
>>  - add comments, group arguments to reduce C-style reference passing arguments
>>  - fix tests, add verify
>>  - add unit tests
>>  - fix template parameter
>>  - refactor
>>  - ... and 1 more: https://git.openjdk.org/jdk/compare/d8e4d3f2...d5ad9f1a
>
> src/hotspot/share/opto/rangeinference.cpp line 56:
> 
>> 54:   static_assert(std::is_unsigned<T>::value, "");
>> 55: 
>> 56:   auto adjust_lo = [](T lo, const KnownBits<T>& bits) {
> 
> This does not even capture anything. Why not make it its own dedicated method with a nice name? I guess this could also be a member method of `KnownBits`.

Since it is only used here I think it would be more sensible to make it a local lambda to lower the visibility, the resulting function is not too large, too.

> src/hotspot/share/opto/type.hpp line 606:
> 
>> 604:   const juint _zeros, _ones; // Bits that are known to be 0 or 1
>> 605: 
>> 606:   static const TypeInt* cast(const Type* t) { return t->is_int(); }
> 
> Is this even used?

I have removed it.

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PR Review Comment: https://git.openjdk.org/jdk/pull/17508#discussion_r1742651668
PR Review Comment: https://git.openjdk.org/jdk/pull/17508#discussion_r1742648644