RFR: 8315066: Add unsigned bounds and known bits to TypeInt/Long [v54]

[Quan Anh Mai]

On Thu, 1 May 2025 09:34:56 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

>> Quan Anh Mai has updated the pull request incrementally with three additional commits since the last revision:
>> 
>>  - new_hi computation
>>  - refer back to the formality section
>>  - clarify where overflow comes from
>
> src/hotspot/share/opto/rangeinference.cpp line 938:
> 
>> 936: 
>> 937: template <class U>
>> 938: const char* TypeIntHelper::bitname(char* buf, size_t buf_size, U zeros, U ones) {
> 
> Wow, these will look incredibly long for 64bit long values, no?
> Well, if it ever gets too much in the way, we can still try to find more compressed representations later.
> Maybe things like: `*..*000` for 8-aligned values.
> Others: `0..0***`, `00*..*`, `1..1***` etc.
> `0..0*..*` would be a little unfortunate as we would lose the position where the bits flip.

It only gets printed when we print verbose the `TypeInt` instance, for normal `dump` bit information is not present.

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PR Review Comment: https://git.openjdk.org/jdk/pull/17508#discussion_r2070142217