RFR: 8315066: Add unsigned bounds and known bits to TypeInt/Long [v15]

[Vladimir Kozlov]

On Tue, 10 Sep 2024 12:17:10 GMT, Quan Anh Mai <qamai at openjdk.org> wrote:

>> src/hotspot/share/opto/rangeinference.cpp line 470:
>> 
>>> 468:   // Neither contains each other, weird?
>>> 469:   // fatal("Integer value range is not subset");
>>> 470:   // return this;
>> 
>> This looks like leftover dead code.
>
> Yes it is, but I don't want to remove it. I think it should be the case the `new_type` contains `old_type`, but apparently sometimes it is not the case and I don't understand it. Returning the bottom type instead of `limit_type` is also weird, too.

Unless you want to investigate it this should be removed. File RFE to look on it later.
Also you can execute it only in debug VM by using #ifdef ASSERT and `assert()` instead of `fatal()`.

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PR Review Comment: https://git.openjdk.org/jdk/pull/17508#discussion_r1752325656