RFR: 8315066: Add unsigned bounds and known bits to TypeInt/Long [v13]

[Quan Anh Mai]

On Thu, 5 Sep 2024 16:59:47 GMT, Vladimir Kozlov <kvn at openjdk.org> wrote:

>> The call:
>> 
>> https://github.com/openjdk/jdk/blob/5990628a8337b9040128857f34359b169326eb23/src/hotspot/share/opto/type.cpp#L1598
>> 
>> And the implementation:
>> 
>> https://github.com/openjdk/jdk/blob/5990628a8337b9040128857f34359b169326eb23/src/hotspot/share/opto/rangeinference.cpp#L358
>> 
>> Notice that `this->contains(_srange._lo)` implies that `_lo <= _hi`
>
> Okay but assert will guard against future incorrect changes by someone who may not familiar with verification code you pointed. Some new path in type construction can be introduced which bypath those checks.

My thought is that a `TypeInt` has many invariants and it would be really expensive if we check all of them at all use sites, and it seems not enough if we only check for one of those invariants. What do you think?

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PR Review Comment: https://git.openjdk.org/jdk/pull/17508#discussion_r1745946303