RFR: 8352635: Improve inferencing of Float16 operations with constant inputs [v11]

[Emanuel Peter]

On Thu, 19 Jun 2025 07:08:52 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

>> Jatin Bhateja has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Adding a stricter constant type check
>
> src/hotspot/share/opto/convertnode.cpp line 285:
> 
>> 283:     if (conF != nullptr &&
>> 284:         varS != nullptr &&
>> 285:         conF->bottom_type()->isa_float_constant() &&
> 
> Yes, it might well have come from here, because `is_float_constant` asserts if it is not a float constant.
> 
> But now you have an implicit null check, right? You should make it explicit, as per the guidelines.

`src/hotspot/share/opto/type.hpp:301:21:  const TypeF      *isa_float_constant() const;  // Returns null if not a FloatCon`

It returns a pointer, not a boolean. So you should write `conF->bottom_type()->isa_float_constant() != nullptr`

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PR Review Comment: https://git.openjdk.org/jdk/pull/24179#discussion_r2156340988