RFR: 8370863: VectorAPI: Optimize the VectorMaskCast chain in specific patterns [v8]

[Eric Fang]

On Tue, 27 Jan 2026 08:10:14 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

>> test/hotspot/jtreg/compiler/vectorapi/VectorMaskCastIdentityTest.java line 121:
>> 
>>> 119:         VectorMask<Integer> mInt128 = mFloat128.cast(IntVector.SPECIES_128);
>>> 120:         return mInt128.not().trueCount();
>>> 121:     }
>> 
>> Why can't the casts be eliminated here? Can you please add a comment to the test?
>
> There used to be a comment, would that one still be accurate?

Yeah, the comment is still there, see line 92 of this file. I refactored this file a bit, now it looks like this:

// comment for testXXXCastToSameType
testOneCastToSameType()
testTwoCastToSameType()

// comment for testXXXCastToDifferentType
testOneCastToDifferentType()
testTwoCastToDifferentType()

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PR Review Comment: https://git.openjdk.org/jdk/pull/28313#discussion_r2730907001