RFR: 8350118: Simplify the layout access VarHandle [v5]

[Chen Liang]

On Fri, 28 Feb 2025 10:37:17 GMT, Maurizio Cimadamore <mcimadamore at openjdk.org> wrote:

>> Chen Liang has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   noStride -> constantOffset, optimize VH classes to have only 2 instead of 3 classes for each type
>
> src/java.base/share/classes/java/lang/invoke/X-VarHandleSegmentView.java.template line 53:
> 
>> 51: 
>> 52:     static final VarForm CONSTANT_OFFSET_FORM = new VarForm(VarHandleSegmentAs$Type$s.class, MemorySegment.class, $type$.class, long.class);
>> 53:     static final VarForm TAKE_OFFSET_FORM = new VarForm(VarHandleSegmentAs$Type$s.class, MemorySegment.class, $type$.class, long.class, long.class);
> 
> what does TAKE mean here? (the old names weren't great either, I realize). I think it would be better to decide, once and for all, how to refer to these things, and then use consistent naming throughout. I see we have discussed using "noStride" vs. "fixedOffset". Since the implementation now uses the term "constantOffset", let's just call the other "variableOffset" ?

Done renaming to `VARIABLE_OFFSET_FORM`. I have also cleaned up some other stale names in the comments.

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/23720#discussion_r1975640481