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Note that will not guarantee stable alignment. The GC can move the allocated array.
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<div>I don’t know if we will ever get to supporting hyper-aligned heap objects, it's likely complex for GCs to support and to surface that up to developers. There are more important things to work on.</div>
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<div>Paul.<br id="lineBreakAtBeginningOfMessage">
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<div>On May 19, 2025, at 6:18 AM, Per-Ake Minborg <per-ake.minborg@oracle.com> wrote:</div>
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Hi again Lee!<br>
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1.<br>
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The VM/GC has its own rules for how arrays are allocated, and so, there is no way (at least not now) to control primitive array alignment except for the way you mentioned — a primitive array is always aligned to its component's natural alignment. A very simple
way to allocate and align heap arrays could be to implement a method similar to this one:<br>
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<span style="font-family: monospace;">static MemorySegment heapSegment(MemoryLayout layout) {<br>
byte[] arr = new byte[(int) layout.byteSize() * (int)layout.byteAlignment() - 1];<br>
SegmentAllocator allocator = SegmentAllocator.slicingAllocator(MemorySegment.ofArray(arr));<br>
return allocator.allocate(layout);<br>
}</span><br>
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If memory efficiency is a concern, a more complex solution can be written that leverages the implicit alignment of arrays of<span class="Apple-converted-space"> </span><code>int</code> and<span class="Apple-converted-space"> </span><code>long.</code></div>
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