RFR: 8366037: Remove oopDesc::mark_addr()

[Stefan Karlsson]

On Sat, 23 Aug 2025 23:02:33 GMT, Kim Barrett <kbarrett at openjdk.org> wrote:

> Please review this change that removes the function oopDesc::mark_addr().
> It's kind of a suspicious function, since it is casting away the volatile for
> a location that has concurrent reads and writes. But there isn't any code that
> examines the value at the obtained address. Instead, it's just used as the
> base address for a few prefetches. We change those places accordingly, and
> remove the now unused mark_addr function.
> 
> Testing: mach5 tier1

Looks good.

I wonder though if it would make sense to have a function, say, `void* oopDesc::base_addr()` and use that instead of the added casts?

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Marked as reviewed by stefank (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/26914#pullrequestreview-3150893071