RFR: 8347830: [premain] UseCompatibleCompressedOops is broken after merging with mainline [v2]

[Ashutosh Mehra]

On Fri, 16 May 2025 18:09:41 GMT, Vladimir Kozlov <kvn at openjdk.org> wrote:

>> The issue was that we did not allocate space "noaccess prefix" before heap for read-only page when we setup type of encoding  with `UseCompatibleCompressedOops` flag. I update code which reserves heap for compressed oops to take into account this flag.
>> 
>> An other issue was that `UseCompatibleCompressedOops` flag was set during CDS arguments consistency checkup. But `UseCompressedOops` flag is set by GC ergonomics. I moved code to CDS ergonomics setting method.
>> 
>> During testing I hit assert that AOT code address table is missing some code blob address. But it was actually card table base address which pointed inside CodeCache. I added special case to check for it early.
>> 
>> Tested premain-tier1.
>
> Vladimir Kozlov has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Added missing checks. Address comment.

looks good to me

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

Marked as reviewed by asmehra (Committer).

PR Review: https://git.openjdk.org/leyden/pull/67#pullrequestreview-2847445506