RFR: 8351194: Clean up Hotspot SA after 32-bit x86 removal [v5]

[Chris Plummer]

On Wed, 22 Oct 2025 08:48:47 GMT, Kerem Kat <krk at openjdk.org> wrote:

>> Remove 32-bit x86 specific code from the HotSpot Serviceability Agent following the removal of 32-bit x86 support.
>> 
>> - Removed x86-specific implementations and ifdef blocks.
>> - Renamed files with X86 in the name when they are also used from AMD64, e.g. `X86Frame` → `AMD64Frame`.
>> - Cleaned up platform detection logic in `PlatformInfo`.
>> - Updated documentation references.
>
> Kerem Kat has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Revert "run RotateLeftNode*IdealizationTests on amd64 too"
>   
>   This reverts commit 1011b304f7cb4d195efc9239acd7784053c67cc1.

Overall the changes look good. I just requested some updates on some of the comments. I'm about to be OOO for close to a week, so I'll follow up on this when I return.

src/jdk.hotspot.agent/doc/hsdb.html line 34:

> 32:  <li> Class Browser - view Java classes, bytecode disassembly,
> 33:    or create .class files for selected classes
> 34:  <li> native disassembly (amd64 only) and nmethod disassembly with annotations for safepoint details.

"requires hsdis"

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/windbg/WindbgDebugger.java line 54:

> 52: 
> 53:   // The returned array of register contents is guaranteed to be in
> 54:   // the same order as in the DbxDebugger for Solaris or amd64; that is,

I think the original wording implied "Solaris/x86 or Solaris/amd64", so I think the updated text should just read "Solaris/amd64".

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/windbg/WindbgDebugger.java line 55:

> 53:   // The returned array of register contents is guaranteed to be in
> 54:   // the same order as in the DbxDebugger for Solaris or amd64; that is,
> 55:   // the indices match those in debugger/amd64/AMD64ThreadContext.java or

Now you have debugger/amd64/AMD64ThreadContext.java both on this line and the next. You need to reduce it to just one occurrence.

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/runtime/amd64/AMD64Frame.java line 39:

> 37: 
> 38: /** Specialization of and implementation of abstract methods of the
> 39:     Frame class for the x86-64 family of CPUs. */

"x86_64"

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

PR Review: https://git.openjdk.org/jdk/pull/27844#pullrequestreview-3367452899
PR Review Comment: https://git.openjdk.org/jdk/pull/27844#discussion_r2453284822
PR Review Comment: https://git.openjdk.org/jdk/pull/27844#discussion_r2453320919
PR Review Comment: https://git.openjdk.org/jdk/pull/27844#discussion_r2453324086
PR Review Comment: https://git.openjdk.org/jdk/pull/27844#discussion_r2453327438