RFR: 8340731: Cleanup remaining IA64 references in hotspot code

[David Holmes]

On Tue, 26 Nov 2024 06:52:51 GMT, Amit Kumar <amitkumar at openjdk.org> wrote:

> This PR cleans up `IA64` entries form hotspot codebase. 
> 
> As mentioned in the JBS, I left `zero` component as-it-is: 
> 
> ./cpu/zero/bytecodeInterpreter_zero.hpp:31:#if defined(PPC) || defined(IA64)
> ./os_cpu/linux_zero/os_linux_zero.cpp:350:#ifdef IA64
> ./os_cpu/linux_zero/os_linux_zero.cpp:351:    // IA64 has two stacks sharing the same area of memory, a normal
> ./os_cpu/linux_zero/os_linux_zero.cpp:360:#endif // IA64
> 
> 
> Fastdebug VM Build on Mac-M1 & Linux/s390x is fine. Tests are in progress.

@offamitkumar thanks for taking up this cleanup!

Generally looks okay, a couple of nits and queries.

Thanks

src/hotspot/share/runtime/frame.hpp line 167:

> 165: 
> 166:   // Every frame needs to return a unique id which distinguishes it from all other frames.
> 167:   // For sparc and ia32 use sp. ia64 can have memory frames that are empty so multiple frames

For now the IA32 part should remain.

src/hotspot/share/runtime/frame.hpp line 168:

> 166:   // Every frame needs to return a unique id which distinguishes it from all other frames.
> 167:   // No real frame should have an id() of null so it is a distinguishing value for an unmatchable frame.
> 168:   // We also have relationals which allow comparing a frame to another frame's id() allow

Suggestion:

  // We also have relationals which allow comparing a frame to another frame's id() allowing

src/hotspot/share/runtime/javaCalls.cpp line 121:

> 119:   // Do this after the transition because this allows us to put an assert
> 120:   // the Java->vm transition which checks to see that stack is not walkable
> 121:   // which will catch violations of the resetting of last_Java_frame

Not clear the comment is still valid given we no longer have sparc or ia64 support.

src/hotspot/share/runtime/os.hpp line 858:

> 856:   // does not require a lookup in the unwind table, which is part of the binary
> 857:   // file but may be unsafe to read after a fatal error. So on x86, we can
> 858:   // only walk stack if %ebp is used as frame pointer;

Suggestion:

  // only walk stack if %ebp is used as frame pointer.

src/hotspot/share/utilities/elfFuncDescTable.hpp line 39:

> 37: 
> 38: On PowerPC-64 a pointer to a function is not just a plain code address,
> 39: but instead a pointer to a so-called function descriptor (which is simply a structure containing 3 pointers).

Suggestion:

On PowerPC-64 a pointer to a function is not just a plain code address, but instead a pointer
to a so-called function descriptor (which is simply a structure containing 3 pointers).

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PR Review: https://git.openjdk.org/jdk/pull/22382#pullrequestreview-2460585995
PR Review Comment: https://git.openjdk.org/jdk/pull/22382#discussion_r1857931749
PR Review Comment: https://git.openjdk.org/jdk/pull/22382#discussion_r1857932776
PR Review Comment: https://git.openjdk.org/jdk/pull/22382#discussion_r1857934114
PR Review Comment: https://git.openjdk.org/jdk/pull/22382#discussion_r1857934547
PR Review Comment: https://git.openjdk.org/jdk/pull/22382#discussion_r1857935992