RFR: 8253457: Remove unimplemented register stack functions

[Ioi Lam]

On Tue, 22 Sep 2020 14:55:39 GMT, Coleen Phillimore <coleenp at openjdk.org> wrote:

> Please review removed functions left over from Itanium.
> 
> Ran tier1 testing on Oracle platforms (linux-x64, macos-x64, windows-x64 and linux-aarch64) and built on
> linux-arm32,linux-ppc64le-debug,linux-s390x-debug,linux-x64-zero.
> Thanks,
> Coleen

Looks good overall to me. I can see all these functions with no callers. Should they also be removed? I saw you removed
only for thread_linux_arm.hpp.

./os_cpu/linux_aarch64/thread_linux_aarch64.hpp:  void  set_last_Java_fp(intptr_t* fp)           {
_anchor.set_last_Java_fp(fp);   } ./os_cpu/linux_x86/thread_linux_x86.hpp:  void  set_last_Java_fp(intptr_t*
fp)           { _anchor.set_last_Java_fp(fp);   } ./os_cpu/windows_x86/thread_windows_x86.hpp:  void
set_last_Java_fp(intptr_t* fp)           { _anchor.set_last_Java_fp(fp);   } ./os_cpu/linux_arm/thread_linux_arm.hpp:
void  set_last_Java_fp(intptr_t* fp)           { _anchor.set_last_Java_fp(fp);  } ./os_cpu/bsd_x86/thread_bsd_x86.hpp:
void  set_last_Java_fp(intptr_t* fp)           { _anchor.set_last_Java_fp(fp);   }
./cpu/aarch64/javaFrameAnchor_aarch64.hpp:  void set_last_Java_fp(intptr_t* fp)                {
OrderAccess::release(); _last_Java_fp = fp; } ./cpu/arm/javaFrameAnchor_arm.hpp:  void set_last_Java_fp(intptr_t*
fp)                { _last_Java_fp = fp; } ./cpu/x86/javaFrameAnchor_x86.hpp:  void set_last_Java_fp(intptr_t*
fp)                { _last_Java_fp = fp; }

./share/runtime/javaFrameAnchor.hpp:  void set_last_Java_pc(address pc)              { _last_Java_pc = pc; }
./os_cpu/linux_arm/thread_linux_arm.hpp:  void  set_last_Java_pc(address pc)             {
_anchor.set_last_Java_pc(pc);  }

I am not sure about `last_Java_fp()` as I didn't check thoroughly.

The other 5 removed function seem OK to me -- they don't do anything. The only exception is the *_zero.hpp versions
that had some asserts, but I guess these asserts never caught anything since they don't exist on other ports anyway.

src/hotspot/os_cpu/linux_arm/thread_linux_arm.hpp line 46:

> 44:   void  set_last_Java_fp(intptr_t* fp)           { _anchor.set_last_Java_fp(fp);  }
> 45:   void  set_last_Java_pc(address pc)             { _anchor.set_last_Java_pc(pc);  }
> 46:

Why is this remove from _arm, but not for thread_linux_aarch64.hpp

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Changes requested by iklam (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/300