RFR: Loom: Add missing stubs to fix build failures on PPC64, S390, ARM32 and Zero

[Alan Bateman]

On Thu, 27 Jan 2022 10:43:14 GMT, Hao Sun <haosun at openjdk.org> wrote:

> PPC64, S390, ARM32, Zero stubs were initially introduced to Loom in
> commit 3a89cd5 [1]. However, necessary updates were missing afterward,
> leading to compilation failures.
> 
> 1. frame_helpers.inline.hpp
> 
> In commit 854a81a [2], platform specific implementation was extracted
> from continuation.cpp to frame_helpers.inline.hpp, and the corresponding
> headers for only x86 and aarch64 were created then.
> 
> This same updates should be done to PPC64/S390/ARM32/Zero as well.
> Otherwise, the following compilation error would be emitted.
> 
> 
> ~/jdk_src/src/hotspot/share/runtime/frame_helpers.inline.hpp:326:1:
> fatal error: frame_helpers_ppc.inline.hpp: No such file or directory
> 
>   326 | #include CPU_HEADER_INLINE(frame_helpers)
> 
>         | ^~~~~~~~~~~~~~~~~
> 
>         compilation terminated.
> 
> 
> Fix: see the updates in continuation_XX.inline.hpp and
> frame_helpers_XX.inline.hpp.
> 
> 2. ZGC support for PPC64
> 
> ZGC support for Loom was implemented two years ago in commit 05b1b53
> [3]. Recently ZGC for PPC64 was supported in the mainline. See commit
> 337b73a [4].
> 
> However, stub `BarrierSetNMethod::arm()` is missing for PPC64 platform.
> 
> Here is the snippet of error log when cross-compiling on PPC64 in my
> local test environment.
> 
> 
> * For target
> * hotspot_variant-server_libjvm_gtest_objs_BUILD_GTEST_LIBJVM_link:

Marked as reviewed by alanb (Committer).

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PR: https://git.openjdk.java.net/loom/pull/87