RFR: 8338303: Linux ppc64le with toolchain clang - detection failure in early JVM startup

[Martin Doerr]

On Fri, 24 Jan 2025 09:09:15 GMT, Matthias Baesken <mbaesken at openjdk.org> wrote:

> When building on Linux ppc64le with the clang toolchain, the new JVM fails already in the build process with an error/crash :
> 
> 
> # SIGILL (0x4) at pc=0x000079198fae03ac, pid=2922849, tid=2923410
> #
> # Problematic frame:
> # v ~BufferBlob::detect_cpu_features 0x000079198fae03ac
> 
> 
> It was noticed the clang build on Linux ppc64le missed some important compile flags, especially  -DABI_ELFv2 (compared to gcc build).

`-DABI_ELFv2` is very important. Otherwise, the wrong calling convention is used. I'm not sure if the `power8` settings make still sense, but ok. We could clean them up separately.

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

Marked as reviewed by mdoerr (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/23292#pullrequestreview-2572336519