Emulator Issues #13350open
PowerPCTest fails on arm64
What's the problem? Describe what went wrong.
Dolphin test "PowerPC" fails on arm64/aarch64 (but not on amd64) builds, as can be seen in the Debian build logs:
What steps will reproduce the problem?
Is the issue present in the latest development version? For future reference, please also write down the version number of the latest development version.
Not tested (it's not trivial for me to test this).
Is the issue present in the latest beta version?
Yes, in 5.0-19870. It was not present in the previous build 19368. It also does not happen on amd64 builds.
What are your PC specifications? (CPU, GPU, Operating System, more)
Is there anything else that can help developers narrow down the issue? (e.g. logs, screenshots,
configuration files, savefiles, savestates)
Debian builds against all possible system libraries.
The only commit in that time span that looks like it could be relevant is https://github.com/dolphin-emu/dolphin/commit/1ebec40e4d4c473bc717b1d5836b8320f4851388. Could you test if reverting it fixes the issue?
For reference, the unit tests are passing on our end on an Apple M1 test runner. And the instruction we started emitting because of that commit is required in all AArch64 implementations, so I'm not sure why it would be considered an illegal instruction only on some systems...
Hold on! There's something more subtle here, I think.
While working on testing a build with the patch removed, I noticed the non-patched 19870 release built in one of Debian's test arm64 machines.
That machine's CPU is:
Architecture: aarch64 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian CPU(s): 4 On-line CPU(s) list: 0-3 Thread(s) per core: 1 Core(s) per socket: 4 Socket(s): 1 NUMA node(s): 1 Vendor ID: APM Model: 1 Model name: X-Gene Stepping: 0x0 BogoMIPS: 100.00 NUMA node0 CPU(s): 0-3 Vulnerability Gather data sampling: Not affected Vulnerability Itlb multihit: Not affected Vulnerability L1tf: Not affected Vulnerability Mds: Not affected Vulnerability Meltdown: Mitigation; PTI Vulnerability Mmio stale data: Not affected Vulnerability Retbleed: Not affected Vulnerability Spec rstack overflow: Not affected Vulnerability Spec store bypass: Vulnerable Vulnerability Spectre v1: Mitigation; __user pointer sanitization Vulnerability Spectre v2: Vulnerable Vulnerability Srbds: Not affected Vulnerability Tsx async abort: Not affected Flags: fp asimd evtstrm cpuid
Looking at the history of Dolphin builds on arm64 (https://buildd.debian.org/status/logs.php?pkg=dolphin-emu&arch=arm64), I found out the previous release 19368 also failed with the same
PowerPCTest error, but that build was retried, picked up by a different build daemon, and built successfully:
So there's either some hardware difference that makes the build fail, or that particular test fails intermittently due to an unknown condition.