[android] .NET Preview 2, AOT w/ LLVM fails with `mini-llvm.c:8581, condition elems <= MAX_VECTOR_ELEMS / 2' not met`

[jonathanpeppers]

Description

We first noticed this happening here: dotnet/android#8716

It appears any Release build using -p:EnableLLVM fails with:

Precompiling failed for /Users/runner/work/1/s/tests/Mono.Android-Tests/Runtime-Microsoft.Android.Sdk/obj/Release/net9.0-android/android-x64/linked/System.Private.CoreLib.dll with exit code 134.
Mono Ahead of Time compiler - compiling assembly /Users/runner/work/1/s/tests/Mono.Android-Tests/Runtime-Microsoft.Android.Sdk/obj/Release/net9.0-android/android-x64/linked/System.Private.CoreLib.dll
AOTID 22717FEB-1950-D4F1-D7BF-6FD5FD5FFC96
* Assertion at /Users/runner/work/1/s/src/mono/mono/mini/mini-llvm.c:8581, condition `elems <= MAX_VECTOR_ELEMS / 2' not met

Reproduction Steps

• dotnet new android
• dotnet build -c Release -p:EnableLLVM=true

Expected behavior

Release builds using -p:EnableLLVM succeed.

Actual behavior

Release builds using -p:EnableLLVM fail with an assertion.

Regression?

Yes, this was working previously in .NET 9 and .NET 8.

Known Workarounds

Use -p:EnableLLVM=false.

Configuration

.NET SDK 9.0.0-preview.2.24109.4
.NET runtime 9.0.0-preview.2.24109.4

Changes: dotnet/installer@fb7b9a4...ab44b49
Changes: d40c654...a79c62d

Other information

Here is a .binlog:

run-Mono.Android.NET_Tests-AotLlvm.binlog.zip

[jonathanpeppers]

/cc @steveisok

I'll also try the newest build in case there is a recent fix for this.

[steveisok]

@vargaz can you please take a look?

[vargaz]

Should be fixed by this:
#98320

[lewing]

dotnet/android#8716 is green now, closing

[jonathanpeppers]

I don't know why, but Maestro PRs only trigger CI like 50% of the time. It should have ~46 green checks when it's green.

I queued one, and will reopen if there is still an issue here:

dotnet/android#8716 (comment)