Failing tests on macOS(aarch64)

[Fusioon]

There are 4 tests that currently fail:

ERROR: Test failed. Assert failed: str == "Test 223 2.2 3.3" at line 82 in /Users/fusion/Dev/Beef/IDEHelper/Tests/src/VarArgs.bf

ERROR: Test failed. Assert failed: ca.mA == 1123 at line 410 in /Users/fusion/Dev/Beef/IDEHelper/Tests/src/Reflection.bf

Failed test 'Tests.Lambdas.TestStructRetCapture' defined at line 103:22 in /Users/fusion/Dev/Beef/IDEHelper/Tests/src/Lambdas.bf

ERROR: Test failed. Assert failed: Func0W(12, sw) == 312 at line 447 in /Users/fusion/Dev/Beef/IDEHelper/Tests/src/Interop.bf

• I believe the Interop issue is related to arm64 HFA (I haven't looked at ASM yet)

• TestStructRetCapture - just crashes when returning StructA and doesn't seem to be related to local capture since it does crash when it's just delegate StructA() myTest = scope () => { return StructA(5); }

• VarArgs - on macOS aarch64 they should be handled the same as on windows (VarList should be just void*)

• Reflection - seems to be problem with returns, Invoke currently just appends the return value as pointer to arg list
  This can be fixed by adding this piece of code to MethodInfo.bf Invoke method where return is handled

#if BF_MACHINE_AARCH64
				let ffiRetElements = scope:: List<FFIType*>(8);
				for (let fi in retType.GetFields(.Instance | .DeclaredOnly))
				{
					let ffiType = GetFFIType!::(fi.FieldType);
					ffiRetElements.Add(ffiType);
				}
				ffiRetElements.Add(null);
				ffiRetType = scope::FFIType(0, 0, .Struct);
				ffiRetType.mElements = ffiRetElements.Ptr;
#else
				ffiRetType = &FFIType.Void;
				ffiParamList.Add(&FFIType.Pointer);
				ffiArgList.Add(&variantData);
				retData = &unusedRetVal;
#endif

But the return value is still wrong because libffi reads the values from register x0, x1 but beef writes the return value at x8, x10
Clang does use x0, x1 when returning struct with 2 int64 values: https://godbolt.org/z/459r5b5Y4

[zerkawei]

On Linux(aarch64) 3 of these 4 tests fail (VarArgs succeeds on Linux).
Investigating the Interop issue it seems that Beef passes the struct containing a single float in a general purpose (X/W) register whereas the C lib expects this parameter to be in a floating point (S) register.

[bfiete]

You're going too low-level with your diagnosis. The key is to look at the LLVM IR from Clang and make the Beef LLVM function signature match.

This is mostly managed through BfTypeInstance::GetLoweredType and BfMethodInstance::GetLoweredReturnType

[zerkawei]

But the return value is still wrong because libffi reads the values from register x0, x1 but beef writes the return value at x8, x10
Clang does use x0, x1 when returning struct with 2 int64 values: https://godbolt.org/z/459r5b5Y4

It seems like StructA is staying as a sret() rather than being lowered into a [2 x i64] in the return type, though I don't understand why yet.

Another solution could be to force libffi to use the indirect return value register even if the struct is small enough to fit in x0, x1.

[zerkawei]

For the Delegate issue it looks like it's maybe caused by the way the Invoke function of the delegate is built.
Examining the IR code the delegate calls the function with the return parameter as a simple ptr rather than a ptr sret() which would make the Invoke method look for the return value in x0 rather than x8 on aarch64.

Target function :
define void @_ZN2bf7testarm7Program4TestEv(ptr noalias sret(%testarm._ZTSN2bf7testarm7StructAE) %0) #0 !dbg !4

Delegate Invoke :
define void @_ZN8delegateIN2bf7testarm7StructAEEENS_06InvokeEv(ptr noalias sret(%testarm._ZTSN2bf7testarm7StructAE) %0, ptr %this) #0 !dbg !4

Call to target :
call void %10(ptr %0, ptr %7), !dbg !32 <- here ptr $0 should be ptr sret(%testarm._ZTSN2bf7testarm7StructAE) %0

I tried looking at the code that generates the delegate invoke method but haven't found how to fix this yet.