[mono] interpreter doesn't extend smaller integer values to register size upon return for arm64 #110649
Description
Description
The interpreter doesn't zero-extend smaller integer values to register size for x0 upon return to native code from functions for arm64.
The test case in question creates an NSPredicate using a block, which is implemented in managed code. The block callback is internally implemented like this:
[UnmanagedCallersOnly]
static unsafe byte Invoke (IntPtr block, NativeHandle evaluatedObject, NativeHandle bindings) {
var retval = /* call the Evaluator function from the test case */
return retval ? (byte) 1 : (byte) 0;
}Upon return from this function, lldb says x0 isn't 0:
(lldb) p/x $x0
(unsigned long) 0x0000600001d64000
while it's 0 when not using the interpreter.
This is the equivalent Objective-C code:
NSPredicate* p = [NSPredicate predicateWithBlock:^BOOL(id item, NSDictionary *bindings)
{
return FALSE;
}];which is compiled into:
(lldb) disassemble
iosapitest`__57-[AppDelegate application:didFinishLaunchingWithOptions:]_block_invoke:
-> 0x100a2e250 <+0>: mov w0, #0x0 ; =0
0x100a2e254 <+4>: ret
Reproduction Steps
Test project: maccatalyst-plain-8d667e2.zip
Do this:
dotnet build
./bin/Debug/net9.0-maccatalyst/maccatalyst-arm64/maccatalyst-plain.app/Contents/MacOS/maccatalyst-plainExpected behavior
It should print:
✅ SUCCESS
Actual behavior
Prints:
❌ FAIL
Regression?
Not sure
Known Workarounds
Don't use the interpreter
Configuration
.NET 9
Other information
No response