fixup: allow streaming compatible callee and check if modes are the same

Author: SamTebbs33

clang/lib/CodeGen/Targets/AArch64.cpp

@@ -827,12 +827,13 @@ void AArch64TargetCodeGenInfo::checkFunctionCallABI(
   if (!Callee->hasAttr<AlwaysInlineAttr>())
     return;
 
-  auto CalleeIsStreaming =
-      Sema::getArmStreamingFnType(Callee) == Sema::ArmStreaming;
-  auto CallerIsStreaming =
-      Sema::getArmStreamingFnType(Caller) == Sema::ArmStreaming;
+  auto CalleeStreamingMode = Sema::getArmStreamingFnType(Callee);
+  auto CallerStreamingMode = Sema::getArmStreamingFnType(Caller);
 
-  if (CalleeIsStreaming && !CallerIsStreaming)
+  // The caller can inline the callee if their streaming modes match or the
+  // callee is streaming compatible
+  if (CalleeStreamingMode != CallerStreamingMode &&
+      CalleeStreamingMode != Sema::ArmStreamingCompatible)
     CGM.getDiags().Report(CallLoc,
                           diag::err_function_alwaysinline_attribute_mismatch)
         << Caller->getDeclName() << Callee->getDeclName() << "streaming";

clang/test/CodeGen/aarch64-sme-func-attrs-inline/sme-inline-streaming-compatible-caller.c

@@ -0,0 +1,9 @@
+// RUN: %clang --target=aarch64-none-linux-gnu -march=armv9-a+sme -O3 -S -Xclang -verify %s
+
+// Conflicting attributes when using always_inline
+__attribute__((always_inline))
+int inlined_fn_streaming(void) __arm_streaming {
+    return 42;
+}
+// expected-error@+1 {{always_inline function 'inlined_fn_streaming' and its caller 'inlined_fn_caller' have mismatched streaming attributes}}
+int inlined_fn_caller(void) __arm_streaming_compatible { return inlined_fn_streaming(); }

clang/test/CodeGen/aarch64-sme-func-attrs-inline/sme-inline-streaming-compatible.c

@@ -0,0 +1,17 @@
+// RUN: %clang --target=aarch64-none-linux-gnu -march=armv9-a+sme -O3 -S -Xclang -verify %s
+
+// Conflicting attributes when using always_inline
+__attribute__((always_inline))
+int inlined_fn_streaming_compatible(void) __arm_streaming_compatible {
+    return 42;
+}
+__attribute__((always_inline))
+int inlined_fn(void) {
+    return 42;
+}
+int inlined_fn_caller(void) { return inlined_fn_streaming_compatible(); }
+__arm_locally_streaming
+int inlined_fn_caller_local(void) { return inlined_fn_streaming_compatible(); }
+int inlined_fn_caller_streaming(void) __arm_streaming { return inlined_fn_streaming_compatible(); }
+// expected-error@+1 {{always_inline function 'inlined_fn' and its caller 'inlined_fn_caller_compatible' have mismatched streaming attributes}}
+int inlined_fn_caller_compatible(void) __arm_streaming_compatible { return inlined_fn(); }