[llvm] [VFABI] Improve VFABI unit tests (PR #73907)

[Maciej Gabka via llvm-commits]

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@@ -40,69 +48,48 @@ class VFABIParserTest : public ::testing::Test {
   LLVMContext Ctx;
   SMDiagnostic Err;
   std::unique_ptr<Module> M;
-  FunctionType *FTy;
-  FunctionCallee F;
+  FunctionType *ScalarFTy = nullptr;
 
 protected:
-  // Referencies to the parser output field.
+  // References to the parser output field.
   ElementCount &VF = Info.Shape.VF;
   VFISAKind &ISA = Info.ISA;
+  /// Parameters for the vectorized function
   SmallVector<VFParameter, 8> &Parameters = Info.Shape.Parameters;
   std::string &ScalarName = Info.ScalarName;
   std::string &VectorName = Info.VectorName;
-  // Invoke the parser. We need to make sure that a function exist in
-  // the module because the parser fails if such function don't
-  // exists. Every time this method is invoked the state of the test
-  // is reset.
-  //
-  // \p MangledName -> the string the parser has to demangle.
-  //
-  // \p VectorName -> optional vector name that the method needs to
-  // use to create the function in the module if it differs from the
-  // standard mangled name.
-  //
-  // \p IRType -> FunctionType string to be used for the signature of
-  // the vector function.  The correct signature is needed by the
-  // parser only for scalable functions. For the sake of testing, the
-  // generic fixed-length case can use as signature `void()`.
-  //
+
+  /// Invoke the parser. Every time this method is invoked the state of the test
+  /// is reset.
+  ///
+  /// \p MangledName string the parser has to demangle.
+  ///
+  /// \p ScalarFTyStr FunctionType string to be used to get the signature of
+  /// the scalar function. Used by `tryDemangleForVFABI` to check for the number
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mgabka wrote:

nit: which is use by...

other wise the subject of the 2nd sentence is incorrect I think.

https://github.com/llvm/llvm-project/pull/73907