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

[Paul Walker via llvm-commits]

================
@@ -40,69 +50,48 @@ 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. Needed by `tryDemangleForVFABI` to check for the
+  /// number of arguments on scalable vectors, and by `matchScalarParamNum` to
+  /// perform some additional checking in the tests in this file.
   bool invokeParser(const StringRef MangledName,
-                    const StringRef ScalarName = "",
-                    const StringRef IRType = "void()") {
-    StringRef Name = MangledName;
-    if (!ScalarName.empty())
-      Name = ScalarName;
-    // Reset the VFInfo and the Module to be able to invoke
-    // `invokeParser` multiple times in the same test.
-    reset(Name, IRType);
-
-    // Fake the arguments to the CallInst.
-    SmallVector<Value *> Args;
-    for (Type *ParamTy : FTy->params()) {
-      Args.push_back(Constant::getNullValue(ParamTy->getScalarType()));
-    }
-    std::unique_ptr<CallInst> CI(CallInst::Create(F, Args));
-    const auto OptInfo =
-        VFABI::tryDemangleForVFABI(MangledName, CI->getFunctionType());
-    if (OptInfo) {
+                    const StringRef ScalarFTyStr = "void()") {
+    // Reset the VFInfo to be able to call `invokeParser` multiple times in
+    // the same test.
+    reset(ScalarFTyStr);
+
+    const auto OptInfo = VFABI::tryDemangleForVFABI(MangledName, ScalarFTy);
+    if (OptInfo)
       Info = *OptInfo;
-      return true;
-    }
 
-    return false;
+    return OptInfo.has_value();
   }
 
-  // Checks that 1. the last Parameter in the Shape is of type
-  // VFParamKind::GlobalPredicate and 2. it is the only one of such
-  // type.
-  bool IsMasked() const {
-    const auto NGlobalPreds =
-        std::count_if(Info.Shape.Parameters.begin(),
-                      Info.Shape.Parameters.end(), [](const VFParameter PK) {
-                        return PK.ParamKind == VFParamKind::GlobalPredicate;
-                      });
-    return NGlobalPreds == 1 && Info.Shape.Parameters.back().ParamKind ==
-                                    VFParamKind::GlobalPredicate;
+  /// Returns whether the parsed function contains a mask
+  bool isMasked() const { return Info.isMasked(); }
+
+  /// Checks that the number of vectorized parameters matches the
+  /// scalar ones. This requires a correct scalar FunctionType string to be fed
+  /// to the 'invokeParser'. It takes into account that vectorized calls may
+  /// also have a Mask.
----------------
paulwalker-arm wrote:

Perhaps "Mask parameters that are only required by the vector function call are ignored.". 

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