[flang-commits] [flang] [flang][OpenMP] Rewrite min/max with more than 2 arguments (PR #146423)

[Krzysztof Parzyszek via flang-commits]

================
@@ -41,6 +43,178 @@ namespace omp {
 using namespace Fortran::lower::omp;
 }
 
+namespace {
+// An example of a type that can be used to get the return value from
+// the visitor:
+//   visitor(type_identity<Xyz>) -> result_type
+using SomeArgType = evaluate::Type<common::TypeCategory::Integer, 4>;
+
+struct GetProc
+    : public evaluate::Traverse<GetProc, const evaluate::ProcedureDesignator *,
+                                false> {
+  using Result = const evaluate::ProcedureDesignator *;
+  using Base = evaluate::Traverse<GetProc, Result, false>;
+  GetProc() : Base(*this) {}
+
+  using Base::operator();
+
+  static Result Default() { return nullptr; }
+
+  Result operator()(const evaluate::ProcedureDesignator &p) const { return &p; }
+  static Result Combine(Result a, Result b) { return a != nullptr ? a : b; }
+};
+
+struct WithType {
+  WithType(const evaluate::DynamicType &t) : type(t) {
+    assert(type.category() != common::TypeCategory::Derived &&
+           "Type cannot be a derived type");
+  }
+
+  template <typename VisitorTy> //
+  auto visit(VisitorTy &&visitor) const
+      -> std::invoke_result_t<VisitorTy, SomeArgType> {
+    switch (type.category()) {
+    case common::TypeCategory::Integer:
+      switch (type.kind()) {
+      case 1:
+        return visitor(llvm::type_identity<evaluate::Type<Integer, 1>>{});
+      case 2:
+        return visitor(llvm::type_identity<evaluate::Type<Integer, 2>>{});
+      case 4:
+        return visitor(llvm::type_identity<evaluate::Type<Integer, 4>>{});
+      case 8:
+        return visitor(llvm::type_identity<evaluate::Type<Integer, 8>>{});
+      case 16:
+        return visitor(llvm::type_identity<evaluate::Type<Integer, 16>>{});
+      }
+      break;
+    case common::TypeCategory::Unsigned:
+      switch (type.kind()) {
+      case 1:
+        return visitor(llvm::type_identity<evaluate::Type<Unsigned, 1>>{});
+      case 2:
+        return visitor(llvm::type_identity<evaluate::Type<Unsigned, 2>>{});
+      case 4:
+        return visitor(llvm::type_identity<evaluate::Type<Unsigned, 4>>{});
+      case 8:
+        return visitor(llvm::type_identity<evaluate::Type<Unsigned, 8>>{});
+      case 16:
+        return visitor(llvm::type_identity<evaluate::Type<Unsigned, 16>>{});
+      }
+      break;
+    case common::TypeCategory::Real:
+      switch (type.kind()) {
+      case 2:
+        return visitor(llvm::type_identity<evaluate::Type<Real, 2>>{});
+      case 3:
+        return visitor(llvm::type_identity<evaluate::Type<Real, 3>>{});
+      case 4:
+        return visitor(llvm::type_identity<evaluate::Type<Real, 4>>{});
+      case 8:
+        return visitor(llvm::type_identity<evaluate::Type<Real, 8>>{});
+      case 10:
+        return visitor(llvm::type_identity<evaluate::Type<Real, 10>>{});
+      case 16:
+        return visitor(llvm::type_identity<evaluate::Type<Real, 16>>{});
+      }
+      break;
+    case common::TypeCategory::Complex:
+      switch (type.kind()) {
+      case 2:
+        return visitor(llvm::type_identity<evaluate::Type<Complex, 2>>{});
+      case 3:
+        return visitor(llvm::type_identity<evaluate::Type<Complex, 3>>{});
+      case 4:
+        return visitor(llvm::type_identity<evaluate::Type<Complex, 4>>{});
+      case 8:
+        return visitor(llvm::type_identity<evaluate::Type<Complex, 8>>{});
+      case 10:
+        return visitor(llvm::type_identity<evaluate::Type<Complex, 10>>{});
+      case 16:
+        return visitor(llvm::type_identity<evaluate::Type<Complex, 16>>{});
+      }
+      break;
+    case common::TypeCategory::Logical:
+      switch (type.kind()) {
+      case 1:
+        return visitor(llvm::type_identity<evaluate::Type<Logical, 1>>{});
+      case 2:
+        return visitor(llvm::type_identity<evaluate::Type<Logical, 2>>{});
+      case 4:
+        return visitor(llvm::type_identity<evaluate::Type<Logical, 4>>{});
+      case 8:
+        return visitor(llvm::type_identity<evaluate::Type<Logical, 8>>{});
+      }
+      break;
+    case common::TypeCategory::Character:
+      switch (type.kind()) {
+      case 1:
+        return visitor(llvm::type_identity<evaluate::Type<Character, 1>>{});
+      case 2:
+        return visitor(llvm::type_identity<evaluate::Type<Character, 2>>{});
+      case 4:
+        return visitor(llvm::type_identity<evaluate::Type<Character, 4>>{});
+      }
+      break;
+    case common::TypeCategory::Derived:
+      break;
+    }
+    llvm_unreachable("Unhandled type");
+  }
+
+  const evaluate::DynamicType &type;
+
+private:
+  // Shorter names.
+  static constexpr auto Character = common::TypeCategory::Character;
+  static constexpr auto Complex = common::TypeCategory::Complex;
+  static constexpr auto Derived = common::TypeCategory::Derived;
----------------
kparzysz wrote:

Fixed.

https://github.com/llvm/llvm-project/pull/146423