1 //===-- lib/Evaluate/fold-complex.cpp -------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "fold-implementation.h"
10 
11 namespace Fortran::evaluate {
12 
13 template <int KIND>
14 Expr<Type<TypeCategory::Complex, KIND>> FoldIntrinsicFunction(
15     FoldingContext &context,
16     FunctionRef<Type<TypeCategory::Complex, KIND>> &&funcRef) {
17   using T = Type<TypeCategory::Complex, KIND>;
18   ActualArguments &args{funcRef.arguments()};
19   auto *intrinsic{std::get_if<SpecificIntrinsic>(&funcRef.proc().u)};
20   CHECK(intrinsic);
21   std::string name{intrinsic->name};
22   if (name == "acos" || name == "acosh" || name == "asin" || name == "asinh" ||
23       name == "atan" || name == "atanh" || name == "cos" || name == "cosh" ||
24       name == "exp" || name == "log" || name == "sin" || name == "sinh" ||
25       name == "sqrt" || name == "tan" || name == "tanh") {
26     if (auto callable{context.hostIntrinsicsLibrary()
27                           .GetHostProcedureWrapper<Scalar, T, T>(name)}) {
28       return FoldElementalIntrinsic<T, T>(
29           context, std::move(funcRef), *callable);
30     } else {
31       context.messages().Say(
32           "%s(complex(kind=%d)) cannot be folded on host"_en_US, name, KIND);
33     }
34   } else if (name == "conjg") {
35     return FoldElementalIntrinsic<T, T>(
36         context, std::move(funcRef), &Scalar<T>::CONJG);
37   } else if (name == "cmplx") {
38     using Part = typename T::Part;
39     if (args.size() == 2) { // CMPLX(X, [KIND])
40       if (auto *x{UnwrapExpr<Expr<SomeComplex>>(args[0])}) {
41         return Fold(context, ConvertToType<T>(std::move(*x)));
42       }
43       Expr<SomeType> re{std::move(*args[0].value().UnwrapExpr())};
44       Expr<SomeType> im{AsGenericExpr(Constant<Part>{Scalar<Part>{}})};
45       return Fold(context,
46           Expr<T>{ComplexConstructor<KIND>{ToReal<KIND>(context, std::move(re)),
47               ToReal<KIND>(context, std::move(im))}});
48     }
49     // CMPLX(X, [Y, KIND])
50     CHECK(args.size() == 3);
51     Expr<SomeType> re{std::move(*args[0].value().UnwrapExpr())};
52     Expr<SomeType> im{args[1] ? std::move(*args[1].value().UnwrapExpr())
53                               : AsGenericExpr(Constant<Part>{Scalar<Part>{}})};
54     return Fold(context,
55         Expr<T>{ComplexConstructor<KIND>{ToReal<KIND>(context, std::move(re)),
56             ToReal<KIND>(context, std::move(im))}});
57   } else if (name == "merge") {
58     return FoldMerge<T>(context, std::move(funcRef));
59   }
60   // TODO: cshift, dot_product, eoshift, matmul, pack, product,
61   // reduce, spread, sum, transfer, transpose, unpack
62   return Expr<T>{std::move(funcRef)};
63 }
64 
65 template <int KIND>
66 Expr<Type<TypeCategory::Complex, KIND>> FoldOperation(
67     FoldingContext &context, ComplexConstructor<KIND> &&x) {
68   if (auto array{ApplyElementwise(context, x)}) {
69     return *array;
70   }
71   using Result = Type<TypeCategory::Complex, KIND>;
72   if (auto folded{OperandsAreConstants(x)}) {
73     return Expr<Result>{
74         Constant<Result>{Scalar<Result>{folded->first, folded->second}}};
75   }
76   return Expr<Result>{std::move(x)};
77 }
78 
79 FOR_EACH_COMPLEX_KIND(template class ExpressionBase, )
80 template class ExpressionBase<SomeComplex>;
81 } // namespace Fortran::evaluate
82