xref: /llvm-project/flang/lib/Evaluate/fold-complex.cpp (revision 0f973ac783aa100cfbce1cd2c6e8a3a8f648fae7)
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 #include "fold-matmul.h"
11 #include "fold-reduction.h"
12 
13 namespace Fortran::evaluate {
14 
15 template <int KIND>
16 Expr<Type<TypeCategory::Complex, KIND>> FoldIntrinsicFunction(
17     FoldingContext &context,
18     FunctionRef<Type<TypeCategory::Complex, KIND>> &&funcRef) {
19   using T = Type<TypeCategory::Complex, KIND>;
20   using Part = typename T::Part;
21   ActualArguments &args{funcRef.arguments()};
22   auto *intrinsic{std::get_if<SpecificIntrinsic>(&funcRef.proc().u)};
23   CHECK(intrinsic);
24   std::string name{intrinsic->name};
25   if (name == "acos" || name == "acosh" || name == "asin" || name == "asinh" ||
26       name == "atan" || name == "atanh" || name == "cos" || name == "cosh" ||
27       name == "exp" || name == "log" || name == "sin" || name == "sinh" ||
28       name == "sqrt" || name == "tan" || name == "tanh") {
29     if (auto callable{GetHostRuntimeWrapper<T, T>(name)}) {
30       return FoldElementalIntrinsic<T, T>(
31           context, std::move(funcRef), *callable);
32     } else if (context.languageFeatures().ShouldWarn(
33                    common::UsageWarning::FoldingFailure)) {
34       context.messages().Say(common::UsageWarning::FoldingFailure,
35           "%s(complex(kind=%d)) cannot be folded on host"_warn_en_US, name,
36           KIND);
37     }
38   } else if (name == "conjg") {
39     return FoldElementalIntrinsic<T, T>(
40         context, std::move(funcRef), &Scalar<T>::CONJG);
41   } else if (name == "cmplx") {
42     if (args.size() > 0 && args[0].has_value()) {
43       if (auto *x{UnwrapExpr<Expr<SomeComplex>>(args[0])}) {
44         // CMPLX(X [, KIND]) with complex X
45         return Fold(context, ConvertToType<T>(std::move(*x)));
46       } else {
47         if (args.size() >= 2 && args[1].has_value()) {
48           // Do not fold CMPLX with an Y argument that may be absent at runtime
49           // into a complex constructor so that lowering can deal with the
50           // optional aspect (there is no optional aspect with the complex
51           // constructor).
52           if (MayBePassedAsAbsentOptional(*args[1]->UnwrapExpr())) {
53             return Expr<T>{std::move(funcRef)};
54           }
55         }
56         // CMPLX(X [, Y [, KIND]]) with non-complex X
57         Expr<SomeType> re{std::move(*args[0].value().UnwrapExpr())};
58         Expr<SomeType> im{args.size() >= 2 && args[1].has_value()
59                 ? std::move(*args[1]->UnwrapExpr())
60                 : AsGenericExpr(Constant<Part>{Scalar<Part>{}})};
61         return Fold(context,
62             Expr<T>{
63                 ComplexConstructor<KIND>{ToReal<KIND>(context, std::move(re)),
64                     ToReal<KIND>(context, std::move(im))}});
65       }
66     }
67   } else if (name == "dot_product") {
68     return FoldDotProduct<T>(context, std::move(funcRef));
69   } else if (name == "matmul") {
70     return FoldMatmul(context, std::move(funcRef));
71   } else if (name == "product") {
72     auto one{Scalar<Part>::FromInteger(value::Integer<8>{1}).value};
73     return FoldProduct<T>(context, std::move(funcRef), Scalar<T>{one});
74   } else if (name == "sum") {
75     return FoldSum<T>(context, std::move(funcRef));
76   }
77   return Expr<T>{std::move(funcRef)};
78 }
79 
80 template <int KIND>
81 Expr<Type<TypeCategory::Complex, KIND>> FoldOperation(
82     FoldingContext &context, ComplexConstructor<KIND> &&x) {
83   if (auto array{ApplyElementwise(context, x)}) {
84     return *array;
85   }
86   using Result = Type<TypeCategory::Complex, KIND>;
87   if (auto folded{OperandsAreConstants(x)}) {
88     return Expr<Result>{
89         Constant<Result>{Scalar<Result>{folded->first, folded->second}}};
90   }
91   return Expr<Result>{std::move(x)};
92 }
93 
94 #ifdef _MSC_VER // disable bogus warning about missing definitions
95 #pragma warning(disable : 4661)
96 #endif
97 FOR_EACH_COMPLEX_KIND(template class ExpressionBase, )
98 template class ExpressionBase<SomeComplex>;
99 } // namespace Fortran::evaluate
100