1 //===-- lib/Evaluate/fold-character.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>
FoldIntrinsicFunction(FoldingContext & context,FunctionRef<Type<TypeCategory::Character,KIND>> && funcRef)14 Expr<Type<TypeCategory::Character, KIND>> FoldIntrinsicFunction(
15     FoldingContext &context,
16     FunctionRef<Type<TypeCategory::Character, KIND>> &&funcRef) {
17   using T = Type<TypeCategory::Character, KIND>;
18   auto *intrinsic{std::get_if<SpecificIntrinsic>(&funcRef.proc().u)};
19   CHECK(intrinsic);
20   std::string name{intrinsic->name};
21   if (name == "achar" || name == "char") {
22     using IntT = SubscriptInteger;
23     return FoldElementalIntrinsic<T, IntT>(context, std::move(funcRef),
24         ScalarFunc<T, IntT>([](const Scalar<IntT> &i) {
25           return CharacterUtils<KIND>::CHAR(i.ToUInt64());
26         }));
27   } else if (name == "adjustl") {
28     return FoldElementalIntrinsic<T, T>(
29         context, std::move(funcRef), CharacterUtils<KIND>::ADJUSTL);
30   } else if (name == "adjustr") {
31     return FoldElementalIntrinsic<T, T>(
32         context, std::move(funcRef), CharacterUtils<KIND>::ADJUSTR);
33   } else if (name == "max") {
34     return FoldMINorMAX(context, std::move(funcRef), Ordering::Greater);
35   } else if (name == "merge") {
36     return FoldMerge<T>(context, std::move(funcRef));
37   } else if (name == "min") {
38     return FoldMINorMAX(context, std::move(funcRef), Ordering::Less);
39   } else if (name == "new_line") {
40     return Expr<T>{Constant<T>{CharacterUtils<KIND>::NEW_LINE()}};
41   } else if (name == "repeat") { // not elemental
42     if (auto scalars{GetScalarConstantArguments<T, SubscriptInteger>(
43             context, funcRef.arguments())}) {
44       return Expr<T>{Constant<T>{
45           CharacterUtils<KIND>::REPEAT(std::get<Scalar<T>>(*scalars),
46               std::get<Scalar<SubscriptInteger>>(*scalars).ToInt64())}};
47     }
48   } else if (name == "trim") { // not elemental
49     if (auto scalar{
50             GetScalarConstantArguments<T>(context, funcRef.arguments())}) {
51       return Expr<T>{Constant<T>{
52           CharacterUtils<KIND>::TRIM(std::get<Scalar<T>>(*scalar))}};
53     }
54   }
55   // TODO: cshift, eoshift, maxval, minval, pack, reduce,
56   // spread, transfer, transpose, unpack
57   return Expr<T>{std::move(funcRef)};
58 }
59 
60 template <int KIND>
FoldOperation(FoldingContext & context,Concat<KIND> && x)61 Expr<Type<TypeCategory::Character, KIND>> FoldOperation(
62     FoldingContext &context, Concat<KIND> &&x) {
63   if (auto array{ApplyElementwise(context, x)}) {
64     return *array;
65   }
66   using Result = Type<TypeCategory::Character, KIND>;
67   if (auto folded{OperandsAreConstants(x)}) {
68     return Expr<Result>{Constant<Result>{folded->first + folded->second}};
69   }
70   return Expr<Result>{std::move(x)};
71 }
72 
73 template <int KIND>
FoldOperation(FoldingContext & context,SetLength<KIND> && x)74 Expr<Type<TypeCategory::Character, KIND>> FoldOperation(
75     FoldingContext &context, SetLength<KIND> &&x) {
76   if (auto array{ApplyElementwise(context, x)}) {
77     return *array;
78   }
79   using Result = Type<TypeCategory::Character, KIND>;
80   if (auto folded{OperandsAreConstants(x)}) {
81     auto oldLength{static_cast<ConstantSubscript>(folded->first.size())};
82     auto newLength{folded->second.ToInt64()};
83     if (newLength < oldLength) {
84       folded->first.erase(newLength);
85     } else {
86       folded->first.append(newLength - oldLength, ' ');
87     }
88     CHECK(static_cast<ConstantSubscript>(folded->first.size()) == newLength);
89     return Expr<Result>{Constant<Result>{std::move(folded->first)}};
90   }
91   return Expr<Result>{std::move(x)};
92 }
93 
94 FOR_EACH_CHARACTER_KIND(template class ExpressionBase, )
95 template class ExpressionBase<SomeCharacter>;
96 } // namespace Fortran::evaluate
97