[flang] Lower selected_char_kind to runtime call (#93095)

Runtime support has been added in
#89691. This patch adds
lowering in a similar way than `selected_int_kind`, `selected_real_kind`
and `selected_logical_kind` added in #93091.

Some gfortran tests can be enabled after this patch is landed.

- `Fortran/gfortran/regression/selected_char_kind_1.f90`
- `Fortran/gfortran/regression/selected_char_kind_4.f90`

Author: clementval

flang/include/flang/Optimizer/Builder/IntrinsicCall.h

@@ -333,6 +333,8 @@ struct IntrinsicLibrary {
                                    llvm::ArrayRef<fir::ExtendedValue>);
   mlir::Value genScale(mlir::Type, llvm::ArrayRef<mlir::Value>);
   fir::ExtendedValue genScan(mlir::Type, llvm::ArrayRef<fir::ExtendedValue>);
+  fir::ExtendedValue genSelectedCharKind(mlir::Type,
+                                         llvm::ArrayRef<fir::ExtendedValue>);
   mlir::Value genSelectedIntKind(mlir::Type, llvm::ArrayRef<mlir::Value>);
   mlir::Value genSelectedLogicalKind(mlir::Type, llvm::ArrayRef<mlir::Value>);
   mlir::Value genSelectedRealKind(mlir::Type, llvm::ArrayRef<mlir::Value>);

flang/include/flang/Optimizer/Builder/Runtime/Numeric.h

@@ -46,6 +46,10 @@ mlir::Value genRRSpacing(fir::FirOpBuilder &builder, mlir::Location loc,
 mlir::Value genScale(fir::FirOpBuilder &builder, mlir::Location loc,
                      mlir::Value x, mlir::Value i);
 
+/// Generate call to Selected_char_kind intrinsic runtime routine.
+mlir::Value genSelectedCharKind(fir::FirOpBuilder &builder, mlir::Location loc,
+                                mlir::Value name, mlir::Value length);
+
 /// Generate call to Selected_int_kind intrinsic runtime routine.
 mlir::Value genSelectedIntKind(fir::FirOpBuilder &builder, mlir::Location loc,
                                mlir::Value x);

flang/lib/Optimizer/Builder/IntrinsicCall.cpp

@@ -549,6 +549,10 @@ static constexpr IntrinsicHandler handlers[]{
        {"back", asValue, handleDynamicOptional},
        {"kind", asValue}}},
      /*isElemental=*/true},
+    {"selected_char_kind",
+     &I::genSelectedCharKind,
+     {{{"name", asAddr}}},
+     /*isElemental=*/false},
     {"selected_int_kind",
      &I::genSelectedIntKind,
      {{{"scalar", asAddr}}},
@@ -5877,6 +5881,18 @@ IntrinsicLibrary::genScan(mlir::Type resultType,
   return readAndAddCleanUp(resultMutableBox, resultType, "SCAN");
 }
 
+// SELECTED_CHAR_KIND
+fir::ExtendedValue
+IntrinsicLibrary::genSelectedCharKind(mlir::Type resultType,
+                                      llvm::ArrayRef<fir::ExtendedValue> args) {
+  assert(args.size() == 1);
+
+  return builder.createConvert(
+      loc, resultType,
+      fir::runtime::genSelectedCharKind(builder, loc, fir::getBase(args[0]),
+                                        fir::getLen(args[0])));
+}
+
 // SELECTED_INT_KIND
 mlir::Value
 IntrinsicLibrary::genSelectedIntKind(mlir::Type resultType,

flang/lib/Optimizer/Builder/Runtime/Numeric.cpp

@@ -468,6 +468,26 @@ mlir::Value fir::runtime::genScale(fir::FirOpBuilder &builder,
   return builder.create<fir::CallOp>(loc, func, args).getResult(0);
 }
 
+/// Generate call to Selected_char_kind intrinsic runtime routine.
+mlir::Value fir::runtime::genSelectedCharKind(fir::FirOpBuilder &builder,
+                                              mlir::Location loc,
+                                              mlir::Value name,
+                                              mlir::Value length) {
+  mlir::func::FuncOp func =
+      fir::runtime::getRuntimeFunc<mkRTKey(SelectedCharKind)>(loc, builder);
+  auto fTy = func.getFunctionType();
+  auto sourceFile = fir::factory::locationToFilename(builder, loc);
+  auto sourceLine =
+      fir::factory::locationToLineNo(builder, loc, fTy.getInput(1));
+  if (!fir::isa_ref_type(name.getType()))
+    fir::emitFatalError(loc, "argument address for runtime not found");
+
+  auto args = fir::runtime::createArguments(builder, loc, fTy, sourceFile,
+                                            sourceLine, name, length);
+
+  return builder.create<fir::CallOp>(loc, func, args).getResult(0);
+}
+
 /// Generate call to Selected_int_kind intrinsic runtime routine.
 mlir::Value fir::runtime::genSelectedIntKind(fir::FirOpBuilder &builder,
                                              mlir::Location loc,

flang/test/Lower/Intrinsics/selected_char_kind.f90

@@ -0,0 +1,17 @@
+! RUN: bbc -emit-hlfir %s -o - | FileCheck %s
+
+subroutine selected_char_kind_test(c)
+  character(*) :: c
+  integer :: res
+  res = selected_char_kind(c)
+end
+
+! CHECK-LABEL: func.func @_QPselected_char_kind_test(
+! CHECK-SAME: %[[ARG0:.*]]: !fir.boxchar<1> {fir.bindc_name = "c"})
+! CHECK: %[[UNBOXCHAR:.*]]:2 = fir.unboxchar %[[ARG0]] : (!fir.boxchar<1>) -> (!fir.ref<!fir.char<1,?>>, index)
+! CHECK: %[[C:.*]]:2 = hlfir.declare %[[UNBOXCHAR]]#0 typeparams %[[UNBOXCHAR]]#1 dummy_scope %0 {uniq_name = "_QFselected_char_kind_testEc"} : (!fir.ref<!fir.char<1,?>>, index, !fir.dscope) -> (!fir.boxchar<1>, !fir.ref<!fir.char<1,?>>)
+! CHECK: %[[RES_ALLOCA:.*]] = fir.alloca i32 {bindc_name = "res", uniq_name = "_QFselected_char_kind_testEres"}
+! CHECK: %[[RES:.*]]:2 = hlfir.declare %[[RES_ALLOCA]] {uniq_name = "_QFselected_char_kind_testEres"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
+! CHECK: %[[CHAR_PTR:.*]] = fir.convert %[[C]]#1 : (!fir.ref<!fir.char<1,?>>) -> !fir.ref<i8>
+! CHECK: %[[CHAR_LEN:.*]] = fir.convert %[[UNBOXCHAR]]#1 : (index) -> i64
+! CHECK: %{{.*}} = fir.call @_FortranASelectedCharKind(%{{.*}}, %{{.*}}, %[[CHAR_PTR]], %[[CHAR_LEN]]) fastmath<contract> : (!fir.ref<i8>, i32, !fir.ref<i8>, i64) -> i32