[flang] Register and lower SECNDS (stubbed implementation)

Author: mlir-maiden

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

@@ -405,6 +405,8 @@ 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 genSecnds(mlir::Type resultType,
+                               llvm::ArrayRef<fir::ExtendedValue> args);
   fir::ExtendedValue genSecond(std::optional<mlir::Type>,
                                mlir::ArrayRef<fir::ExtendedValue>);
   fir::ExtendedValue genSelectedCharKind(mlir::Type,

flang/lib/Evaluate/intrinsics.cpp

@@ -921,6 +921,11 @@ static const IntrinsicInterface genericIntrinsicFunction[]{
             {"back", AnyLogical, Rank::elemental, Optionality::optional},
             DefaultingKIND},
         KINDInt},
+    {"secnds",
+        {{"x", TypePattern{RealType, KindCode::exactKind, 4}, Rank::scalar,
+            Optionality::required, common::Intent::In}},
+        TypePattern{RealType, KindCode::exactKind, 4}, Rank::scalar,
+        IntrinsicClass::impureSubroutine},
     {"second", {}, DefaultReal, Rank::scalar},
     {"selected_char_kind", {{"name", DefaultChar, Rank::scalar}}, DefaultInt,
         Rank::scalar, IntrinsicClass::transformationalFunction},

flang/lib/Optimizer/Builder/IntrinsicCall.cpp

@@ -864,6 +864,10 @@ static constexpr IntrinsicHandler handlers[]{
        {"back", asValue, handleDynamicOptional},
        {"kind", asValue}}},
      /*isElemental=*/true},
+    {"secnds",
+     &I::genSecnds,
+     {{{"x", asValue}}},
+     /*isElemental=*/false},
     {"second",
      &I::genSecond,
      {{{"time", asAddr}}},
@@ -7813,6 +7817,14 @@ IntrinsicLibrary::genScan(mlir::Type resultType,
   return readAndAddCleanUp(resultMutableBox, resultType, "SCAN");
 }
 
+// SECNDS
+// Lowering is registered, runtime not yet implemented
+fir::ExtendedValue
+IntrinsicLibrary::genSecnds(mlir::Type resultType,
+                            llvm::ArrayRef<fir::ExtendedValue> args) {
+  TODO(loc, "not yet implemented: SECNDS");
+}
+
 // SECOND
 fir::ExtendedValue
 IntrinsicLibrary::genSecond(std::optional<mlir::Type> resultType,

flang/test/Lower/Intrinsics/secnds.f90

@@ -0,0 +1,12 @@
+!---------------------------------------------------------------------
+! RUN: %flang_fc1 -emit-fir %s -o - 2>&1 | FileCheck %s
+! XFAIL: *
+!---------------------------------------------------------------------
+
+program test_secnds
+  real :: x
+  x = secnds(1.0)
+end program
+
+! CHECK: not yet implemented: SECNDS
+