[flang] dsecnds test: reuse captured defs in call (review feedback)

Author: mlir-maiden

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

@@ -250,7 +250,7 @@ struct IntrinsicLibrary {
   mlir::Value genCospi(mlir::Type, llvm::ArrayRef<mlir::Value>);
   void genDateAndTime(llvm::ArrayRef<fir::ExtendedValue>);
   fir::ExtendedValue genDsecnds(mlir::Type resultType,
-                               llvm::ArrayRef<fir::ExtendedValue> args);
+                                llvm::ArrayRef<fir::ExtendedValue> args);
   mlir::Value genDim(mlir::Type, llvm::ArrayRef<mlir::Value>);
   fir::ExtendedValue genDotProduct(mlir::Type,
                                    llvm::ArrayRef<fir::ExtendedValue>);

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

@@ -46,7 +46,7 @@ void genDateAndTime(fir::FirOpBuilder &, mlir::Location,
                     std::optional<fir::CharBoxValue> zone, mlir::Value values);
 
 mlir::Value genDsecnds(fir::FirOpBuilder &builder, mlir::Location loc,
-                      mlir::Value refTime);
+                       mlir::Value refTime);
 
 void genEtime(fir::FirOpBuilder &builder, mlir::Location loc,
               mlir::Value values, mlir::Value time);

flang/lib/Optimizer/Builder/IntrinsicCall.cpp

@@ -3949,7 +3949,7 @@ mlir::Value IntrinsicLibrary::genDprod(mlir::Type resultType,
 // Double precision variant of SECNDS (PGI extension)
 fir::ExtendedValue
 IntrinsicLibrary::genDsecnds(mlir::Type resultType,
-                            llvm::ArrayRef<fir::ExtendedValue> args) {
+                             llvm::ArrayRef<fir::ExtendedValue> args) {
   assert(args.size() == 1 && "DSECNDS expects one argument");
 
   mlir::Value refTime = fir::getBase(args[0]);

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

@@ -107,7 +107,7 @@ void fir::runtime::genDateAndTime(fir::FirOpBuilder &builder,
 }
 
 mlir::Value fir::runtime::genDsecnds(fir::FirOpBuilder &builder,
-                                    mlir::Location loc, mlir::Value refTime) {
+                                     mlir::Location loc, mlir::Value refTime) {
   auto runtimeFunc =
       fir::runtime::getRuntimeFunc<mkRTKey(Dsecnds)>(loc, builder);
 

flang/test/Lower/Intrinsics/dsecnds.f90

@@ -7,16 +7,27 @@ function use_dsecnds(refTime) result(elapsed)
   elapsed = dsecnds(refTime)
 end function
 
-! Verify filename and line operands are passed into runtime call
+! The argument is lowered with hlfir.declare, which returns two results.
+! Capture it here to check that the correct SSA value (%...#0)
+! is passed to the runtime call later
+! CHECK: %[[DECL:.*]]:2 = hlfir.declare %[[arg0]] dummy_scope
+
+! The file name and source line are also lowered and passed as runtime arguments
+! Capture the constant line number and convert the file name to i8*.
 ! CHECK: %[[STRADDR:.*]] = fir.address_of(
 ! CHECK: %[[LINE:.*]] = arith.constant {{.*}} : i32
 ! CHECK: %[[FNAME8:.*]] = fir.convert %[[STRADDR]] : (!fir.ref<!fir.char<1,{{.*}}>>) -> !fir.ref<i8>
 
-! Call the runtime DSECNDS with (refTime, file, line)
-! CHECK: %[[CALL:.*]] = fir.call @_FortranADsecnds(%{{.*}}, %{{.*}}, %{{.*}}) {{.*}} : (!fir.ref<f64>, !fir.ref<i8>, i32) -> f64
+! Verify the runtime call is made with:
+!   - the declared refTime value (%[[DECL]]#0)
+!   - the converted filename
+!   - the source line constant
+! CHECK: %[[CALL:.*]] = fir.call @_FortranADsecnds(%[[DECL]]#0, %[[FNAME8]], %[[LINE]]) {{.*}} : (!fir.ref<f64>, !fir.ref<i8>, i32) -> f64
 
-! Guard: no illegal ref conversion
+! Ensure there is no illegal conversion of a value result into a reference
 ! CHECK-NOT: fir.convert {{.*}} : (f64) -> !fir.ref<f64>
 
-! Function returns f64
+! Confirm the function result is returned as a plain f64
 ! CHECK: return {{.*}} : f64
+
+