[flang][hlfir] Use the HLFIR base of hlfir.declare if possible.

[vzakhari]

Summary

This patch makes use of the HLFIR box produced for hlfir.declare
in place of the FIR box (the memref of hlfir.declare) when possible.

This makes the representation a little bit more clear, because
all accesses are made via a single box.
This reduces the life range of the original box, because the new
temporary box produced by embox/rebox is used from now.
Apparently, this works around some issues in the current HLFIR codegen,
for example, look at the LIT tests changes around fir.array_coor
produced by hlfir.designate codegen - using the FIR box for fir.array_coor
might result in using incorrect lbounds.
Apparently, this change enables more intrinsics simplifications
because the SimplifyIntrinsicsPass looks for explicit embox/rebox
in findBoxDef() to decide whether to apply the optimization.
This change also provides better association of the base addresses
referenced by OpenACC clauses with the corresponding boxes
that might be used explicitly in OpenACC regions (e.g. for reading
the lbounds).

[vzakhari]

FYI, my local testing was clean except for one nag test failure. It is related to the intrinsics simplification pass that can now do better due to the explicit embox/rebox. Apparently, there is an issue with MAXVAL for f128 values - LLVM ends up using the fmaxl, which is a long double version. I am going to address this issue separately.

[clementval]

Thanks Slava. LGTM

[razvanlupusoru]

Doing this way makes a lot of sense. Looks great to me.

flang/lib/Lower/OpenACC.cpp

genBoundsOpsFromBox(fir::FirOpBuilder &builder, mlir::Location loc,
                     Fortran::lower::AbstractConverter &converter,
                     fir::ExtendedValue dataExv, mlir::Value box) {
   llvm::SmallVector<mlir::Value> bounds;
   mlir::Type idxTy = builder.getIndexType();
   mlir::Type boundTy = builder.getType<mlir::acc::DataBoundsType>();
   mlir::Value one = builder.createIntegerConstant(loc, idxTy, 1);
   assert(box.getType().isa<fir::BaseBoxType>() &&
          "expect fir.box or fir.class");
+  // Note that with the HLFIR lowering the 'box' is the FIR box
+  // which may not have correct local lbounds. As long as we only
+  // use the extents, it should be okay to read the dimensions
+  // from this box.
   for (unsigned dim = 0; dim < dataExv.rank(); ++dim) {
     mlir::Value d = builder.createIntegerConstant(loc, idxTy, dim);
     mlir::Value baseLb =
         fir::factory::readLowerBound(builder, loc, dataExv, dim, one);
     auto dimInfo =
         builder.create<fir::BoxDimsOp>(loc, idxTy, idxTy, idxTy, box, d);
     mlir::Value lb = builder.createIntegerConstant(loc, idxTy, 0);
     mlir::Value ub =

flang/lib/Optimizer/HLFIR/Transforms/ConvertToFIR.cpp

if (hlfirBaseType.isa<fir::BaseBoxType>()) {
           return builder.create<fir::ReboxOp>(loc, hlfirBaseType, firBase,
                                               declareOp.getShape(),
                                               /*slice=*/mlir::Value{});
         }
       };
       if (!mlir::cast<fir::FortranVariableOpInterface>(declareOp.getOperation())
                .isOptional()) {
         hlfirBase = genHlfirBox();
+        // If the original base is a box too, we could as well
+        // use the HLFIR box as the FIR base: otherwise, the two
+        // boxes are "alive" at the same time, and the FIR box
+        // is used for accessing the base_addr and the HLFIR box
+        // is used for accessing the bounds etc. Using the HLFIR box,
+        // that holds the same base_addr at this point, makes
+        // the representation a little bit more clear.
+        if (hlfirBase.getType() == firBase.getType())
+          firBase = hlfirBase;
       } else {
         // Need to conditionally rebox/embox the optional: the input fir.box
         // may be null and the rebox would be illegal. It is also important to
         // preserve the optional aspect: the hlfir fir.box should be null if
         // the entity is absent so that later fir.is_present on the hlfir base
         // are valid.
         mlir::Value isPresent =
             builder.create<fir::IsPresentOp>(loc, builder.getI1Type(), firBase);

flang/test/HLFIR/assign-codegen.fir

 // CHECK:  %[[VAL_2:.*]] = fir.alloca !fir.box<!fir.array<?xi32>>
 // CHECK:  %[[VAL_4:.*]] = arith.constant 100 : index
 // CHECK:  %[[VAL_5:.*]] = fir.declare %[[VAL_0]] {uniq_name = "x"} : (!fir.box<!fir.array<?xi32>>) -> !fir.box<!fir.array<?xi32>>
 // CHECK:  %[[VAL_6:.*]] = fir.rebox %[[VAL_5]] : (!fir.box<!fir.array<?xi32>>) -> !fir.box<!fir.array<?xi32>>
 // CHECK:  %[[VAL_7:.*]] = fir.shape %[[VAL_4]] : (index) -> !fir.shape<1>
 // CHECK:  %[[VAL_8:.*]] = fir.declare %[[VAL_1]](%[[VAL_7]]) {uniq_name = "y"} : (!fir.ref<!fir.array<100xi32>>, !fir.shape<1>) -> !fir.ref<!fir.array<100xi32>>
 // CHECK:  %[[VAL_9:.*]] = fir.shape %[[VAL_4]] : (index) -> !fir.shape<1>
 // CHECK:  %[[VAL_10:.*]] = fir.embox %[[VAL_8]](%[[VAL_9]]) : (!fir.ref<!fir.array<100xi32>>, !fir.shape<1>) -> !fir.box<!fir.array<100xi32>>
-// CHECK:  fir.store %[[VAL_5]] to %[[VAL_2]] : !fir.ref<!fir.box<!fir.array<?xi32>>>
+// CHECK:  fir.store %[[VAL_6]] to %[[VAL_2]] : !fir.ref<!fir.box<!fir.array<?xi32>>>
 // CHECK:  %[[VAL_26:.*]] = fir.convert %[[VAL_2]] : (!fir.ref<!fir.box<!fir.array<?xi32>>>) -> !fir.ref<!fir.box<none>>
 // CHECK:  %[[VAL_27:.*]] = fir.convert %[[VAL_10]] : (!fir.box<!fir.array<100xi32>>) -> !fir.box<none>
 // CHECK:  %[[VAL_29:.*]] = fir.call @_FortranAAssign(%[[VAL_26]], %[[VAL_27]], %{{.*}}, %{{.*}}) : (!fir.ref<!fir.box<none>>, !fir.box<none>, !fir.ref<i8>, i32) -> none
 
 
 func.func @array_temp(%arg0: !fir.box<!fir.array<?xi32>>, %arg1: !fir.ref<!fir.array<100xi32>>) {
   %c100 = arith.constant 100 : index
   %0:2 = hlfir.declare %arg0 {uniq_name = "x"} : (!fir.box<!fir.array<?xi32>>) -> (!fir.box<!fir.array<?xi32>>, !fir.box<!fir.array<?xi32>>)
   %1 = fir.shape %c100 : (index) -> !fir.shape<1>
   %2:2 = hlfir.declare %arg1(%1) {uniq_name = "y"} : (!fir.ref<!fir.array<100xi32>>, !fir.shape<1>) -> (!fir.ref<!fir.array<100xi32>>, !fir.ref<!fir.array<100xi32>>)
   hlfir.assign %2#0 to %0#0 temporary_lhs : !fir.ref<!fir.array<100xi32>>, !fir.box<!fir.array<?xi32>>
   return
 }
 // CHECK-LABEL:   func.func @array_temp(
 // CHECK-SAME:    %[[VAL_0:.*]]: !fir.box<!fir.array<?xi32>>,
 // CHECK-SAME:    %[[VAL_1:.*]]: !fir.ref<!fir.array<100xi32>>) {
 // CHECK:  %[[VAL_2:.*]] = fir.alloca !fir.box<!fir.array<?xi32>>
 // CHECK:  %[[VAL_4:.*]] = arith.constant 100 : index
 // CHECK:  %[[VAL_5:.*]] = fir.declare %[[VAL_0]] {uniq_name = "x"} : (!fir.box<!fir.array<?xi32>>) -> !fir.box<!fir.array<?xi32>>
 // CHECK:  %[[VAL_6:.*]] = fir.rebox %[[VAL_5]] : (!fir.box<!fir.array<?xi32>>) -> !fir.box<!fir.array<?xi32>>
 // CHECK:  %[[VAL_7:.*]] = fir.shape %[[VAL_4]] : (index) -> !fir.shape<1>
 // CHECK:  %[[VAL_8:.*]] = fir.declare %[[VAL_1]](%[[VAL_7]]) {uniq_name = "y"} : (!fir.ref<!fir.array<100xi32>>, !fir.shape<1>) -> !fir.ref<!fir.array<100xi32>>
 // CHECK:  %[[VAL_9:.*]] = fir.shape %[[VAL_4]] : (index) -> !fir.shape<1>
 // CHECK:  %[[VAL_10:.*]] = fir.embox %[[VAL_8]](%[[VAL_9]]) : (!fir.ref<!fir.array<100xi32>>, !fir.shape<1>) -> !fir.box<!fir.array<100xi32>>
-// CHECK:  fir.store %[[VAL_5]] to %[[VAL_2]] : !fir.ref<!fir.box<!fir.array<?xi32>>>
+// CHECK:  fir.store %[[VAL_6]] to %[[VAL_2]] : !fir.ref<!fir.box<!fir.array<?xi32>>>
 // CHECK:  %[[VAL_26:.*]] = fir.convert %[[VAL_2]] : (!fir.ref<!fir.box<!fir.array<?xi32>>>) -> !fir.ref<!fir.box<none>>
 // CHECK:  %[[VAL_27:.*]] = fir.convert %[[VAL_10]] : (!fir.box<!fir.array<100xi32>>) -> !fir.box<none>
 // CHECK:  %[[VAL_29:.*]] = fir.call @_FortranAAssignTemporary(%[[VAL_26]], %[[VAL_27]], %{{.*}}, %{{.*}}) : (!fir.ref<!fir.box<none>>, !fir.box<none>, !fir.ref<i8>, i32) -> none
 
 
 func.func @test_scalar_to_array(%lhs: !fir.box<!fir.array<?xi32>>, %rhs: i32) {
   hlfir.assign %rhs to %lhs : i32, !fir.box<!fir.array<?xi32>>
   return

 // CHECK:           %[[VAL_3:.*]] = arith.constant 0 : index
 // CHECK:           %[[VAL_4:.*]] = fir.declare %[[VAL_0]] {uniq_name = "_QFtestEy"} : (!fir.class<!fir.array<?xnone>>) -> !fir.class<!fir.array<?xnone>>
 // CHECK:           %[[VAL_5:.*]] = fir.rebox %[[VAL_4]] : (!fir.class<!fir.array<?xnone>>) -> !fir.class<!fir.array<?xnone>>
 // CHECK:           %[[VAL_6:.*]]:3 = fir.box_dims %[[VAL_5]], %[[VAL_3]] : (!fir.class<!fir.array<?xnone>>, index) -> (index, index, index)
 // CHECK:           %[[VAL_7:.*]] = fir.declare %[[VAL_2]] {fortran_attrs = #fir.var_attrs<allocatable>, uniq_name = ".tmp.array"} : (!fir.ref<!fir.class<!fir.heap<!fir.array<?xnone>>>>) -> !fir.ref<!fir.class<!fir.heap<!fir.array<?xnone>>>>
 // CHECK:           %[[VAL_8:.*]] = fir.load %[[VAL_7]] : !fir.ref<!fir.class<!fir.heap<!fir.array<?xnone>>>>
 // CHECK:           %[[VAL_9:.*]] = arith.constant 1 : index
 // CHECK:           fir.do_loop %[[VAL_10:.*]] = %[[VAL_9]] to %[[VAL_6]]#1 step %[[VAL_9]] unordered {
-// CHECK:             %[[VAL_11:.*]] = fir.array_coor %[[VAL_4]] %[[VAL_10]] : (!fir.class<!fir.array<?xnone>>, index) -> !fir.ref<none>
-// CHECK:             %[[VAL_12:.*]] = fir.embox %[[VAL_11]] source_box %[[VAL_4]] : (!fir.ref<none>, !fir.class<!fir.array<?xnone>>) -> !fir.class<none>
+// CHECK:             %[[VAL_11:.*]] = fir.array_coor %[[VAL_5]] %[[VAL_10]] : (!fir.class<!fir.array<?xnone>>, index) -> !fir.ref<none>
+// CHECK:             %[[VAL_12:.*]] = fir.embox %[[VAL_11]] source_box %[[VAL_5]] : (!fir.ref<none>, !fir.class<!fir.array<?xnone>>) -> !fir.class<none>
 // CHECK:             %[[VAL_13:.*]] = arith.constant 0 : index
 // CHECK:             %[[VAL_14:.*]]:3 = fir.box_dims %[[VAL_8]], %[[VAL_13]] : (!fir.class<!fir.heap<!fir.array<?xnone>>>, index) -> (index, index, index)
 // CHECK:             %[[VAL_15:.*]] = arith.constant 1 : index
 // CHECK:             %[[VAL_16:.*]] = arith.subi %[[VAL_14]]#0, %[[VAL_15]] : index
 // CHECK:             %[[VAL_17:.*]] = arith.addi %[[VAL_10]], %[[VAL_16]] : index
 // CHECK:             %[[VAL_18:.*]] = arith.constant 0 : index
 // CHECK:             %[[VAL_19:.*]]:3 = fir.box_dims %[[VAL_8]], %[[VAL_18]] : (!fir.class<!fir.heap<!fir.array<?xnone>>>, index) -> (index, index, index)
 // CHECK:             %[[VAL_20:.*]] = fir.shift %[[VAL_19]]#0 : (index) -> !fir.shift<1>

flang/test/HLFIR/designate-codegen-complex-part.fir

 }
 // CHECK-LABEL: func.func @test_scalar_at_index(
 // CHECK-SAME: %[[VAL_0:.*]]: !fir.box<!fir.array<?x!fir.complex<4>>>, %[[VAL_1:.*]]: !fir.ref<i32>) {
 // CHECK: %[[VAL_2:.*]] = fir.declare %[[VAL_0]] {uniq_name = "a"} : (!fir.box<!fir.array<?x!fir.complex<4>>>) -> !fir.box<!fir.array<?x!fir.complex<4>>>
 // CHECK: %[[VAL_3:.*]] = fir.rebox %[[VAL_2]] : (!fir.box<!fir.array<?x!fir.complex<4>>>) -> !fir.box<!fir.array<?x!fir.complex<4>>>
 // CHECK: %[[VAL_4:.*]] = fir.declare %[[VAL_1]] {uniq_name = "b"} : (!fir.ref<i32>) -> !fir.ref<i32>
 // CHECK: %[[VAL_5:.*]] = fir.load %[[VAL_4]] : !fir.ref<i32>
 // CHECK: %[[VAL_6:.*]] = fir.convert %[[VAL_5]] : (i32) -> i64
-// CHECK: %[[VAL_7:.*]] = fir.array_coor %[[VAL_2]] %[[VAL_6]] : (!fir.box<!fir.array<?x!fir.complex<4>>>, i64) -> !fir.ref<!fir.complex<4>>
+// CHECK: %[[VAL_7:.*]] = fir.array_coor %[[VAL_3]] %[[VAL_6]] : (!fir.box<!fir.array<?x!fir.complex<4>>>, i64) -> !fir.ref<!fir.complex<4>>
 // CHECK: %[[VAL_8:.*]] = arith.constant 0 : index
 // CHECK: %[[VAL_9:.*]] = fir.coordinate_of %[[VAL_7]], %[[VAL_8]] : (!fir.ref<!fir.complex<4>>, index) -> !fir.ref<f32>
 
 func.func @test_complete_slice(%arg0: !fir.box<!fir.array<?x!fir.complex<4>>>) {
   %c0 = arith.constant 0 : index
   %0:2 = hlfir.declare %arg0 {uniq_name = "a"} : (!fir.box<!fir.array<?x!fir.complex<4>>>) -> (!fir.box<!fir.array<?x!fir.complex<4>>>, !fir.box<!fir.array<?x!fir.complex<4>>>)
   %1:3 = fir.box_dims %0#0, %c0 : (!fir.box<!fir.array<?x!fir.complex<4>>>, index) -> (index, index, index)
   %2 = fir.shape %1#1 : (index) -> !fir.shape<1>
   %3 = hlfir.designate %0#0  imag shape %2 : (!fir.box<!fir.array<?x!fir.complex<4>>>, !fir.shape<1>) -> !fir.box<!fir.array<?xf32>>
   return
 }
 // CHECK-LABEL: func.func @test_complete_slice(
 // CHECK-SAME: %[[VAL_0:.*]]: !fir.box<!fir.array<?x!fir.complex<4>>>) {
 // CHECK: %[[VAL_1:.*]] = arith.constant 0 : index
 // CHECK: %[[VAL_2:.*]] = fir.declare %[[VAL_0]] {uniq_name = "a"} : (!fir.box<!fir.array<?x!fir.complex<4>>>) -> !fir.box<!fir.array<?x!fir.complex<4>>>
 // CHECK: %[[VAL_3:.*]] = fir.rebox %[[VAL_2]] : (!fir.box<!fir.array<?x!fir.complex<4>>>) -> !fir.box<!fir.array<?x!fir.complex<4>>>
 // CHECK: %[[VAL_4:.*]]:3 = fir.box_dims %[[VAL_3]], %[[VAL_1]] : (!fir.box<!fir.array<?x!fir.complex<4>>>, index) -> (index, index, index)
 // CHECK: %[[VAL_5:.*]] = fir.shape %[[VAL_4]]#1 : (index) -> !fir.shape<1>
 // CHECK: %[[VAL_6:.*]] = arith.constant 1 : index
 // CHECK: %[[VAL_7:.*]] = arith.constant 1 : index
 // CHECK: %[[VAL_8:.*]] = arith.constant 0 : index
-// CHECK: %[[VAL_9:.*]]:3 = fir.box_dims %[[VAL_2]], %[[VAL_8]] : (!fir.box<!fir.array<?x!fir.complex<4>>>, index) -> (index, index, index)
+// CHECK: %[[VAL_9:.*]]:3 = fir.box_dims %[[VAL_3]], %[[VAL_8]] : (!fir.box<!fir.array<?x!fir.complex<4>>>, index) -> (index, index, index)
 // CHECK: %[[VAL_10:.*]] = arith.constant 1 : index
 // CHECK: %[[VAL_11:.*]] = fir.slice %[[VAL_7]], %[[VAL_9]]#1, %[[VAL_6]] path %[[VAL_10]] : (index, index, index, index) -> !fir.slice<1>
-// CHECK: %[[VAL_12:.*]] = fir.rebox %[[VAL_2]] [%[[VAL_11]]] : (!fir.box<!fir.array<?x!fir.complex<4>>>, !fir.slice<1>) -> !fir.box<!fir.array<?xf32>>
+// CHECK: %[[VAL_12:.*]] = fir.rebox %[[VAL_3]] [%[[VAL_11]]] : (!fir.box<!fir.array<?x!fir.complex<4>>>, !fir.slice<1>) -> !fir.box<!fir.array<?xf32>>
 
 func.func @test_slice_steps(%arg0: !fir.box<!fir.array<?x!fir.complex<4>>>) {
   %c3 = arith.constant 3 : index
   %c12 = arith.constant 12 : index
   %c4 = arith.constant 4 : index
   %0:2 = hlfir.declare %arg0 {uniq_name = "a"} : (!fir.box<!fir.array<?x!fir.complex<4>>>) -> (!fir.box<!fir.array<?x!fir.complex<4>>>, !fir.box<!fir.array<?x!fir.complex<4>>>)
   %1 = fir.shape %c3 : (index) -> !fir.shape<1>
   %2 = hlfir.designate %0#0 (%c4:%c12:%c3) real shape %1 : (!fir.box<!fir.array<?x!fir.complex<4>>>, index, index, index, !fir.shape<1>) -> !fir.box<!fir.array<3xf32>>
   return
 }
 // CHECK-LABEL: func.func @test_slice_steps(
 // CHECK-SAME: %[[VAL_0:.*]]: !fir.box<!fir.array<?x!fir.complex<4>>>) {
 // CHECK: %[[VAL_1:.*]] = arith.constant 3 : index
 // CHECK: %[[VAL_2:.*]] = arith.constant 12 : index
 // CHECK: %[[VAL_3:.*]] = arith.constant 4 : index
 // CHECK: %[[VAL_4:.*]] = fir.declare %[[VAL_0]] {uniq_name = "a"} : (!fir.box<!fir.array<?x!fir.complex<4>>>) -> !fir.box<!fir.array<?x!fir.complex<4>>>
 // CHECK: %[[VAL_5:.*]] = fir.rebox %[[VAL_4]] : (!fir.box<!fir.array<?x!fir.complex<4>>>) -> !fir.box<!fir.array<?x!fir.complex<4>>>
 // CHECK: %[[VAL_6:.*]] = fir.shape %[[VAL_1]] : (index) -> !fir.shape<1>
 // CHECK: %[[VAL_7:.*]] = arith.constant 0 : index
 // CHECK: %[[VAL_8:.*]] = fir.slice %[[VAL_3]], %[[VAL_2]], %[[VAL_1]] path %[[VAL_7]] : (index, index, index, index) -> !fir.slice<1>
-// CHECK: %[[VAL_9:.*]] = fir.rebox %[[VAL_4]] [%[[VAL_8]]] : (!fir.box<!fir.array<?x!fir.complex<4>>>, !fir.slice<1>) -> !fir.box<!fir.array<3xf32>>
+// CHECK: %[[VAL_9:.*]] = fir.rebox %[[VAL_5]] [%[[VAL_8]]] : (!fir.box<!fir.array<?x!fir.complex<4>>>, !fir.slice<1>) -> !fir.box<!fir.array<3xf32>>

flang/test/HLFIR/designate-codegen-component-refs.fir

 // CHECK:  %[[VAL_2:.*]] = fir.rebox %[[VAL_1]] : (!fir.box<!fir.array<?x!fir.type<t1{scalar_i:i32,scalar_x:f32}>>>) -> !fir.box<!fir.array<?x!fir.type<t1{scalar_i:i32,scalar_x:f32}>>>
 // CHECK:  %[[VAL_3:.*]] = arith.constant 0 : index
 // CHECK:  %[[VAL_4:.*]]:3 = fir.box_dims %[[VAL_2]], %[[VAL_3]] : (!fir.box<!fir.array<?x!fir.type<t1{scalar_i:i32,scalar_x:f32}>>>, index) -> (index, index, index)
 // CHECK:  %[[VAL_5:.*]] = fir.shape %[[VAL_4]]#1 : (index) -> !fir.shape<1>
 // CHECK:  %[[VAL_6:.*]] = fir.field_index scalar_x, !fir.type<t1{scalar_i:i32,scalar_x:f32}>
 // CHECK:  %[[VAL_7:.*]] = arith.constant 1 : index
 // CHECK:  %[[VAL_8:.*]] = arith.constant 1 : index
 // CHECK:  %[[VAL_9:.*]] = arith.constant 0 : index
-// CHECK:  %[[VAL_10:.*]]:3 = fir.box_dims %[[VAL_1]], %[[VAL_9]] : (!fir.box<!fir.array<?x!fir.type<t1{scalar_i:i32,scalar_x:f32}>>>, index) -> (index, index, index)
+// CHECK:  %[[VAL_10:.*]]:3 = fir.box_dims %[[VAL_2]], %[[VAL_9]] : (!fir.box<!fir.array<?x!fir.type<t1{scalar_i:i32,scalar_x:f32}>>>, index) -> (index, index, index)
 // CHECK:  %[[VAL_11:.*]] = fir.slice %[[VAL_8]], %[[VAL_10]]#1, %[[VAL_7]] path %[[VAL_6]] : (index, index, index, !fir.field) -> !fir.slice<1>
-// CHECK:  %[[VAL_12:.*]] = fir.rebox %[[VAL_1]] {{\[}}%[[VAL_11]]] : (!fir.box<!fir.array<?x!fir.type<t1{scalar_i:i32,scalar_x:f32}>>>, !fir.slice<1>) -> !fir.box<!fir.array<?xf32>>
+// CHECK:  %[[VAL_12:.*]] = fir.rebox %[[VAL_2]] {{\[}}%[[VAL_11]]] : (!fir.box<!fir.array<?x!fir.type<t1{scalar_i:i32,scalar_x:f32}>>>, !fir.slice<1>) -> !fir.box<!fir.array<?xf32>>
 
 func.func @test_array_char(%arg0: !fir.ref<!fir.array<?x!fir.type<t_char{scalar_i:i32,scalar_char:!fir.char<1,5>}>>>, %n : index) {
   %5 = fir.shape %n : (index) -> !fir.shape<1>
   %6:2 = hlfir.declare %arg0(%5) {uniq_name = "a"} : (!fir.ref<!fir.array<?x!fir.type<t_char{scalar_i:i32,scalar_char:!fir.char<1,5>}>>>, !fir.shape<1>) -> (!fir.box<!fir.array<?x!fir.type<t_char{scalar_i:i32,scalar_char:!fir.char<1,5>}>>>, !fir.ref<!fir.array<?x!fir.type<t_char{scalar_i:i32,scalar_char:!fir.char<1,5>}>>>)
   %c5 = arith.constant 5 : index
   %10 = hlfir.designate %6#0{"scalar_char"}   shape %5 typeparams %c5 : (!fir.box<!fir.array<?x!fir.type<t_char{scalar_i:i32,scalar_char:!fir.char<1,5>}>>>, !fir.shape<1>, index) -> !fir.box<!fir.array<?x!fir.char<1,5>>>
   return
 }

flang/test/HLFIR/designate-codegen.fir

 // Test code generation to FIR of hlfir.designate operations
 // without component reference.
 // RUN: fir-opt %s -convert-hlfir-to-fir | FileCheck %s
 
 func.func @array_ref(%arg0: !fir.box<!fir.array<?xf32>>, %arg1: !fir.ref<i64>) {
   %0:2 = hlfir.declare %arg1 {uniq_name = "n"} : (!fir.ref<i64>) -> (!fir.ref<i64>, !fir.ref<i64>)
   %1:2 = hlfir.declare %arg0 {uniq_name = "x"} : (!fir.box<!fir.array<?xf32>>) -> (!fir.box<!fir.array<?xf32>>, !fir.box<!fir.array<?xf32>>)
   %2 = fir.load %0#0 : !fir.ref<i64>
   %3 = hlfir.designate %1#0 (%2)  : (!fir.box<!fir.array<?xf32>>, i64) -> !fir.ref<f32>
   return
 }
 // CHECK-LABEL:   func.func @array_ref(
 // CHECK-SAME:    %[[VAL_0:.*]]: !fir.box<!fir.array<?xf32>>,
 // CHECK-SAME:    %[[VAL_1:.*]]: !fir.ref<i64>) {
 // CHECK:  %[[VAL_2:.*]] = fir.declare %[[VAL_1]] {uniq_name = "n"} : (!fir.ref<i64>) -> !fir.ref<i64>
 // CHECK:  %[[VAL_3:.*]] = fir.declare %[[VAL_0]] {uniq_name = "x"} : (!fir.box<!fir.array<?xf32>>) -> !fir.box<!fir.array<?xf32>>
+// CHECK:  %[[VAL_4:.*]] = fir.rebox %[[VAL_3]] : (!fir.box<!fir.array<?xf32>>) -> !fir.box<!fir.array<?xf32>>
 // CHECK:  %[[VAL_5:.*]] = fir.load %[[VAL_2]] : !fir.ref<i64>
-// CHECK:  %[[VAL_6:.*]] = fir.array_coor %[[VAL_3]] %[[VAL_5]] : (!fir.box<!fir.array<?xf32>>, i64) -> !fir.ref<f32>
+// CHECK:  %[[VAL_6:.*]] = fir.array_coor %[[VAL_4]] %[[VAL_5]] : (!fir.box<!fir.array<?xf32>>, i64) -> !fir.ref<f32>
 
 
 func.func @char_array_ref(%arg0: !fir.box<!fir.array<?x!fir.char<1,?>>>, %arg1: !fir.ref<i32>) {
   %0:2 = hlfir.declare %arg1 {uniq_name = "n"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
   %1:2 = hlfir.declare %arg0 {uniq_name = "x"} : (!fir.box<!fir.array<?x!fir.char<1,?>>>) -> (!fir.box<!fir.array<?x!fir.char<1,?>>>, !fir.box<!fir.array<?x!fir.char<1,?>>>)
   %2 = fir.box_elesize %1#1 : (!fir.box<!fir.array<?x!fir.char<1,?>>>) -> index
   %c10 = arith.constant 10 : index
   %3 = hlfir.designate %1#0 (%c10)  typeparams %2 : (!fir.box<!fir.array<?x!fir.char<1,?>>>, index, index) -> !fir.boxchar<1>
   return
 }
 // CHECK-LABEL:   func.func @char_array_ref(
 // CHECK-SAME:    %[[VAL_0:.*]]: !fir.box<!fir.array<?x!fir.char<1,?>>>,
 // CHECK-SAME:    %[[VAL_1:.*]]: !fir.ref<i32>) {
 // CHECK:  %[[VAL_2:.*]] = fir.declare %[[VAL_1]] {uniq_name = "n"} : (!fir.ref<i32>) -> !fir.ref<i32>
 // CHECK:  %[[VAL_3:.*]] = fir.declare %[[VAL_0]] {uniq_name = "x"} : (!fir.box<!fir.array<?x!fir.char<1,?>>>) -> !fir.box<!fir.array<?x!fir.char<1,?>>>
-// CHECK:  %[[VAL_5:.*]] = fir.box_elesize %[[VAL_3]] : (!fir.box<!fir.array<?x!fir.char<1,?>>>) -> index
+// CHECK:  %[[VAL_4:.*]] = fir.rebox %[[VAL_3]] : (!fir.box<!fir.array<?x!fir.char<1,?>>>) -> !fir.box<!fir.array<?x!fir.char<1,?>>>
+// CHECK:  %[[VAL_5:.*]] = fir.box_elesize %[[VAL_4]] : (!fir.box<!fir.array<?x!fir.char<1,?>>>) -> index
 // CHECK:  %[[VAL_6:.*]] = arith.constant 10 : index
-// CHECK:  %[[VAL_7:.*]] = fir.array_coor %[[VAL_3]] %[[VAL_6]] : (!fir.box<!fir.array<?x!fir.char<1,?>>>, index) -> !fir.ref<!fir.char<1,?>>
+// CHECK:  %[[VAL_7:.*]] = fir.array_coor %[[VAL_4]] %[[VAL_6]] : (!fir.box<!fir.array<?x!fir.char<1,?>>>, index) -> !fir.ref<!fir.char<1,?>>
 // CHECK:  %[[VAL_8:.*]] = fir.emboxchar %[[VAL_7]], %[[VAL_5]] : (!fir.ref<!fir.char<1,?>>, index) -> !fir.boxchar<1>
 
 
 func.func @char_array_ref_cst_len(%arg0: !fir.box<!fir.array<?x!fir.char<1,5>>>, %arg1: !fir.ref<i32>) {
   %0:2 = hlfir.declare %arg1 {uniq_name = "n"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
   %c5 = arith.constant 5 : index
   %1:2 = hlfir.declare %arg0 typeparams %c5 {uniq_name = "x"} : (!fir.box<!fir.array<?x!fir.char<1,5>>>, index) -> (!fir.box<!fir.array<?x!fir.char<1,5>>>, !fir.box<!fir.array<?x!fir.char<1,5>>>)
   %c10 = arith.constant 10 : index
   %2 = hlfir.designate %1#0 (%c10)  typeparams %c5 : (!fir.box<!fir.array<?x!fir.char<1,5>>>, index, index) -> !fir.ref<!fir.char<1,5>>
   return
 }
 // CHECK-LABEL:   func.func @char_array_ref_cst_len(
 // CHECK-SAME:    %[[VAL_0:.*]]: !fir.box<!fir.array<?x!fir.char<1,5>>>,
 // CHECK-SAME:    %[[VAL_1:.*]]: !fir.ref<i32>) {
 // CHECK:  %[[VAL_2:.*]] = fir.declare %[[VAL_1]] {uniq_name = "n"} : (!fir.ref<i32>) -> !fir.ref<i32>
 // CHECK:  %[[VAL_3:.*]] = arith.constant 5 : index
 // CHECK:  %[[VAL_4:.*]] = fir.declare %[[VAL_0]] typeparams %[[VAL_3]] {uniq_name = "x"} : (!fir.box<!fir.array<?x!fir.char<1,5>>>, index) -> !fir.box<!fir.array<?x!fir.char<1,5>>>
+// CHECK:  %[[VAL_5:.*]] = fir.rebox %[[VAL_4]] : (!fir.box<!fir.array<?x!fir.char<1,5>>>) -> !fir.box<!fir.array<?x!fir.char<1,5>>>
 // CHECK:  %[[VAL_6:.*]] = arith.constant 10 : index
-// CHECK:  %[[VAL_7:.*]] = fir.array_coor %[[VAL_4]] %[[VAL_6]] : (!fir.box<!fir.array<?x!fir.char<1,5>>>, index) -> !fir.ref<!fir.char<1,5>>
+// CHECK:  %[[VAL_7:.*]] = fir.array_coor %[[VAL_5]] %[[VAL_6]] : (!fir.box<!fir.array<?x!fir.char<1,5>>>, index) -> !fir.ref<!fir.char<1,5>>
 
 
 func.func @char_array_ref_3(%arg0: !fir.ref<!fir.array<100x!fir.char<1,?>>>, %arg1: !fir.ref<i32>) {
   %0:2 = hlfir.declare %arg1 {uniq_name = "n"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
   %c5 = arith.constant 5 : index
   %c100 = arith.constant 100 : index
   %sh = fir.shape %c100 : (index) -> !fir.shape<1>
   %1:2 = hlfir.declare %arg0(%sh) typeparams %c5 {uniq_name = "x"} : (!fir.ref<!fir.array<100x!fir.char<1,?>>>, !fir.shape<1>, index) -> (!fir.box<!fir.array<100x!fir.char<1,?>>>, !fir.ref<!fir.array<100x!fir.char<1,?>>>)
func.func @array_section_2(%arg0: !fir.box<!fir.array<?xf32>>, %arg1: !fir.ref<i64>) {
   %6 = hlfir.designate %1#0 (%4:%3#1:%c3)  shape %5 : (!fir.box<!fir.array<?xf32>>, index, index, index, !fir.shape<1>) -> !fir.box<!fir.array<?xf32>>
   return
 }
 // CHECK-LABEL:   func.func @array_section_2(
 // CHECK-SAME:    %[[VAL_0:.*]]: !fir.box<!fir.array<?xf32>>,
 // CHECK-SAME:    %[[VAL_1:.*]]: !fir.ref<i64>) {
 // CHECK:  %[[VAL_2:.*]] = fir.declare %[[VAL_1]] {uniq_name = "n"} : (!fir.ref<i64>) -> !fir.ref<i64>
 // CHECK:  %[[VAL_3:.*]] = fir.declare %[[VAL_0]] {uniq_name = "x"} : (!fir.box<!fir.array<?xf32>>) -> !fir.box<!fir.array<?xf32>>
+// CHECK:  %[[VAL_4:.*]] = fir.rebox %[[VAL_3]] : (!fir.box<!fir.array<?xf32>>) -> !fir.box<!fir.array<?xf32>>
 // CHECK:  %[[VAL_5:.*]] = fir.load %[[VAL_2]] : !fir.ref<i64>
 // CHECK:  %[[VAL_6:.*]] = arith.constant 0 : index
-// CHECK:  %[[VAL_7:.*]]:3 = fir.box_dims %[[VAL_3]], %[[VAL_6]] : (!fir.box<!fir.array<?xf32>>, index) -> (index, index, index)
+// CHECK:  %[[VAL_7:.*]]:3 = fir.box_dims %[[VAL_4]], %[[VAL_6]] : (!fir.box<!fir.array<?xf32>>, index) -> (index, index, index)
 // CHECK:  %[[VAL_8:.*]] = fir.convert %[[VAL_5]] : (i64) -> index
 // CHECK:  %[[VAL_9:.*]] = arith.constant 3 : index
 // CHECK:  %[[VAL_10:.*]] = arith.constant 42 : index
 // CHECK:  %[[VAL_11:.*]] = fir.shape %[[VAL_10]] : (index) -> !fir.shape<1>
 // CHECK:  %[[VAL_12:.*]] = fir.undefined index
 // CHECK:  %[[VAL_13:.*]] = fir.slice %[[VAL_8]], %[[VAL_7]]#1, %[[VAL_9]] : (index, index, index) -> !fir.slice<1>
-// CHECK:  %[[VAL_14:.*]] = fir.rebox %[[VAL_3]] {{\[}}%[[VAL_13]]] : (!fir.box<!fir.array<?xf32>>, !fir.slice<1>) -> !fir.box<!fir.array<?xf32>>
+// CHECK:  %[[VAL_14:.*]] = fir.rebox %[[VAL_4]] {{\[}}%[[VAL_13]]] : (!fir.box<!fir.array<?xf32>>, !fir.slice<1>) -> !fir.box<!fir.array<?xf32>>
 
 
 func.func @char_array_section(%arg0: !fir.box<!fir.array<?x!fir.char<1,?>>>, %arg1: !fir.ref<i32>) {
   %0:2 = hlfir.declare %arg1 {uniq_name = "n"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
   %1:2 = hlfir.declare %arg0 {uniq_name = "x"} : (!fir.box<!fir.array<?x!fir.char<1,?>>>) -> (!fir.box<!fir.array<?x!fir.char<1,?>>>, !fir.box<!fir.array<?x!fir.char<1,?>>>)
   %2 = fir.box_elesize %1#1 : (!fir.box<!fir.array<?x!fir.char<1,?>>>) -> index
   %c1 = arith.constant 1 : index
   %c0 = arith.constant 0 : index
   %3:3 = fir.box_dims %1#1, %c0 : (!fir.box<!fir.array<?x!fir.char<1,?>>>, index) -> (index, index, index)
   %c3 = arith.constant 3 : index
   %c42 = arith.constant 42 : index
   %4 = fir.shape %c42 : (index) -> !fir.shape<1>
   %5 = hlfir.designate %1#0 (%c1:%3#1:%c3)  shape %4 typeparams %2 : (!fir.box<!fir.array<?x!fir.char<1,?>>>, index, index, index, !fir.shape<1>, index) -> !fir.box<!fir.array<?x!fir.char<1,?>>>
   return
 }
 // CHECK-LABEL:   func.func @char_array_section(
 // CHECK-SAME:    %[[VAL_0:.*]]: !fir.box<!fir.array<?x!fir.char<1,?>>>,
 // CHECK-SAME:    %[[VAL_1:.*]]: !fir.ref<i32>) {
 // CHECK:  %[[VAL_2:.*]] = fir.declare %[[VAL_1]] {uniq_name = "n"} : (!fir.ref<i32>) -> !fir.ref<i32>
 // CHECK:  %[[VAL_3:.*]] = fir.declare %[[VAL_0]] {uniq_name = "x"} : (!fir.box<!fir.array<?x!fir.char<1,?>>>) -> !fir.box<!fir.array<?x!fir.char<1,?>>>
-// CHECK:  %[[VAL_5:.*]] = fir.box_elesize %[[VAL_3]] : (!fir.box<!fir.array<?x!fir.char<1,?>>>) -> index
+// CHECK:  %[[VAL_4:.*]] = fir.rebox %[[VAL_3]] : (!fir.box<!fir.array<?x!fir.char<1,?>>>) -> !fir.box<!fir.array<?x!fir.char<1,?>>>
+// CHECK:  %[[VAL_5:.*]] = fir.box_elesize %[[VAL_4]] : (!fir.box<!fir.array<?x!fir.char<1,?>>>) -> index
 // CHECK:  %[[VAL_6:.*]] = arith.constant 1 : index
 // CHECK:  %[[VAL_7:.*]] = arith.constant 0 : index
-// CHECK:  %[[VAL_8:.*]]:3 = fir.box_dims %[[VAL_3]], %[[VAL_7]] : (!fir.box<!fir.array<?x!fir.char<1,?>>>, index) -> (index, index, index)
+// CHECK:  %[[VAL_8:.*]]:3 = fir.box_dims %[[VAL_4]], %[[VAL_7]] : (!fir.box<!fir.array<?x!fir.char<1,?>>>, index) -> (index, index, index)
 // CHECK:  %[[VAL_9:.*]] = arith.constant 3 : index
 // CHECK:  %[[VAL_10:.*]] = arith.constant 42 : index
 // CHECK:  %[[VAL_11:.*]] = fir.shape %[[VAL_10]] : (index) -> !fir.shape<1>
 // CHECK:  %[[VAL_12:.*]] = fir.undefined index
 // CHECK:  %[[VAL_13:.*]] = fir.slice %[[VAL_6]], %[[VAL_8]]#1, %[[VAL_9]] : (index, index, index) -> !fir.slice<1>
-// CHECK:  %[[VAL_14:.*]] = fir.rebox %[[VAL_3]] {{\[}}%[[VAL_13]]] : (!fir.box<!fir.array<?x!fir.char<1,?>>>, !fir.slice<1>) -> !fir.box<!fir.array<?x!fir.char<1,?>>>
+// CHECK:  %[[VAL_14:.*]] = fir.rebox %[[VAL_4]] {{\[}}%[[VAL_13]]] : (!fir.box<!fir.array<?x!fir.char<1,?>>>, !fir.slice<1>) -> !fir.box<!fir.array<?x!fir.char<1,?>>>
 
 
 func.func @char_array_section_cst_len(%arg0: !fir.box<!fir.array<?x!fir.char<1,5>>>, %arg1: !fir.ref<i32>) {
   %0:2 = hlfir.declare %arg1 {uniq_name = "n"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
   %c5 = arith.constant 5 : index
   %1:2 = hlfir.declare %arg0 typeparams %c5 {uniq_name = "x"} : (!fir.box<!fir.array<?x!fir.char<1,5>>>, index) -> (!fir.box<!fir.array<?x!fir.char<1,5>>>, !fir.box<!fir.array<?x!fir.char<1,5>>>)
   %c1 = arith.constant 1 : index
   %c0 = arith.constant 0 : index
   %2:3 = fir.box_dims %1#1, %c0 : (!fir.box<!fir.array<?x!fir.char<1,5>>>, index) -> (index, index, index)
   %c3 = arith.constant 3 : index
   %c42 = arith.constant 42 : index
   %3 = fir.shape %c42 : (index) -> !fir.shape<1>
   %4 = hlfir.designate %1#0 (%c1:%2#1:%c3)  shape %3 typeparams %c5 : (!fir.box<!fir.array<?x!fir.char<1,5>>>, index, index, index, !fir.shape<1>, index) -> !fir.box<!fir.array<?x!fir.char<1,5>>>
   return
 }
 // CHECK-LABEL:   func.func @char_array_section_cst_len(
 // CHECK-SAME:    %[[VAL_0:.*]]: !fir.box<!fir.array<?x!fir.char<1,5>>>,
 // CHECK-SAME:    %[[VAL_1:.*]]: !fir.ref<i32>) {
 // CHECK:  %[[VAL_2:.*]] = fir.declare %[[VAL_1]] {uniq_name = "n"} : (!fir.ref<i32>) -> !fir.ref<i32>
 // CHECK:  %[[VAL_3:.*]] = arith.constant 5 : index
 // CHECK:  %[[VAL_4:.*]] = fir.declare %[[VAL_0]] typeparams %[[VAL_3]] {uniq_name = "x"} : (!fir.box<!fir.array<?x!fir.char<1,5>>>, index) -> !fir.box<!fir.array<?x!fir.char<1,5>>>
+// CHECK:  %[[VAL_5:.*]] = fir.rebox %[[VAL_4]] : (!fir.box<!fir.array<?x!fir.char<1,5>>>) -> !fir.box<!fir.array<?x!fir.char<1,5>>>
 // CHECK:  %[[VAL_6:.*]] = arith.constant 1 : index
 // CHECK:  %[[VAL_7:.*]] = arith.constant 0 : index
-// CHECK:  %[[VAL_8:.*]]:3 = fir.box_dims %[[VAL_4]], %[[VAL_7]] : (!fir.box<!fir.array<?x!fir.char<1,5>>>, index) -> (index, index, index)
+// CHECK:  %[[VAL_8:.*]]:3 = fir.box_dims %[[VAL_5]], %[[VAL_7]] : (!fir.box<!fir.array<?x!fir.char<1,5>>>, index) -> (index, index, index)
 // CHECK:  %[[VAL_9:.*]] = arith.constant 3 : index
 // CHECK:  %[[VAL_10:.*]] = arith.constant 42 : index
 // CHECK:  %[[VAL_11:.*]] = fir.shape %[[VAL_10]] : (index) -> !fir.shape<1>
 // CHECK:  %[[VAL_12:.*]] = fir.undefined index
 // CHECK:  %[[VAL_13:.*]] = fir.slice %[[VAL_6]], %[[VAL_8]]#1, %[[VAL_9]] : (index, index, index) -> !fir.slice<1>
-// CHECK:  %[[VAL_14:.*]] = fir.rebox %[[VAL_4]] {{\[}}%[[VAL_13]]] : (!fir.box<!fir.array<?x!fir.char<1,5>>>, !fir.slice<1>) -> !fir.box<!fir.array<?x!fir.char<1,5>>>
+// CHECK:  %[[VAL_14:.*]] = fir.rebox %[[VAL_5]] {{\[}}%[[VAL_13]]] : (!fir.box<!fir.array<?x!fir.char<1,5>>>, !fir.slice<1>) -> !fir.box<!fir.array<?x!fir.char<1,5>>>
 
 func.func @test_polymorphic_array_elt(%arg0: !fir.class<!fir.array<?x!fir.type<_QMtypesTt1>>> {fir.bindc_name = "x"}) {
   %0:2 = hlfir.declare %arg0 {uniq_name = "_QFtest1Ex"} : (!fir.class<!fir.array<?x!fir.type<_QMtypesTt1>>>) -> (!fir.class<!fir.array<?x!fir.type<_QMtypesTt1>>>, !fir.class<!fir.array<?x!fir.type<_QMtypesTt1>>>)
   %c7 = arith.constant 7 : index
   %1 = hlfir.designate %0#0 (%c7)  : (!fir.class<!fir.array<?x!fir.type<_QMtypesTt1>>>, index) -> !fir.class<!fir.type<_QMtypesTt1>>
   return
 }
 // CHECK-LABEL:   func.func @test_polymorphic_array_elt(
 // CHECK-SAME:        %[[VAL_0:.*]]: !fir.class<!fir.array<?x!fir.type<_QMtypesTt1>>> {fir.bindc_name = "x"}) {
 // CHECK:           %[[VAL_1:.*]] = fir.declare %[[VAL_0]] {uniq_name = "_QFtest1Ex"} : (!fir.class<!fir.array<?x!fir.type<_QMtypesTt1>>>) -> !fir.class<!fir.array<?x!fir.type<_QMtypesTt1>>>
 // CHECK:           %[[VAL_2:.*]] = fir.rebox %[[VAL_1]] : (!fir.class<!fir.array<?x!fir.type<_QMtypesTt1>>>) -> !fir.class<!fir.array<?x!fir.type<_QMtypesTt1>>>
 // CHECK:           %[[VAL_3:.*]] = arith.constant 7 : index
-// CHECK:           %[[VAL_4:.*]] = fir.array_coor %[[VAL_1]] %[[VAL_3]] : (!fir.class<!fir.array<?x!fir.type<_QMtypesTt1>>>, index) -> !fir.ref<!fir.type<_QMtypesTt1>>
-// CHECK:           %[[VAL_5:.*]] = fir.embox %[[VAL_4]] source_box %[[VAL_1]] : (!fir.ref<!fir.type<_QMtypesTt1>>, !fir.class<!fir.array<?x!fir.type<_QMtypesTt1>>>) -> !fir.class<!fir.type<_QMtypesTt1>>
+// CHECK:           %[[VAL_4:.*]] = fir.array_coor %[[VAL_2]] %[[VAL_3]] : (!fir.class<!fir.array<?x!fir.type<_QMtypesTt1>>>, index) -> !fir.ref<!fir.type<_QMtypesTt1>>
+// CHECK:           %[[VAL_5:.*]] = fir.embox %[[VAL_4]] source_box %[[VAL_2]] : (!fir.ref<!fir.type<_QMtypesTt1>>, !fir.class<!fir.array<?x!fir.type<_QMtypesTt1>>>) -> !fir.class<!fir.type<_QMtypesTt1>>
 // CHECK:           return
 // CHECK:         }