[flang][hlfir] support optional args for intrinsic ops

[tblah]

Summary

This also adds support for allocatable non-optional arguments.

Of the transformational intrinsics which currently have their own hlfir
operations, all of the dynamically optional arguments are lowered as
boxes, so that is all that is implemented for now.

One alternative approach would have been to deal with the dynamically
optional arguments when lowering to FIR runtime calls. I decided not to
do this so that any passes working on the intrinsic operations would not
have to know about and handle the dynamically optional arguments.

Depends on D154235

[vzakhari]

Looks good to me. Thank you!

[jeanPerier]

Looks good to me. If any of these ops get some custom rewrites/inlined implementation from HLFIR, it may be worth adding an explicit attribute on the operations to denote that the fir.box argument should be manipulated with care. But it is probably best to do that when and if these pass are added and the requirement is clearer.

flang/lib/Lower/HlfirIntrinsics.cpp

 //===-- HlfirIntrinsics.cpp
 //---------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 // Coding style: https://mlir.llvm.org/getting_started/DeveloperGuide/
 //
 //===----------------------------------------------------------------------===//
 
 #include "flang/Lower/HlfirIntrinsics.h"
 
+#include "flang/Optimizer/Builder/BoxValue.h"
 #include "flang/Optimizer/Builder/FIRBuilder.h"
 #include "flang/Optimizer/Builder/HLFIRTools.h"
 #include "flang/Optimizer/Builder/IntrinsicCall.h"
+#include "flang/Optimizer/Builder/MutableBox.h"
+#include "flang/Optimizer/Builder/Todo.h"
 #include "flang/Optimizer/Dialect/FIRType.h"
 #include "flang/Optimizer/HLFIR/HLFIRDialect.h"
 #include "flang/Optimizer/HLFIR/HLFIROps.h"
 #include "mlir/IR/Value.h"
 #include "llvm/ADT/SmallVector.h"
 #include <mlir/IR/ValueRange.h>
 
 namespace {
 
 class HlfirTransformationalIntrinsic {
 public:
   explicit HlfirTransformationalIntrinsic(fir::FirOpBuilder &builder,
                                           mlir::Location loc)
       : builder(builder), loc(loc) {}
 
   virtual ~HlfirTransformationalIntrinsic() = default;
 
   hlfir::EntityWithAttributes
   lower(const Fortran::lower::PreparedActualArguments &loweredActuals,
         const fir::IntrinsicArgumentLoweringRules *argLowering,
         mlir::Type stmtResultType) {
     mlir::Value res = lowerImpl(loweredActuals, argLowering, stmtResultType);
+    for (const hlfir::CleanupFunction &fn : cleanupFns)
+      fn();
     return {hlfir::EntityWithAttributes{res}};
   }
 
 protected:
   fir::FirOpBuilder &builder;
   mlir::Location loc;
+  llvm::SmallVector<hlfir::CleanupFunction, 3> cleanupFns;
 
   virtual mlir::Value
   lowerImpl(const Fortran::lower::PreparedActualArguments &loweredActuals,
             const fir::IntrinsicArgumentLoweringRules *argLowering,
             mlir::Type stmtResultType) = 0;
 
   llvm::SmallVector<mlir::Value> getOperandVector(
       const Fortran::lower::PreparedActualArguments &loweredActuals,
       const fir::IntrinsicArgumentLoweringRules *argLowering);
 
   mlir::Type computeResultType(mlir::Value argArray, mlir::Type stmtResultType);
 
   template <typename OP, typename... BUILD_ARGS>
   inline OP createOp(BUILD_ARGS... args) {
     return builder.create<OP>(loc, args...);
   }
+
+  mlir::Value loadBoxAddress(
+      const std::optional<Fortran::lower::PreparedActualArgument> &arg);
+
+  void addCleanup(std::optional<hlfir::CleanupFunction> cleanup) {
+    if (cleanup)
+      cleanupFns.emplace_back(std::move(*cleanup));
+  }
 };
 
 template <typename OP, bool HAS_MASK>
 class HlfirReductionIntrinsic : public HlfirTransformationalIntrinsic {
 public:
   using HlfirTransformationalIntrinsic::HlfirTransformationalIntrinsic;
 
 protected:
lowerImpl(const Fortran::lower::PreparedActualArguments &loweredActuals,
             mlir::Type stmtResultType) override;
 
 protected:
   hlfir::CharExtremumPredicate pred;
 };
 
 } // namespace
 
+mlir::Value HlfirTransformationalIntrinsic::loadBoxAddress(
+    const std::optional<Fortran::lower::PreparedActualArgument> &arg) {
+  if (!arg)
+    return mlir::Value{};
+
+  hlfir::Entity actual = arg->getOriginalActual();
+
+  if (!arg->handleDynamicOptional()) {
+    if (actual.isMutableBox()) {
+      // this is a box address type but is not dynamically optional. Just load
+      // the box, assuming it is well formed (!fir.ref<!fir.box<...>> ->
+      // !fir.box<...>)
+      return builder.create<fir::LoadOp>(loc, actual.getBase());
+    }
+    return actual;
+  }
+
+  auto [exv, cleanup] = hlfir::translateToExtendedValue(loc, builder, actual);
+  addCleanup(cleanup);
+
+  mlir::Value isPresent = arg->getIsPresent();
+  // createBox will not do create any invalid memory dereferences if exv is
+  // absent. The created fir.box will not be usable, but the SelectOp below
+  // ensures it won't be.
+  mlir::Value box = builder.createBox(loc, exv);
+  mlir::Type boxType = box.getType();
+  auto absent = builder.create<fir::AbsentOp>(loc, boxType);
+  auto boxOrAbsent = builder.create<mlir::arith::SelectOp>(
+      loc, boxType, isPresent, box, absent);
+
+  return boxOrAbsent;
+}
+
 llvm::SmallVector<mlir::Value> HlfirTransformationalIntrinsic::getOperandVector(
     const Fortran::lower::PreparedActualArguments &loweredActuals,
     const fir::IntrinsicArgumentLoweringRules *argLowering) {
   llvm::SmallVector<mlir::Value> operands;
   operands.reserve(loweredActuals.size());
 
   for (size_t i = 0; i < loweredActuals.size(); ++i) {
     std::optional<Fortran::lower::PreparedActualArgument> arg =
         loweredActuals[i];
     if (!arg) {
       operands.emplace_back();
       continue;
     }
     hlfir::Entity actual = arg->getOriginalActual();
     mlir::Value valArg;
 
     if (!argLowering) {
       valArg = hlfir::loadTrivialScalar(loc, builder, actual);
     } else {
       fir::ArgLoweringRule argRules =
           fir::lowerIntrinsicArgumentAs(*argLowering, i);
-      if (!argRules.handleDynamicOptional &&
+      if (argRules.lowerAs == fir::LowerIntrinsicArgAs::Box)
+        valArg = loadBoxAddress(arg);
+      else if (!argRules.handleDynamicOptional &&
                argRules.lowerAs != fir::LowerIntrinsicArgAs::Inquired)
         valArg = hlfir::derefPointersAndAllocatables(loc, builder, actual);
+      else if (argRules.handleDynamicOptional)
+        TODO(loc, "hlfir transformational intrinsic dynamically optional "
+                  "argument without box lowering");
       else
         valArg = actual.getBase();
     }
 
     operands.emplace_back(valArg);
   }
   return operands;
 }
mlir::Value HlfirReductionIntrinsic<OP, HAS_MASK>::lowerImpl(
   // dim, mask can be NULL if these arguments are not given
   if (dim)
     dim = hlfir::loadTrivialScalar(loc, builder, hlfir::Entity{dim});
 
   mlir::Type resultTy = computeResultType(array, stmtResultType);
 
   OP op;
   if constexpr (HAS_MASK)
-    op = createOp<OP>(resultTy, array, dim, /*mask=*/operands[2]);
+    op = createOp<OP>(resultTy, array, dim,
+                      /*mask=*/operands[2]);
   else
     op = createOp<OP>(resultTy, array, dim);
   return op;
 }
 
 template <typename OP>
 mlir::Value HlfirProductIntrinsic<OP>::lowerImpl(
     const Fortran::lower::PreparedActualArguments &loweredActuals,
if (name == "min")
           .lower(loweredActuals, argLowering, stmtResultType);
     if (name == "max")
       return HlfirCharExtremumLowering{builder, loc,
                                        hlfir::CharExtremumPredicate::max}
           .lower(loweredActuals, argLowering, stmtResultType);
   }
   return std::nullopt;
 }
 No newline at end of file

flang/test/Lower/HLFIR/all.f90

 ! CHECK-NEXT:    %[[DIM_ADDR:.*]] = fir.box_addr %[[DIM_BOX]] : (!fir.box<!fir.ptr<i32>>) -> !fir.ptr<i32>
 ! CHECK-NEXT:    %[[DIM0:.*]] = fir.load %[[DIM_ADDR]] : !fir.ptr<i32>
 ! CHECK-NEXT:    %[[DIM1:.*]] = hlfir.no_reassoc %[[DIM0]] : i32
 ! CHECK-NEXT:    %[[EXPR:.*]] = hlfir.all %[[ARRAY]]#0 dim %[[DIM1]] : (!fir.box<!fir.array<?x?x!fir.logical<4>>>, i32) -> !hlfir.expr<?x!fir.logical<4>>
 ! CHECK-NEXT:    hlfir.assign %[[EXPR]] to %[[OUT]]#0 : !hlfir.expr<?x!fir.logical<4>>, !fir.box<!fir.array<?x!fir.logical<4>>>
 ! CHECK-NEXT:    hlfir.destroy %[[EXPR]] : !hlfir.expr<?x!fir.logical<4>>
 ! CHECK-NEXT:    return
 ! CHECK-NEXT:  }
+
+subroutine all5(a, s)
+  logical, allocatable :: a(:)
+  logical :: s
+  s = ALL(a)
+end subroutine
+! CHECK-LABEL: func.func @_QPall5(
+! CHECK:           %[[ARG0:.*]]: !fir.ref<!fir.box<!fir.heap<!fir.array<?x!fir.logical<4>>>>>
+! CHECK:           %[[ARG1:.*]]: !fir.ref<!fir.logical<4>>
+! CHECK-DAG:     %[[MASK:.*]]:2 = hlfir.declare %[[ARG0]]
+! CHECK-DAG:     %[[OUT:.*]]:2 = hlfir.declare %[[ARG1]]
+! CHECK-NEXT:    %[[MASK_LOADED:.*]] = fir.load %[[MASK]]#0
+! CHECK-NEXT:    %[[EXPR:.*]] = hlfir.all %[[MASK_LOADED]] : (!fir.box<!fir.heap<!fir.array<?x!fir.logical<4>>>>) -> !fir.logical<4>
+! CHECK-NEXT:    hlfir.assign %[[EXPR]] to %[[OUT]]#0  : !fir.logical<4>, !fir.ref<!fir.logical<4>>
+! CHECK-NEXT:    return
+! CHECK-NEXT:  }

flang/test/Lower/HLFIR/any.f90

 ! CHECK-NEXT:    %[[DIM_ADDR:.*]] = fir.box_addr %[[DIM_BOX]] : (!fir.box<!fir.ptr<i32>>) -> !fir.ptr<i32>
 ! CHECK-NEXT:    %[[DIM0:.*]] = fir.load %[[DIM_ADDR]] : !fir.ptr<i32>
 ! CHECK-NEXT:    %[[DIM1:.*]] = hlfir.no_reassoc %[[DIM0]] : i32
 ! CHECK-NEXT:    %[[EXPR:.*]] = hlfir.any %[[ARRAY]]#0 dim %[[DIM1]] : (!fir.box<!fir.array<?x?x!fir.logical<4>>>, i32) -> !hlfir.expr<?x!fir.logical<4>>
 ! CHECK-NEXT:    hlfir.assign %[[EXPR]] to %[[OUT]]#0 : !hlfir.expr<?x!fir.logical<4>>, !fir.box<!fir.array<?x!fir.logical<4>>>
 ! CHECK-NEXT:    hlfir.destroy %[[EXPR]] : !hlfir.expr<?x!fir.logical<4>>
 ! CHECK-NEXT:    return
 ! CHECK-NEXT:  }
+
+subroutine any5(a, s)
+  logical, allocatable :: a(:)
+  logical :: s
+  s = ANY(a)
+end subroutine
+! CHECK-LABEL: func.func @_QPany5(
+! CHECK:           %[[ARG0:.*]]: !fir.ref<!fir.box<!fir.heap<!fir.array<?x!fir.logical<4>>>>>
+! CHECK:           %[[ARG1:.*]]: !fir.ref<!fir.logical<4>>
+! CHECK-DAG:     %[[MASK:.*]]:2 = hlfir.declare %[[ARG0]]
+! CHECK-DAG:     %[[OUT:.*]]:2 = hlfir.declare %[[ARG1]]
+! CHECK-NEXT:    %[[MASK_LOADED:.*]] = fir.load %[[MASK]]#0
+! CHECK-NEXT:    %[[EXPR:.*]] = hlfir.any %[[MASK_LOADED]] : (!fir.box<!fir.heap<!fir.array<?x!fir.logical<4>>>>) -> !fir.logical<4>
+! CHECK-NEXT:    hlfir.assign %[[EXPR]] to %[[OUT]]#0  : !fir.logical<4>, !fir.ref<!fir.logical<4>>
+! CHECK-NEXT:    return
+! CHECK-NEXT:  }

flang/test/Lower/HLFIR/count.f90

 ! CHECK-DAG:     %[[EXPR:.*]] = hlfir.count %[[MASK]]#0 dim %[[DIM]] kind %[[C8]] : (!fir.box<!fir.array<?x?x!fir.logical<4>>>, i32, i32) -> !hlfir.expr<?xi64>
 ! CHECK-DAG:     %[[RES_SHAPE:.*]] = hlfir.shape_of %[[EXPR]]
 ! CHECK-DAG:     %[[RES:.*]] = hlfir.elemental %[[RES_SHAPE]] unordered : (!fir.shape<1>) -> !hlfir.expr<?xi32>
 ! CHECK-DAG:     hlfir.assign %[[RES]] to %[[OUT]]#0
 ! CHECK-NEXT:    hlfir.destroy %[[RES]] : !hlfir.expr<?xi32>
 ! CHECK-NEXT:    hlfir.destroy %[[EXPR]] : !hlfir.expr<?xi64>
 ! CHECK-NEXT:    return
 ! CHECK-NEXT:  }
+
+subroutine count5(a, s)
+  logical, allocatable :: a(:)
+  integer :: s
+  s = COUNT(a)
+end subroutine
+! CHECK-LABEL: func.func @_QPcount5(
+! CHECK:           %[[ARG0:.*]]: !fir.ref<!fir.box<!fir.heap<!fir.array<?x!fir.logical<4>>>>>
+! CHECK:           %[[ARG1:.*]]: !fir.ref<i32>
+! CHECK-DAG:     %[[MASK:.*]]:2 = hlfir.declare %[[ARG0]]
+! CHECK-DAG:     %[[OUT:.*]]:2 = hlfir.declare %[[ARG1]]
+! CHECK-NEXT:    %[[MASK_LOADED:.*]] = fir.load %[[MASK]]#0
+! CHECK-NEXT:    %[[EXPR:.*]] = hlfir.count %[[MASK_LOADED]] : (!fir.box<!fir.heap<!fir.array<?x!fir.logical<4>>>>) -> i32
+! CHECK-NEXT:    hlfir.assign %[[EXPR]] to %[[OUT]]#0 : i32, !fir.ref<i32>
+! CHECK-NEXT:    return
+! CHECK-NEXT:  }

flang/test/Lower/HLFIR/dot_product.f90

 ! CHECK:           %[[RES:.*]]: !fir.ref<i32> {fir.bindc_name = "res"}
 ! CHECK-DAG:     %[[LHS_VAR:.*]]:2 = hlfir.declare %[[LHS]]
 ! CHECK-DAG:     %[[RHS_VAR:.*]]:2 = hlfir.declare %[[RHS]]
 ! CHECK-DAG:     %[[RES_VAR:.*]]:2 = hlfir.declare %[[RES]]
 ! CHECK-NEXT:    %[[EXPR:.*]] = hlfir.dot_product %[[LHS_VAR]]#0 %[[RHS_VAR]]#0 {fastmath = #arith.fastmath<contract>} : (!fir.ref<!fir.array<5xi32>>, !fir.ref<!fir.array<5xi32>>) -> i32
 ! CHECK-NEXT:    hlfir.assign %[[EXPR]] to %[[RES_VAR]]#0 : i32, !fir.ref<i32>
 ! CHECK-NEXT:    return
 ! CHECK-NEXT:  }
+
+subroutine dot_product4(lhs, rhs, res)
+  integer, allocatable :: lhs(:), rhs(:)
+  integer :: res
+  res = dot_product(lhs, rhs)
+endsubroutine
+! CHECK-LABEL: func.func @_QPdot_product4
+! CHECK:           %[[LHS:.*]]: !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>> {fir.bindc_name = "lhs"}
+! CHECK:           %[[RHS:.*]]: !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>> {fir.bindc_name = "rhs"}
+! CHECK:           %[[RES:.*]]: !fir.ref<i32> {fir.bindc_name = "res"}
+! CHECK-DAG:     %[[LHS_VAR:.*]]:2 = hlfir.declare %[[LHS]]
+! CHECK-DAG:     %[[RHS_VAR:.*]]:2 = hlfir.declare %[[RHS]]
+! CHECK-DAG:     %[[RES_VAR:.*]]:2 = hlfir.declare %[[RES]]
+! CHECK-NEXT:    %[[LHS_LD:.*]] = fir.load %[[LHS_VAR]]#0
+! CHECK-NEXT:    %[[RHS_LD:.*]] = fir.load %[[RHS_VAR]]#0
+! CHECK-NEXT:    %[[PROD:.*]] = hlfir.dot_product %[[LHS_LD]] %[[RHS_LD]] {fastmath = #arith.fastmath<contract>} : (!fir.box<!fir.heap<!fir.array<?xi32>>>, !fir.box<!fir.heap<!fir.array<?xi32>>>) -> i32
+! CHECK-NEXT:    hlfir.assign %[[PROD]] to %[[RES_VAR]]#0 : i32, !fir.ref<i32>
+! CHECK-NEXT:    return
+! CHECK-NEXT:   }

flang/test/Lower/HLFIR/matmul.f90

 ! CHECK-NEXT:    %[[B_SHAPE:.*]] = fir.shape %[[B_DIMS_0]]#1, %[[B_DIMS_1]]#1
 ! CHECK-NEXT:    %[[ELEMENTAL:.*]] = hlfir.elemental %[[B_SHAPE]] unordered : (!fir.shape<2>) -> !hlfir.expr<?x?xi32> {
 
 ! CHECK:         }
 ! CHECK-NEXT:    %[[A_BOX:.*]] = fir.load %{{.*}} : !fir.ref<!fir.box<!fir.heap<!fir.array<?x?xi32>>>>
 
 ! The shapes in these types are what is being tested:
 ! CHECK-NEXT:    %[[MATMUL:.*]] = hlfir.matmul %[[A_BOX]] %[[ELEMENTAL]] {{.*}} : (!fir.box<!fir.heap<!fir.array<?x?xi32>>>, !hlfir.expr<?x?xi32>) -> !hlfir.expr<?x4xi32>
+
+subroutine matmul3(lhs, rhs, res)
+  integer, allocatable :: lhs(:,:), rhs(:,:), res(:,:)
+  res = MATMUL(lhs, rhs)
+endsubroutine
+! CHECK-LABEL: func.func @_QPmatmul3
+! CHECK:           %[[LHS:.*]]: !fir.ref<!fir.box<!fir.heap<!fir.array<?x?xi32>>>> {fir.bindc_name = "lhs"}
+! CHECK:           %[[RHS:.*]]: !fir.ref<!fir.box<!fir.heap<!fir.array<?x?xi32>>>> {fir.bindc_name = "rhs"}
+! CHECK:           %[[RES:.*]]: !fir.ref<!fir.box<!fir.heap<!fir.array<?x?xi32>>>> {fir.bindc_name = "res"}
+! CHECK-DAG:     %[[LHS_VAR:.*]]:2 = hlfir.declare %[[LHS]]
+! CHECK-DAG:     %[[RHS_VAR:.*]]:2 = hlfir.declare %[[RHS]]
+! CHECK-DAG:     %[[RES_VAR:.*]]:2 = hlfir.declare %[[RES]]
+! CHECK-NEXT:    %[[LHS_LD:.*]] = fir.load %[[LHS_VAR]]#0
+! CHECK-NEXT:    %[[RHS_LD:.*]] = fir.load %[[RHS_VAR]]#0
+! CHECK-NEXT:    %[[EXPR:.*]] = hlfir.matmul %[[LHS_LD]] %[[RHS_LD]] {fastmath = #arith.fastmath<contract>} : (!fir.box<!fir.heap<!fir.array<?x?xi32>>>, !fir.box<!fir.heap<!fir.array<?x?xi32>>>) -> !hlfir.expr<?x?xi32>
+! CHECK-NEXT:    hlfir.assign %[[EXPR]] to %[[RES_VAR]]#0 realloc : !hlfir.expr<?x?xi32>, !fir.ref<!fir.box<!fir.heap<!fir.array<?x?xi32>>>>
+! CHECK-NEXT:    hlfir.destroy %[[EXPR]]
+! CHECK-NEXT:    return
+! CHECK-NEXT:   }

flang/test/Lower/HLFIR/product.f90

 ! CHECK-NEXT:    %[[DIM_ADDR:.*]] = fir.box_addr %[[DIM_BOX]]  : (!fir.box<!fir.ptr<i32>>) -> !fir.ptr<i32>
 ! CHECK-NEXT:    %[[DIM0:.*]] = fir.load %[[DIM_ADDR]] : !fir.ptr<i32>
 ! CHECK-NEXT:    %[[DIM1:.*]] = hlfir.no_reassoc %[[DIM0]] : i32
 ! CHECK-NEXT:    %[[EXPR:.*]] = hlfir.product %[[ARRAY]]#0 dim %[[DIM1]]  {fastmath = #arith.fastmath<contract>} : (!fir.box<!fir.array<?x?xf32>>, i32) -> !hlfir.expr<?xf32>
 ! CHECK-NEXT:    hlfir.assign %[[EXPR]] to %[[OUT]]#0 : !hlfir.expr<?xf32>, !fir.box<!fir.array<?xf32>>
 ! CHECK-NEXT:    hlfir.destroy %[[EXPR]]
 ! CHECK-NEXT:    return
 ! CHECK-NEXT:  }
+
+subroutine testDynamicallyOptionalMask(array, mask, res)
+  integer :: array(:), res
+  logical, allocatable :: mask(:)
+  res = PRODUCT(array, mask=mask)
+end subroutine
+! CHECK-LABEL: func.func @_QPtestdynamicallyoptionalmask(
+! CHECK-SAME:      %[[ARG0:.*]]: !fir.box<!fir.array<?xi32>>
+! CHECK-SAME:      %[[ARG1:.*]]: !fir.ref<!fir.box<!fir.heap<!fir.array<?x!fir.logical<4>>>>>
+! CHECK-SAME:      %[[ARG2:.*]]: !fir.ref<i32>
+! CHECK-DAG:     %[[ARRAY:.*]]:2 = hlfir.declare %[[ARG0]]
+! CHECK-DAG:     %[[MASK:.*]]:2 = hlfir.declare %[[ARG1]]
+! CHECK-DAG:     %[[RES:.*]]:2 = hlfir.declare %[[ARG2]]
+! CHECK-NEXT:    %[[MASK_LOAD:.*]] = fir.load %[[MASK]]#1
+! CHECK-NEXT:    %[[MASK_ADDR:.*]] = fir.box_addr %[[MASK_LOAD]]
+! CHECK-NEXT:    %[[MASK_ADDR_INT:.*]] = fir.convert %[[MASK_ADDR]]
+! CHECK-NEXT:    %[[C0:.*]] = arith.constant 0 : i64
+! CHECK-NEXT:    %[[CMP:.*]] = arith.cmpi ne, %[[MASK_ADDR_INT]], %[[C0]] : i64
+! CHECK-NEXT:    %[[MASK_LOAD2:.*]] = fir.load %[[MASK]]#1
+! CHECK-NEXT:    %[[ABSENT:.*]] = fir.absent !fir.box<!fir.heap<!fir.array<?x!fir.logical<4>>>>
+! CHECK-NEXT:    %[[SELECT:.*]] = arith.select %[[CMP]], %[[MASK_LOAD2]], %[[ABSENT]]
+! CHECK-NEXT:    %[[PRODUCT:.*]] = hlfir.product %[[ARRAY]]#0 mask %[[SELECT]]
+! CHECK-NEXT:    hlfir.assign %[[PRODUCT]] to %[[RES]]#0
+! CHECK-NEXT:    return
+! CHECK-NEXT:  }
+
+subroutine testAllocatableArray(array, mask, res)
+  integer, allocatable :: array(:)
+  integer :: res
+  logical :: mask(:)
+  res = PRODUCT(array, mask=mask)
+end subroutine
+! CHECK-LABEL: func.func @_QPtestallocatablearray(
+! CHECK-SAME:      %[[ARG0:.*]]: !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>
+! CHECK-SAME:      %[[ARG1:.*]]: !fir.box<!fir.array<?x!fir.logical<4>>>
+! CHECK-SAME:      %[[ARG2:.*]]: !fir.ref<i32>
+! CHECK-DAG:     %[[ARRAY:.*]]:2 = hlfir.declare %[[ARG0]]
+! CHECK-DAG:     %[[MASK:.*]]:2 = hlfir.declare %[[ARG1]]
+! CHECK-DAG:     %[[RES:.*]]:2 = hlfir.declare %[[ARG2]]
+! CHECK-NEXT:    %[[LOADED_ARRAY:.*]] = fir.load %[[ARRAY]]#0
+! CHECK-NEXT:    %[[PRODUCT:.*]] = hlfir.product %[[LOADED_ARRAY]] mask %[[MASK]]#0
+! CHECK-NEXT:    hlfir.assign %[[PRODUCT]] to %[[RES]]#0
+! CHECK-NEXT:    return
+! CHECK-NEXT:  }
+
+function testOptionalScalar(array, mask)
+  integer :: array(:)
+  logical, optional :: mask
+  integer :: testOptionalScalar
+  testOptionalScalar = product(array, mask)
+end function
+! CHECK-LABEL:   func.func @_QPtestoptionalscalar(
+! CHECK-SAME:                                     %[[ARRAY_ARG:.*]]: !fir.box<!fir.array<?xi32>> {fir.bindc_name = "array"},
+! CHECK-SAME:                                     %[[MASK_ARG:.*]]: !fir.ref<!fir.logical<4>> {fir.bindc_name = "mask", fir.optional}) -> i32
+! CHECK:           %[[ARRAY_VAR:.*]]:2 = hlfir.declare %[[ARRAY_ARG]]
+! CHECK:           %[[MASK_VAR:.*]]:2 = hlfir.declare %[[MASK_ARG]]
+! CHECK:           %[[RET_ALLOC:.*]] = fir.alloca i32 {bindc_name = "testoptionalscalar", uniq_name = "_QFtestoptionalscalarEtestoptionalscalar"}
+! CHECK:           %[[RET_VAR:.*]]:2 = hlfir.declare %[[RET_ALLOC]]
+! CHECK:           %[[MASK_IS_PRESENT:.*]] = fir.is_present %[[MASK_VAR]]#0 : (!fir.ref<!fir.logical<4>>) -> i1
+! CHECK:           %[[MASK_BOX:.*]] = fir.embox %[[MASK_VAR]]#1
+! CHECK:           %[[ABSENT:.*]] = fir.absent !fir.box<!fir.logical<4>>
+! CHECK:           %[[MASK_SELECT:.*]] = arith.select %[[MASK_IS_PRESENT]], %[[MASK_BOX]], %[[ABSENT]]
+! CHECK:           %[[RES:.*]] = hlfir.product %[[ARRAY_VAR]]#0 mask %[[MASK_SELECT]] {{.*}}: (!fir.box<!fir.array<?xi32>>, !fir.box<!fir.logical<4>>) -> i32
+! CHECK:           hlfir.assign %[[RES]] to %[[RET_VAR]]#0
+! CHECK:           %[[RET:.*]] = fir.load %[[RET_VAR]]#1 : !fir.ref<i32>
+! CHECK:           return %[[RET]] : i32
+! CHECK:         }
 No newline at end of file

flang/test/Lower/HLFIR/sum.f90

 ! CHECK-NEXT:    %[[DIM_ADDR:.*]] = fir.box_addr %[[DIM_BOX]] : (!fir.box<!fir.ptr<i32>>) -> !fir.ptr<i32>
 ! CHECK-NEXT:    %[[DIM0:.*]] = fir.load %[[DIM_ADDR]] : !fir.ptr<i32>
 ! CHECK-NEXT:    %[[DIM1:.*]] = hlfir.no_reassoc %[[DIM0]] : i32
 ! CHECK-NEXT:    %[[EXPR:.*]] = hlfir.sum %[[ARRAY]]#0 dim %[[DIM1]] {fastmath = #arith.fastmath<contract>} : (!fir.box<!fir.array<?x?xf32>>, i32) -> !hlfir.expr<?xf32>
 ! CHECK-NEXT:    hlfir.assign %[[EXPR]] to %[[OUT]]#0 : !hlfir.expr<?xf32>, !fir.box<!fir.array<?xf32>>
 ! CHECK-NEXT:    hlfir.destroy %[[EXPR]]
 ! CHECK-NEXT:    return
 ! CHECK-NEXT:  }
+
+subroutine testDynamicallyOptionalMask(array, mask, res)
+  integer :: array(:), res
+  logical, allocatable :: mask(:)
+  res = SUM(array, mask=mask)
+end subroutine
+! CHECK-LABEL: func.func @_QPtestdynamicallyoptionalmask(
+! CHECK-SAME:      %[[ARG0:.*]]: !fir.box<!fir.array<?xi32>>
+! CHECK-SAME:      %[[ARG1:.*]]: !fir.ref<!fir.box<!fir.heap<!fir.array<?x!fir.logical<4>>>>>
+! CHECK-SAME:      %[[ARG2:.*]]: !fir.ref<i32>
+! CHECK-DAG:     %[[ARRAY:.*]]:2 = hlfir.declare %[[ARG0]]
+! CHECK-DAG:     %[[MASK:.*]]:2 = hlfir.declare %[[ARG1]]
+! CHECK-DAG:     %[[RES:.*]]:2 = hlfir.declare %[[ARG2]]
+! CHECK-NEXT:    %[[MASK_LOAD:.*]] = fir.load %[[MASK]]#1
+! CHECK-NEXT:    %[[MASK_ADDR:.*]] = fir.box_addr %[[MASK_LOAD]]
+! CHECK-NEXT:    %[[MASK_ADDR_INT:.*]] = fir.convert %[[MASK_ADDR]]
+! CHECK-NEXT:    %[[C0:.*]] = arith.constant 0 : i64
+! CHECK-NEXT:    %[[CMP:.*]] = arith.cmpi ne, %[[MASK_ADDR_INT]], %[[C0]] : i64
+! it is a shame there is a second load here. The first is generated for
+! PreparedActualArgument::isPresent, the second is for optional handling
+! CHECK-NEXT:    %[[MASK_LOAD2:.*]] = fir.load %[[MASK]]#1
+! CHECK-NEXT:    %[[ABSENT:.*]] = fir.absent !fir.box<!fir.heap<!fir.array<?x!fir.logical<4>>>>
+! CHECK-NEXT:    %[[SELECT:.*]] = arith.select %[[CMP]], %[[MASK_LOAD2]], %[[ABSENT]]
+! CHECK-NEXT:    %[[SUM:.*]] = hlfir.sum %[[ARRAY]]#0 mask %[[SELECT]]
+! CHECK-NEXT:    hlfir.assign %[[SUM]] to %[[RES]]#0
+! CHECK-NEXT:    return
+! CHECK-NEXT:  }
+
+subroutine testAllocatableArray(array, mask, res)
+  integer, allocatable :: array(:)
+  integer :: res
+  logical :: mask(:)
+  res = SUM(array, mask=mask)
+end subroutine
+! CHECK-LABEL: func.func @_QPtestallocatablearray(
+! CHECK-SAME:      %[[ARG0:.*]]: !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>
+! CHECK-SAME:      %[[ARG1:.*]]: !fir.box<!fir.array<?x!fir.logical<4>>>
+! CHECK-SAME:      %[[ARG2:.*]]: !fir.ref<i32>
+! CHECK-DAG:     %[[ARRAY:.*]]:2 = hlfir.declare %[[ARG0]]
+! CHECK-DAG:     %[[MASK:.*]]:2 = hlfir.declare %[[ARG1]]
+! CHECK-DAG:     %[[RES:.*]]:2 = hlfir.declare %[[ARG2]]
+! CHECK-NEXT:    %[[LOADED_ARRAY:.*]] = fir.load %[[ARRAY]]#0
+! CHECK-NEXT:    %[[SUM:.*]] = hlfir.sum %[[LOADED_ARRAY]] mask %[[MASK]]#0
+! CHECK-NEXT:    hlfir.assign %[[SUM]] to %[[RES]]#0
+! CHECK-NEXT:    return
+! CHECK-NEXT:  }
+
+function testOptionalScalar(array, mask)
+  integer :: array(:)
+  logical, optional :: mask
+  integer :: testOptionalScalar
+  testOptionalScalar = sum(array, mask)
+end function
+! CHECK-LABEL:   func.func @_QPtestoptionalscalar(
+! CHECK-SAME:                                     %[[ARRAY_ARG:.*]]: !fir.box<!fir.array<?xi32>> {fir.bindc_name = "array"},
+! CHECK-SAME:                                     %[[MASK_ARG:.*]]: !fir.ref<!fir.logical<4>> {fir.bindc_name = "mask", fir.optional}) -> i32
+! CHECK:           %[[ARRAY_VAR:.*]]:2 = hlfir.declare %[[ARRAY_ARG]]
+! CHECK:           %[[MASK_VAR:.*]]:2 = hlfir.declare %[[MASK_ARG]]
+! CHECK:           %[[RET_ALLOC:.*]] = fir.alloca i32 {bindc_name = "testoptionalscalar", uniq_name = "_QFtestoptionalscalarEtestoptionalscalar"}
+! CHECK:           %[[RET_VAR:.*]]:2 = hlfir.declare %[[RET_ALLOC]]
+! CHECK:           %[[MASK_IS_PRESENT:.*]] = fir.is_present %[[MASK_VAR]]#0 : (!fir.ref<!fir.logical<4>>) -> i1
+! CHECK:           %[[MASK_BOX:.*]] = fir.embox %[[MASK_VAR]]#1
+! CHECK:           %[[ABSENT:.*]] = fir.absent !fir.box<!fir.logical<4>>
+! CHECK:           %[[MASK_SELECT:.*]] = arith.select %[[MASK_IS_PRESENT]], %[[MASK_BOX]], %[[ABSENT]]
+! CHECK:           %[[RES:.*]] = hlfir.sum %[[ARRAY_VAR]]#0 mask %[[MASK_SELECT]] {{.*}}: (!fir.box<!fir.array<?xi32>>, !fir.box<!fir.logical<4>>) -> i32
+! CHECK:           hlfir.assign %[[RES]] to %[[RET_VAR]]#0
+! CHECK:           %[[RET:.*]] = fir.load %[[RET_VAR]]#1 : !fir.ref<i32>
+! CHECK:           return %[[RET]] : i32
+! CHECK:         }
 No newline at end of file

flang/test/Lower/HLFIR/transpose.f90

subroutine transpose2(a, out)
   real, dimension(:,:) :: out
   integer, parameter :: N = 3
   integer, parameter :: M = 4
 
   allocate(a(N*M))
   out = transpose(reshape(a, (/N, M/)))
 end subroutine
 ! CHECK-LABEL: func.func @_QPtranspose2(
+
+subroutine transpose3(m, res)
+  integer, allocatable :: m(:,:)
+  integer :: res(2, 1)
+  res = TRANSPOSE(m)
+endsubroutine
+! CHECK-LABEL: func.func @_QPtranspose3
+! CHECK:           %[[M_ARG:.*]]: !fir.ref<!fir.box<!fir.heap<!fir.array<?x?xi32>>>>
+! CHECK:           %[[RES_ARG:.*]]: !fir.ref<!fir.array<2x1xi32>>
+! CHECK-DAG:     %[[ARG:.*]]:2 = hlfir.declare %[[M_ARG]]
+! CHECK-DAG:     %[[RES:.*]]:2 = hlfir.declare %[[RES_ARG]](%[[RES_SHAPE:.*]]) {[[NAME2:.*]]} : (!fir.ref<!fir.array<2x1xi32>>, !fir.shape<2>) -> (!fir.ref<!fir.array<2x1xi32>>, !fir.ref<!fir.array<2x1xi32>>)
+! CHECK:         %[[ARG_LOADED:.*]] = fir.load %[[ARG]]#0
+! CHECK:         %[[EXPR:.*]] = hlfir.transpose %[[ARG_LOADED]] : (!fir.box<!fir.heap<!fir.array<?x?xi32>>>) -> !hlfir.expr<?x?xi32>
+! CHECK-NEXT:    hlfir.assign %[[EXPR]] to %[[RES]]#0
+! CHECK-NEXT:    hlfir.destroy %[[EXPR]]
+! CHECK-NEXT:    return
+! CHECK-NEXT:  }