diff --git a/flang/lib/Lower/ConvertCall.cpp b/flang/lib/Lower/ConvertCall.cpp --- a/flang/lib/Lower/ConvertCall.cpp +++ b/flang/lib/Lower/ConvertCall.cpp @@ -608,6 +608,23 @@ mlir::Value firBase = fir::getBase(exv); if (fir::isa_trivial(firBase.getType())) return hlfir::EntityWithAttributes{firBase}; + if (auto charTy = firBase.getType().dyn_cast()) { + // CHAR() intrinsic and BIND(C) procedures returning CHARACTER(1) + // are lowered to a fir.char that is not in memory. + // This tends to cause a lot of bugs because the rest of the + // infrastructure is mostly tested with characters that are + // in memory. + // To avoid having to deal with this special case here and there, + // place it in memory here. If this turns out to be suboptimal, + // this could be fixed, but for now llvm opt -O1 is able to get + // rid of the memory indirection in a = char(b), so there is + // little incentive to increase the compiler complexity. + hlfir::Entity storage{builder.createTemporary(loc, charTy)}; + builder.create(loc, firBase, storage); + auto asExpr = builder.create( + loc, storage, /*mustFree=*/builder.createBool(loc, false)); + return hlfir::EntityWithAttributes{asExpr.getResult()}; + } return hlfir::genDeclare(loc, builder, exv, name, fir::FortranVariableFlagsAttr{}); } @@ -1118,7 +1135,7 @@ loc, builder, resultExv, ".tmp.intrinsic_result"); // Move result into memory into an hlfir.expr since they are immutable from // that point, and the result storage is some temp. - if (!fir::isa_trivial(resultEntity.getType())) { + if (resultEntity.isVariable()) { hlfir::AsExprOp asExpr; // Character/Derived MERGE lowering returns one of its argument address // (this is the only intrinsic implemented in that way so far). The diff --git a/flang/test/Lower/HLFIR/calls-character-singleton-result.f90 b/flang/test/Lower/HLFIR/calls-character-singleton-result.f90 new file mode 100644 --- /dev/null +++ b/flang/test/Lower/HLFIR/calls-character-singleton-result.f90 @@ -0,0 +1,57 @@ +! Test handling of intrinsics and BIND(C) functions returning CHARACTER(1). +! This is a special case because characters are always returned +! or handled in memory otherwise. + +! RUN: bbc -emit-fir -hlfir -o - %s | FileCheck %s + +subroutine scalar_char(c, i) + character(1) :: c + integer(8) :: i + c = char(i) +end subroutine +! CHECK-LABEL: func.func @_QPscalar_char( +! CHECK: %[[VAL_2:.*]] = fir.alloca !fir.char<1> +! CHECK: %[[VAL_5:.*]]:2 = hlfir.declare %{{.*}}#0 typeparams %{{.*}} {{.*}}Ec +! CHECK: %[[VAL_6:.*]]:2 = hlfir.declare %{{.*}} {{.*}}Ei +! CHECK: %[[VAL_7:.*]] = fir.load %[[VAL_6]]#1 : !fir.ref +! CHECK: %[[VAL_8:.*]] = fir.convert %[[VAL_7]] : (i64) -> i8 +! CHECK: %[[VAL_9:.*]] = fir.undefined !fir.char<1> +! CHECK: %[[VAL_10:.*]] = fir.insert_value %[[VAL_9]], %[[VAL_8]], [0 : index] : (!fir.char<1>, i8) -> !fir.char<1> +! CHECK: fir.store %[[VAL_10]] to %[[VAL_2]] : !fir.ref> +! CHECK: %[[VAL_11:.*]] = arith.constant false +! CHECK: %[[VAL_12:.*]] = hlfir.as_expr %[[VAL_2]] move %[[VAL_11]] : (!fir.ref>, i1) -> !hlfir.expr> +! CHECK: hlfir.assign %[[VAL_12]] to %[[VAL_5]]#0 : !hlfir.expr>, !fir.boxchar<1> + +subroutine scalar_bindc(c) + character(1) :: c + interface + character(1) function bar() bind(c) + end function + end interface + c = bar() +end subroutine +! CHECK-LABEL: func.func @_QPscalar_bindc( +! CHECK: %[[VAL_1:.*]] = fir.alloca !fir.char<1> +! CHECK: %[[VAL_4:.*]]:2 = hlfir.declare %{{.*}}#0 typeparams %{{.*}} {{.*}}Ec +! CHECK: %[[VAL_5:.*]] = fir.call @bar() fastmath : () -> !fir.char<1> +! CHECK: fir.store %[[VAL_5]] to %[[VAL_1]] : !fir.ref> +! CHECK: %[[VAL_6:.*]] = arith.constant false +! CHECK: %[[VAL_7:.*]] = hlfir.as_expr %[[VAL_1]] move %[[VAL_6]] : (!fir.ref>, i1) -> !hlfir.expr> +! CHECK: hlfir.assign %[[VAL_7]] to %[[VAL_4]]#0 : !hlfir.expr>, !fir.boxchar<1> + +subroutine array_char(c, i) + character(1) :: c(100) + integer(8) :: i(100) + c = char(i) +end subroutine +! CHECK-LABEL: func.func @_QParray_char( +! CHECK: %[[VAL_2:.*]] = fir.alloca !fir.char<1> +! CHECK: %[[VAL_13:.*]] = hlfir.elemental %{{.*}} typeparams %{{.*}} : (!fir.shape<1>, index) -> !hlfir.expr<100x!fir.char<1>> { +! CHECK: ^bb0(%[[VAL_14:.*]]: index): +! CHECK: %[[VAL_19:.*]] = fir.insert_value {{.*}} -> !fir.char<1> +! CHECK: fir.store %[[VAL_19]] to %[[VAL_2]] : !fir.ref> +! CHECK: %[[VAL_20:.*]] = arith.constant false +! CHECK: %[[VAL_21:.*]] = hlfir.as_expr %[[VAL_2]] move %[[VAL_20]] : (!fir.ref>, i1) -> !hlfir.expr> +! CHECK: hlfir.yield_element %[[VAL_21]] : !hlfir.expr> +! CHECK: } +! CHECK: hlfir.assign %[[VAL_13]] to %{{.*}} : !hlfir.expr<100x!fir.char<1>>, !fir.ref>>