[flang] Use input type to recover the type desc when emboxing

[clementval]

Summary

When emboxing to a polymorphic entity without a type source box,
the type desc address must be retrived from the input type and
not from the box type.

[jeanPerier]

flang/lib/Frontend/CompilerInvocation.cpp

959 ↗

(On Diff #491640)

Probably not intended here?

flang/lib/Optimizer/CodeGen/CodeGen.cpp

1581

Is the input type the base type or the "base type after applying component refs" ?

e.g: if you have "call foo(some_derived1(:)%some_derived2)" beinging passed to a polymoprhic some_derived2_base_type, would input type here be "some_derived1" or "some_derived2" ?

[clementval]

Remove polymorphic type flag

[clementval]

flang/lib/Optimizer/CodeGen/CodeGen.cpp

1581

This should be some_derived2 but let me double check.

[clementval]

flang/lib/Optimizer/CodeGen/CodeGen.cpp

1581

So in this case we have a fir.embox first that goes to a fir.box of the correct type. The polymorphic box is created with a fir.rebox. So the embox is taking the normal codegen where the result box type is used. So the correct type is used.

type p1
  integer :: a
  integer :: b
end type
type outer
  type(p1) :: inner
end type
... 
subroutine test2(p)
   class(p1) :: p(:)
end subroutine

subroutine test1()
  type(outer) :: o(10)
  call test2(o(:)%inner)
end subroutine

%7 = fir.embox %0(%5) [%6] : (!fir.ref<!fir.array<10x!fir.type<_QMpolymorphic_testTouter{inner:!fir.type<_QMpolymorphic_testTp1{a:i32,b:i32}>}>>>, !fir.shape<1>, !fir.slice<1>) -> !fir.box<!fir.array<?x!fir.type<_QMpolymorphic_testTp1{a:i32,b:i32}>>>
  %8 = fir.rebox %7 : (!fir.box<!fir.array<?x!fir.type<_QMpolymorphic_testTp1{a:i32,b:i32}>>>) -> !fir.class<!fir.array<?x!fir.type<_QMpolymorphic_testTp1{a:i32,b:i32}>>>

[jeanPerier]

Thanks for checking, looks good

flang/lib/Optimizer/CodeGen/CodeGen.cpp

mlir::Value populateDescriptor(mlir::Location loc, mlir::ModuleOp mod,
                                  mlir::ConversionPatternRewriter &rewriter,
                                  unsigned rank, mlir::Value eleSize,
                                  mlir::Value cfiTy,
                                  mlir::Value typeDesc) const {
     auto convTy = this->lowerTy().convertBoxType(boxTy, rank);
     auto llvmBoxPtrTy = convTy.template cast<mlir::LLVM::LLVMPointerType>();
     auto llvmBoxTy = llvmBoxPtrTy.getElementType();
     bool isUnlimitedPolymorphic = fir::isUnlimitedPolymorphicType(boxTy);
+    bool useInputType = fir::isPolymorphicType(boxTy) || isUnlimitedPolymorphic;
     mlir::Value descriptor =
         rewriter.create<mlir::LLVM::UndefOp>(loc, llvmBoxTy);
     descriptor =
         insertField(rewriter, loc, descriptor, {kElemLenPosInBox}, eleSize);
     descriptor = insertField(rewriter, loc, descriptor, {kVersionPosInBox},
                              this->genI32Constant(loc, rewriter, CFI_VERSION));
     descriptor = insertField(rewriter, loc, descriptor, {kRankPosInBox},
                              this->genI32Constant(loc, rewriter, rank));
     descriptor = insertField(rewriter, loc, descriptor, {kTypePosInBox}, cfiTy);
     descriptor =
         insertField(rewriter, loc, descriptor, {kAttributePosInBox},
                     this->genI32Constant(loc, rewriter, getCFIAttr(boxTy)));
     const bool hasAddendum = isDerivedType(boxTy) || isUnlimitedPolymorphic;
     descriptor =
         insertField(rewriter, loc, descriptor, {kF18AddendumPosInBox},
                     this->genI32Constant(loc, rewriter, hasAddendum ? 1 : 0));
 
     if (hasAddendum) {
       unsigned typeDescFieldId = getTypeDescFieldId(boxTy);
       if (!typeDesc) {
-        if (isUnlimitedPolymorphic) {
+        if (useInputType) {
           mlir::Type innerType = fir::unwrapInnerType(inputType);
           if (innerType && innerType.template isa<fir::RecordType>()) {
             auto recTy = innerType.template dyn_cast<fir::RecordType>();
             typeDesc = getTypeDescriptor(mod, rewriter, loc, recTy);
           } else {
             // Unlimited polymorphic type descriptor with no record type. Set
             // type descriptor address to a clean state.
             typeDesc = rewriter.create<mlir::LLVM::NullOp>(

flang/test/Fir/polymorphic.fir

 // CHECK-LABEL: define void @_QMmod2Pinitp(
 // CHECK-SAME: ptr %[[ARG0:.*]]) {
 // CHECK: %[[ALLOCA_CLASS_NONE:.*]] = alloca { ptr, i64, i32, i8, i8, i8, i8, ptr, [1 x i64] }
 // CHECK: %[[LOAD:.*]] = load { ptr, i64, i32, i8, i8, i8, i8, ptr, [1 x i64] }, ptr %[[ARG0]]
 // CHECK: store { ptr, i64, i32, i8, i8, i8, i8, ptr, [1 x i64] } %[[LOAD]], ptr %[[ALLOCA_CLASS_NONE]]
 // CHECK: %{{.*}} = call {} @_FortranAPointerAssociate(ptr @_QMmod2Ep, ptr %[[ALLOCA_CLASS_NONE]])
 // CHECK: ret void
 
+fir.global linkonce_odr @_QMmod1E.dt.p1 constant target : !fir.type<_QM__fortran_type_infoTderivedtype{binding:!fir.box<!fir.ptr<!fir.array<?x!fir.type<_QM__fortran_type_infoTbinding{proc:!fir.type<_QM__fortran_builtinsT__builtin_c_funptr{__address:i64}>,name:!fir.box<!fir.ptr<!fir.char<1,?>>>}>>>>,name:!fir.box<!fir.ptr<!fir.char<1,?>>>,sizeinbytes:i64,uninstantiated:!fir.box<!fir.ptr<!fir.type<_QM__fortran_type_infoTderivedtype>>>,kindparameter:!fir.box<!fir.ptr<!fir.array<?xi64>>>,lenparameterkind:!fir.box<!fir.ptr<!fir.array<?xi8>>>,component:!fir.box<!fir.ptr<!fir.array<?x!fir.type<_QM__fortran_type_infoTcomponent{name:!fir.box<!fir.ptr<!fir.char<1,?>>>,genre:i8,category:i8,kind:i8,rank:i8,__padding0:!fir.array<4xi8>,offset:i64,characterlen:!fir.type<_QM__fortran_type_infoTvalue{genre:i8,__padding0:!fir.array<7xi8>,value:i64}>,derived:!fir.box<!fir.ptr<!fir.type<_QM__fortran_type_infoTderivedtype>>>,lenvalue:!fir.box<!fir.ptr<!fir.array<?x!fir.type<_QM__fortran_type_infoTvalue{genre:i8,__padding0:!fir.array<7xi8>,value:i64}>>>>,bounds:!fir.box<!fir.ptr<!fir.array<?x?x!fir.type<_QM__fortran_type_infoTvalue{genre:i8,__padding0:!fir.array<7xi8>,value:i64}>>>>,initialization:!fir.type<_QM__fortran_builtinsT__builtin_c_ptr{__address:i64}>}>>>>,procptr:!fir.box<!fir.ptr<!fir.array<?x!fir.type<_QM__fortran_type_infoTprocptrcomponent{name:!fir.box<!fir.ptr<!fir.char<1,?>>>,offset:i64,initialization:!fir.type<_QM__fortran_builtinsT__builtin_c_funptr{__address:i64}>}>>>>,special:!fir.box<!fir.ptr<!fir.array<?x!fir.type<_QM__fortran_type_infoTspecialbinding{which:i8,isargdescriptorset:i8,__padding0:!fir.array<6xi8>,proc:!fir.type<_QM__fortran_builtinsT__builtin_c_funptr{__address:i64}>}>>>>,specialbitset:i32,hasparent:i8,noinitializationneeded:i8,nodestructionneeded:i8,nofinalizationneeded:i8,__padding0:!fir.array<4xi8>}> {
+}
+
+fir.global linkonce_odr @_QMmod1E.dt.p2 constant target : !fir.type<_QM__fortran_type_infoTderivedtype{binding:!fir.box<!fir.ptr<!fir.array<?x!fir.type<_QM__fortran_type_infoTbinding{proc:!fir.type<_QM__fortran_builtinsT__builtin_c_funptr{__address:i64}>,name:!fir.box<!fir.ptr<!fir.char<1,?>>>}>>>>,name:!fir.box<!fir.ptr<!fir.char<1,?>>>,sizeinbytes:i64,uninstantiated:!fir.box<!fir.ptr<!fir.type<_QM__fortran_type_infoTderivedtype>>>,kindparameter:!fir.box<!fir.ptr<!fir.array<?xi64>>>,lenparameterkind:!fir.box<!fir.ptr<!fir.array<?xi8>>>,component:!fir.box<!fir.ptr<!fir.array<?x!fir.type<_QM__fortran_type_infoTcomponent{name:!fir.box<!fir.ptr<!fir.char<1,?>>>,genre:i8,category:i8,kind:i8,rank:i8,__padding0:!fir.array<4xi8>,offset:i64,characterlen:!fir.type<_QM__fortran_type_infoTvalue{genre:i8,__padding0:!fir.array<7xi8>,value:i64}>,derived:!fir.box<!fir.ptr<!fir.type<_QM__fortran_type_infoTderivedtype>>>,lenvalue:!fir.box<!fir.ptr<!fir.array<?x!fir.type<_QM__fortran_type_infoTvalue{genre:i8,__padding0:!fir.array<7xi8>,value:i64}>>>>,bounds:!fir.box<!fir.ptr<!fir.array<?x?x!fir.type<_QM__fortran_type_infoTvalue{genre:i8,__padding0:!fir.array<7xi8>,value:i64}>>>>,initialization:!fir.type<_QM__fortran_builtinsT__builtin_c_ptr{__address:i64}>}>>>>,procptr:!fir.box<!fir.ptr<!fir.array<?x!fir.type<_QM__fortran_type_infoTprocptrcomponent{name:!fir.box<!fir.ptr<!fir.char<1,?>>>,offset:i64,initialization:!fir.type<_QM__fortran_builtinsT__builtin_c_funptr{__address:i64}>}>>>>,special:!fir.box<!fir.ptr<!fir.array<?x!fir.type<_QM__fortran_type_infoTspecialbinding{which:i8,isargdescriptorset:i8,__padding0:!fir.array<6xi8>,proc:!fir.type<_QM__fortran_builtinsT__builtin_c_funptr{__address:i64}>}>>>>,specialbitset:i32,hasparent:i8,noinitializationneeded:i8,nodestructionneeded:i8,nofinalizationneeded:i8,__padding0:!fir.array<4xi8>}> {
+}
+
+func.func @_QQembox_input_type(%arg0 : !fir.ref<!fir.type<_QMmod1Tp2{v:!fir.array<2xi32>}>>) -> !fir.class<!fir.type<_QMmod1Tp1{v:!fir.array<2xi32>}>> {
+  %0 = fir.embox %arg0 : (!fir.ref<!fir.type<_QMmod1Tp2{v:!fir.array<2xi32>}>>) -> !fir.class<!fir.type<_QMmod1Tp1{v:!fir.array<2xi32>}>>
+  return %0 : !fir.class<!fir.type<_QMmod1Tp1{v:!fir.array<2xi32>}>>
+}
 
+// CHECK-LABEL: define void @_QQembox_input_type
+// CHECK: %{{.*}} = insertvalue { ptr, i64, i32, i8, i8, i8, i8, ptr, [1 x i64] } { ptr undef, i64 ptrtoint (ptr getelementptr (%_QMmod1Tp2, ptr null, i32 1) to i64), i32 20180515, i8 0, i8 42, i8 0, i8 1, ptr @_QMmod1E.dt.p2, [1 x i64] undef }, ptr %{{.*}}, 0