ISO Fortran now accepts a non-pointer actual argument to associate with
a dummy argument with the POINTER attribute if it is also INTENT(IN), so
long as the actual argument is a valid target for the pointer. But
passed-object dummy arguments still have a blanket prohibition against
being pointers in the ISO standard. Relax that constraint in the case of
INTENT(IN) so that passed objects can also benefit from the feature.
Fixes https://github.com/llvm/llvm-project/issues/172157.
ArrayRef has a constructor that accepts std::nullopt. This
constructor dates back to the days when we still had llvm::Optional.
Since the use of std::nullopt outside the context of std::optional is
kind of abuse and not intuitive to new comers, I would like to move
away from the constructor and eventually remove it.
This patch replaces std::nullopt with {}. There are a couple of
places where std::nullopt is replaced with TypeRange() to accommodate
perfect forwarding.
OpenACC routines annotations in separate compilation units currently get
ignored, which leads to errors in compilation. There are two reason for
currently ignoring open acc routine information and this PR is
addressing both.
- The module file reader doesn't read back in openacc directives from
module files.
- Simple fix in `flang/lib/Semantics/mod-file.cpp`
- The lowering to HLFIR doesn't generate routine directives for symbols
imported from other modules that are openacc routines.
- This is the majority of this diff, and is address by the changes that
start in `flang/lib/Lower/CallInterface.cpp`.
[RFC on
discourse](https://discourse.llvm.org/t/rfc-volatile-representation-in-flang/85404/1)
Flang currently lacks support for volatile variables. For some cases,
the compiler produces TODO error messages and others are ignored. Some
of our tests are like the example from _C.4 Clause 8 notes: The VOLATILE
attribute (8.5.20)_ and require volatile variables.
Prior commits:
```
c9ec1bc753b0 [flang] Handle volatility in lowering and codegen (#135311)
e42f8609858f [flang][nfc] Support volatility in Fir ops (#134858)
b2711e1526f9 [flang][nfc] Support volatile on ref, box, and class types (#134386)
```
Move non-common files from FortranCommon to FortranSupport (analogous to
LLVMSupport) such that
* declarations and definitions that are only used by the Flang compiler,
but not by the runtime, are moved to FortranSupport
* declarations and definitions that are used by both ("common"), the
compiler and the runtime, remain in FortranCommon
* generic STL-like/ADT/utility classes and algorithms remain in
FortranCommon
This allows a for cleaner separation between compiler and runtime
components, which are compiled differently. For instance, runtime
sources must not use STL's `<optional>` which causes problems with CUDA
support. Instead, the surrogate header `flang/Common/optional.h` must be
used. This PR fixes this for `fast-int-sel.h`.
Declarations in include/Runtime are also used by both, but are
header-only. `ISO_Fortran_binding_wrapper.h`, a header used by compiler
and runtime, is also moved into FortranCommon.
When constructing the characteristics of a particular reference to an
intrinsic procedure that was passed a non-coindexed reference to local
coarray data as an actual argument, don't add the corank of the actual
argument to those characteristics.
Also clean up the TypeAndShape characteristics class a little; the
Attr::Coarray is redundant since the corank() accessor can be used to
the same effect.
To determine if a function's dummy argument is nocapture, add the
asynchronous attribute to the FIR attribute. The volatile attribute will
also be used to determine nocapture assignment, but this will remain a
TODO until other processing using volatile is implemented.
I will post another patch to apply nocapture. See also the discussion in
the following discourse post.
https://discourse.llvm.org/t/applying-the-nocapture-attribute-to-reference-passed-arguments-in-fortran-subroutines/81401
BIND(C) ABI need care in the TargetRewrite pass. currently, we are not
able to accurately identify fun.func that are BIND(C) in FIR (the
fir.bindc_name is used in other contexts, like for program names).
This patch adds the fir.proc_attrs to func.func just like it was done
for calls recently. This replace the previous named attribute for
PURE/ELEMENTAL/RECURSIVE (note that RECURSIVE is changed to
NON_RECURSIVE, which brings more data since RECURSIVE is the default for
procedures that do not have explicit RECURSIVE/NON_RECUSRIVE
attributes).
Follow-up from a previous patch that turned bind_c into an enum for
procedure attribute.
This patch carries the elemental and pure Fortran attribute into FIR so
that the optimizer can leverage that info in the future (I think debug
info may also need to know these aspects since DWARF has DW_AT_elemental
and DW_AT_pure nodes).
SIMPLE from F2023 will be translated once it is handled in the
front-end.
NON_RECURSIVE is only meaningful on func.func since we are not
guaranteed to know that aspect on the caller side (it is not part of
Fortran characteristics). There is a DW_AT_recursive DWARF node. I will
do it while dealing with func.func attributes.
SIZEOF and C_SIZEOF were broken for assumed-ranks because
`TypeAndShape::MeasureSizeInBytes` behaved as a scalar because the
`TypeAndShape::shape_` member was the same for scalar and assumed-ranks.
The easy fix would have been to add special handling in
`MeasureSizeInBytes` for assumed-ranks using the TypeAndShape
attributes, but I think this solution would leave `TypeAndShape::shape_`
manipulation fragile to future developers. Hence, I went for the
solution that turn shape_ into a `std::optional<Shape>`.
The number of operations dedicated to CUF grew and where all still in
FIR. In order to have a better organization, the CUF operations,
attributes and code is moved into their specific dialect and files. CUF
dialect is tightly coupled with HLFIR/FIR and their types.
The CUF attributes are bundled into their own library since some
HLFIR/FIR operations depend on them and the CUF dialect depends on the
FIR types. Without having the attributes into a separate library there
would be a dependency cycle.
…ted. (#89998)" (#90250)
This partially reverts commit 7aedd7dc754c74a49fe84ed2640e269c25414087.
This change removes calls to the deprecated member functions. It does
not mark the functions deprecated yet and does not disable the
deprecation warning in TypeSwitch. This seems to cause problems with
MSVC.
When the characteristics of a procedure depend on a procedure that
hasn't yet been defined, the compiler currently emits an unconditional
error message. This includes the case of a procedure whose
characteristics depend, perhaps indirectly, on itself. However, in the
case where the characteristics of a procedure are needed to resolve a
generic, we should not emit an error for a hitherto undefined procedure
-- either the call will resolve to another specific procedure, in which
case the error is spurious, or it won't, and then an error will issue
anyway.
Fixes https://github.com/llvm/llvm-project/issues/88677.
Currently, it is not possible to find back which fun.func is the host
procedure of some internal procedure because the mangling of the
internal procedure does not contain info about the BIND(C) name of the
host.
This info may be useful to ensure dwarf DW_TAG_subprogram of internal
procedures are nested under DW_TAG_subprogram of host procedures for
instance.
Fortran mandates "CHARACTER(1), VALUE" be passed as a C "char" in calls
to BIND(C) procedures (F'2023 18.3.7 (4)). Lowering passed them by
memory instead. Update call interface lowering code to pass them by
register. Fix related test and update it to use HLFIR.
Whenever lowering is checking if a function or global already exists in
the mlir::Module, it was doing module->lookup.
On big programs (~5000 globals and functions), this causes important
slowdowns because these lookups are linear. Use mlir::SymbolTable to
speed-up these lookups. The SymbolTable has to be created from the
ModuleOp and maintained in sync. It is therefore placed in the
converter, and FirOPBuilders can take a pointer to it to speed-up the
lookups.
This patch does not bring mlir::SymbolTable to FIR/HLFIR passes, but
some passes creating a lot of runtime calls could benefit from it too.
More analysis will be needed.
As an example of the speed-ups, this patch speeds-up compilation of
Whizard compare_amplitude_UFO.F90 from 5 mins to 2 mins on my machine
(there is still room for speed-ups).
Polymorphic entity lowering status is good. The main remaining TODO is
to allow lowering of vector subscripted polymorphic entity, but this
does not deserve blocking all application using polymorphism.
Remove experimental option and enable lowering of polymorphic entity by
default.
The current lowering did not handle sequence associated argument passed
by descriptor. This case is special because sequence association implies
that the actual and dummy argument need to to agree in rank and shape.
Usually, arguments that can be sequence associated are passed by raw
address, and the shape mistmatch is transparent. But there are three
cases of explicit and assumed-size arrays passed by descriptors:
- polymorphic arguments
- BIND(C) assumed-length arguments (F'2023 18.3.7 (5)).
- length parametrized derived types (TBD)
The callee side is expecting a descriptor containing the dummy rank and
shape. This was not the case. This patch fix that by evaluating the
dummy shape on the caller side using the interface (that has to be
available when arguments are passed by descriptors).
This PR adds a new attribute to carry over the information from
`cluster_dims`. The new attribute `CUDAClusterDimsAttr` holds 3 integer
attributes and is added to `func.func` operation.
This PR adds a new attribute to carry over the information from
`launch_bounds`. The new attribute `CUDALaunchBoundsAttr` holds 2 to 3
integer attrinbutes and is added to `func.func` operation.
This PR adds a new attribute to represent the CUDA attribute attached to
procedure. This attribute is attached to the func.func operation during
lowering.
Other procedures information such as `launch_bounds` and `cluster_dims`
will be added separately.
The newly introduced `CUDAAttribute` is meant for CUDA attributes
associated with variable. In order to not clash with the future
attribute for function/subroutine, rename `CUDAAttribute` to
`CUDADataAttribute`.
Runtime derived type info contains information to tell the runtime if
some argument in a user defined assignment must be passed with a
descriptor or not. This information was not properly build, it would
tell the runtime that TARGET argument must be passed via descriptor,
which is incorrect.
Share the logic between lowering and runtime info generation to
determine if an argument must be passed by descriptor or not.
Lower CUDA attribute for simple dummy argument. This is done in a
similar way than `TARGET`, `OPTIONAL` and so on.
This patch also move the `Fortran::common::CUDADataAttr` to
`fir::CUDAAttributeAttr` mapping to
`flang/include/flang/Optimizer/Support/Utils.h` so that it can be reused
where needed.
Finish plugging-in ASYNCHRONOUS IO in lowering (GetAsynchronousId was
not used yet).
Add a runtime implementation for GetAsynchronousId (only the signature
was defined). Always return zero since flang runtime "fakes"
asynchronous IO (data transfer are always complete, see
flang/docs/IORuntimeInternals.md).
Update all runtime integer argument and results for IDs to use the
AsynchronousId int alias for consistency.
In lowering, asynchronous attribute is added on the hlfir.declare of
ASYNCHRONOUS variable, but nothing else is done. This is OK given the
synchronous aspects of flang IO, but it would be safer to treat these
variable as volatile (prevent code motion of related store/loads) since
the asynchronous data change can also be done by C defined user
procedure (see 18.10.4 Asynchronous communication). Flang lowering
anyway does not give enough info for LLVM to do such code motions (the
variables that are passed in a call are not given the noescape
attribute, so LLVM will assume any later opaque call may modify the
related data and would not move load/stores of such variables
before/after calls even if it could from a pure Fortran point of view
without ASYNCHRONOUS).
This PR adds lowering the reference to a function that returns a
procedure pointer. It also fixed intrinsic ASSOCIATED to take such
argument.
---------
Co-authored-by: jeanPerier <jperier@nvidia.com>
Start implementing assumed-rank support as described in
https://github.com/llvm/llvm-project/blob/main/flang/docs/AssumedRank.md
This commit holds the minimal support for lowering calls to procedure
with assumed-rank arguments where the procedure implementation is done
in C.
The case for passing assumed-size to assumed-rank is left TODO since it
will be done a change in assumed-size lowering that is better done in
another patch.
Care is taken to set the lower bounds to zero when passing non allocatable no pointer as descriptor
to a BIND(C) procedure as required per 18.5.3 point 3. This was not done before while the requirements also applies to non assumed-rank descriptors. This change required special attention with IGNORE_TKR(t) to avoid emitting invalid fir.rebox operations (the actual argument type must be used in this case as the output type).
Implementation of Fortran procedure with assumed-rank arguments is still
TODO.
Lower procedure pointer components, except in the context of structure
constructor (left TODO).
Procedure pointer components lowering share most of the lowering logic
of procedure poionters with the following particularities:
- They are components, so an hlfir.designate must be generated to
retrieve the procedure pointer address from its derived type base.
- They may have a PASS argument. While there is no dispatching as with
type bound procedure, special care must be taken to retrieve the derived
type component base in this case since semantics placed it in the
argument list and not in the evaluate::ProcedureDesignator.
These components also bring a new level of recursive MLIR types since a
fir.type may now contain a component with an MLIR function type where
one of the argument is the fir.type itself. This required moving the
"derived type in construction" stackto the converter so that the object
and function type lowering utilities share the same state (currently the
function type utilty would end-up creating a new stack when lowering its
arguments, leading to infinite loops). The BoxedProcedurePass also
needed an update to deal with this recursive aspect.
This patch is fixing two issue relative to the dynamic dispatch for
polymorphic entities.
1. Fix the `requireDispatchCall` function. It was checking for the first
symbol of the component but this is not the one to be checked. Instead
the last symbol of the base of the component object is the one to check
to know if it is polymorphic object with a dispatch call or not. This is
demonstrated in the new added test in `flang/test/Lower/dispatch.f90`
where the first symbol would point to `q` which is monomorphic and would
result in a simple `fir.call`
2. Fix the pass object in a no pass situation. In a no pass situation
the pass object is lowered anyway to be able to do the lookup in the
binding table. It was previously lowered wrongly an lead to unresolved
lookup. The base of the component is the passed object and should be
lowered. To achieve this, the `gen(DataRef)` entry point is exposed form
`ConvertExprToHLFIR` through a `convertDataRefToValue` function. The
same test added in `flang/test/Lower/dispatch.f90` is checking for the
correct passed object.
In addition couple of tests were updated to HLFIR since the lowering
used only works with it.
**Scope of the PR:**
1. Lowering global and local procedure pointer declaration statement
with explicit or implicit interface. The explicit interface can be from
an interface block, a module procedure or an internal procedure.
2. Lowering procedure pointer assignment, where the target procedure
could be external, module or internal procedures.
3. Lowering reference to procedure pointers so that it works end to end.
**PR notes:**
1. The first commit of the PR does not include testing. I would like to
collect some comments first, which may alter the output. Once I confirm
the implementation, I will add some testing as a follow up commit to
this PR.
2. No special handling of the host-associated entities when an internal
procedure is the target of a procedure pointer assignment in this PR.
**Implementation notes:**
1. The implementation is using the HLFIR path.
2. Flang currently uses `getUntypedBoxProcType` to get the
`fir::BoxProcType` for `ProcedureDesignator` when getting the address of
a procedure in order to pass it as an actual argument. This PR inherits
the same design decision for procedure pointer as the `fir::StoreOp`
requires the same memory type.
Note: this commit is actually resubmitting the original commit from
PR #70461 that was reverted. See PR #73221.
**Scope of the PR:**
1. Lowering global and local procedure pointer declaration statement
with explicit or implicit interface. The explicit interface can be from
an interface block, a module procedure or an internal procedure.
2. Lowering procedure pointer assignment, where the target procedure
could be external, module or internal procedures.
3. Lowering reference to procedure pointers so that it works end to end.
**PR notes:**
1. The first commit of the PR does not include testing. I would like to
collect some comments first, which may alter the output. Once I confirm
the implementation, I will add some testing as a follow up commit to
this PR.
2. No special handling of the host-associated entities when an internal
procedure is the target of a procedure pointer assignment in this PR.
**Implementation notes:**
1. The implementation is using the HLFIR path.
2. Flang currently uses `getUntypedBoxProcType` to get the
`fir::BoxProcType` for `ProcedureDesignator` when getting the address of
a procedure in order to pass it as an actual argument. This PR inherits
the same design decision for procedure pointer as the `fir::StoreOp`
requires the same memory type.
Semantics is emitting an error when an actual argument to a procedure
that has an implicit interface has a polymorphic type. This is too
general; while TYPE(*) and CLASS(*) unlimited polymorphic items require
the presence of an explicit procedure interface, CLASS(T) data can be
passed over an implicit interface to a procedure expecting a
corresponding dummy argument with TYPE(T), so long as T is not
parameterized.
(Only XLF handles this usage correctly among other Fortran compilers.)
(Making this work in the case of an actual CLASS(T) array may well
require additional changes in lowering to copy data to/from a temporary
buffer to ensure contiguity when the actual type of the array is an
extension of T.)
Update evaluate::ActualArgument to propagate the %VAL and %REF markers
until lowering.
Semantic checks are added to %VAL to ensure the argument is a numerical
or logical scalar.
I did not push these markers into the characteristics because other
compilers do not complain about inconsistent usages (e.g. using %VAL in
a call on a procedure with an interface without VALUE dummies is not
flagged by any compilers I tested, and it is not an issue for lowering,
so I decided to stay simple here and minimize the footprint of these
legacy features).
Lowering retrieves these markers and does the right thing: pass %VAL in
registers and pass %REF by address without adding any extra arguments
for characters.
Currently, if the first usage of a procedure not defined in the file was
inside a procedure designator reference (not a call to it), the lowered
func.func lacked the argument attributes if any.
Fix this by using `CallInterface<T>::declare` too in SignatureBuilder to
create a new func.func instead of using custom code.
Note: this problem was made worse by the fact that module variables
fir.global are currently lowered before the module procedures func.func
are created. I will try to fix that in a later patch (the debug location
may still be wrong in certain cases) because there is quite some test
fallout when changing the order of globals/funcop in the output.
1. Deal with BIND(C,NAME="")
BIND(C,NAME="") is different from BIND(C). The latter implies that there
us a binding label which is the Fortran symbol name (no Fortran mangling
must be added like underscores). The former implies there is no binding
label (the name in the object file must be the same as if it there was
no BIND(C) attribute at all).
This is correctly implemented in the front-end, but lowering mistakenly
overrode this in the code dealing with the case where BIND(C) is
inherited from a procedure interface. Handling of this last case is moved into name
resolution.
2. Deal with BIND(C) internal procedure
Also according to 18.10.2, BIND(C) does not give a p prevent name
resolution from adding a label to them, otherwise,
bindc_internal_proc.f90 was not going through semantics (bogus error
about conflicting global names). Nothing TODO in lowering other than
removing the TODO.
Outside of BIND(C), assumed length character scalar and explicit shape
are passed by address + an extra length argument (fir.boxchar in FIR).
The standard mandates that they be passed via CFI descriptor in BIND(C)
interface (fir.box in FIR). This patch fix the handling for this case.
The following PowerPC vector type syntax is added:
VECTOR ( element-type-spec )
where element-type-sec is integer-type-spec, real-type-sec or unsigned-type-spec.
Two opaque types (__VECTOR_PAIR and __VECTOR_QUAD) are also added.
A finite set of functionalities are implemented in order to support the new types:
1. declare objects
2. declare function result
3. declare type dummy arguments
4. intrinsic assignment between the new type objects (e.g. v1=v2)
5. reference functions that return the new types
Submit on behalf of @tislam @danielcchen
Authors: @tislam @danielcchen
Differential Revision: https://reviews.llvm.org/D150876
There are several observations regarding the copy-in/copy-out:
* Actual argument associated with INTENT(OUT) dummy argument that
requires finalization (7.5.6.3 p. 7) may be read by the finalization
function, so a copy-in is required.
* A temporary created for the copy-in/copy-out must be destroyed
without finalization after the call (or after the corresponding copy-out),
otherwise, memory leaks may occur.
* The copy-out assignment must not perform finalization for the LHS.
* The copy-out assignment from the temporary to the actual argument
may or may not need to initialize the LHS.
This change-set introduces new runtime methods: CopyOutAssign and
DestroyWithoutFinalization. They are called by the compiler generated
code to match the behavior described above.
Reviewed By: jeanPerier
Differential Revision: https://reviews.llvm.org/D151135
Reboxing of the actual argument according to the type of the dummy
argument has to be aware of the potential rank mismatch, when
IGNORE_TKR(R) is used. This change only adds support for the mismatching
rank when the dummy argument has unlimited polymorphic type.
Reviewed By: jeanPerier
Differential Revision: https://reviews.llvm.org/D151016
