Ensure volatility is reflected not just on the reference to an
allocatable, but on the box, too. When we declare a volatile
allocatable, we now get a volatile reference to a volatile box.
Some related cleanups:
* SELECT TYPE constructs check the selector's type for volatility when
creating and designating the type used in the selecting block.
* Refine the verifier for fir.convert. In general, I think it is ok to
implicitly drop volatility in any ptr-to-int conversion because it means
we are in codegen (and representing volatility on the LLVM ops and
intrinsics) or we are calling an external function (are there any cases
I'm not thinking of?)
* An allocatable test that was XFAILed is now passing. Making
allocatables' boxes volatile resulted in accesses of those boxes being
volatile, which resolved some errors coming from the strict verifier.
* I noticed a runtime function was missing the fir.runtime attribute.
Fixed an issue in `genCUDAImplicitDataTransfer` where creating an
`hlfir::Entity` from a symbol address could fail when the address comes
from a `hlfir.declare` operation. Fix is to check if the address comes
from a `hlfir.declare` operation. If so, use the base value from the
declare op when available. Falling back to the original address
otherwise.
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`.
Adds support for lowering `do concurrent` nests from PFT to the new
`fir.do_concurrent` MLIR op as well as its special terminator
`fir.do_concurrent.loop` which models the actual loop nest.
To that end, this PR emits the allocations for the iteration variables
within the block of the `fir.do_concurrent` op and creates a region for
the `fir.do_concurrent.loop` op that accepts arguments equal in number
to the number of the input `do concurrent` iteration ranges.
For example, given the following input:
```fortran
do concurrent(i=1:10, j=11:20)
end do
```
the changes in this PR emit the following MLIR:
```mlir
fir.do_concurrent {
%22 = fir.alloca i32 {bindc_name = "i"}
%23:2 = hlfir.declare %22 {uniq_name = "_QFsub1Ei"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
%24 = fir.alloca i32 {bindc_name = "j"}
%25:2 = hlfir.declare %24 {uniq_name = "_QFsub1Ej"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
fir.do_concurrent.loop (%arg1, %arg2) = (%18, %20) to (%19, %21) step (%c1, %c1_0) {
%26 = fir.convert %arg1 : (index) -> i32
fir.store %26 to %23#0 : !fir.ref<i32>
%27 = fir.convert %arg2 : (index) -> i32
fir.store %27 to %25#0 : !fir.ref<i32>
}
}
```
[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)
```
The nesting of fir.dummy_scope operations defines the roots
of the TBAA forest. If we do not generate fir.dummy_scope
in functions that do not have any dummy arguments, then
the globals accessed in the function and the dummy arguments
accessed by the callee may end up in different sub-trees
of the same root. The added tbaa-with-dummy-scope2.fir
demonstrates the issue.
This reverts commit 04b87e15e40f8857e29ade8321b8b67691545a50.
The reasons for reverting is that the following:
1. I still need need to upstream some part of the do concurrent to
OpenMP pass from our downstream implementation and taking this in
downstream will make things more difficult.
2. I still need to work on a solution for modeling locality specifiers
on `hlfir.do_concurrent` ops. I would prefer to do that and merge the
entire stack together instead of having a partial solution.
After merging the revert I will reopen the origianl PR and keep it
updated against main until I finish the above.
Adds support for lowering `do concurrent` nests from PFT to the new
`fir.do_concurrent` MLIR op as well as its special terminator
`fir.do_concurrent.loop` which models the actual loop nest.
To that end, this PR emits the allocations for the iteration variables
within the block of the `fir.do_concurrent` op and creates a region for
the `fir.do_concurrent.loop` op that accepts arguments equal in number
to the number of the input `do concurrent` iteration ranges.
For example, given the following input:
```fortran
do concurrent(i=1:10, j=11:20)
end do
```
the changes in this PR emit the following MLIR:
```mlir
fir.do_concurrent {
%22 = fir.alloca i32 {bindc_name = "i"}
%23:2 = hlfir.declare %22 {uniq_name = "_QFsub1Ei"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
%24 = fir.alloca i32 {bindc_name = "j"}
%25:2 = hlfir.declare %24 {uniq_name = "_QFsub1Ej"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
fir.do_concurrent.loop (%arg1, %arg2) = (%18, %20) to (%19, %21) step (%c1, %c1_0) {
%26 = fir.convert %arg1 : (index) -> i32
fir.store %26 to %23#0 : !fir.ref<i32>
%27 = fir.convert %arg2 : (index) -> i32
fir.store %27 to %25#0 : !fir.ref<i32>
}
}
```
Delete duplicated creation of hlfir.declare op of do concurrent
induction variables when inside cuf kernel directive.
Obtain the correct hlfir.declare op generated from bindSymbol, and add
it to ivValues.
Hi,
This patch implements support for the following directives :
- `!DIR$ NOUNROLL_AND_JAM` to disable unrolling and jamming on a DO
LOOP.
- `!DIR$ NOUNROLL` to disable unrolling on a DO LOOP.
- `!DIR$ NOVECTOR` to disable vectorization on a DO LOOP.
Implement handling of `NULL()` RHS, polymorphic pointers, as well as
lower bounds or bounds remapping in pointer assignment inside FORALL.
These cases eventually do not require updating hlfir.region_assign,
lowering can simply prepare the new descriptor for the LHS inside the
RHS region.
Looking more closely at the polymorphic cases, there is not need to call
the runtime, fir.rebox and fir.embox do handle the dynamic type setting
correctly.
After this patch, the last remaining TODO is the allocatable assignment
inside FORALL, which like some cases here, is more likely an accidental
feature given FORALL was deprecated in F2003 at the same time than
allocatable components where added.
Very similar to object pointer assignment, the difference is the SSA
types of the LHS (!fir.ref<!fir.boxproc<()->()>> and RHS
(!fir.boxproc<()->()).
The RHS must be saved as simple address, not descriptors (it is not
possible to make CFI descriptor out of procedure entity).
The semantic of pointer assignments inside FORALL requires evaluating
the targets (RHS) and pointer variables (LHS) of all iterations before
evaluating the assignments.
In practice, if the compiler can prove that the RHS and LHS evaluations
are not impacted by the assignments, the evaluation of the FORALL
assignment statement can be done in a single loop. However, if the
compiler cannot prove this, it needs to "save" the addresses of the
targets and/or the pointer descriptors of each iterations before doing
the assignments.
This patch implements the most common cases where there is no lower bound
spec, no bounds remapping, the LHS is not polymorphic, and the RHS is
not NULL.
The HLFIR operation used to represent assignments inside FORALL can be
used for pointer assignments to (the only difference being that the LHS
is a descriptor address).
The analysis for intrinsic assignment can be reused, with the
distinction that the RHS data is not read during the assignment.
The logic that is used to save LHS in intrinsic assignments inside
FORALL is extracted to be used for the RHS of pointer assignments when
needed (saving a descriptor value).
Pointer assignment LHS are just descriptor addresses and are saved as
int_ptr values.
This patch implements support for the UNROLL_AND_JAM directive to enable
or disable unrolling and jamming on a `DO LOOP`.
It must be placed immediately before a `DO LOOP` and applies only to the
loop that follows. N is an integer that specifying the unrolling factor.
This is done by adding an attribute to the branch into the loop in LLVM
to indicate that the loop should unrolled and jammed.
https://github.com/llvm/llvm-project/pull/123331 added support for the
unrolling directive. In the presence of an explicit unrolling factor,
that unrolling factor would be unconditionally passed into the metadata
even when it was 1 or 0. These special cases should instead disable
unrolling. Adding an explicit unrolling factor of 0 triggered this
assertion which is fixed by this patch:
```
unsigned int unrollCountPragmaValue(const llvm::Loop*):
Assertion `Count >= 1 && "Unroll count must be positive."' failed.
```
Updated tests and documentation.
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.
This patch implements support for the UNROLL directive to control how
many times a loop should be unrolled.
It must be placed immediately before a `DO LOOP` and applies only to the
loop that follows. N is an integer that specifying the unrolling factor.
This is done by adding an attribute to the branch into the loop in LLVM
to indicate that the loop should unrolled.
The code pushed to support the directive `VECTOR ALWAYS` has been
modified to take account of the fact that several directives can be used
before a `DO LOOP`.
This patch adds a call to the CUFInit function just after `ProgramStart`
when CUDA Fortran is enabled to initialize the CUDA context. This allows
us to set up some context information like the stack limit that can be
defined by an environment variable `ACC_OFFLOAD_STACKSIZE=<value>`.
Fixes https://github.com/llvm/llvm-project/issues/113191
Issue: [flang][OpenMP] Runtime segfault when an allocatable variable is
used with copyin
Rootcause: The value of the threadprivate variable is not being copied
from the primary thread to the other threads within a parallel region.
As a result it tries to access a null pointer inside a parallel region
which causes segfault.
Fix: When allocatables used with copyin clause need to ensure that, on
entry to any parallel region each thread’s copy of a variable will
acquire the allocation status of the primary thread, before copying the
value of a threadprivate variable of the primary thread to the
threadprivate variable of each other member of the team.
This fixes a bug when the same variable is used in `firstprivate` and
`lastprivate` clauses on the same construct. The issue boils down to the
fact that `copyHostAssociateVar` was deciding the direction of the copy
assignment (i.e. the `lhs` and `rhs`) based on whether the
`copyAssignIP`
parameter is set. This is not the best way to do it since it is not
related to whether we doing a copy from host to localized copy or the
other way around. When we set the insertion for `firstprivate` in
delayed privatization, this resulted in switching the direction of the
copy assignment. Instead, this PR adds a new paramter to explicitely
tell
the function the direction of the assignment.
This is a follow up PR for
https://github.com/llvm/llvm-project/pull/122471, only the latest commit
is relevant.
Descriptors of allocatable components of firstprivate derived type
copies need to be set-up. Otherwise the program later die when
manipulating them inside OpenMP region.
This commit fixes some but not all memory leaks in Flang. There are
still 91 tests that fail with ASAN.
- Use `mlir::OwningOpRef` instead of `std::unique_ptr`. The latter does
not free allocations of nested blocks.
- Pass `ModuleOp` as value instead of reference.
- Add few missing deallocations in test cases and other places.
Allocatable members of privatized derived types must be allocated,
with the same bounds as the original object, whenever that member
is also allocated in it, but Flang was not performing such
initialization.
The `Initialize` runtime function can't perform this task unless
its signature is changed to receive an additional parameter, the
original object, that is needed to find out which allocatable
members, with their bounds, must also be allocated in the clone.
As `Initialize` is used not only for privatization, sometimes this
other object won't even exist, so this new parameter would need
to be optional.
Because of this, it seemed better to add a new runtime function:
`InitializeClone`.
To avoid unnecessary calls, lowering inserts a call to it only for
privatized items that are derived types with allocatable members.
Fixes https://github.com/llvm/llvm-project/issues/114888
Fixes https://github.com/llvm/llvm-project/issues/114889
Implement the UNSIGNED extension type and operations under control of a
language feature flag (-funsigned).
This is nearly identical to the UNSIGNED feature that has been available
in Sun Fortran for years, and now implemented in GNU Fortran for
gfortran 15, and proposed for ISO standardization in J3/24-116.txt.
See the new documentation for details; but in short, this is C's
unsigned type, with guaranteed modular arithmetic for +, -, and *, and
the related transformational intrinsic functions SUM & al.
This re-applies #117867 with a small fix that hopefully prevents build
bot failures. The fix is avoiding `dyn_cast` for the result of
`getOperation()`. Instead we can assign the result to `mlir::ModuleOp`
directly since the type of the operation is known statically (`OpT` in
`OperationPass`).
This is a starting PR to implicitly map allocatable record fields.
This PR contains the following changes:
1. Re-purposes some of the utils used in `Lower/OpenMP.cpp` so that
these utils work on the `mlir::Value` level rather than the
`semantics::Symbol` level. This takes one step towards to enabling
MLIR passes to more easily do some lowering themselves (e.g. creating
`omp.map.bounds` ops for implicitely caputured data like this PR
does).
2. Adds support for implicitely capturing and mapping allocatable fields
in record types.
There is quite some distant to still cover to have full support for
this. I added a number of todos to guide further development.
Co-authored-by: Andrew Gozillon <andrew.gozillon@amd.com>
Co-authored-by: Andrew Gozillon <andrew.gozillon@amd.com>
-frealloc-lhs is the default.
If -fno-realloc-lhs is specified, then an allocatable on the left
side of an intrinsic assignment is not implicitly (re)allocated
to conform with the right hand side. Fortran runtime will issue
an error if there is a mismatch in shape/type/allocation-status.
Split some headers into headers for public and private declarations in
preparation for #110217. Moving the runtime-private headers in
runtime-private include directory will occur in #110298.
* Do not use `sizeof(Descriptor)` in the compiler. The size of the
descriptor is target-dependent while `sizeof(Descriptor)` is the size of
the Descriptor for the host platform which might be too small when
cross-compiling to a different platform. Another problem is that the
emitted assembly ((cross-)compiling to the same target) is not identical
between Flang's running on different systems. Moving the declaration of
`class Descriptor` out of the included header will also reduce the
amount of #included sources.
* Do not use `sizeof(ArrayConstructorVector)` and
`alignof(ArrayConstructorVector)` in the compiler. Same reason as with
`Descriptor`.
* Compute the descriptor's extra flags without instantiating a
Descriptor. `Fortran::runtime::Descriptor` is defined in the runtime
source, but not the compiler source.
* Move `InquiryKeywordHashDecode` into runtime-private header. The
function is defined in the runtime sources and trying to call it in the
compiler would lead to a link-error.
* Move allocator-kind magic numbers into common header. They are the
only declarations out of `allocator-registry.h` in the compiler as well.
This does not make Flang cross-compile ready yet, the main goal is to
avoid transitive header dependencies from Flang to clang-rt. There are
more assumptions that host platform is the same as the target platform.
Both OpenMP privatization and DO CONCURRENT LOCAL lowering was incorrect
for pointers and derived type with default initialization.
For pointers, the descriptor was not established with the rank/type
code/element size, leading to undefined behavior if any inquiry was made
to it prior to a pointer assignment (and if/when using the runtime for
pointer assignments, the descriptor must have been established).
For derived type with default initialization, the copies were not
default initialized.
When the rhs expression has some constants and a device symbol, an
implicit data transfer needs to be generated for the device symbol and
the computation with the constant is done on the host.
This patch adds a flag to mark hlfir.declare of host variables that are
captured in some internal procedure.
It enables implementing a simple fir.call handling in
fir::AliasAnalysis::getModRef leveraging Fortran language specifications
and without a data flow analysis.
This will allow implementing an optimization for "array =
array_function()" where array storage is passed directly into the hidden
result argument to "array_function" when it can be proven that
arraY_function does not reference "array".
Captured host variables are very tricky because they may be accessed
indirectly in any calls if the internal procedure address was captured
via some global procedure pointer. Without flagging them, there is no
way around doing a complex inter procedural data flow analysis:
- checking that the call is not made to an internal procedure is not
enough because of the possibility of indirect calls made to internal
procedures inside the callee.
- checking that the current func.func has no internal procedure is not
enough because this would be invalid with inlining when an procedure
with internal procedures is inlined inside a procedure without internal
procedure.
We generate `cuf.free` and `func.return` twice if a return statement
exists at the end of program.
```f90
program test
integer, device :: a(10)
return
end
```
```
% flang -x cuda test.cuf -mmlir --mlir-print-ir-after-all
error: loc("/path/to/test.cuf":3:3): 'func.return' op must be the last operation in the parent block
// -----// IR Dump After Fortran::lower::VerifierPass Failed () //----- //
```
Dumped IR:
```mlir
"func.func"() <{function_type = () -> (), sym_name = "_QQmain"}> ({
...
"cuf.free"(%5#1) <{data_attr = #cuf.cuda<device>}> : (!fir.ref<!fir.array<10xi32>>) -> ()
"func.return"() : () -> ()
"cuf.free"(%5#1) <{data_attr = #cuf.cuda<device>}> : (!fir.ref<!fir.array<10xi32>>) -> ()
"func.return"() : () -> ()
}
...
```
The routine `genExitRoutine` in `Bridge.cpp` is guarded by
`blockIsUnterminated()` to make sure that `func.return` is generated
only at the end of a block. However, we redundantly run
`bridge.fctCtx().finalizeAndKeep()` before `genExitRoutine` in this
case, resulting in two pairs of `cuf.free` and `func.return`. This PR
fixes `Bridge.cpp` by using `blockIsUnterminated()` to guard
`finalizeAndKeep` as well.
