Advise to place the alloca at the start of the first block of whichever
region (init or combiner) we are currently inside.
It probably isn't safe to put an alloca inside of a combiner region
because this will be executed multiple times. But that would be a bug to
fix in Lower/OpenMP.cpp, not here.
OpenMP array reductions 1/6
Next PR: https://github.com/llvm/llvm-project/pull/84953
The FIR dialect has been initiated before many interfaces have been
introduced to MLIR. This patch expose the FIR to LLVM patterns in a
`populateFIRToLLVMConversionPatterns` function. The idea is to be able
to add the `ConvertToLLVMPatternInterface`. This is not directly
possible since the FIR dialect does not currently use the table
infrastructure for its definition.
Follow up patches will move the FIR dialect definition to table gen and
then implement the interface.
Descriptor addendum have a field to hold length parameters (currently
only one). This field is currently never used because flang does not
lowered derived types with length parameters.
However, leaving it uninitialized is causing bugs in code like gFTL
where the code is trying to sort POINTERs (see [1]). More precisely, it
is an issue when two pointers should compare equal (same base address),
because the uninitialized values in the addendum may differ depending on
the "stack history" and optimization level.
Always initialized the length parameters field in the addendum to zero.
[1]:
dc93a5fc2f/include/v1/templates/set_impl.inc (L312)
The type being transferred to an integer array may look like:
```
TYPE :: localwrapper
TYPE(T), POINTER :: item
END TYPE localwrapper
```
Which in flang case ends-up transferring a descriptor to an integer
array, the code in gFTL later compare the integer arrays. This logic is
used when building set data structures in gFTL.
This patch seeks to add an initial lowering for pointers and allocatable variables
captured by implicit and explicit map in Flang OpenMP for Target operations that
take map clauses e.g. Target, Target Update. Target Exit/Enter etc.
Currently this is done by treating the type that lowers to a descriptor
(allocatable/pointer/assumed shape) as a map of a record type (e.g. a structure) as that's
effectively what descriptor types lower to in LLVM-IR and what they're represented as
in the Fortran runtime (written in C/C++). The descriptor effectively lowers to a structure
containing scalar and array elements that represent various aspects of the underlying
data being mapped (lower bound, upper bound, extent being the main ones of interest
in most cases) and a pointer to the allocated data. In this current iteration of the mapping
we map the structure in it's entirety and then attach the underlying data pointer and map
the data to the device, this allows most of the required data to be resident on the device
for use. Currently we do not support the addendum (another block of pointer data), but
it shouldn't be too difficult to extend this to support it.
The MapInfoOp generation for descriptor types is primarily handled in an optimization
pass, where it expands BoxType (descriptor types) map captures into two maps, one for
the structure (scalar elements) and the other for the pointer data (base address) and
links them in a Parent <-> Child relationship. The later lowering processes will then treat
them as a conjoined structure with a pointer member map.
This patch forwards the target CPU and features information from the
Flang frontend to MLIR func.func operation attributes, which are later
used to populate the target_cpu and target_features llvm.func
attributes.
This is achieved in two stages:
1. Introduce the `fir.target_cpu` and `fir.target_features` module
attributes with information from the target machine immediately after
the initial creation of the MLIR module in the lowering bridge.
2. Update the target rewrite flang pass to get this information from the
module and pass it along to all func.func MLIR operations, respectively
as attributes named `target_cpu` and `target_features`. These attributes
will be automatically picked up during Func to LLVM dialect lowering and
used to initialize the corresponding llvm.func named attributes.
The target rewrite and FIR to LLVM lowering passes are updated with the
ability to override these module attributes, and the `CodeGenSpecifics`
optimizer class is augmented to make this information available to
target-specific MLIR transformations.
This completes a full flow by which target CPU and features make it all
the way from compiler options to LLVM IR function attributes.
A user defining and using free/malloc via BIND(C) would previously cause
flang to crash when generating LLVM IR with error "redefinition of
symbol named 'free'". This was caused by flang codegen not expecting to
find a mlir::func::FuncOp definition of these function and emitting a
new mlir::LLVM::FuncOp that later conflicted when translating the
mlir::func::FuncOp.
This is a slightly more slimmed down and up-to-date version of the older
PR from here: https://reviews.llvm.org/D144203, written by @jsjodin,
which has already under gone some review.
This PR places allocas in the alloca address space specified by the
provided data layout (default is 0 for all address spaces, unless
explicitly specified by the layout), and then will cast these alloca's
to the program address space if this address space is different from the
allocation address space. For most architectures data layouts, this will
be a no-op, as they have a flat address space. But in the case of AMDGPU
it will result in allocas being placed in the correct address space (5,
private), and then casted into the correct program address space (0,
generic). This results in correct (partially, a follow up PR will be
forthcoming soon) generation of allocations inside of device code.
This PR is in addition to the work by @skatrak in this PR:
https://github.com/llvm/llvm-project/pull/69599 and adds seperate and
neccesary functionality of casting alloca's from their address space to
the program address space, both are independent PRs, although there is
some minor overlap e.g. this PR incorporates some of the useful helper
functions from 69599, so whichever lands first will need a minor rebase.
Co-author: jsjodin
This commit renames 4 pattern rewriter API functions:
* `updateRootInPlace` -> `modifyOpInPlace`
* `startRootUpdate` -> `startOpModification`
* `finalizeRootUpdate` -> `finalizeOpModification`
* `cancelRootUpdate` -> `cancelOpModification`
The term "root" is a misnomer. The root is the op that a rewrite pattern
matches against
(https://mlir.llvm.org/docs/PatternRewriter/#root-operation-name-optional).
A rewriter must be notified of all in-place op modifications, not just
in-place modifications of the root
(https://mlir.llvm.org/docs/PatternRewriter/#pattern-rewriter). The old
function names were confusing and have contributed to various broken
rewrite patterns.
Note: The new function names use the term "modify" instead of "update"
for consistency with the `RewriterBase::Listener` terminology
(`notifyOperationModified`).
In the context of C/Fortran interoperability (BIND(C)), it is possible
to give the VALUE attribute to a BIND(C) derived type dummy, which
according to Fortran 2018 18.3.6 - 2. (4) implies that it must be passed
like the equivalent C structure value. The way C structure value are
passed is ABI dependent.
LLVM does not implement the C struct ABI passing for LLVM aggregate type
arguments. It is up to the front-end, like clang is doing, to split the
struct into registers or pass the struct on the stack (llvm "byval") as
required by the target ABI.
So the logic for C struct passing sits in clang. Using it from flang
requires setting up a lot of clang context and to bridge FIR/MLIR
representation to clang AST representation for function signatures (in
both directions). It is a non trivial task.
See
https://stackoverflow.com/questions/39438033/passing-structs-by-value-in-llvm-ir/75002581#75002581.
Since BIND(C) struct are rather limited as opposed to generic C struct
(e.g. no bit fields). It is easier to provide a limited implementation
of it for the case that matter to Fortran.
This patch:
- Updates the generic target rewrite pass to keep track of both the new
argument type and attributes. The motivation for this is to be able to
tell if a previously marshalled argument is passed in memory (it is a C
pointer), or if it is being passed on the stack (has the byval llvm
attributes).
- Adds an entry point in the target specific codegen to marshal struct
arguments, and use it in the generic target rewrite pass.
- Implements limited support for the X86-64 case. So far, the support
allows telling if a struct must be passed in register or on the stack,
and to deal with the stack case. The register case is left TODO in this
patch.
The X86-64 ABI implemented is the System V ABI for AMD64 version 1.0
`nsw` is a flag for LLVM arithmetic operations meaning "no signed wrap".
If this keyword is present, the result of the operation is a poison
value if overflow occurs. Adding this keyword permits LLVM to re-order
integer arithmetic more aggressively.
In
https://discourse.llvm.org/t/rfc-changes-to-fircg-xarray-coor-codegen-to-allow-better-hoisting/75257/16
@vzakhari observed that adding nsw is useful to enable hoisting of
address calculations after some loops (or is at least a step in that
direction).
Classic flang also adds nsw to address calculations.
`llvm.fcmp` does support fast math attributes therefore so should
`arith.cmpf`.
The heavy churn in flang tests are because flang sets
`fastmath<contract>` by default on all operations that support the fast
math interface. Downstream users of MLIR should not be so effected.
This was requested in https://github.com/llvm/llvm-project/issues/74263
This operation allows computing the address of descriptor fields. It is
needed to help attaching descriptors in OpenMP/OpenACC target region.
The pointers inside the descriptor structure must be mapped too, but the
fir.box is abstract, so these fields cannot be computed with
fir.coordinate_of.
To preserve the abstraction of the descriptor layout in FIR, introduce
an operation specifically to !fir.ref<fir.box<>> address fields based on
field names (base_addr or derived_type).
Propagate fast math flags through complex number lowering (when lowering
fir.*c directly to llvm floating point operations).
The lowering path through the MLIR complex dialect is unchanged.
This leads to a small improvement in spec2017 fotonik3d_r.
!llvm.ptr<T> typed pointers are depreciated in MLIR LLVM dialects. Flang
codegen still generated them and relied on mlir.llvm codegen to LLVM to
turn them into opaque pointers.
This patch update FIR codegen to directly emit and work with LLVM opaque
pointers.
Addresses https://github.com/llvm/llvm-project/issues/69303
- All places generating GEPs need to add an extra type argument with the
base type (the T that was previously in the llvm.ptr<T> of the base).
- llvm.alloca must also be provided the object type. In the process, I
doscovered that we were shamelessly copying all the attribute from
fir.alloca to the llvm.alloca, which makes no sense for the operand
segments. The updated code that cannot take an attribute dictionnary in
the llvm.alloca builder with opaque pointers only propagate the "pinned"
and "bindc_name" attributes to help debugging the generated IR.
- Updating all the places that rely on getting the llvm object type from
lowered llvm.ptr<T> arguments to get it from a type conversion of the
original fir types.
- Updating all the places that were generating llvm.ptr<T> types to
generate the opaque llvm.ptr type.
- Updating all the codegen tests checking generated MLIR llvm dialect.
Many tests are testing directly LLVM IR, and this change is a no-op for
those (which is expected).
The ultimate intention is to have this pass enabled by default whenever
we are optimizing for speed. But for now, just add the arguments so this
can be more easily tested.
PR: https://github.com/llvm/llvm-project/pull/68595
This interface allows (HL)FIR passes to add TBAA information to fir.load
and fir.store. If present, these TBAA tags take precedence over those
added during CodeGen.
We can't reuse mlir::LLVMIR::AliasAnalysisOpInterface because that uses
the mlir::LLVMIR namespace so it tries to define methods for fir
operations in the wrong namespace. But I did re-use the tbaa tag type to
minimise boilerplate code.
The new builders are to preserve the old interface without the tbaa tag.
The goal is to progressively propagate all the derived type info that is
currently in the runtime type info globals into a FIR operation that can
be easily queried and used by FIR/HLFIR passes.
When this will be complete, the last step will be to stop generating the
runtime info global in lowering, but to do that later in or just before
codegen to keep the FIR files readable (on the added type-info.f90
tests, the lowered runtime info globals takes a whooping 2.6 millions
characters on 1600 lines of the FIR textual output. The fir.type_info that
contains all the info required to generate those globals for such
"trivial" types takes 1721 characters on 9 lines).
So far this patch simply starts by replacing the fir.dispatch_table
operation by the fir.type_info operation and to add the noinit/
nofinal/nodestroy flags to it. These flags will soon be used in HLFIR to
better rewrite hlfir.assign with derived types.
This is not standard but is vastly expected by existing code.
This was implemented by https://reviews.llvm.org/D149877 for simple
scalars, but MLIR lacked a generic way to deal with aggregate types
(arrays and derived type).
Support was recently added in
https://github.com/llvm/llvm-project/pull/65508. Leverage it to zero
initialize all types.
This revision replaces the LLVM dialect NullOp by the recently
introduced ZeroOp. The ZeroOp is more generic in the sense that it
represents zero values of any LLVM type rather than null pointers only.
This is a follow to https://github.com/llvm/llvm-project/pull/65508
This fixes a bug where functions generated by the MLIR Math dialect, for
example ipowi, would fail to link with link.exe on Windows due to having
linkonce linkage but no associated comdat. Adding the comdat on ELF also
allows linkers to perform better garbage collection in the binary.
Simply adding comdats to all functions with this linkage type should
also cover future cases where linkonce or linkonce_odr functions might
be necessary.
While creating a temporary alloca for a box in OpenMp region, the
insertion point should be the OpenMP region block instead of the
function entry block.
ConversionPatterns do not (and should not) modify the type converter that they are using.
* Make `ConversionPattern::typeConverter` const.
* Make member functions of the `LLVMTypeConverter` const.
* Conversion patterns take a const type converter.
* Various helper functions (that are called from patterns) now also take a const type converter.
Differential Revision: https://reviews.llvm.org/D157601
For character type with unknown length we end up generating
a GEP with the base type `llvm.ptr<i[width]>`. The GEP produces
the address of the first element of the slice, and it should be
using the offset computed in the number of characters, while we were
providing the offset in bytes.
Simple reproducer fails with and w/o HLFIR:
```
program test
integer,parameter :: ck = 4
character(:,ck),allocatable :: res(:,:)
allocate(character(3,ck) :: res(2,2))
res(1,1) = ck_'111'
res(1,2) = ck_'222'
res(2,1) = ck_'333'
res(2,2) = ck_'444'
call check(res)
contains
subroutine check(res)
character(:,ck),allocatable :: res(:,:)
print *, res(2,:)
end subroutine check
end program test
```
Reviewed By: clementval
Differential Revision: https://reviews.llvm.org/D156849
Identify multidimensional array indices in subcomponents and
convert them from column-major to row-major ordering.
This fixes codegen for fircg.ext_array_coor, fircg.ext_embox and,
possibly, fircg.ext_rebox.
Fixes https://github.com/llvm/llvm-project/issues/62038
Reviewed By: jeanPerier
Differential Revision: https://reviews.llvm.org/D154214
The code generation of the fir.embox op creating descriptors for
array substring with a non constant length base was using the
substring length to compute the first dimension result stride.
Fix it to use the input length instead.
Reviewed By: PeteSteinfeld
Differential Revision: https://reviews.llvm.org/D154086
fir.rebox is emitting an llvm.sdiv to compute the character length
given the byte size from the input descriptor.
Inside a fir.global, this is not needed given the target length must
be accessible via the type, and it caused MLIR to fail LLVM IR
code generation (and crash).
Use the input type length when available instead.
Reviewed By: PeteSteinfeld, vzakhari
Differential Revision: https://reviews.llvm.org/D154072
On platforms which support COMDAT sections we should use them when
linkonce or linkonce_odr linkage is requested. This is required on
Windows (PE/COFF) and provides better behaviour than weak symbols on
ELF-based platforms.
This patch also reverts string literals to use linkonce instead of
internal linkage now that comdats are supported.
Differential Revision: https://reviews.llvm.org/D153768
The information needed for translation is now encoded in the dialect
operations and does not require a dedicated pass to be extracted.
Remove the obsolete passes that were performing operand legalization.
Reviewed By: jeanPerier
Differential Revision: https://reviews.llvm.org/D150248
Instead of filling uninitialized global variables with "undef",
initialize them with 0. Only for Integer, Float or Logical type
variables. Complex, user defined data structures, arrays, etc
are not supported at this point.
This patch fixes the main problem of
https://github.com/llvm/llvm-project/issues/62432
Reviewed By: jeanPerier
Differential Revision: https://reviews.llvm.org/D149877
Fir.GlobalOp's currently do not respect attributes that
are applied to them, this change will do two things:
- Allow lowering of arbitrary attributes applied to
Fir.GlobalOp's to LLVMGlobalOp's during CodeGen
- Allow printing and parsing of arbitrarily applied attributes
This allows applying other dialects attributes (or other
fir attributes) to fir.GlobalOps on the fly and have them
exist in the resulting LLVM dialect IR or FIR IR.
Reviewer: jeanPerier
Differential Revision: https://reviews.llvm.org/D148352
The code was using the original operand of the operation, while
it should have been using the remapped operands via the adaptor.
Differential Revision: https://reviews.llvm.org/D148587
When dealing with "derived_array(j)%component" where derived_array
is not a contiguous array, but for which we know the extent, lowering
generates a fir.array_coor op on a !fir.box<!fir.array<cst x T>> with
a fir.slice containing "j" in the component path.
Codegen first computes "derived_array(j)" address using the byte
strides inside the descriptor, and then computes the offset of "j"
from that address with a second GEP.
The type of the address in that second GEP matters since "j" is passed
in the GEP via an index indicating its component position in the type.
The code was using the LLVM type of "derived_array" instead of
"derived_array(j)".
In general, with fir.box, the extent ("cst" above) is unknown and those
types match. But if the extent of "derived_array" is a compile time
constant, its LLVM type will be [cst x T] instead of T*, and the produced
GEP will compute the address of the nth T instead of the nth component
inside T leading to undefined behaviors.
Fix this by computing the element type for the second GEP.
Differential Revision: https://reviews.llvm.org/D148226
After the extraction of the TypeConverter, move the header files
to the include dir so the shared library build is fine.
Reviewed By: PeteSteinfeld
Differential Revision: https://reviews.llvm.org/D147979
Currently `fir.divc` is always lowered to a sequence of llvm operations to perform complex division, however this causes issues for extreme values when the calculations overflow. While this behaviour would be fine at -Ofast, this is currently the default at all levels.
This patch changes `fir.divc` to lower to a library call instead, except for when KIND=3 as there is no appropriate library call for this case.
Reviewed By: vzakhari
Differential Revision: https://reviews.llvm.org/D145808
Flang was missing value normalization for logical<->integer conversions
which is required by Flang specification. The shrinking logical<->logical
conversions were also incorrectly truncating the input.
This change performs value normalization for all logical<->integer
conversions and logical<->logical conversions between different kinds.
Note that value normalization is not strictly required for
logical(kind=k1)->logical(kind=k2) conversions when k1 < k2.
Differential Revision: https://reviews.llvm.org/D147019
