This change fixes the issue
https://github.com/llvm/llvm-project/issues/95977 due to commit
c0cba51981 inserting allocas after the
terminator op in the insertion block in the case where the block had
only a single operation, its terminator, in it. With this change, the
hoisted constant-sized allocas are placed at the front of the insertion
block, rather than right after the first operation in it.
The frontend computes the necessary alignment for COMMON blocks but this
information is never carried over to the code generation and can lead to
segfault for COMMON block that requires a non default alignment.
This patch add an optional attribute on fir.global and carries over the
information.
First commit is reviewed in
https://github.com/llvm/llvm-project/pull/93682.
Lower RANK using fir.box_rank. This patches updates fir.box_rank to
accept box reference, this avoids the need of generating an assumed-rank
fir.load just for the sake of reading ALLOCATABLE/POINTER rank. The
fir.load would generate a "dynamic" memcpy that is hard to optimize
without further knowledge. A read effect is conditionally given to the
operation.
- Update LLVM type conversion of assumed-rank fir.box/class to generate
the type of the maximum ranked descriptor. That way, alloca for assumed
rank descriptor copies are always big enough. This is needed in the
fir.load case that generates a new storage for the value
- Add a "computeBoxSize" helper to compute the dynamic size of a
descriptor.
- Use that size to generate an llvm.memcpy intrinsic to copy the input
descriptor into the new storage.
Looking at https://reviews.llvm.org/D108221?id=404635, it seems valid to
add the TBAA node on the memcpy, which I did.
In a further patch, I think we should likely always use a memcpy since
LLVM seems to have a better time optimizing it than fir.load/fir.store
patterns.
fir.box_rank codegen was invalid, it was assuming the rank field in the
descriptor was an i32. This is not correct. Do not hard code the type,
use the named position to find the type, and convert as needed in the
patterns.
`SelectCaseOp::getCompareOperands` may return an empty range for the
"default" case. Do not dereference the range until it is expected to be
non-empty.
This was detected by address-sanitizer.
This PR add debug info for module variables. The module variables are
added as global variables but their scope is set to module instead of
compile unit. The scope of function declared inside a module is also set
accordingly.
After this patch, a module variable could be evaluated in the GDB as `p
helper::gli` where helper is name of the module and gli is the name of
the variable. A future patch will add the import module functionality
which will remove the need to prefix the name with helper::.
The line number where is module is declared is a best guess at the
moment as this information is not part of the GlobalOp.
This is same as #90905 with an added fix. The issue was that we
generated variable info even when user asked for line-tables-only. This
caused llvm dwarf generation code to fail an assertion as it expected an
empty variable list.
Fixed by not generating debug info for variables when user wants only
line table. I also updated a test check for this case.
We need the information in the `DeclareOp` to generate debug information
for variables. Currently, cg-rewrite removes the `DeclareOp`. As
`AddDebugInfo` runs after that, it cannot process the `DeclareOp`. My
initial plan was to make the `AddDebugInfo` pass run before the cg-rewrite
but that has few issues.
1. Initially I was thinking to use the memref op to carry the variable
attr. But as @tblah suggested in the #86939, it makes more sense to
carry that information on `DeclareOp`. It also makes it easy to handle
it in codegen and there is no special handling needed for arguments. For
this reason, we need to preserve the `DeclareOp` till the codegen.
2. Running earlier, we will miss the changes in passes that run between
cg-rewrite and codegen.
But not removing the DeclareOp in cg-rewrite has the issue that ShapeOp
remains and it causes errors during codegen. To solve this problem, I
convert DeclareOp to XDeclareOp in cg-rewrite instead of removing
it. This was mentioned as possible solution by @jeanPerier in
https://reviews.llvm.org/D136254
The conversion follows similar logic as used for other operators in that
file. The FortranAttr and CudaAttr are currently not converted but left
as TODO when the need arise.
Now `AddDebugInfo` pass can extracts information about local variables
from `XDeclareOp` and creates `DILocalVariableAttr`. These are attached
to `XDeclareOp` using `FusedLoc` approach. Codegen can use them to
create `DbgDeclareOp`. I have added tests that checks the debug
information in mlir from and also in llvm ir.
Currently we only handle very limited types. Rest are given a place
holder type. The previous placeholder type was basic type with
`DW_ATE_address` encoding. When variables are added, it started
causing assertions in the llvm debug info generation logic for some
types. It has been changed to an interger type to prevent these issues
until we handle those types properly.
I'm planning to remove StringRef::equals in favor of
StringRef::operator==.
- StringRef::operator==/!= outnumber StringRef::equals by a factor of
276 under llvm-project/ in terms of their usage.
- The elimination of StringRef::equals brings StringRef closer to
std::string_view, which has operator== but not equals.
- S == "foo" is more readable than S.equals("foo"), especially for
!Long.Expression.equals("str") vs Long.Expression != "str".
…ted. (#89998)" (#90250)
This partially reverts commit 7aedd7dc75.
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.
This PR extracts `FIROpConversion` and `FIROpAndTypeConversion`
templated base patterns to a header file. All the functions from
FIROpConversion that do not require the template argument are moved to a
base class named `ConvertFIRToLLVMPattern`.
This move is done so the `FIROpConversion` pattern and all its utility
functions can be reused outside of the codegen pass.
For the most part the code is only moved to the new files and not
modified. The only update is that addition of the PatternBenefit
argument with a default value to the constructor so it can be forwarded
to the `ConversionPattern` ctor.
This split is done in a similar way for the `ConvertOpToLLVMPattern`
base pattern that is based on the `ConvertToLLVMPattern` base class in
`mlir/include/mlir/Conversion/LLVMCommon/Pattern.h`.
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
