Verification of the LLVM IR produced when translating various MLIR dialects was
only active when calling the translation programmatically. This has led to
several cases of invalid LLVM IR being generated that could not be caught with
textual mlir-translate tests. Add verifiers for these cases and fix the tests
in preparation for enforcing the validation of LLVM IR.
Reviewed By: nicolasvasilache
Differential Revision: https://reviews.llvm.org/D96774
After the LLVM dialect types were ported to use built-in types, the parser kept
supporting the old syntax for LLVM dialect types to produce built-in types for
compatibility. Drop this support.
Reviewed By: mehdi_amini
Differential Revision: https://reviews.llvm.org/D96275
Historically, the Vector to LLVM dialect conversion subsumed the Standard to
LLVM dialect conversion patterns. This was necessary because the conversion
infrastructure did not have sufficient support for reconciling type
conversions. This support is now available. Only keep the patterns related to
the Vector dialect in the Vector to LLVM conversion and require type casts
operations to be inserted if necessary. These casts will be removed by
following conversions if possible. Update integration tests to also run the
Standard to LLVM conversion.
There is a significant amount of test churn, which is due to (a) unnecessarily
strict tests in VectorToLLVM and (b) many patterns actually targeting Standard
dialect ops instead of LLVM dialect ops leading to tests actually exercising a
Vector->Standard->LLVM conversion. This churn is a good illustration of the
reason to make the conversion partial: now the tests only check the code in the
Vector to LLVM conversion and will not be randomly broken by changes in
Standard to LLVM conversion.
Arguably, it may be possible to extract Vector to Standard patterns into a
separate pass, but given the ongoing splitting of the Standard dialect, such
pass will be short-lived and will require further refactoring.
Depends On D95626
Reviewed By: nicolasvasilache, aartbik
Differential Revision: https://reviews.llvm.org/D95685
It is no longer necessary to also convert other "standard" ops along with the
complex dialect: the element types are now built-in integers or floating point
types, and the top-level cast between complex and struct is automatically
inserted and removed in progressive lowering.
Reviewed By: herhut
Differential Revision: https://reviews.llvm.org/D95625
Continue the convergence between LLVM dialect and built-in types by using the
built-in vector type whenever possible, that is for fixed vectors of built-in
integers and built-in floats. LLVM dialect vector type is still in use for
pointers, less frequent floating point types that do not have a built-in
equivalent, and scalable vectors. However, the top-level `LLVMVectorType` class
has been removed in favor of free functions capable of inspecting both built-in
and LLVM dialect vector types: `LLVM::getVectorElementType`,
`LLVM::getNumVectorElements` and `LLVM::getFixedVectorType`. Additional work is
necessary to design an implemented the extensions to built-in types so as to
remove the `LLVMFixedVectorType` entirely.
Note that the default output format for the built-in vectors does not have
whitespace around the `x` separator, e.g., `vector<4xf32>` as opposed to the
LLVM dialect vector type format that does, e.g., `!llvm.vec<4 x fp128>`. This
required changing the FileCheck patterns in several tests.
Reviewed By: mehdi_amini, silvas
Differential Revision: https://reviews.llvm.org/D94405
Continue the convergence between LLVM dialect and built-in types by replacing
the bfloat, half, float and double LLVM dialect types with their built-in
counterparts. At the API level, this is a direct replacement. At the syntax
level, we change the keywords to `bf16`, `f16`, `f32` and `f64`, respectively,
to be compatible with the built-in type syntax. The old keywords can still be
parsed but produce a deprecation warning and will be eventually removed.
Depends On D94178
Reviewed By: mehdi_amini, silvas, antiagainst
Differential Revision: https://reviews.llvm.org/D94179
to the conversion of LLVM IR dialect. These attributes are used in FIR to
support the lowering of Fortran using target-specific calling conventions.
Add roundtrip tests.
Add changes per review comments/concerns.
Reviewed By: ftynse
Differential Revision: https://reviews.llvm.org/D94052
The LLVM dialect type system has been closed until now, i.e. did not support
types from other dialects inside containers. While this has had obvious
benefits of deriving from a common base class, it has led to some simple types
being almost identical with the built-in types, namely integer and floating
point types. This in turn has led to a lot of larger-scale complexity: simple
types must still be converted, numerous operations that correspond to LLVM IR
intrinsics are replicated to produce versions operating on either LLVM dialect
or built-in types leading to quasi-duplicate dialects, lowering to the LLVM
dialect is essentially required to be one-shot because of type conversion, etc.
In this light, it is reasonable to trade off some local complexity in the
internal implementation of LLVM dialect types for removing larger-scale system
complexity. Previous commits to the LLVM dialect type system have adapted the
API to support types from other dialects.
Replace LLVMIntegerType with the built-in IntegerType plus additional checks
that such types are signless (these are isolated in a utility function that
replaced `isa<LLVMType>` and in the parser). Temporarily keep the possibility
to parse `!llvm.i32` as a synonym for `i32`, but add a deprecation notice.
Reviewed By: mehdi_amini, silvas, antiagainst
Differential Revision: https://reviews.llvm.org/D94178
the conversion of LLVM IR dialect. These attributes are used in FIR to
support the lowering of Fortran using target-specific calling
conventions.
Add roundtrip tests. Add changes per review comments/concerns.
Reviewed By: ftynse
Differential Revision: https://reviews.llvm.org/D94052
LLVM dialect type parsing and printing have been using a local stack object
forwarded between recursive functions responsible for parsing or printing
specific types. This stack is necessary to intercept (mutually) recursive
structure types and avoid inifinite recursion. This approach works only thanks
to the closedness of the LLVM dialect type system: types that don't belong to
the dialect are not allowed. Switch the approach to using a `thread_local`
stack inside the functions parsing the structure types. This makes the code
slightly cleaner by avoiding the need to pass the stack object around and, more
importantly, makes it possible to reconsider the closedness of the LLVM dialect
type system. As a nice side effect of this change, container LLVM dialect types
now support type aliases in their body (although it is currently impossible to
also use the alises when printing).
Depends On D93713
Reviewed By: mehdi_amini
Differential Revision: https://reviews.llvm.org/D93714
BEGIN_PUBLIC
[mlir] Remove LLVMType, LLVM dialect types now derive Type directly
This class has become a simple `isa` hook with no proper functionality.
Removing will allow us to eventually make the LLVM dialect type infrastructure
open, i.e., support non-LLVM types inside container types, which itself will
make the type conversion more progressive.
Introduce a call `LLVM::isCompatibleType` to be used instead of
`isa<LLVMType>`. For now, this is strictly equivalent.
END_PUBLIC
Depends On D93681
Reviewed By: mehdi_amini
Differential Revision: https://reviews.llvm.org/D93713
LLVMType contains multiple instance methods that were introduced initially for
compatibility with LLVM API. These methods boil down to `cast` followed by
type-specific call. Arguably, they are mostly used in an LLVM cast-follows-isa
anti-pattern. This doesn't connect nicely to the rest of the MLIR
infrastructure and actively prevents it from making the LLVM dialect type
system more open, e.g., reusing built-in types when appropriate. Remove such
instance methods and replaces their uses with apporpriate casts and methods on
derived classes. In some cases, the result may look slightly more verbose, but
most cases should actually use a stricter subtype of LLVMType anyway and avoid
the isa/cast.
Reviewed By: mehdi_amini
Differential Revision: https://reviews.llvm.org/D93680
The LLVM IR 'switch' instruction allows control flow to be transferred
to one of any number of branches depending on an integer control value,
or a default value if the control does not match any branch values. This patch
adds `llvm.switch` to the MLIR LLVMIR dialect, as well as translation routines
for lowering it to LLVM IR.
To store a variable number of operands for a variable number of branch
destinations, the new op makes use of the `AttrSizedOperandSegments`
trait. It stores its default branch operands as one segment, and all
remaining case branches' operands as another. It also stores pairs of
begin and end offset values to delineate the sub-range of each case branch's
operands. There's probably a better way to implement this, since the
offset computation complicates several parts of the op definition. This is the
approach I settled on because in doing so I was able to delegate to the default
op builder member functions. However, it may be preferable to instead specify
`skipDefaultBuilders` in the op's ODS, or use a completely separate
approach; feedback is welcome!
Another contentious part of this patch may be the custom printer and
parser functions for the op. Ideally I would have liked the MLIR to be
printed in this way:
```
llvm.switch %0, ^bb1(%1 : !llvm.i32) [
1: ^bb2,
2: ^bb3(%2, %3 : !llvm.i32, !llvm.i32)
]
```
The above would resemble how LLVM IR is formatted for the 'switch'
instruction. But I found it difficult to print and parse something like
this, whether I used the declarative assembly format or custom functions.
I also was not sure a multi-line format would be welcome -- it seems
like most MLIR ops do not use newlines. Again, I'd be happy to hear any
feedback here as well, or on any other aspect of the patch.
Differential Revision: https://reviews.llvm.org/D93005
This operation is designed to support partial conversion, more specifically the
IR state in which some operations expect or produce built-in types and some
operations produce and expect LLVM dialect types. It is reasonable for it to
support cast between built-in types and any equivalent that could be produced
by the type conversion. (At the same time, we don't want the dialect to depend
on the type conversion as it could lead to a dependency cycle). Introduce
support for casting from index to any integer type and back, and from memref to
bare pointer or memref descriptor type and back.
Contrary to what the TODO in the code stated, there are no particular
precautions necessary to handle the bare pointer conversion for memerfs. This
conversion applies exclusively to statically-shaped memrefs, so we can always
recover the full descriptor contents from the type.
This patch simultaneously tightens the verification for other types to only
accept matching pairs of types, e.g., i64 and !llvm.i64, as opposed to the
previous implementation that only checked if the types were generally allowed
byt not for matching, e.g. i64 could be "casted" to !llvm.bfloat, which is not
the intended semantics.
Move the relevant test under test/Dialect/LLVMIR because it is not specific to
the conversion pass, but rather exercises an op in the dialect. If we decide
this op does not belong to the LLVM dialect, both the dialect and the op should
move together.
Reviewed By: silvas, ezhulenev
Differential Revision: https://reviews.llvm.org/D93405
Now that we have predicates for LLVM dialect types in ODS, we can use them to
restrict the types allowed in results of LLVM dialect operations. This also
serves as additional documentation for these operations.
Reviewed By: rriddle
Differential Revision: https://reviews.llvm.org/D93329
The InlineAsmOp mirrors the underlying LLVM semantics with a notable
exception: the embedded `asm_string` is not allowed to define or reference
any symbol or any global variable: only the operands of the op may be read,
written, or referenced.
Attempting to define or reference any symbol or any global behavior is
considered undefined behavior at this time.
The asm dialect syntax is currently specified with an integer (0 [default] for the "att dialect", 1 for the intel dialect) to circumvent the ODS limitation on string enums.
Translation to LLVM is provided and raises the fact that the asm constraints string must be well-formed with respect to in/out operands. No check is performed on the asm_string.
An InlineAsm instruction in LLVM is a special call operation to a function that is constructed on the fly.
It does not fit the current model of MLIR calls with symbols.
As a consequence, the current implementation constructs the function type in ModuleTranslation.cpp.
This should be refactored in the future.
The mlir-cpu-runner is augmented with the global initialization of the X86 asm parser to allow proper execution in JIT mode. Previously, only the X86 asm printer was initialized.
Differential revision: https://reviews.llvm.org/D92166
The alignment attribute in the 'alloca' op treats the '0' value as 'unset'.
When parsing the custom form of the 'alloca' op, ignore the alignment attribute
with if its value is '0' instead of actually creating it and producing a
slightly different textually yet equivalent semantically form in the output.
Reviewed By: rriddle
Differential Revision: https://reviews.llvm.org/D90179
This aligns the behavior with the standard call as well as the LLVM verifier.
Reviewed By: ftynse, dcaballe
Differential Revision: https://reviews.llvm.org/D88362
Historically, the operations in the MLIR's LLVM dialect only checked that the
operand are of LLVM dialect type without more detailed constraints. This was
due to LLVM dialect types wrapping LLVM IR types and having clunky verification
methods. With the new first-class modeling, it is possible to define type
constraints similarly to other dialects and use them to enforce some
correctness rules in verifiers instead of having LLVM assert during translation
to LLVM IR. This hardening discovered several issues where MLIR was producing
LLVM dialect operations that cannot exist in LLVM IR.
Depends On D85900
Reviewed By: rriddle
Differential Revision: https://reviews.llvm.org/D85901
Unsigned and Signless attributes use uintN_t and signed attributes use intN_t, where N is the fixed width. The 1-bit variants use bool.
Differential Revision: https://reviews.llvm.org/D86739
According to the LLVM Language Reference, 'cmpxchg' accepts integer or pointer
types. Several MLIR tests were using it with floats as it appears possible to
programmatically construct and print such an instruction, but it cannot be
parsed back. Use integers instead.
Depends On D85899
Reviewed By: flaub, rriddle
Differential Revision: https://reviews.llvm.org/D85900
Legacy implementation of the LLVM dialect in MLIR contained an instance of
llvm::Module as it was required to parse LLVM IR types. The access to the data
layout of this module was exposed to the users for convenience, but in practice
this layout has always been the default one obtained by parsing an empty layout
description string. Current implementation of the dialect no longer relies on
wrapping LLVM IR types, but it kept an instance of DataLayout for
compatibility. This effectively forces a single data layout to be used across
all modules in a given MLIR context, which is not desirable. Remove DataLayout
from the LLVM dialect and attach it as a module attribute instead. Since MLIR
does not yet have support for data layouts, use the LLVM DataLayout in string
form with verification inside MLIR. Introduce the layout when converting a
module to the LLVM dialect and keep the default "" description for
compatibility.
This approach should be replaced with a proper MLIR-based data layout when it
becomes available, but provides an immediate solution to compiling modules with
different layouts, e.g. for GPUs.
This removes the need for LLVMDialectImpl, which is also removed.
Depends On D85650
Reviewed By: aartbik
Differential Revision: https://reviews.llvm.org/D85652
Now that LLVM dialect types are implemented directly in the dialect, we can use
MLIR hooks for verifying type construction invariants. Implement the verifiers
and use them in the parser.
Reviewed By: rriddle
Differential Revision: https://reviews.llvm.org/D85663
This dialect was introduced during the bring-up of the new LLVM dialect type
system for testing purposes. The main LLVM dialect now uses the new type system
and the test dialect is no longer necessary, so remove it.
Reviewed By: rriddle
Differential Revision: https://reviews.llvm.org/D85224
A new first-party modeling for LLVM IR types in the LLVM dialect has been
developed in parallel to the existing modeling based on wrapping LLVM `Type *`
instances. It resolves the long-standing problem of modeling identified
structure types, including recursive structures, and enables future removal of
LLVMContext and related locking mechanisms from LLVMDialect.
This commit only switches the modeling by (a) renaming LLVMTypeNew to LLVMType,
(b) removing the old implementaiton of LLVMType, and (c) updating the tests. It
is intentionally minimal. Separate commits will remove the infrastructure built
for the transition and update API uses where appropriate.
Depends On D85020
Reviewed By: rriddle
Differential Revision: https://reviews.llvm.org/D85021
The current modeling of LLVM IR types in MLIR is based on the LLVMType class
that wraps a raw `llvm::Type *` and delegates uniquing, printing and parsing to
LLVM itself. This model makes thread-safe type manipulation hard and is being
progressively replaced with a cleaner MLIR model that replicates the type
system. Introduce a set of classes reflecting the LLVM IR type system in MLIR
instead of wrapping the existing types. These are currently introduced as
separate classes without affecting the dialect flow, and are exercised through
a test dialect. Once feature parity is reached, the old implementation will be
gradually substituted with the new one.
Depends On D84171
Reviewed By: rriddle
Differential Revision: https://reviews.llvm.org/D84339
`llvm.mlir.constant` was originally introduced as an LLVM dialect counterpart
to `std.constant`. As such, it was supporting "function pointer" constants
derived from the symbol name. This is different from `std.constant` that allows
for creation of a "function" constant since MLIR, unlike LLVM IR, supports
this. Later, `llvm.mlir.addressof` was introduced as an Op that obtains a
constant pointer to a global in the LLVM dialect. It naturally extends to
functions (in LLVM IR, functions are globals) and should be used for defining
"function pointer" values instead.
Fixes PR46344.
Differential Revision: https://reviews.llvm.org/D82667
This test largely predates MLIR testing guidelines. Update it to match the
guidelines. In particular, avoid pattern-matching SSA value names, avoid
unnecessary CHECK-NEXT, relax assumptions about the form of SSA names.
Value-returning operations are still matched agaist _any_ name in order to
check that the operation indeed produces values.
Differential Revision: https://reviews.llvm.org/D82656
Initially, unranked memref descriptors in the LLVM dialect were designed only
to be passed into functions. An assertion was guarding against returning
unranked memrefs from functions in the standard-to-LLVM conversion. This is
insufficient for functions that wish to return an unranked memref such that the
caller does not know the rank in advance, and hence cannot allocate the
descriptor and pass it in as an argument.
Introduce a calling convention for returning unranked memref descriptors as
follows. An unranked memref descriptor always points to a ranked memref
descriptor stored on stack of the current function. When an unranked memref
descriptor is returned from a function, the ranked memref descriptor it points
to is copied to dynamically allocated memory, the ownership of which is
transferred to the caller. The caller is responsible for deallocating the
dynamically allocated memory and for copying the pointed-to ranked memref
descriptor onto its stack.
Provide default lowerings for std.return, std.call and std.indirect_call that
maintain the conversion defined above.
This convention is additionally exercised by a runtime test to guard against
memory errors.
Differential Revision: https://reviews.llvm.org/D82647
Introduced `llvm.intr.bitreverse` and `llvm.intr.ctpop` LLVM bit
intrinsics to LLVM dialect. These intrinsics help with SPIR-V to
LLVM conversion, allowing a direct mapping from `spv.BitReverse`
and `spv.BitCount` respectively. Tests are added to `roundtrip.mlir`
and `llvm-intrinsics.mlir`.
Differential Revision: https://reviews.llvm.org/D82285
Summary:
With this change, a function argument attribute of the form
"llvm.align" = <int> will be translated to the corresponding align
attribute in LLVM by the ModuleConversion.
Differential Revision: https://reviews.llvm.org/D82161
This allows verifying op-indepent attributes (e.g., attributes that do not require the op to have been created) before constructing an operation. These include checking whether required attributes are defined or constraints on attributes (such as I32 attribute). This is not perfect (e.g., if one had a disjunctive constraint where one part relied on the op and the other doesn't, then this would not try and extract the op independent from the op dependent).
The next step is to move these out to a trait that could be verified earlier than in the generated method. The first use case is for inferring the return type while constructing the op. At that point you don't have an Operation yet and that ends up in one having to duplicate the same checks, e.g., verify that attribute A is defined before querying A in shape function which requires that duplication. Instead this allows one to invoke a method to verify all the traits and, if this is checked first during verification, then all other traits could use attributes knowing they have been verified.
It is a little bit funny to have these on the adaptor, but I see the adaptor as a place to collect information about the op before the op is constructed (e.g., avoiding stringly typed accessors, verifying what is possible to verify before the op is constructed) while being cheap to use even with constructed op (so layer of indirection between the op constructed/being constructed). And from that point of view it made sense to me.
Differential Revision: https://reviews.llvm.org/D80842
Similarly to actual LLVM IR, and to `llvm.mlir.func`, allow the custom syntax
of `llvm.mlir.global` to omit the linkage keyword. If omitted, the linkage is
assumed to be external. This makes the modeling of globals in the LLVM dialect
more consistent, both within the dialect and with LLVM IR.
Differential Revision: https://reviews.llvm.org/D78096
Summary: This revision adds support for marking the last region as variadic in the ODS region list with the VariadicRegion directive.
Differential Revision: https://reviews.llvm.org/D77455
MLIR supports terminators that have the same successor block with different
block operands, which cannot be expressed in the LLVM's phi-notation as the
block identifier is used to tell apart the predecessors. This limitation can be
worked around by branching to a new block instead, with this new block
unconditionally branching to the original successor and forwarding the
argument. Until now, this transformation was performed during the conversion
from the Standard to the LLVM dialect. This does not scale well to multiple
dialects targeting the LLVM dialect as all of them would have to be aware of
this limitation and perform the preparatory transformation. Instead, do it as a
separate pass and run it immediately before the translation.
Differential Revision: https://reviews.llvm.org/D75619
