Non-32-bit scalar types requires special hardware support that may
not exist on all Vulkan-capable GPUs. This is reflected as non-32-bit
scalar types require special capabilities or extensions to be used.
This commit makes SPIRVTypeConverter target environment aware so
that it can properly convert standard types to what is accepted on
the target environment.
Right now if a scalar type bitwidth is not supported in the target
environment, we use 32-bit unconditionally. This requires Vulkan
runtime to also feed in data with a matched bitwidth and layout,
especially for interface types. The Vulkan runtime can do that by
inspecting the SPIR-V module. Longer term, we might want to introduce
a way to control how such case are handled and explicitly fail
if wanted.
Differential Revision: https://reviews.llvm.org/D76244
Types should be checked with the type hierarchy. This should result in
better responsibility division and API surface.
Differential Revision: https://reviews.llvm.org/D76243
This commit unifies target environment queries into a new wrapper
class spirv::TargetEnv and shares across various places needing
the functionality. We still create multiple instances of TargetEnv
though given the parent components (type converters, passes,
conversion targets) have different lifetimes.
In the meantime, LowerABIAttributesPass is updated to take into
consideration the target environment, which requires updates to
tests to provide that.
Differential Revision: https://reviews.llvm.org/D76242
Previously we only consider the version/extension/capability requirement
on the op itself. This commit updates SPIRVConversionTarget to also
take into consideration the values' types when deciding op legality.
Differential Revision: https://reviews.llvm.org/D75876
Previously in SPIRVTypeConverter, we always convert memref types
to StorageBuffer regardless of their memory spaces. This commit
fixes that to let the conversion to look into memory space
properly. For this purpose, a mapping between SPIR-V storage class
and memref memory space is introduced. The mapping is arbitary
decided at the moment and the hope is that we can leverage
string memory space later to be more clear.
Now spv.interface_var_abi cannot contain storage class unless it's
attached to a scalar value, where we need the storage class as side
channel information. Verifications and tests are properly adjusted.
Differential Revision: https://reviews.llvm.org/D76241
Summary:
This revision refactors the TypeConverter class to not use inheritance to add type conversions. It instead moves to a registration based system, where conversion callbacks are added to the converter with `addConversion`. This method takes a conversion callback, which must be convertible to any of the following forms(where `T` is a class derived from `Type`:
* Optional<Type> (T type)
- This form represents a 1-1 type conversion. It should return nullptr
or `llvm::None` to signify failure. If `llvm::None` is returned, the
converter is allowed to try another conversion function to perform
the conversion.
* Optional<LogicalResult>(T type, SmallVectorImpl<Type> &results)
- This form represents a 1-N type conversion. It should return
`failure` or `llvm::None` to signify a failed conversion. If the new
set of types is empty, the type is removed and any usages of the
existing value are expected to be removed during conversion. If
`llvm::None` is returned, the converter is allowed to try another
conversion function to perform the conversion.
When attempting to convert a type, the TypeConverter walks each of the registered converters starting with the one registered most recently.
Differential Revision: https://reviews.llvm.org/D74584
Thus far we have been using builtin func op to model SPIR-V functions.
It was because builtin func op used to have special treatment in
various parts of the core codebase (e.g., pass pipelines, etc.) and
it's easy to bootstrap the development of the SPIR-V dialect. But
nowadays with general op concepts and region support we don't have
such limitations and it's time to tighten the SPIR-V dialect for
completeness.
This commits introduces a spv.func op to properly model SPIR-V
functions. Compared to builtin func op, it can provide the following
benefits:
* We can control the full op so we can integrate SPIR-V information
bits (e.g., function control) in a more integrated way and define
our own assembly form and enforcing better verification.
* We can have a better dialect and library boundary. At the current
moment only functions are modelled with an external op. With this
change, all ops modelling SPIR-V concpets will be spv.* ops and
registered to the SPIR-V dialect.
* We don't need to special-case func op anymore when creating
ConversionTarget declaring SPIR-V dialect as legal. This is quite
important given we'll see more and more conversions in the future.
In the process, bumps a few FuncOp methods to the FunctionLike trait.
Differential Revision: https://reviews.llvm.org/D74226
We were using normal dictionary attribute for target environment
specification. It becomes cumbersome with more and more fields.
This commit changes the modelling to a dialect-specific attribute,
where we can have control over its storage and assembly form.
Differential Revision: https://reviews.llvm.org/D73959
This commit adds a pattern to lower linalg.generic for reduction
to spv.GroupNonUniform* ops. Right now this only supports integer
reduction on 1-D input memref. Shader entry point ABI is queried
to make sure that the input memref's shape matches the local
workgroup's invocation configuration. This makes sure that the
workload fits in one local workgroup so that we can leverage
SPIR-V group non-uniform operations.
linglg.generic is a structured op that preserves the right level
of information. It is easier to recognize reduction at this level
than performing analysis on loops.
This commit also exposes `getElementPtr` in SPIRVLowering.h given
that it's a generally useful utility function.
Differential Revision: https://reviews.llvm.org/D73437
This commit changes the logic of `getBuiltinVariableValue` to get
or create the builtin variable in the nearest symbol table. This
will allow us to use this function in other partial conversion
cases where we haven't created the spv.module yet.
Differential Revision: https://reviews.llvm.org/D73416
This commit exposes the func op conversion pattern via a new
`populateBuiltinFuncToSPIRVPatterns` function from the standard
to SPIR-V conversion passs. This is structurally better given
that func op belongs to the builtin dialect. More importantly,
this makes the pattern reusable to other dialect to SPIR-V
dialect conversion as other dialect can well adopt builtin
func op instead of having its own. Besides, it's very common
to use func ops as test wrappers in lit tests, so test passes
will need to handle func ops too.
Differential Revision: https://reviews.llvm.org/D73421
Add lowering for constant operation with ranked tensor type to
spv.constant with spv.array type.
Differential Revision: https://reviews.llvm.org/D73022
This makes the local variable `implies` to have the correct
type to satisfy ArrayRef's constructor:
/*implicit*/ constexpr ArrayRef(const T (&Arr)[N])
Hopefully this should please GCC 5.
Differential Revision: https://reviews.llvm.org/D72924
In SPIR-V, when a new version is introduced, it is possible some
existing extensions will be incorporated into it so that it becomes
implicitly declared if targeting the new version. This affects
conversion target specification because we need to take this into
account when allowing what extensions to use.
For a capability, it may also implies some other capabilities,
for example, the `Shader` capability implies `Matrix` the capability.
This should also be taken into consideration when preparing the
conversion target: when we specify an capability is allowed, all
its recursively implied capabilities are also allowed.
This commit adds utility functions to query implied extensions for
a given version and implied capabilities for a given capability
and updated SPIRVConversionTarget to use them.
This commit also fixes a bug in availability spec. When a symbol
(op or enum case) can be enabled by an extension, we should drop
it's minimal version requirement. Being enabled by an extension
naturally means the symbol can be used by *any* SPIR-V version
as long as the extension is supported. The grammar still encodes
the 'version' field for such cases, but it should be interpreted
as a different way: rather than meaning a minimal version
requirement, it says the symbol becomes core at that specific
version.
Differential Revision: https://reviews.llvm.org/D72765
This commit defines a new SPIR-V dialect attribute for specifying
a SPIR-V target environment. It is a dictionary attribute containing
the SPIR-V version, supported extension list, and allowed capability
list. A SPIRVConversionTarget subclass is created to take in the
target environment and sets proper dynmaically legal ops by querying
the op availability interface of SPIR-V ops to make sure they are
available in the specified target environment. All existing conversions
targeting SPIR-V is changed to use this SPIRVConversionTarget. It
probes whether the input IR has a `spv.target_env` attribute,
otherwise, it uses the default target environment: SPIR-V 1.0 with
Shader capability and no extra extensions.
Differential Revision: https://reviews.llvm.org/D72256
This allows us to include the definitions of these attributes in
other files without pulling in all dependencies for lowering.
Reviewed By: mravishankar
Differential Revision: https://reviews.llvm.org/D72054
This is an initial step to refactoring the representation of OpResult as proposed in: https://groups.google.com/a/tensorflow.org/g/mlir/c/XXzzKhqqF_0/m/v6bKb08WCgAJ
This change will make it much simpler to incrementally transition all of the existing code to use value-typed semantics.
PiperOrigin-RevId: 286844725
This updates the lowering pipelines from the GPU dialect to lower-level
dialects (NVVM, SPIRV) to use the recently introduced gpu.func operation
instead of a standard function annotated with an attribute. In particular, the
kernel outlining is updated to produce gpu.func instead of std.func and the
individual conversions are updated to consume gpu.funcs and disallow standard
funcs after legalization, if necessary. The attribute "gpu.kernel" is preserved
in the generic syntax, but can also be used with the custom syntax on
gpu.funcs. The special kind of function for GPU allows one to use additional
features such as memory attribution.
PiperOrigin-RevId: 285822272
Add some convenience build methods to SPIR-V ops and update the
lowering to use these methods where possible.
For SPIRV::CompositeExtractOp move the method to deduce type of
element based on base and indices into a convenience function. Some
additional functionality needed to handle differences between parsing
and verification methods.
PiperOrigin-RevId: 284794404
The existing GPU to SPIR-V lowering created a spv.module for every
function with gpu.kernel attribute. A better approach is to lower the
module that the function lives in (which has the attribute
gpu.kernel_module) to a spv.module operation. This better captures the
host-device separation modeled by GPU dialect and simplifies the
lowering as well.
PiperOrigin-RevId: 284574688
The SPIR-V lowering used nested !spv.arrays to represented
multi-dimensional arrays, with the hope that in-conjunction with the
layout annotations, the shape and layout of memref can be represented
directly. It is unclear though how portable this representation will
end up being. It will rely on driver compilers implementing complex
index computations faithfully. A more portable approach is to use
linearized arrays to represent memrefs and explicitly instantiate all
the index computation in SPIR-V. This gives added benefit that we can
further optimize the generated code in MLIR before generating the
SPIR-V binary.
PiperOrigin-RevId: 283571167
Updated comments and used static instead of anonymous namspace
to hide functions to be consistent with the existing codebase.
PiperOrigin-RevId: 282847784
These changes to SPIR-V lowering while adding support for lowering
SUbViewOp, but are not directly related.
- Change the lowering of MemRefType to
!spv.ptr<!spv.struct<!spv.array<...>[offset]>, ..>
This is consistent with the Vulkan spec.
- To enable testing a simple pattern of lowering functions is added to
ConvertStandardToSPIRVPass. This is just used to convert the type of
the arguments of the function. The added function lowering itself is
not meant to be the way functions are eventually lowered into SPIR-V
dialect.
PiperOrigin-RevId: 282589644
To simplify the lowering into SPIR-V, while still respecting the ABI
requirements of SPIR-V/Vulkan, split the process into two
1) While lowering a function to SPIR-V (when the function is an entry
point function), allow specifying attributes on arguments and
function itself that describe the ABI of the function.
2) Add a pass that materializes the ABI described in the function.
Two attributes are needed.
1) Attribute on arguments of the entry point function that describe
the descriptor_set, binding, storage class, etc, of the
spv.globalVariable this argument will be replaced by
2) Attribute on function that specifies workgroup size, etc. (for now
only workgroup size).
Add the pass -spirv-lower-abi-attrs to materialize the ABI described
by the attributes.
This change makes the SPIRVBasicTypeConverter class unnecessary and is
removed, further simplifying the SPIR-V lowering path.
PiperOrigin-RevId: 282387587
Refactoring the conversion from StandardOps/GPU dialect to SPIR-V
dialect:
1) Move the SPIRVTypeConversion and SPIRVOpLowering class into SPIR-V
dialect.
2) Add header files that expose functions to add patterns for the
dialects to SPIR-V lowering, as well as a pass that does the
dialect to SPIR-V lowering.
3) Make SPIRVOpLowering derive from OpLowering class.
PiperOrigin-RevId: 280486871
