This CL extends declarative rewrite rules to support matching and
generating ops with variadic operands/results. For this, the
generated `matchAndRewrite()` method for each pattern now are
changed to
* Use "range" types for the local variables used to store captured
values (`operand_range` for operands, `ArrayRef<Value *>` for
values, *Op for results). This allows us to have a unified way
of handling both single values and value ranges.
* Create local variables for each operand for op creation. If the
operand is variadic, then a `SmallVector<Value*>` will be created
to collect all values for that operand; otherwise a `Value*` will
be created.
* Use a collective result type builder. All result types are
specified via a single parameter to the builder.
We can use one result pattern to replace multiple results of the
matched root op. When that happens, it will require specifying
types for multiple results. Add a new collective-type builder.
PiperOrigin-RevId: 264588559
Previously we use one single method with lots of branches to
generate multiple builders. This makes the method difficult
to follow and modify. This CL splits the method into multiple
dedicated ones, by extracting common logic into helper methods
while leaving logic specific to each builder in their own
methods.
PiperOrigin-RevId: 261011082
Some operations need to override the default behavior of builders, in
particular region-holding operations such as affine.for or tf.graph want to
inject default terminators into the region upon construction, which default
builders won't do. Provide a flag that disables the generation of default
builders so that the custom builders could use the same function signatures.
This is an intentionally low-level and heavy-weight feature that requires the
entire builder to be implemented, and it should be used sparingly. Injecting
code into the end of a default builder would depend on the naming scheme of the
default builder arguments that is not visible in the ODS. Checking that the
signature of a custom builder conflicts with that of a default builder to
prevent emission would require teaching ODG to differentiate between types and
(optional) argument names in the generated C++ code. If this flag ends up
being used a lot, we should consider adding traits that inject specific code
into the default builder.
PiperOrigin-RevId: 256640069
This CL enables verification code generation for variadic operands and results.
In verify(), we use fallback getter methods to access all the dynamic values
belonging to one static variadic operand/result to reuse the value range
calculation there.
PiperOrigin-RevId: 252288219
This CL added getODSOperands() and getODSResults() as fallback getter methods for
getting all the dynamic values corresponding to a static operand/result (which
can be variadic). It should provide a uniform way of calculating the value ranges.
All named getter methods are layered on top of these methods now.
PiperOrigin-RevId: 252284270
Considered adding more placeholders to designate types in the replacement pattern, but convinced for now sticking to simpler approach. This should at least enable specifying constraints across operands/results/attributes and we can start getting rid of the special cases.
PiperOrigin-RevId: 251564893
When manipulating generic operations, such as in dialect conversion /
rewriting, it is often necessary to view a list of Values as operands to an
operation without creating the operation itself. The absence of such view
makes dialect conversion patterns, among others, to use magic numbers to obtain
specific operands from a list of rewritten values when converting an operation.
Introduce XOpOperandAdaptor classes that wrap an ArrayRef<Value *> and provide
accessor functions identical to those available in XOp. This makes it possible
for conversions to use these adaptors to address the operands with names rather
than rely on their position in the list. The adaptors are generated from ODS
together with the actual operation definitions.
This is another step towards making dialect conversion patterns specific for a
given operation.
Illustrate the approach on conversion patterns in the standard to LLVM dialect
conversion.
PiperOrigin-RevId: 251232899
Similar to arguments and results, now we require region definition in ops to
be specified as a DAG expression with the 'region' operator. This way we can
specify the constraints for each region and optionally give the region a name.
Two kinds of region constraints are added, one allowing any region, and the
other requires a certain number of blocks.
--
PiperOrigin-RevId: 250790211
This allow specifying $x to refer to an operand's named argument (operand or attribute) or result. Skip variadic operands/results for now pending autogenerated discussion of their accessors.
This adds a new predicate, following feedback on the naming but does not remove the old one. Post feedback I'll do that, potentially in follow up.
--
PiperOrigin-RevId: 250720003
Previously we force the C++ namespaces to be `NS` if `SomeOp` is defined as
`NS_SomeOp`. This is too rigid as it does not support nested namespaces
well. This CL adds a "namespace" field into the Dialect class to allow
flexible namespaces.
--
PiperOrigin-RevId: 249064981
If the attribute needs to exist for the validity of the op, then no need to use
dyn_cast_or_null as the op would be invalid in the cases where cast fails, so
just use cast.
--
PiperOrigin-RevId: 247617696
Simple mechanism to allow specifying arbitrary function declarations. The modelling will not cover all cases so allow a means for users to declare a method function that they will define in their C++ files. The goal is to allow full C++ flexibility as the goal is to cover cases not modelled.
--
PiperOrigin-RevId: 245889819
Certain ops can have multiple variadic operands/results, e.g., `tf.DynamicStitch`.
Even if an op has only one variadic operand/result, it is not necessarily the
very last one, e.g., `tf.RaggedGather`. This CL enhances TableGen subsystem to be
able to represent such cases.
In order to deduce the operand/result value range for each variadic operand,
currently we only support variadic operands/results all of the same size.
So two new traits, `SameVariadicOperandSize` and `SameVariadicResultSize` are
introduced.
--
PiperOrigin-RevId: 245310628
For ops with the SameValueType trait, we generate a builder without requiring
result type; we get the result type from the operand. However, if the operand
is variadic, we need to index into the first value in the pack.
--
PiperOrigin-RevId: 243866647
Now, op attribute names don't have '.' in their names so the special handling for it
can be removed. Attributes for functions still have dialect prefix with '.' as separator but TableGen does not deal with functions.
TESTED with existing unit tests
--
PiperOrigin-RevId: 243287462
This CL changes various predicates and rewrite rules to use $-placeholders and
`tgfmt` as the driver for substitution. This will make the predicates and rewrite
rules more consistent regarding their arguments and more readable.
--
PiperOrigin-RevId: 243250739
Previously we bundle the existence check and the MLIR attribute kind check
in one call. Further constraints (like element bitwidth) have to be split
into following checks. That is not a nice separation given that we have more
checks for constraints. Instead, this CL changes to generate a local variable
for every attribute, check its existence first, then check the constraints.
Creating a local variable for each attribute also avoids querying it multiple
times using the raw getAttr() API. This is a win for both performance the
readability of the generated code.
This CL also changed the error message to be more greppable by delimiting
the error message from constraints with boilerplate part with colon.
--
PiperOrigin-RevId: 241906132
Attributes can have default values or be optional. Checking the validity of
attributes in aggregate builder should consider that. And to be accurate,
we should check all required attributes are indeed provided in the list.
This is actually duplicating the work done by verifier. Checking the validity
of attributes should be the responsiblity of verifiers. This CL removes
the assertion for attributes in aggregate builders for the above reason.
(Assertions for operands/results are still kept since they are trivial.)
Also added more tests for aggregate builders.
--
PiperOrigin-RevId: 241746059
The `Builder*` parameter is unused in both generated build() methods so that we can
leave it unnamed. Changed stand-alone parameter build() to take `_tblgen_state` instead
of `result` to allow `result` to avoid having name collisions with op operand,
attribute, or result.
PiperOrigin-RevId: 240637700
Before this CL, the result type of the pattern match results need to be as same
as the first operand type, operand broadcast type or a generic tensor type.
This CL adds a new trait to set the result type by attribute. For example, the
TFL_ConstOp can use this to set the output type to its value attribute.
PiperOrigin-RevId: 240441249
inherited constructors, which is cleaner and means you can now use DimOp()
to get a null op, instead of having to use Instruction::getNull<DimOp>().
This removes another 200 lines of code.
PiperOrigin-RevId: 240068113
This should probably be changed to instead use the negated form (e.g., get predicate + negate it + get resulting template), but this fixes it locally.
PiperOrigin-RevId: 240067116
tblgen be non-const. This requires introducing some const_cast's at the
moment, but those (and lots more stuff) will disappear in subsequent patches.
This significantly simplifies those patches because the various tblgen op emitters
get adjusted.
PiperOrigin-RevId: 239954566
Previously we emit both op declaration and definition into one file and include it
in *Ops.h. That pulls in lots of implementation details in the header file and we
cannot hide symbols local to implementation. This CL splits them to provide a cleaner
interface.
The way how we define custom builders in TableGen is changed accordingly because now
we need to distinguish signatures and implementation logic. Some custom builders with
complicated logic now can be moved to be implemented in .cpp entirely.
PiperOrigin-RevId: 239509594
Previously Value was a pair of name & Type, but for operands/result a TypeConstraint rather then a Type is specified. Update C++ side to match declarative side.
PiperOrigin-RevId: 238984799
The LLVM IR Dialect strives to be close to the original LLVM IR instructions.
The conversion from the LLVM IR Dialect to LLVM IR proper is mostly mechanical
and can be automated. Implement TableGen support for generating conversions
from a concise pattern form in the TableGen definition of the LLVM IR Dialect
operations. It is used for all operations except calls and branches. These
operations need access to function and block remapping tables and would require
significantly more code to generate the conversions from TableGen definitions
than the current manually written conversions.
This implementation is accompanied by various necessary changes to the TableGen
operation definition infrastructure. In particular, operation definitions now
contain named accessors to results as well as named accessors to the variadic
operand (returning a vector of operands). The base operation support TableGen
file now contains a FunctionAttr definition. The TableGen now allows to query
the names of the operation results.
PiperOrigin-RevId: 237203077
The existing implementation of the Op definition generator assumes and relies
on the fact that native Op Attributes appear after its value-based operands in
the Arguments list. Furthermore, the same order is used in the generated
`build` function for the operation. This is not desirable for some operations
with mandatory attributes that would want the attribute to appear upfront for
better consistency with their textual representation, for example `cmpi` would
prefer the `predicate` attribute to be foremost in the argument list.
Introduce support for using attributes and operands in the Arguments DAG in no
particular order. This is achieved by maintaining a list of Arguments that
point to either the value or the attribute and are used to generate the `build`
method.
PiperOrigin-RevId: 237002921
The recently introduced support for generating MLIR Operations with optional
attributes did not handle the formatted string emission properly, in particular
it did not escape `{` and `}` in calls to `formatv` leading to assertions
during TableGen op definition generation. Fix this by splitting out the
unncessary braces from the format string. Additionally, fix the emission of
the builder argument comment to correctly indicate which attributes are indeed
optional and which are not.
PiperOrigin-RevId: 236832230
The only reason in starting with a fixedpoint add is that it is the absolute simplest variant and illustrates the level of abstraction I'm aiming for.
The overall flow would be:
1. Determine quantization parameters (out of scope of this cl).
2. Source dialect rules to lower supported math ops to the quantization dialect (out of scope of this cl).
3. Quantization passes: [-quant-convert-const, -quant-lower-uniform-real-math, -quant-lower-unsupported-to-float] (the last one not implemented yet)
4. Target specific lowering of the integral arithmetic ops (roughly at the level of gemmlowp) to more fundamental operations (i.e. calls to gemmlowp, simd instructions, DSP instructions, etc).
How I'm doing this should facilitate implementation of just about any kind of backend except TFLite, which has a very course, adhoc surface area for its quantized kernels. Options there include (I'm not taking an opinion on this - just trying to provide options):
a) Not using any of this: just match q/dbarrier + tf math ops to the supported TFLite quantized op set.
b) Implement the more fundamental integer math ops on TFLite and convert to those instead of the current op set.
Note that I've hand-waved over the process of choosing appropriate quantization parameters. Getting to that next. As you can see, different implementations will likely have different magic combinations of specific math support, and we will need the target system that has been discussed for some of the esoteric cases (i.e. many DSPs only support POT fixedpoint).
Two unrelated changes to the overall goal of this CL and can be broken out of desired:
- Adding optional attribute support to TabelGen
- Allowing TableGen native rewrite hooks to return nullptr, signalling that no rewrite has been done.
PiperOrigin-RevId: 235267229
* Introduce a OpTrait class in C++ to wrap the TableGen definition;
* Introduce PredOpTrait and rename previous usage of OpTrait to NativeOpTrait;
* PredOpTrait allows specifying a trait of the operation by way of predicate on the operation. This will be used in future to create reusable set of trait building blocks in the definition of operations. E.g., indicating whether to operands have the same type and allowing locally documenting op requirements by trait composition.
- Some of these building blocks could later evolve into known fixed set as LLVMs backends do, but that can be considered with more data.
* Use the modelling to address one verify TODO in a very local manner.
This subsumes the current custom verify specification which will be removed in a separate mechanical CL.
PiperOrigin-RevId: 234827169
This CL extended TableGen Operator class to provide accessors for information on op
results.
In OpDefinitionGen, added checks to make sure only the last result can be variadic,
and adjusted traits and builders generation to consider variadic results.
PiperOrigin-RevId: 234596124
The parameter to emitStandaloneParamBuilder() was renamed from hasResultType to
isAllSameType, which is the opposite boolean value. The logic should be changed
to make them consistent.
Also re-ordered some methods in Operator. And few other tiny improvements.
PiperOrigin-RevId: 234478316
We specify op operands and results in TableGen op definition using the same syntax.
They should be modelled similarly in TableGen driver wrapper classes.
PiperOrigin-RevId: 234153332
For ops with the SameOperandsAndResultType trait, we know that all result types
should be the same as the first operand's type. So we can generate a build()
method without requiring result types as parameters and also invoke this method
when constructing such ops during expanding rewrite patterns.
Similarly for ops have broadcast behavior, we can define build() method to use
the deduced type as the result type. So we can also calling into this build()
method when constructing ops in RewriterGen.
PiperOrigin-RevId: 233988307
* Add tf.LeakyRelu op definition + folders (well one is really canonicalizer)
* Change generated error message to use attribute description instead;
* Change the return type of F32Attr to be APFloat - internally it is already
stored as APFloat so let the caller decides if they want to convert it or
not. I could see varying opinions here though :) (did not change i32attr
similarly)
PiperOrigin-RevId: 232923358
Previously, we were using the trait mechanism to specify that an op has variadic operands.
That led a discrepancy between how we handle ops with deterministic number of operands.
Besides, we have no way to specify the constraints and match against the variadic operands.
This CL introduced Variadic<Type> as a way to solve the above issues.
PiperOrigin-RevId: 232656104
They are essentially both modelling MLIR OpTrait; the former achieves the
purpose via introducing corresponding symbols in TableGen, while the latter
just uses plain strings.
Unify them to provide a single mechanism to avoid confusion and to better
reflect the definitions on MLIR C++ side.
Ideally we should be able to deduce lots of these traits automatically via
other bits of op definitions instead of manually specifying them; but not
for now though.
PiperOrigin-RevId: 232191401
Similar to op operands and attributes, use DAG to specify operation's results.
This will allow us to provide names and matchers for outputs.
Also Defined `outs` as a marker to indicate the start of op result list.
PiperOrigin-RevId: 231422455
canonicalizations of operations. The ultimate important user of this is
going to be a funcBuilder->foldOrCreate<YourOp>(...) API, but for now it
is just a more convenient way to write certain classes of canonicalizations
(see the change in StandardOps.cpp).
NFC.
PiperOrigin-RevId: 230770021
Add default values to attributes, to allow attribute being left unspecified. The attr getter will always return an attribute so callers need not check for it, if the attribute is not set then the default will be returned (at present the default will be constructed upon query but this will be changed).
Add op definition for tf.AvgPool in ops.td, rewrite matcher using pattern using attribute matching & transforms. Adding some helper functions to make it simpler.
Handle attributes with dialect prefix and map them to getter without dialect prefix.
Note: VerifyAvgPoolOp could probably be autogenerated by know given the predicate specification on attributes, but deferring that to a follow up.
PiperOrigin-RevId: 230364857
Start doc generation pass that generates simple markdown output. The output is formatted simply[1] in markdown, but this allows seeing what info we have, where we can refine the op description (e.g., the inputs is probably redundant), what info is missing (e.g., the attributes could probably have a description).
The formatting of the description is still left up to whatever was in the op definition (which luckily, due to the uniformity in the .td file, turned out well but relying on the indentation there is fragile). The mechanism to autogenerate these post changes has not been added yet either. The output file could be run through a markdown formatter too to remove extra spaces.
[1]. This is not proposal for final style :) There could also be a discussion around single doc vs multiple (per dialect, per op), whether we want a TOC, whether operands/attributes should be headings or just formatted differently ...
PiperOrigin-RevId: 230354538
Change MinMaxAttr to match hasValidMinMaxAttribute behavior. Post rewriting the other users of that function it could be removed too. The currently generated error message is:
error: 'tfl.fake_quant' op attribute 'minmax' failed to satisfy constraint of MinMaxAttr
PiperOrigin-RevId: 229775631
Start simple with single predicate match & transform rules for attributes.
* Its unclear whether modelling Attr predicates will be needed so start with allowing matching attributes with a single predicate.
* The input and output attr type often differs and so add ability to specify a transform between the input and output format.
PiperOrigin-RevId: 229580879
MLIR has support for type-polymorphic instructions, i.e. instructions that may
take arguments of different types. For example, standard arithmetic operands
take scalars, vectors or tensors. In order to express such instructions in
TableGen, we need to be able to verify that a type object satisfies certain
constraints, but we don't need to construct an instance of this type. The
existing TableGen definition of Type requires both. Extract out a
TypeConstraint TableGen class to define restrictions on types. Define the Type
TableGen class as a subclass of TypeConstraint for consistency. Accept records
of the TypeConstraint class instead of the Type class as values in the
Arguments class when defining operators.
Replace the predicate logic TableGen class based on conjunctive normal form
with the predicate logic classes allowing for abitrary combinations of
predicates using Boolean operators (AND/OR/NOT). The combination is
implemented using simple string rewriting of C++ expressions and, therefore,
respects the short-circuit evaluation order. No logic simplification is
performed at the TableGen level so all expressions must be valid C++.
Maintaining CNF using TableGen only would have been complicated when one needed
to introduce top-level disjunction. It is also unclear if it could lead to a
significantly simpler emitted C++ code. In the future, we may replace inplace
predicate string combination with a tree structure that can be simplified in
TableGen's C++ driver.
Combined, these changes allow one to express traits like ArgumentsAreFloatLike
directly in TableGen instead of relying on C++ trait classes.
PiperOrigin-RevId: 229398247
* Check was returning success instead of failure when reporting illegal type;
* TFL ops only support tensor types so update tests with corrected logic.
- Removed some checks in broadcasting that don't work with tensor input requirement;
PiperOrigin-RevId: 228770184
This CL added a tblgen::Attribute class to wrap around raw TableGen
Record getValue*() calls on Attr defs, which will provide a nicer
API for handling TableGen Record.
PiperOrigin-RevId: 228581107
Bind attributes similar to operands. Use to rewrite leakyreulo and const rewrite pattern. The attribute type/attributes are not currently checked so should only be used where the attributes match due to the construction of the op.
To support current attribute namespacing, convert __ in attribute name to "$" for matching purposes ('$' is not valid character in variable in TableGen).
Some simplification to make it simpler to specify indented ostream and avoid so many spaces. The goal is not to have perfectly formatted code generated but good enough so that its still easy to read for a user.
PiperOrigin-RevId: 228183639
Expand type to include matcher predicates. Use CNF form to allow specifying combinations of constraints for type. The matching call for the type is used to verify the construction of the operation as well as in rewrite pattern generation.
The matching initially includes redundant checks (e.g., even if the operand of the op is guaranteed to satisfy some requirement, it is still checked during matcher generation for now). As well as some of the traits specified now check what the generated code already checks. Some of the traits can be removed in future as the verify method will include the relevant checks based on the op definition already.
More work is needed for variadic operands.
CNF form is used so that in the follow up redundant checks in the rewrite patterns could be omitted (e.g., when matching a F32Tensor, one does not need to verify that op X's operand 0 is a Tensor if that is guaranteed by op X's definition). The alternative was to have single matcher function specified, but this would not allow for reasoning about what attributes already hold (at the level of PredAtoms).
Use this new operand type restrictions to rewrite BiasAdd with floating point operands as declarative pattern.
PiperOrigin-RevId: 227991412
Use tablegen to generate definitions of the standard binary arithmetic
operations. These operations share a lot of boilerplate that is better off
generated by a tool.
Using tablegen for standard binary arithmetic operations requires the following
modifications.
1. Add a bit field `hasConstantFolder` to the base Op tablegen class; generate
the `constantFold` method signature if the bit is set. Differentiate between
single-result and zero/multi-result functions that use different signatures.
The implementation of the method remains in C++, similarly to canonicalization
patterns, since it may be large and non-trivial.
2. Define the `AnyType` record of class `Type` since `BinaryOp` currently
provided in op_base.td is supposed to operate on tensors and other tablegen
users may rely on this behavior.
Note that this drops the inline documentation on the operation classes that was
copy-pasted around anyway. Since we don't generate g3doc from tablegen yet,
keep LangRef.md as it is. Eventually, the user documentation can move to the
tablegen definition file as well.
PiperOrigin-RevId: 227820815
Add ops.td for TF dialect and start by adding tf.Add (op used in legalizer pattern). This CL does not add TensorOp trait (that's not part of OpTrait namespace).
Remove OpCode emission that is not currently used and can be added back later if needed.
PiperOrigin-RevId: 227590973
StmtResult -> InstResult, StmtOperand -> InstOperand, and remove the old names.
This is step 17/n towards merging instructions and statements, NFC.
PiperOrigin-RevId: 227121537
is the new base of the SSA value hierarchy. This CL also standardizes all the
nomenclature and comments to use 'Value' where appropriate. This also eliminates a large number of cast<MLValue>(x)'s, which is very soothing.
This is step 11/n towards merging instructions and statements, NFC.
PiperOrigin-RevId: 227064624
Prakalp Srivastava