none-type ::= `none`
The `none` type is a unit type, i.e. a type with exactly one possible value, where its value does not have a defined dynamic representation.
--
PiperOrigin-RevId: 245599248
The parser currently expects region arguments to have a fixed, known type when
the %-name of the region argument is parsed. This may not necessarily be the
case, for example, if the region argument types are the same as the operand
types, located at the end of the operation. Furthermore, the parser currently
stores the values for region arguments internally and attaches them to the next
parsed region implicitly. This makes it impossible to attach some of the
arguments to one region and some other arguments to another region if the
regions are not textually interleaved with operation arguments.
Provide `OpAsmParser::parseRegionArgument` that parses an SSA identifier and
delays its type assignment until the region is parsed, similarly to operands.
Update `OpAsmParser::parseRegion` to accept a list of pre-parsed SSA
identifiers and a list of types instead of using SSA identifiers stored in the
parser.
--
PiperOrigin-RevId: 245491133
A unit attribute is an attribute that represents a value of `unit` type. The
`unit` type allows only one value forming a singleton set. This attribute value
is used to represent attributes that only have meaning from their existence.
One example of such an attribute could be the `swift.self` attribute. This attribute indicates that a function parameter is the self/context
parameter. It could be represented as a boolean attribute(true or false), but a
value of false doesn't really bring any value. The parameter either is the
self/context or it isn't.
```mlir {.mlir}
// A unit attribute defined with the `unit` value specifier.
func @verbose_form(i1 {unitAttr : unit})
// A unit attribute can also be defined without the `unit` value specifier.
func @simple_form(i1 {unitAttr})
```
--
PiperOrigin-RevId: 245254045
other characters within the <>'s now that we can. This will allow quantized
types to use the pretty syntax (among others) after a few changes.
--
PiperOrigin-RevId: 243521268
making the IR dumps much nicer.
This is part 2/3 of the path to making dialect types more nice. Part 3/3 will
slightly generalize the set of characters allowed in pretty types and make it
more principled.
--
PiperOrigin-RevId: 242249955
restricted grammar. This will make certain common types much easier to read.
This is part tensorflow/mlir#1 of 2, which allows us to accept the new syntax. Part 2 will
change the asmprinter to automatically use it when appropriate, which will
require updating a bunch of tests.
This is motivated by the EuroLLVM tutorial and cleaning up the LLVM dialect aesthetics a bit more.
--
PiperOrigin-RevId: 242234821
Historically, the LLVM IR dialect has been using the generic form of MLIR
operation syntax. It is verbose and often redundant. Introduce the custom
printing and parsing for all existing operations in the LLVM IR dialect.
Update the relevant documentation and tests.
--
PiperOrigin-RevId: 241617393
have no standard ops for working with these yet, this is simply enough to
represent and round trip them in the printer and parser.
--
PiperOrigin-RevId: 241102728
Example:
%call:2 = call @multi_return() : () -> (f32, i32)
use(%calltensorflow/mlir#0, %calltensorflow/mlir#1)
This cl also adds parser support for uniquely named result values. This means that a test writer can now write something like:
%foo, %bar = call @multi_return() : () -> (f32, i32)
use(%foo, %bar)
Note: The printer will still print the collapsed form.
PiperOrigin-RevId: 240860058
Currently, regions can only be constructed by passing in a `Function` or an
`Instruction` pointer referencing the parent object, unlike `Function`s or
`Instruction`s themselves that can be created without a parent. It leads to a
rather complex flow in operation construction where one has to create the
operation first before being able to work with its regions. It may be
necessary to work with the regions before the operation is created. In
particular, in `build` and `parse` functions that are executed _before_ the
operation is created in cases where boilerplate region manipulation is required
(for example, inserting the hypothetical default terminator in affine regions).
Allow creating standalone regions. Such regions are meant to own a list of
blocks and transfer them to other regions on demand.
Each instruction stores a fixed number of regions as trailing objects and has
ownership of them. This decreases the size of the Instruction object for the
common case of instructions without regions. Keep this behavior intact. To
allow some flexibility in construction, make OperationState store an owning
vector of regions. When the Builder creates an Instruction from
OperationState, the bodies of the regions are transferred into the
instruction-owned regions to minimize copying. Thus, it becomes possible to
fill standalone regions with blocks and move them to an operation when it is
constructed, or move blocks from a region to an operation region, e.g., for
inlining.
PiperOrigin-RevId: 240368183
Dialect attributes are defined as:
dialect-namespace `.` attr-name `:` attribute-value
Dialects can override any of the following hooks to verify the validity of a given attribute:
* verifyFunctionAttribute
* verifyFunctionArgAttribute
* verifyInstructionAttribute
PiperOrigin-RevId: 236507970
Associates opaque constants with a particular dialect. Adds general mechanism to register dialect-specific hooks defined in external components. Adds hooks to decode opaque tensor constant and extract an element of an opaque tensor constant.
This CL does not change the existing mechanism for registering constant folding hook yet. One thing at a time.
PiperOrigin-RevId: 233544757
Aggregate types where at least one dimension is zero do not fully make sense as
they cannot contain any values (their total size is zero). However, TensorFlow
and XLA support tensors with zero sizes, so we must support those too. This is
relatively safe since, unlike vectors and memrefs, we don't have first-class
element accessors for MLIR tensors.
To support sparse element attributes of vector types that have no non-zero
elements, make sure that index and value element attributes have tensor type so
that we never need to create a zero vector type internally. Note that this is
already consistent with the inline documentation of the sparse elements
attribute. Users of the sparse elements attribute should not rely on the
storage schema anyway.
PiperOrigin-RevId: 232896707
Existing IR syntax is ambiguous in type declarations in presence of zero sizes.
In particular, `0x1` in the type size can be interpreted as either a
hexadecimal literal corresponding to 1, or as two distinct decimal literals
separated by an `x` for sizes. Furthermore, the shape `<0xi32>` fails lexing
because it is expected to be an integer literal.
Fix the lexer to treat `0xi32` as an integer literal `0` followed by a bare
identifier `xi32` (look one character ahead and early return instead of
erroring out).
Disallow hexadecimal literals in type declarations and forcibly split the token
into multiple parts while parsing the type. Note that the splitting trick has
been already present to separate the element type from the preceding `x`
character.
PiperOrigin-RevId: 232880373
Existing type syntax contains the following productions:
function-type ::= type-list-parens `->` type-list
type-list ::= type | type-list-parens
type ::= <..> | function-type
Due to these rules, when the parser sees `->` followed by `(`, it cannot
disambiguate if `(` starts a parenthesized list of function result types, or a
parenthesized list of operands of another function type, returned from the
current function. We would need an unknown amount of lookahead to try to find
the `->` at the right level of function nesting to differentiate between type
lists and singular function types.
Instead, require the result type of the function that is a function type itself
to be always parenthesized, at the syntax level. Update the spec and the
parser to correspond to the production rule names used in the spec (although it
would have worked without modifications). Fix the function type parsing bug in
the process, as it used to accept the non-parenthesized list of types for
arguments, disallowed by the spec.
PiperOrigin-RevId: 232528361
River Riddle