Dialect conversion currently clones the operations that did not match any
pattern. This includes cloning any regions that belong to these operations.
Instead, apply conversion recursively to the nested regions.
Note that if an operation matched one of the conversion patterns, it is up to
the pattern rewriter to fill in the regions of the converted operation. This
may require calling back to the converter and is left for future work.
PiperOrigin-RevId: 240872410
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
Due to legacy reasons (ML/CFG function separation), regions in affine control
flow operations require contained blocks not to have terminators. This is
inconsistent with the notion of the block and may complicate code motion
between regions of affine control operations and other regions.
Introduce `affine.terminator`, a special terminator operation that must be used
to terminate blocks inside affine operations and transfers the control back to
he region enclosing the affine operation. For brevity and readability reasons,
allow `affine.for` and `affine.if` to omit the `affine.terminator` in their
regions when using custom printing and parsing format. The custom parser
injects the `affine.terminator` if it is missing so as to always have it
present in constructed operations.
Update transformations to account for the presence of terminator. In
particular, most code motion transformation between loops should leave the
terminator in place, and code motion between loops and non-affine blocks should
drop the terminator.
PiperOrigin-RevId: 240536998
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
This combined match/rewrite functionality allows simplifying the majority of existing RewritePatterns, as they do not benefit from separate match and rewrite functions.
Some of the existing canonicalization patterns in StandardOps have been modified to take advantage of this functionality.
PiperOrigin-RevId: 240187856
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
This also eliminates some incorrect reinterpret_cast logic working around it, and numerous const-incorrect issues (like block argument iteration).
PiperOrigin-RevId: 239712029
This fixes a bug: previously, during conversion function argument
attributes were neither beings passed through nor converted. This fix
extends DialectConversion to allow for simultaneous conversion of the
function type and the argument attributes.
This was important when lowering MLIR to LLVM where attribute
information (e.g. noalias) needs to be preserved in MLIR(LLVMDialect).
Longer run it seems reasonable that we want to convert both the
function attribute and its type and the argument attributes, but that
requires a small refactoring in Function.h to aggregate these three
fields in an inner struct, which will require some discussion.
PiperOrigin-RevId: 236709409
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
Alex Zinenko