7 Commits

Author SHA1 Message Date
River Riddle
8bb8421b0d [mlir] Add an overload of parseOptionalAttribute for SymbolRefAttr
Avoids parsing other types of attributes when checking if there is
a SymbolRefAttr.
2022-12-17 19:54:44 -08:00
Kazu Hirata
1a36588ec6 [mlir] Use std::nullopt instead of None (NFC)
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated.  The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-12-03 18:50:27 -08:00
Alex Zinenko
519847fefc [mlir] materialize strided memref layout as attribute
Introduce a new attribute to represent the strided memref layout. Strided
layouts are omnipresent in code generation flows and are the only kind of
layouts produced and supported by a half of operation in the memref dialect
(view-related, shape-related). However, they are internally represented as
affine maps that require a somewhat fragile extraction of the strides from the
linear form that also comes with an overhead. Furthermore, textual
representation of strided layouts as affine maps is difficult to read: compare
`affine_map<(d0, d1, d2)[s0, s1] -> (d0*32 + d1*s0 + s1 + d2)>` with
`strides: [32, ?, 1], offset: ?`. While a rudimentary support for parsing a
syntactically sugared version of the strided layout has existed in the codebase
for a long time, it does not go as far as this commit to make the strided
layout a first-class attribute in the IR.

This introduces the attribute and updates the tests that using the pre-existing
sugared form to use the new attribute instead. Most memref created
programmatically, e.g., in passes, still use the affine form with further
extraction of strides and will be updated separately.

Update and clean-up the memref type documentation that has gotten stale and has
been referring to the details of affine map composition that are long gone.

See https://discourse.llvm.org/t/rfc-materialize-strided-memref-layout-as-an-attribute/64211.

Reviewed By: nicolasvasilache

Differential Revision: https://reviews.llvm.org/D132864
2022-08-30 17:19:58 +02:00
Jeff Niu
2092d1438c [mlir] Change the syntax of dense arrays
Follow-up to D123774, where the syntax of dense arrays was discussed. It
was included that the syntax should be changed to `array<i32: 1, 2>`.
This patch changes the syntax but importantly preserves the `[1, 2]`
syntax when embedding these attributes in assembly formats through ODS.

Reviewed By: mehdi_amini, jpienaar

Differential Revision: https://reviews.llvm.org/D131738
2022-08-11 20:56:42 -04:00
River Riddle
40abd7ea64 [mlir] Remove OpaqueElementsAttr
This attribute is technical debt from the early stages of MLIR, before
ElementsAttr was an interface and when it was more difficult for
dialects to define their own types of attributes. At present it isn't
used at all in tree (aside from being convenient for eliding other
ElementsAttr), and has had little to no evolution in the past three years.

Differential Revision: https://reviews.llvm.org/D129917
2022-08-01 15:00:54 -07:00
River Riddle
995ab92964 [mlir] Add a new builtin DenseResourceElementsAttr
This attributes is intended cover the current set of use cases that abuse
DenseElementsAttr, e.g. when the data is large. Using resources for large
data is one of the major reasons why they were added; e.g. they can be
deallocated mid-compilation, they support a wide variety of data origins
(e.g, heap allocated, mmap'd, etc.), they can support mutation, etc.

I considered at length not having a builtin variant of this, and instead
having multiple versions of this attribute for dialects that are interested,
but they all boiled down to the exact same attribute definition. Given the
generality of this attribute, it feels more aligned to keep it next to DenseArrayAttr
(given that DenseArrayAttr covers the "small" case, and DenseResourcesElementsAttr
covers the "large" case). The underlying infra used to build this attribute is
general, and having a builtin attribute doesn't preclude users from defining
their own when it makes sense (they can even share a blob manager with the
builtin dialect to avoid data duplication).

Differential Revision: https://reviews.llvm.org/D130022
2022-08-01 12:37:16 -07:00
River Riddle
c60b897d22 [mlir] Refactor the Parser library in preparation for an MLIR binary format
The current Parser library is solely focused on providing API for
the textual MLIR format, but MLIR will soon also provide a binary
format. This commit renames the current Parser library to AsmParser to
better correspond to what the library is actually intended for. A new
Parser library is added which will act as a unified parser interface
between both text and binary formats. Most parser clients are
unaffected, given that the unified interface is essentially the same as
the current interface. Only clients that rely on utilizing the
AsmParserState, or those that want to parse Attributes/Types need to be
updated to point to the AsmParser library.

Differential Revision: https://reviews.llvm.org/D129605
2022-07-25 16:33:01 -07:00