Inserting a symbol into a SymbolTable may lead to the name of the symbol being
changed in order to ensure uniqueness of symbol names in the table. Return this
new name to spare the caller the need to extract it from the symbol operation.
Depends On D112700
Reviewed By: mehdi_amini
Differential Revision: https://reviews.llvm.org/D112886
This patch extends the SubElementAttr interface to allow replacing a contained sub attribute. The attribute that should be replaced is identified by an index which denotes the n-th element returned by the accompanying walkImmediateSubElements method.
Using this addition the patch implements replacing SymbolRefAttrs contained within any dialect attributes.
Differential Revision: https://reviews.llvm.org/D111357
SymbolRefAttr is fundamentally a base string plus a sequence
of nested references. Instead of storing the string data as
a copies StringRef, store it as an already-uniqued StringAttr.
This makes a lot of things simpler and more efficient because:
1) references to the symbol are already stored as StringAttr's:
there is no need to copy the string data into MLIRContext
multiple times.
2) This allows pointer comparisons instead of string
comparisons (or redundant uniquing) within SymbolTable.cpp.
3) This allows SymbolTable to hold a DenseMap instead of a
StringMap (which again copies the string data and slows
lookup).
This is a moderately invasive patch, so I kept a lot of
compatibility APIs around. It would be nice to explore changing
getName() to return a StringAttr for example (right now you have
to use getNameAttr()), and eliminate things like the StringRef
version of getSymbol.
Differential Revision: https://reviews.llvm.org/D108899
This revision adds support for hover on region operations, by temporarily removing the regions during printing. This revision also tweaks the hover format for operations to include symbol information, now that FuncOp can be shown in the hover.
Differential Revision: https://reviews.llvm.org/D103727
In particular for Graph Regions, the terminator needs is just a
historical artifact of the generalization of MLIR from CFG region.
Operations like Module don't need a terminator, and before Module
migrated to be an operation with region there wasn't any needed.
To validate the feature, the ModuleOp is migrated to use this trait and
the ModuleTerminator operation is deleted.
This patch is likely to break clients, if you're in this case:
- you may iterate on a ModuleOp with `getBody()->without_terminator()`,
the solution is simple: just remove the ->without_terminator!
- you created a builder with `Builder::atBlockTerminator(module_body)`,
just use `Builder::atBlockEnd(module_body)` instead.
- you were handling ModuleTerminator: it isn't needed anymore.
- for generic code, a `Block::mayNotHaveTerminator()` may be used.
Differential Revision: https://reviews.llvm.org/D98468
This class provides efficient implementations of symbol queries related to uses, such as collecting the users of a symbol, replacing all uses, etc. This provides similar benefits to use related queries, as SymbolTableCollection did for lookup queries.
Differential Revision: https://reviews.llvm.org/D98071
This reverts commit 511dd4f438 along with
a couple fixes.
Original message:
Now the context is the first, rather than the last input.
This better matches the rest of the infrastructure and makes
it easier to move these types to being declaratively specified.
Phabricator: https://reviews.llvm.org/D96111
Now the context is the first, rather than the last input.
This better matches the rest of the infrastructure and makes
it easier to move these types to being declaratively specified.
Differential Revision: https://reviews.llvm.org/D96111
This class used to serve a few useful purposes:
* Allowed containing a null DictionaryAttr
* Provided some simple mutable API around a DictionaryAttr
The first of which is no longer an issue now that there is much better caching support for attributes in general, and a cache in the context for empty dictionaries. The second results in more trouble than it's worth because it mutates the internal dictionary on every action, leading to a potentially large number of dictionary copies. NamedAttrList is a much better alternative for the second use case, and should be modified as needed to better fit it's usage as a DictionaryAttrBuilder.
Differential Revision: https://reviews.llvm.org/D93442
Previous behavior would fail if inserting an operation that already
existed. Now SymbolTable::insert can also be used as a way to make a
symbol's name unique even after insertion.
Further TODOs have been left over naming and consistent behavior
considerations.
Differential Revision: https://reviews.llvm.org/D93349
- Change syntax for FuncOp to be `func <visibility>? @name` instead of printing the
visibility in the attribute dictionary.
- Since printFunctionLikeOp() and parseFunctionLikeOp() are also used by other
operations, make the "inline visibility" an opt-in feature.
- Updated unit test to use and check the new syntax.
Differential Revision: https://reviews.llvm.org/D90859
* Check region count for unknown symbol tables first, as it is a faster check
* Add an accessor to MutableDictionaryAttr to get the internal dictionary without creating a new one if it is empty. This avoids an otherwise unnecessary lookup of an MLIRContext.
Using an Identifier is much more efficient for attribute lookups because it uses pointer comparison as opposed to string comparison.
Differential Revision: https://reviews.llvm.org/D89660
The initial goal of this interface is to fix the current problems with verifying symbol user operations, but can extend beyond that in the future. The current problems with the verification of symbol uses are:
* Extremely inefficient:
Most current symbol users perform the symbol lookup using the slow O(N) string compare methods, which can lead to extremely long verification times in large modules.
* Invalid/break the constraints of verification pass
If the symbol reference is not-flat(and even if it is flat in some cases) a verifier for an operation is not permitted to touch the referenced operation because it may be in the process of being mutated by a different thread within the pass manager.
The new SymbolUserOpInterface exposes a method `verifySymbolUses` that will be invoked from the parent symbol table to allow for verifying the constraints of any referenced symbols. This method is passed a `SymbolTableCollection` to allow for O(1) lookups of any necessary symbol operation.
Differential Revision: https://reviews.llvm.org/D89512
This revision contains two optimizations related to symbol checking:
* Optimize SymbolOpInterface to only check for a name attribute if the operation is an optional symbol.
This removes an otherwise unnecessary attribute lookup from a majority of symbols.
* Add a new SymbolTableCollection class to represent a collection of SymbolTables.
This allows for perfoming non-flat symbol lookups in O(1) time by caching SymbolTables for symbol table operations. This class is very useful for algorithms that operate on multiple symbol tables, either recursively or not.
Differential Revision: https://reviews.llvm.org/D89505
This is a wrapper around vector of NamedAttributes that keeps track of whether sorted and does some minimal effort to remain sorted (doing more, e.g., appending attributes in sorted order, could be done in follow up). It contains whether sorted and if a DictionaryAttr is queried, it caches the returned DictionaryAttr along with whether sorted.
Change MutableDictionaryAttr to always return a non-null Attribute even when empty (reserve null cases for errors). To this end change the getter to take a context as input so that the empty DictionaryAttr could be queried. Also create one instance of the empty dictionary attribute that could be reused without needing to lock context etc.
Update infer type op interface to use DictionaryAttr and use NamedAttrList to avoid incurring multiple conversion costs.
Fix bug in sorting helper function.
Differential Revision: https://reviews.llvm.org/D79463
This allows for walking the operations nested directly within a region, without traversing nested regions.
Differential Revision: https://reviews.llvm.org/D79056
Makes the relationship and function clearer. Accordingly rename getAttrList to getMutableAttrDict.
Differential Revision: https://reviews.llvm.org/D79125
This revision adds support for propagating constants across symbol-based callgraph edges. It uses the existing Call/CallableOpInterfaces to detect the dataflow edges, and propagates constants through arguments and out of returns.
Differential Revision: https://reviews.llvm.org/D78592
This provides a much cleaner interface into Symbols, and allows for users to start injecting op-specific information. For example, derived op can now inject when a symbol can be discarded if use_empty. This would let us drop unused external functions, which generally have public visibility.
This revision also adds a new `extraTraitClassDeclaration` field to ODS OpInterface to allow for injecting declarations into the trait class that gets attached to the operations.
Differential Revision: https://reviews.llvm.org/D78522
This revision moves the various range utilities present in MLIR to LLVM to enable greater reuse. This revision moves the following utilities:
* indexed_accessor_*
This is set of utility iterator/range base classes that allow for building a range class where the iterators are represented by an object+index pair.
* make_second_range
Given a range of pairs, returns a range iterating over the `second` elements.
* hasSingleElement
Returns if the given range has 1 element. size() == 1 checks end up being very common, but size() is not always O(1) (e.g., ilist). This method provides O(1) checks for those cases.
Differential Revision: https://reviews.llvm.org/D78064
This revision moves several type_trait utilities from MLIR into LLVM. Namely, this revision adds:
is_detected - This matches the experimental std::is_detected
is_invocable - This matches the c++17 std::is_invocable
function_traits - A utility traits class for getting the argument and result types of a callable type
Differential Revision: https://reviews.llvm.org/D78059
Summary: This pass deletes all symbols that are found to be unreachable. This is done by computing the set of operations that are known to be live, propagating that liveness to other symbols, and then deleting all symbols that are not within this live set.
Differential Revision: https://reviews.llvm.org/D72482
Summary: This revision refactors the implementation of the symbol use-list functionality to be a bit cleaner, as well as easier to reason about. Aside from code cleanup, this revision updates the user contract to never recurse into operations if they define a symbol table. The current functionality, which does recurse, makes it difficult to examine the uses held by a symbol table itself. Moving forward users may provide a specific region to examine for uses instead.
Differential Revision: https://reviews.llvm.org/D73427
Summary:
The visibility defines the structural reachability of the symbol within the IR. Symbols can define one of three visibilities:
* Public
The symbol \may be accessed from outside of the visible IR. We cannot assume that we can observe all of the uses of this symbol.
* Private
The symbol may only be referenced from within the operations in the current symbol table, via SymbolRefAttr.
* Nested
The symbol may be referenced by operations in symbol tables above the current symbol table, as long as each symbol table parent also defines a non-private symbol. This allows or referencing the symbol from outside of the defining symbol table, while retaining the ability for the compiler to see all uses.
These properties help to reason about the properties of a symbol, and will be used in a follow up to implement a dce pass on dead symbols.
A few examples of what this would look like in the IR are shown below:
module @public_module {
// This function can be accessed by 'live.user'
func @nested_function() attributes { sym_visibility = "nested" }
// This function cannot be accessed outside of 'public_module'
func @private_function() attributes { sym_visibility = "private" }
}
// This function can only be accessed from within this module.
func @private_function() attributes { sym_visibility = "private" }
// This function may be referenced externally.
func @public_function()
"live.user"() {uses = [@public_module::@nested_function,
@private_function,
@public_function]} : () -> ()
Depends On D72043
Reviewed By: mehdi_amini
Differential Revision: https://reviews.llvm.org/D72044
Summary: This updates the use list algorithms to support querying from a specific symbol, allowing for the collection and detection of nested references. This works by walking the parent "symbol scopes" and applying the existing algorithm at each level.
Reviewed By: jpienaar
Differential Revision: https://reviews.llvm.org/D72042
Refactor the implementation to be much cleaner by adding a `make_second_range` utility to walk the `second` value of a range of pairs.
PiperOrigin-RevId: 275598985
This enhances the symbol table utility methods to handle the case where an unknown operation may define a symbol table. When walking symbols, we now collect all symbol uses before allowing the user to iterate. This prevents the user from assuming that all symbols are actually known before performing a transformation.
PiperOrigin-RevId: 273651963
MLIR uses symbol references to model references to many global entities, such as functions/variables/etc. Before this change, there is no way to actually reason about the uses of such entities. This change provides a walker for symbol references(via SymbolTable::walkSymbolUses), as well as 'use_empty' support(via SymbolTable::symbol_use_empty). It also resolves some deficiencies in the LangRef definition of SymbolRefAttr, namely the restrictions on where a SymbolRefAttr can be stored, ArrayAttr and DictionaryAttr, and the relationship with operations containing the SymbolTable trait.
PiperOrigin-RevId: 273549331
Using the two call interfaces, CallOpInterface and CallableOpInterface, this change adds support for an initial multi-level CallGraph. This call graph builds a set of nodes for each callable region, and connects them via edges. An edge may be any of the following types:
* Abstract
- An edge not produced by a call operation, used for connecting to internal nodes from external nodes.
* Call
- A call edge is an edge defined via a call-like operation.
* Child
- This is an artificial edge connecting nested callgraph nodes.
This callgraph will be used, and improved upon, to begin supporting more interesting interprocedural analyses and transformation. In a followup, this callgraph will be used to support more complex inlining support.
PiperOrigin-RevId: 270724968
Operations must only contain a single region. Once attached, all operations that contain a 'mlir::SymbolTable::getSymbolAttrName()' StringAttr attribute within the child region will be verified to ensure that the names are uniqued. Operations using this trait also gain access to the 'SymbolTable' class, which can be used to manage the symbol table of the operation. This class also provides constant-time lookup of symbols by name, and will automatically rename symbols on insertion.
PiperOrigin-RevId: 257123573
Modules can now contain more than just Functions, this just updates the iteration API to reflect that. The 'begin'/'end' methods have also been updated to iterate over opaque Operations.
PiperOrigin-RevId: 257099084
This is an important step in allowing for the top-level of the IR to be extensible. FuncOp and ModuleOp contain all of the necessary functionality, while using the existing operation infrastructure. As an interim step, many of the usages of Function and Module, including the name, will remain the same. In the future, many of these will be relaxed to allow for many different types of top-level operations to co-exist.
PiperOrigin-RevId: 256427100
Mehdi Amini