Commit Graph

8 Commits

Author SHA1 Message Date
Mehdi Amini 973ddb7d6e Define a `NoTerminator` traits that allows operations with a single block region to not provide a terminator
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
2021-03-25 03:59:03 +00:00
River Riddle 7bc7d0ac7a [mlir] Optimize symbol related checks in SymbolDCE
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
2020-10-16 12:08:48 -07:00
River Riddle 7c221a7d4f [mlir][Symbol] Change Symbol from a Trait into an OpInterface.
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
2020-04-27 13:04:49 -07:00
River Riddle 1834ad4a69 [mlir][Pass] Update the PassGen to generate base classes instead of utilities
Summary:
This is much cleaner, and fits the same structure as many other tablegen backends. This was not done originally as the CRTP in the pass classes made it overly verbose/complex.

Differential Revision: https://reviews.llvm.org/D77367
2020-04-07 14:08:52 -07:00
River Riddle 80aca1eaf7 [mlir][Pass] Remove the use of CRTP from the Pass classes
This revision removes all of the CRTP from the pass hierarchy in preparation for using the tablegen backend instead. This creates a much cleaner interface in the C++ code, and naturally fits with the rest of the infrastructure. A new utility class, PassWrapper, is added to replicate the existing behavior for passes not suitable for using the tablegen backend.

Differential Revision: https://reviews.llvm.org/D77350
2020-04-07 14:08:52 -07:00
River Riddle 9a277af2d4 [mlir][Pass] Add support for generating pass utilities via tablegen
This revision adds support for generating utilities for passes such as options/statistics/etc. that can be inferred from the tablegen definition. This removes additional boilerplate from the pass, and also makes it easier to remove the reliance on the pass registry to provide certain things(e.g. the pass argument).

Differential Revision: https://reviews.llvm.org/D76659
2020-04-01 02:10:46 -07:00
River Riddle 8155e41ac6 [mlir][Pass] Add a tablegen backend for defining Pass information
This will greatly simplify a number of things related to passes:
* Enables generation of pass registration
* Enables generation of boiler plate pass utilities
* Enables generation of pass documentation

This revision focuses on adding the basic structure and adds support for generating the registration for passes in the Transforms/ directory. Future revisions will add more support and move more passes over.

Differential Revision: https://reviews.llvm.org/D76656
2020-04-01 02:10:46 -07:00
River Riddle b276dec5b6 [mlir] Add a DCE pass for dead symbols.
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
2020-01-27 23:29:30 -08:00