This cl begins a large refactoring over how signature types are converted in the DialectConversion infrastructure. The signatures of blocks are now converted on-demand when an operation held by that block is being converted. This allows for handling the case where a region is created as part of a pattern, something that wasn't possible previously.
This cl also generalizes the region signature conversion used by FuncOp to work on any region of any operation. This generalization allows for removing the 'apply*Conversion' functions that were specific to FuncOp/ModuleOp. The implementation currently uses a new hook on TypeConverter, 'convertRegionSignature', but this should ideally be removed in favor of using Patterns. That depends on adding support to the PatternRewriter used by ConversionPattern to allow applying signature conversions to regions, which should be coming in a followup.
PiperOrigin-RevId: 258645733
This explicit tag is useful is several ways:
*) This simplifies how to mark sub sections of a dialect as explicitly unsupported, e.g. my target supports all operations in the foo dialect except for these select few. This is useful for partial lowerings between dialects.
*) Partial conversions will now verify that operations that were explicitly marked as illegal must be converted. This provides some guarantee that the operations that need to be lowered by a specific pass will be.
PiperOrigin-RevId: 258582879
Users generally want several different modes of conversion. This cl refactors DialectConversion to provide two:
* Partial (applyPartialConversion)
- This mode allows for illegal operations to exist in the IR, and does not fail if an operation fails to be legalized.
* Full (applyFullConversion)
- This mode fails if any operation is not properly legalized to the conversion target. This allows for ensuring that the IR after a conversion only contains operations legal for the target.
PiperOrigin-RevId: 258412243
These methods don't compose well with the rest of conversion framework, and create artificial breaks in conversion. Replace these methods with two(populateAffineToStdConversionPatterns and populateLoopToStdConversionPatterns respectively) that populate a list of patterns to perform the same behavior.
PiperOrigin-RevId: 258219277
This cl changes the way that operations/blocks to convert are collected/traversed so that parent region operations can be legalized before their bodies. Most RewritePatterns for region operations assume that the entry arguments to each region are yet to be converted. Given that the bodies are currently converted first, this makes it difficult to fit these patterns into the same run as one converting types.
The operations/blocks to convert are now collected before any legalization has run, which simplifies the conversion logic itself, as legalization may insert new operations, move blocks, etc.
PiperOrigin-RevId: 258170158
ConversionPattern should ideally only be used when the types of the operands are changing, which in this case they aren't. Using OpRewritePattern also lends to much simpler code.
PiperOrigin-RevId: 258158474
Multiple (perfectly) nested loops with independent bounds can be combined into
a single loop and than subdivided into blocks of arbitrary size for load
balancing or more efficient parallelism exploitation. However, MLIR wants to
preserve the multi-dimensional multi-loop structure at higher levels of
abstraction. Introduce a transformation that coalesces nested loops with
independent bounds so that they can be further subdivided by tiling.
PiperOrigin-RevId: 258151016
These ops should not belong to the std dialect.
This CL extracts them in their own dialect and updates the corresponding conversions and tests.
PiperOrigin-RevId: 258123853
When using a RewritePattern and replacing an operation with an existing value, that value may have already been replaced by something else. This cl ensures that only the final value is used when applying rewrites.
PiperOrigin-RevId: 258058488
This field wasn't updated as the insertion point changed, making it potentially dangerous given the multi-level of MLIR(e.g. 'createBlock' would always insert the new block in 'region'). This also allows for building an OpBuilder with just a context.
PiperOrigin-RevId: 257829135
The GreedyPatternRewriteDriver currently does not notify the OperationFolder when constants are removed as part of a pattern match. This materializes in a nasty bug where a different operation may be allocated to the same address. This causes an assertion in the OperationFolder when it gets notified of the new operations removal.
PiperOrigin-RevId: 257817627
This CL splits the lowering of affine to LLVM into 2 parts:
1. affine -> std
2. std -> LLVM
The conversions mostly consists of splitting concerns between the affine and non-affine worlds from existing conversions.
Short-circuiting of affine `if` conditions was never tested or exercised and is removed in the process, it can be reintroduced later if needed.
LoopParametricTiling.cpp is updated to reflect the newly added ForOp::build.
PiperOrigin-RevId: 257794436
This allows for the attribute to hold symbolic references to other operations than FuncOp. This also allows for removing the dependence on FuncOp from the base Builder.
PiperOrigin-RevId: 257650017
Standard load and store operations are evolving to be separated from the Affine
constructs. Special affine.load/store have been introduced to uphold the
restrictions of the Affine control flow constructs on their operands.
EDSC-produced loads and stores were originally intended to uphold those
restrictions as well so they should use affine.load/store instead of
std.load/store.
PiperOrigin-RevId: 257443307
Parametric tiling can be used to extract outer loops with fixed number of
iterations. This in turn enables mapping to GPU kernels on a fixed grid
independently of the range of the original loops, which may be unknown
statically, making the kernel adaptable to different sizes. Provide a utility
function that also computes the parametric tile size given the range of the
loop. Exercise the utility function through a simple pass that applies it to
all top-level loop nests. Permutability or parallelism checks must be
performed before calling this utility function in actual passes.
Note that parametric tiling cannot be implemented in a purely affine way,
although it can be encoded using semi-affine maps. The choice to implement it
on standard loops is guided by them being the common representation between
Affine loops, Linalg and GPU kernels.
PiperOrigin-RevId: 257180251
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
These methods assume that a function is a valid builtin top-level operation, and removing these methods allows for decoupling FuncOp and IR/. Utility "getParentOfType" methods have been added to Operation/OpState to allow for querying the first parent operation of a given type.
PiperOrigin-RevId: 257018913
In most places, this is just a name change (with the exception of affine.dma_start swapping the operand positions of its tag memref and num_elements operands).
Significant code changes occur here:
*) Vectorization: LoopAnalysis.cpp, Vectorize.cpp
*) Affine Transforms: Transforms/Utils/Utils.cpp
PiperOrigin-RevId: 256395088
As with Functions, Module will soon become an operation, which are value-typed. This eases the transition from Module to ModuleOp. A new class, OwningModuleRef is provided to allow for owning a reference to a Module, and will auto-delete the held module on destruction.
PiperOrigin-RevId: 256196193
Move the data members out of Function and into a new impl storage class 'FunctionStorage'. This allows for Function to become value typed, which will greatly simplify the transition of Function to FuncOp(given that FuncOp is also value typed).
PiperOrigin-RevId: 255983022
Type conversion does not necessarily affect all types, some of them may remain
untouched. The type conversion tool from the dialect conversion framework will
unconditionally insert a temporary cast operation from the type to itself
anyway, and will try to materialize it to a real conversion operation if there
are remaining uses. Simply use the original value instead.
PiperOrigin-RevId: 255975450
During conversion, if a type conversion has dangling uses a type conversion must persist after conversion has finished to maintain valid IR. In these cases, we now query the TypeConverter to materialize a conversion for us. This allows for the default case of a full conversion to continue working as expected, but also handle the degenerate cases more robustly.
PiperOrigin-RevId: 255637171
Now that Locations are attributes, they have direct access to the MLIR context. This allows for simplifying error emission by removing unnecessary context lookups.
PiperOrigin-RevId: 255112791
The OperationFolder currently just inserts into the entry block of a Function, but regions may be isolated above, i.e. explicit capture only, and blindly inserting constants may break the invariants of these regions.
PiperOrigin-RevId: 254987796
Now that Locations are Attributes they contain a direct reference to the MLIRContext, i.e. the context can be directly accessed from the given location instead of being explicitly passed in.
PiperOrigin-RevId: 254568329
* Support for 1->0 type mappings, i.e. when the argument is being removed.
* Reordering types when converting a type signature.
* Adding new inputs when converting a type signature.
This cl also lays down the initial foundation for supporting 1->N type mappings, but full support will come in a followup.
Moving forward, function signature changes will be driven by populating a SignatureConversion instance. This class contains all of the necessary information for adding/removing/remapping function signatures; e.g. addInputs, addResults, remapInputs, etc.
PiperOrigin-RevId: 254064665
River Riddle