inherited constructors, which is cleaner and means you can now use DimOp()
to get a null op, instead of having to use Instruction::getNull<DimOp>().
This removes another 200 lines of code.
PiperOrigin-RevId: 240068113
This allows the indexing sugar to just work naturally with other type of load and store ops than the affine ones we currently have.
This is needed for the EuroLLVM tutorial.
PiperOrigin-RevId: 239602257
This CL introduces a ValueArrayHandle helper to manage the implicit conversion
of ArrayRef<ValueHandle> -> ArrayRef<Value*> by converting first to ValueArrayHandle.
Without this, boilerplate operations that take ArrayRef<Value*> cannot be removed easily.
This all seems to boil down to decoupling Value from Type.
Alternative solutions exist (e.g. MLIR using Value by value everywhere) but they would be very intrusive. This seems to be the lowest impedance change.
Intrinsics are also lowercased by popular demand.
PiperOrigin-RevId: 238974125
This CL removes the dependency of LowerVectorTransfers on the AST version of EDSCs which will be retired.
This exhibited a pretty fundamental staging difference in AST-based vs declarative based emission.
Since the delayed creation with an AST was staged, the loop order came into existence after the clipping expressions were computed.
This now changes as the loops first need to be created declaratively in fixed order and then the clipping expressions are created.
Also, due to lack of staging, coalescing cannot be done on the fly anymore and
needs to be done either as a pre-pass (current implementation) or as a local transformation on the generated IR (future work).
Tests are updated accordingly.
PiperOrigin-RevId: 238971631
In particular, expose comparison operators as Python operator overloads on
ValueHandles. The comparison currently emits signed integer comparisons only,
which is compatible with the behavior of emitter-based EDSC interface. This is
sub-optimal and must be reconsidered in the future. Note that comparison
operators are not overloaded in the C++ declarative builder API precisely
because this avoids the premature decision on the signedness of comparisons.
Implement the declarative construction of boolean expressions using
ValueHandles by overloading the boolean operators in the `op` namespace to
differentiate between `operator!` for nullity check and for boolean negation.
The operands must be of i1 type. Also expose boolean operations as Python
operator overloads on ValueHandles.
PiperOrigin-RevId: 238421615
Declarative builders want to provide the same nesting interface for blocks and loops. MLIR on the other hand has different behaviors:
1. when an AffineForOp is created the insertion point does not enter the loop body;
2. when a Block is created, the insertion point does enter the block body.
Guard against the second behavior in EDSC to make the interface unsurprising.
This also surfaces two places in the eager branch API where I was guarding against this behavior indirectly by creating a new ScopedContext.
Instead, uniformize everything to properly reset the insertion point in the unique place that builds the mlir::Block*.
PiperOrigin-RevId: 237619513
This CL addresses a few post-submit comments:
1. better comments,
2. check number of results before dyn_cast (which is a less common case)
3. test usage for multi-result InstructionHandle
PiperOrigin-RevId: 237549333
This CL adds support for named custom instructions in declarative builders.
To allow this, it introduces a templated `CustomInstruction` class.
This CL also splits ValueHandle which can capture only the **value** in single-valued instructions from InstructionHandle which can capture any instruction but provide no typing and sugaring to extract the potential Value*.
PiperOrigin-RevId: 237543222
This CL adds the same helper classes that exist in the AST form of EDSCs to support a basic indexing notation and emit the proper load and store operations and capture MemRefViews as function arguments.
This CL also adds a wrapper class LoopNestBuilder to allow generic rank-agnostic loops over indices.
PiperOrigin-RevId: 237113755
An implicit OpPointer -> OpType* conversion results in AddressSanitizer triggering a stack-use-after-scope error (which may be a false positive).
Avoid using such patterns to make life good again.
PiperOrigin-RevId: 237053863
When building unstructured control-flow there is a need to construct mlir::Block* before being able to fill them. This invites goto-style programming.
This CL introduces an alternative eager API for BR and COND_BR in which blocks are created eagerly and captured on the fly.
This allows reducing the number of calls to `BlockBuilder` from 4 to 2 in the `builder_blocks_eager` test and from 3 to 2 in the `builder_cond_branch_eager` test.
PiperOrigin-RevId: 237046114
This CL adds support for BranchHandle and BranchBuilder that require a slightly different
abstraction since an mlir::Block is not an mlir::Value.
This CL also adds support for the BR and COND_BR instructions and the relevant tests.
PiperOrigin-RevId: 237034312
This CL reworks the design of EDSCs from first principles.
It introduces a ValueHandle which can hold either:
1. an eagerly typed, delayed Value*
2. a precomputed Value*
A ValueHandle can be manipulated with intrinsic operations a nested within a NestedBuilder. These NestedBuilder are a more idiomatic nested builder abstraction that should feel intuitive to program in C++.
Notably, this abstraction does not require an AST to stage the construction of MLIR snippets from C++. Instead, the abstraction makes use of orderings between definition and declaration of ValueHandles and provides a NestedBuilder and a LoopBuilder helper classes to handle those orderings.
All instruction creations are meant to use the templated ValueHandle::create<> which directly calls mlir::Builder.create<>.
For now the EDSC AST and the builders live side-by-side until the C API is ported.
PiperOrigin-RevId: 237030945
- change this for consistency - everything else similar takes/returns a
Function pointer - the FuncBuilder ctor,
Block/Value/Instruction::getFunction(), etc.
- saves a whole bunch of &s everywhere
PiperOrigin-RevId: 236928761
This CL changes dialect op source files (.h, .cpp, .td) to follow the following
convention:
<full-dialect-name>/<dialect-namespace>Ops.{h|cpp|td}
Builtin and standard dialects are specially treated, though. Both of them do
not have dialect namespace; the former is still named as BuiltinOps.* and the
latter is named as Ops.*.
Purely mechanical. NFC.
PiperOrigin-RevId: 236371358
EDSC Expressions can now be used to build arbitrary MLIR operations identified
by their canonical name, i.e. the name obtained from
`OpClass::getOperationName()` for registered operations. Expose this
functionality to the C API and Python bindings. This exposes builder-level
interface to Python and avoids the need for experimental Python code to
implement EDSC free function calls for constructing each op type.
This modification required exposing mlir::Attribute to the C API and Python
bindings, which only supports integer attributes for now.
This is step 4/n to making EDSCs more generalizable.
PiperOrigin-RevId: 236306776
EDSC provide APIs for constructing and modifying the IR. These APIs are
currently tested by a "test" module pass that reads the dummy IR (empty
functions), recognizes certain function names and injects the IR into those
functions based on their name. This situation is unsatisfactory because the
expected outcome of the test lives in a different file than the input to the
test, i.e. the API calls.
Create a new binary for tests that constructs the IR from scratch using EDSC
APIs and prints it. Put FileCheck comments next to the printing. This removes
the need to have a file with dummy inputs and assert on its contents in the
test driver. The test source includes a simplistic test harness that runs all
functions marked as TEST_FUNC but intentionally does not include any
value-testing functionality.
PiperOrigin-RevId: 235886629
This CL adds a primitive to perform stripmining of a loop by a given factor and
sinking it under multiple target loops.
In turn this is used to implement imperfectly nested loop tiling (with interchange) by repeatedly calling the stripmineSink primitive.
The API returns the point loops and allows repeated invocations of tiling to achieve declarative, multi-level, imperfectly-nested tiling.
Note that this CL is only concerned with the mechanical aspects and does not worry about analysis and legality.
The API is demonstrated in an example which creates an EDSC block, emits the corresponding MLIR and applies imperfectly-nested tiling:
```cpp
auto block = edsc::block({
For(ArrayRef<edsc::Expr>{i, j}, {zero, zero}, {M, N}, {one, one}, {
For(k1, zero, O, one, {
C({i, j, k1}) = A({i, j, k1}) + B({i, j, k1})
}),
For(k2, zero, O, one, {
C({i, j, k2}) = A({i, j, k2}) + B({i, j, k2})
}),
}),
});
// clang-format on
emitter.emitStmts(block.getBody());
auto l_i = emitter.getAffineForOp(i), l_j = emitter.getAffineForOp(j),
l_k1 = emitter.getAffineForOp(k1), l_k2 = emitter.getAffineForOp(k2);
auto indicesL1 = mlir::tile({l_i, l_j}, {512, 1024}, {l_k1, l_k2});
auto l_ii1 = indicesL1[0][0], l_jj1 = indicesL1[1][0];
mlir::tile({l_jj1, l_ii1}, {32, 16}, l_jj1);
```
The edsc::Expr for the induction variables (i, j, k_1, k_2) provide the programmatic hooks from which tiling can be applied declaratively.
PiperOrigin-RevId: 235548228
Leverage the recently introduced support for multiple argument groups and
multiple destination blocks in EDSC Expressions to implement conditional
branches in EDSC. Conditional branches have two successors and three argument
groups. The first group contains a single expression of i1 type that
corresponds to the condition of the branch. The two following groups contain
arguments of the two successors of the conditional branch instruction, in the
same order as the successors. Expose this instruction to the C API and Python
bindings.
PiperOrigin-RevId: 235542768
The new implementation of blocks was designed to support blocks with arguments.
More specifically, StmtBlock can be constructed with a list of Bindables that
will be bound to block aguments upon construction. Leverage this functionality
to implement branch instructions with arguments.
This additionally requires the statement storage to have a list of successors,
similarly to core IR operations.
Becauase successor chains can form loops, we need a possibility to decouple
block declaration, after which it becomes usable by branch instructions, from
block body definition. This is achieved by creating an empty block and by
resetting its body with a new list of instructions. Note that assigning a
block from another block will not affect any instructions that may have
designated this block as their successor (this behavior is necessary to make
value-type semantics of EDSC types consistent). Combined, one can now write
generators like
EDSCContext context;
Type indexType = ...;
Bindable i(indexType), ii(indexType), zero(indexType), one(indexType);
StmtBlock loopBlock({i}, {});
loopBlock.set({ii = i + one,
Branch(loopBlock, {ii})});
MLIREmitter(&builder)
.bindConstant<ConstantIndexOp>(zero, 0)
.bindConstant<ConstantIndexOp>(one, 1)
.emitStmt(Branch(loopBlock, {zero}));
where the emitter will emit the statement and its successors, if present.
PiperOrigin-RevId: 235541892
This came up in post-submit review. Use LLVM's support for outputting APInt
values directly instead of obtaining a 64-bit integer value from APInt, which
will not work for wider integers.
PiperOrigin-RevId: 235531574
This change introduces three new operators in EDSC: Div (also exposed
via Expr.__div__ aka /) -- floating-point division, FloorDiv and CeilDiv
for flooring/ceiling index division.
The lowering to LLVM will be implemented in b/124872679.
PiperOrigin-RevId: 234963217
Introduce support for binding MLIR functions as constant expressions. Standard
constant operation supports functions as possible constant values.
Provide C APIs to look up existing named functions in an MLIR module and expose
them to the Python bindings. Provide Python bindings to declare a function in
an MLIR module without defining it and to add a definition given a function
declaration. These declarations are useful when attempting to link MLIR
modules with, e.g., the standard library.
Introduce EDSC support for direct and indirect calls to other MLIR functions.
Internally, an indirect call is always emitted to leverage existing support for
delayed construction of MLIR Values using EDSC Exprs. If the expression is
bound to a constant function (looked up or declared beforehand), MLIR constant
folding will be able to replace an indirect call by a direct call. Currently,
only zero- and one-result functions are supported since we don't have support
for multi-valued expressions in EDSC.
Expose function calling interface to Python bindings on expressions by defining
a `__call__` function accepting a variable number of arguments.
PiperOrigin-RevId: 234959444
The recent rework of MLIREmitter switched to using the generic call to
`builder.createOperation` from OperationState instead of individual customized
calls to `builder.create<>`. As a result, regular non-composed affine apply
operations where emitted. Introduce a special case in Expr::build to always
create composed affine maps instead, as it used to be the case before the
rework.
Such special-casing goes against the idea of EDSC generality and extensibility.
Instead, we should consider declaring the composed form canonical for
affine.apply operations and using the builder support for creating operations
and canonicalizing them immediately (ongoing effort).
PiperOrigin-RevId: 234790129
Introduce a type-safe way of building a 'for' loop with max/min bounds in EDSC.
Define new types MaxExpr and MinExpr in C++ EDSC API and expose them to Python
bindings. Use values of these type to construct 'for' loops with max/min in
newly introduced overloads of the `edsc::For` factory function. Note that in C
APIs, we still must expose MaxMinFor as a different function because C has no
overloads. Also note that MaxExpr and MinExpr do _not_ derive from Expr
because they are not allowed to be used in a regular Expr context (which may
produce `affine.apply` instructions not expecting `min` or `max`).
Factory functions `Min` and `Max` in Python can be further overloaded to
produce chains of comparisons and selects on non-index types. This is not
trivial in C++ since overloaded functions cannot differ by the return type only
(`MaxExpr` or `Expr`) and making `MaxExpr` derive from `Expr` defies the
purpose of type-safe construction.
PiperOrigin-RevId: 234786131
MLIR supports 'for' loops with lower(upper) bound defined by taking a
maximum(minimum) of a list of expressions, but does not have first-class affine
constructs for the maximum(minimum). All these expressions must have affine
provenance, similarly to a single-expression bound. Add support for
constructing such loops using EDSC. The expression factory function is called
`edsc::MaxMinFor` to (1) highlight that the maximum(minimum) operation is
applied to the lower(upper) bound expressions and (2) differentiate it from a
`edsc::For` that creates multiple perfectly nested loops (and should arguably
be called `edsc::ForNest`).
PiperOrigin-RevId: 234785996
Introduce a functionality to create EDSC expressions from typed constants.
This complements the current functionality that uses "unbound" expressions and
binds them to a specific constant before emission. It comes in handy in cases
where we want to check if something is a constant early during construciton
rather than late during emission, for example multiplications and divisions in
affine expressions. This is also consistent with MLIR vision of constants
being defined by an operation (rather than being special kinds of values in the
IR) by exposing this operation as EDSC expression.
PiperOrigin-RevId: 234758020
This CL fixes 2 recent issues with EDSCs:
1. the type of the LHS in Stmt::operator=(Expr rhs) should be the same as the (asserted unique) return type;
2. symbols coming from DimOp should be admissible as lower / upper bounds in For
The relevant tests are added.
PiperOrigin-RevId: 234750249
Originally, edsc::Expr had a long enum edsc::ExprKind with all supported types
of operations. Recent Expr extensibility support removed the need to specify
supported types in advance. Replace the no-longer-used blocks of enum values
reserved for unary/binary/ternary/variadic expressions with simple values (it
is still useful to know if an expression is, e.g., binary to access it through
a simpler API).
Furthermore, wrap string-comparison now used to identify specific ops into an
`Expr::is_op<>` function template, that acts similarly to `Instruction::isa<>`.
Introduce `{Unary,Binary,Ternary,Variadic}Expr::make<> ` function template that
creates a Expression emitting the MLIR Op specified as template argument.
PiperOrigin-RevId: 234612916
Expose the result types of edsc::Expr, which are now stored for all types of
Exprs and not only for the variadic ones. Require return types when an Expr is
constructed, if it will ever have some. An empty return type list is
interpreted as an Expr that does not create a value (e.g. `return` or `store`).
Conceptually, all edss::Exprs are now typed, with the type being a (potentially
empty) tuple of return types. Unbound expressions and Bindables must now be
constructed with a specific type they will take. This makes EDSC less
evidently type-polymorphic, but we can still write generic code such as
Expr sumOfSquares(Expr lhs, Expr rhs) { return lhs * lhs + rhs * rhs; }
and use it to construct different typed expressions as
sumOfSquares(Bindable(IndexType::get(ctx)), Bindable(IndexType::get(ctx)));
sumOfSquares(Bindable(FloatType::getF32(ctx)),
Bindable(FloatType::getF32(ctx)));
On the positive side, we get the following.
1. We can now perform type checking when constructing Exprs rather than during
MLIR emission. Nevertheless, this is still duplicates the Op::verify()
until we can factor out type checking from that.
2. MLIREmitter is significantly simplified.
3. ExprKind enum is only used for actual kinds of expressions. Data structures
are converging with AbstractOperation, and the users can now create a
VariadicExpr("canonical_op_name", {types}, {exprs}) for any operation, even
an unregistered one without having to extend the enum and make pervasive
changes to EDSCs.
On the negative side, we get the following.
1. Typed bindables are more verbose, even in Python.
2. We lose the ability to do print debugging for higher-level EDSC abstractions
that are implemented as multiple MLIR Ops, for example logical disjunction.
This is the step 2/n towards making EDSC extensible.
***
Move MLIR Op construction from MLIREmitter::emitExpr to Expr::build since Expr
now has sufficient information to build itself.
This is the step 3/n towards making EDSC extensible.
Both of these strive to minimize the amount of irrelevant changes. In
particular, this introduces more complex pretty-printing for affine and binary
expression to make sure tests continue to pass. It also relies on string
comparison to identify specific operations that an Expr produces.
PiperOrigin-RevId: 234609882
EDSC currently implement a block as a statement that is itself a list of
statements. This suffers from two modeling problems: (1) these blocks are not
addressable, i.e. one cannot create an instruction where thus constructed block
is a successor; (2) they support block nesting, which is not supported by MLIR
blocks. Furthermore, emitting such "compound statement" (misleadingly named
`Block` in Python bindings) does not actually produce a new Block in the IR.
Implement support for creating actual IR Blocks in EDSC. In particular, define
a new StmtBlock EDSC class that is neither an Expr nor a Stmt but contains a
list of Stmts. Additionally, StmtBlock may have (early-) typed arguments.
These arguments are Bindable expressions that can be used inside the block.
Provide two calls in the MLIREmitter, `emitBlock` that actually emits a new
block and `emitBlockBody` that only emits the instructions contained in the
block without creating a new block. In the latter case, the instructions must
not use block arguments.
Update Python bindings to make it clear when instruction emission happens
without creating a new block.
PiperOrigin-RevId: 234556474
The existing implementation of makeFunctionType in EDSC contains a bug: the
array of input types is overwritten using output types passed as arguments and
the array of output types is never filled in. This leads to all sorts of
incorrect memory behavior. Fill in the array of output types using the proper
argument.
PiperOrigin-RevId: 234177221
In LowerEDSCTestPass, there are two range-for loops that only do assertions on
the loop variable. With assertions disabled, the variable becomes unused and
triggers a warning promoted to error. Cast it to void in the loop to supress
the warning.
PiperOrigin-RevId: 233936171
EDSC expressions evolved to have different types of underlying storage.
Separate classes are used for unary, binary, ternary and variadic expressions.
The latter covers all the needs of the three special cases. Remove these
special cases and use a single ExprStorage class everywhere while maintaining
the same APIs at the Expr level (ExprStorage is an internal implementation
class).
This is step 1/n to converging EDSC expressions and Ops and making EDSCs
support custom operations.
PiperOrigin-RevId: 233704912
River Riddle