Due to legacy reasons (ML/CFG function separation), regions in affine control
flow operations require contained blocks not to have terminators. This is
inconsistent with the notion of the block and may complicate code motion
between regions of affine control operations and other regions.
Introduce `affine.terminator`, a special terminator operation that must be used
to terminate blocks inside affine operations and transfers the control back to
he region enclosing the affine operation. For brevity and readability reasons,
allow `affine.for` and `affine.if` to omit the `affine.terminator` in their
regions when using custom printing and parsing format. The custom parser
injects the `affine.terminator` if it is missing so as to always have it
present in constructed operations.
Update transformations to account for the presence of terminator. In
particular, most code motion transformation between loops should leave the
terminator in place, and code motion between loops and non-affine blocks should
drop the terminator.
PiperOrigin-RevId: 240536998
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 eliminate ConstOpPointer (but keeps OpPointer for now) by making OpPointer
implicitly launder const in a const incorrect way. It will eventually go away
entirely, this is a progressive step towards the new const model.
PiperOrigin-RevId: 239512640
This CL fixes an issue where cloned loop induction variables were not properly
propagated and beefs up the corresponding test.
PiperOrigin-RevId: 239422961
multi-result upper bounds, complete TODOs, fix/improve test cases.
- complete TODOs for loop unroll/unroll-and-jam. Something as simple as
"for %i = 0 to %N" wasn't being unrolled earlier (unless it had been written
as "for %i = ()[s0] -> (0)()[%N] to %N"; addressed now.
- update/replace getTripCountExpr with buildTripCountMapAndOperands; makes it
more powerful as it composes inputs into it
- getCleanupLowerBound and getUnrolledLoopUpperBound actually needed the same
code; refactor and remove one.
- reorganize test cases, write previous ones better; most of these changes are
"label replacements".
- fix wrongly labeled test cases in unroll-jam.mlir
PiperOrigin-RevId: 238014653
* bool succeeded(Status)
- Return if the status corresponds to a success value.
* bool failed(Status)
- Return if the status corresponds to a failure value.
PiperOrigin-RevId: 237153884
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
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
Analysis - NFC
- refactor AffineExprFlattener (-> SimpleAffineExprFlattener) so that it
doesn't depend on FlatAffineConstraints, and so that FlatAffineConstraints
could be moved out of IR/; the simplification that the IR needs for
AffineExpr's doesn't depend on FlatAffineConstraints
- have AffineExprFlattener derive from SimpleAffineExprFlattener to use for
all Analysis/Transforms purposes; override addLocalFloorDivId in the derived
class
- turn addAffineForOpDomain into a method on FlatAffineConstraints
- turn AffineForOp::getAsValueMap into an AffineValueMap ctor
PiperOrigin-RevId: 235283610
*) Adds utility to LoopUtils to perform loop interchange of two AffineForOps.
*) Adds utility to LoopUtils to sink a loop to a specified depth within a loop nest, using a series of loop interchanges.
*) Computes dependences between all loads and stores in the loop nest, and classifies each loop as parallel or sequential.
*) Computes loop interchange permutation required to sink sequential loops (and raise parallel loop nests) while preserving relative order among them.
*) Checks each dependence against the permutation to make sure that dependences would not be violated by the loop interchange transformation.
*) Calls loop interchange in LoopFusion pass on consumer loop nests before fusing in producers, sinking loops with loop carried dependences deeper into the consumer loop nest.
*) Adds and updates related unit tests.
PiperOrigin-RevId: 234158370
Addresses b/122486036
This CL addresses some leftover crumbs in AffineMap and IntegerSet by removing
the Null method and cleaning up the constructors.
As the ::Null uses were tracked down, opportunities appeared to untangle some
of the Parsing logic and make it explicit where AffineMap/IntegerSet have
ambiguous syntax. Previously, ambiguous cases were hidden behind the implicit
pointer values of AffineMap* and IntegerSet* that were passed as function
parameters. Depending the values of those pointers one of 3 behaviors could
occur.
This parsing logic convolution is one of the rare cases where I would advocate
for code duplication. The more proper fix would be to make the syntax
unambiguous or to allow some lookahead.
PiperOrigin-RevId: 231058512
- unrolling a single iteration loop by a factor of one should promote its body
into its parent; this makes it consistent with the behavior/expectation that
unrolling a loop by a factor equal to its trip count makes the loop go away.
PiperOrigin-RevId: 230426499
- the size of the private memref created for the slice should be based on
the memref region accessed at the depth at which the slice is being
materialized, i.e., symbolic in the outer IVs up until that depth, as opposed
to the region accessed based on the entire domain.
- leads to a significant contraction of the temporary / intermediate memref
whenever the memref isn't reduced to a single scalar (through store fwd'ing).
Other changes
- update to promoteIfSingleIteration - avoid introducing unnecessary identity
map affine_apply from IV; makes it much easier to write and read test cases
and pass output for all passes that use promoteIfSingleIteration; loop-fusion
test cases become much simpler
- fix replaceAllMemrefUsesWith bug that was exposed by the above update -
'domInstFilter' could be one of the ops erased due to a memref replacement in
it.
- fix getConstantBoundOnDimSize bug: a division by the coefficient of the identifier was
missing (the latter need not always be 1); add lbFloorDivisors output argument
- rename getBoundingConstantSizeAndShape -> getConstantBoundingSizeAndShape
PiperOrigin-RevId: 230405218
Function::walk functionality into f->walkInsts/Ops which allows visiting all
instructions, not just ops. Eliminate Function::getBody() and
Function::getReturn() helpers which crash in CFG functions, and were only kept
around as a bridge.
This is step 25/n towards merging instructions and statements.
PiperOrigin-RevId: 227243966
consistent and moving the using declarations over. Hopefully this is the last
truly massive patch in this refactoring.
This is step 21/n towards merging instructions and statements, NFC.
PiperOrigin-RevId: 227178245
The last major renaming is Statement -> Instruction, which is why Statement and
Stmt still appears in various places.
This is step 19/n towards merging instructions and statements, NFC.
PiperOrigin-RevId: 227163082
FuncBuilder class. Also rename SSAValue.cpp to Value.cpp
This is step 12/n towards merging instructions and statements, NFC.
PiperOrigin-RevId: 227067644
is the new base of the SSA value hierarchy. This CL also standardizes all the
nomenclature and comments to use 'Value' where appropriate. This also eliminates a large number of cast<MLValue>(x)'s, which is very soothing.
This is step 11/n towards merging instructions and statements, NFC.
PiperOrigin-RevId: 227064624
