Commit Graph

5 Commits

Author SHA1 Message Date
Matthias Springer 8e8b70aa84 [mlir][scf] Simplify affine.min ops after loop peeling
Simplify affine.min ops, enabling various other canonicalizations inside the peeled loop body.

affine.min ops such as:
```
map = affine_map<(d0)[s0, s1] -> (s0, -d0 + s1)>
%r = affine.min #affine.min #map(%iv)[%step, %ub]
```
are rewritten them into (in the case the peeled loop):
```
%r = %step
```

To determine how an affine.min op should be rewritten and to prove its correctness, FlatAffineConstraints is utilized.

Differential Revision: https://reviews.llvm.org/D107222
2021-08-19 17:24:53 +09:00
Tres Popp 2060155480 [mlir] NFC Replace some code snippets with equivalent method calls
Replace some code snippets With scf::ForOp methods. Additionally,
share a listener at one more point (although this pattern is still
not safe to roll back currently)

Differential Revision: https://reviews.llvm.org/D107754
2021-08-10 08:22:08 +02:00
Matthias Springer 767974f344 [mlir][scf] Fix bug in peelForLoop
Insertion point should be set before creating new operations.

Differential Revision: https://reviews.llvm.org/D107326
2021-08-04 10:20:46 +09:00
Matthias Springer 3a41ff4883 [mlir][SCF] Peel scf.for loops for even step divison
Add ForLoopBoundSpecialization pass, which specializes scf.for loops into a "main loop" where `step` divides the iteration space evenly and into an scf.if that handles the last iteration.

This transformation is useful for vectorization and loop tiling. E.g., when vectorizing loads/stores, programs will spend most of their time in the main loop, in which only unmasked loads/stores are used. Only the in the last iteration (scf.if), slower masked loads/stores are used.

Subsequent commits will apply this transformation in the SparseDialect and in Linalg's loop tiling.

Differential Revision: https://reviews.llvm.org/D105804
2021-08-03 10:21:38 +09:00
Stephan Herhut 4bcd08eb1c [mlir] Add for loop specialization
Summary:
We already had a parallel loop specialization pass that is used to
enable unrolling and consecutive vectorization by rewriting loops
whose bound is defined as a min of a constant and a dynamic value
into a loop with static bound (the constant) and the minimum as
bound, wrapped into a conditional to dispatch between the two.
This adds the same rewriting for for loops.

Differential Revision: https://reviews.llvm.org/D82189
2020-06-22 10:14:17 +02:00