In `Gather1DToConditionalLoads`, currently we will check if the stride
of the most minor dim of the input memref is 1. And if not, the
rewriting pattern will not be applied. However, according to the
verification of `vector.load` here:
4e32271e8b/mlir/lib/Dialect/Vector/IR/VectorOps.cpp (L4971-L4975)
.. if the output vector type of `vector.load` contains only one element,
we can ignore the requirement of the stride of the input memref, i.e.
the input memref can be with any stride layout attribute in such case.
So here we can allow more cases in lowering `vector.gather` by relaxing
such check.
As shown in the test case attached in this patch
[here](1933fbad58/mlir/test/Dialect/Vector/vector-gather-lowering.mlir (L151)),
now `vector.gather` of memref with non-trivial stride can be lowered
successfully if the result vector contains only one element.
---------
Signed-off-by: PragmaTwice <twice@apache.org>
Co-authored-by: Andrzej Warzyński <andrzej.warzynski@gmail.com>
This pattern flattens vector.gather ops by unrolling the outermost
dimension for rank > 2 vectors. There's two issues with this pattern for
scalable vectors:
1. The unrolling doesn't take vscale into account. A constraint is
added to disable this pattern for vectors with leading scalable
dims.
2. The scalable dims are dropped when creating the new gather. Fixed
by propagating the flags.
Depends on #96049.
Vector dialect patterns have grown enormously in the past year to a point where they are now impenetrable.
Start reorganizing them towards finer-grained control.
Differential Revision: https://reviews.llvm.org/D146736
