Slowly we are moving toward full support of sparse tensor *outputs*. First
step was support for all-dense annotated "sparse" tensors. This step adds
support for truly sparse tensors, but only for operations in which the values
of a tensor change, but not the nonzero structure (this was refered to as
"simply dynamic" in the [Bik96] thesis).
Some background text was posted on discourse:
https://llvm.discourse.group/t/sparse-tensors-in-mlir/3389/25
Reviewed By: gussmith23
Differential Revision: https://reviews.llvm.org/D104577
This is a very careful start with alllowing sparse tensors at the
left-hand-side of tensor index expressions (viz. sparse output).
Note that there is a subtle difference between non-annotated tensors
(dense, remain n-dim, handled by classic bufferization) and all-dense
annotated "sparse" tensors (linearized to 1-dim without overhead
storage, bufferized by sparse compiler, backed by runtime support library).
This revision gently introduces some new IR to facilitate annotated outputs,
to be generalized to truly sparse tensors in the future.
Reviewed By: gussmith23, bixia
Differential Revision: https://reviews.llvm.org/D104074
A very elaborate, but also very fun revision because all
puzzle pieces are finally "falling in place".
1. replaces lingalg annotations + flags with proper sparse tensor types
2. add rigorous verification on sparse tensor type and sparse primitives
3. removes glue and clutter on opaque pointers in favor of sparse tensor types
4. migrates all tests to use sparse tensor types
NOTE: next CL will remove *all* obsoleted sparse code in Linalg
Reviewed By: bixia
Differential Revision: https://reviews.llvm.org/D102095
Aart Bik