llvm-project

34c58c8b - [mlir][sparse] Include sparse emit strategy in wrapping iterator (#165611)

[mlir][sparse] Include sparse emit strategy in wrapping iterator (#165611) When we create a `SparseIterator`, we sometimes wrap it in a `FilterIterator`, which delegates _some_ calls to the underlying `SparseIterator`. After construction, e.g. in `makeNonEmptySubSectIterator()`, we call `setSparseEmitStrategy()`. This sets the strategy only in one of the filters -- if we call `setSparseEmitStrategy()` immediately after creating the `SparseIterator`, then the wrapped `SparseIterator` will have the right strategy, and the `FilterIterator` strategy will be unintialized; if we call `setSparseEmitStrategy()` after wrapping the iterator in `FilterIterator`, then the opposite happens. If we make `setSparseEmitStrategy()` a virtual method so that it's included in the `FilterIterator` pattern, and then do all reads of `emitStrategy` via a virtual method as well, it's pretty simple to ensure that the value of `strategy` is being set consistently and correctly. Without this, the UB of strategy being uninitialized manifests as a sporadic test failure in mlir/test/Integration/Dialect/SparseTensor/CPU/sparse_strided_conv_2d_nhwc_hwcf.mlir, when run downstream with the right flags (e.g. asan + assertions off). The test sometimes fails with `ne_sub<trivial<dense[0,1]>>.begin' op created with unregistered dialect`. It can also be directly observed w/ msan that this uninitialized read is the cause of that issue, but msan causes other problems w/ this test.