Avoid redundancy with resize ops

[naoyam]

Closes #3710

[naoyam]

!test

[github-actions]

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⚡ Recommended focus areas for review Logic Change The function getPredicates has been modified to predicate the input ID of a resize operation. This change may have unintended consequences and should be thoroughly reviewed. std::vector<IterDomain*> predicate_domains = getPredicateDomains(tv, expr); const IndexingInfo& index_info = computeIndex(expr, predicate_domains, for_loops); const auto& index_map = index_info.index_map; const std::unordered_map<Val*, Val*> replacement_map_start = getPredicateIndexReplacementMap( tv, for_loops, index_map, traversalGraph(), index_info.traversal_path, id_model_, /*is_start_predicate=*/true, /*unswitched_loop=*/unswitched_loop); const std::unordered_map<Val*, Val*> replacement_map_stop = getPredicateIndexReplacementMap( tv, for_loops, index_map, traversalGraph(), index_info.traversal_path, id_model_, /*is_start_predicate=*/false, /*unswitched_loop=*/unswitched_loop); // When resize is involved, predicate its input ID as well to avoid // redudancy. This is only necessary if a predicated resize is // preceded by a split, however, for now it's always predicated // with an exception of static resize. See // PredicateIndexingTest.SplitThenPad for a concrete example. for (const auto& [eg, direction] : index_info.traversal_path) { auto resize = dynamic_cast<Resize*>(eg->front()); if (resize == nullptr) { continue; } // TODO: It seems this shouldn't be predicated when the direction is // Forward, i.e., when resize ops are propagated from // producers to consumers. For example, ResizeTest.SliceThenPadLeftHalf // would fail with this. Revisit for the Forward case if necessary. if (direction == Direction::Forward) { continue; } // If the input ID is guaranteed to cover the output ID, then // the input index should never exceed its boundary. if (resize->leftExpand()->isConstInt() && resize->rightExpand()->isConstInt()) { auto left_int = resize->leftExpand()->evaluate().as<int64_t>(); auto right_int = resize->rightExpand()->evaluate().as<int64_t>(); // If the traversal direction is forward, the predicate is not // necessary if both of the left and right factors are // non-negative as the ouput ID is guaranteed to cover the // input ID. Similarly, if it's backward, it is not necessary // if they are non-positive. if ((direction == Direction::Forward && left_int >= 0 && right_int >= 0) || (direction == Direction::Backward && left_int <= 0 && right_int <= 0)) { continue; } } IterDomain* id_to_predicate = direction == Direction::Forward ? resize->out() : resize->in(); predicate_domains.push_back(id_to_predicate); } Potential Bug The TODO comment on line 1107 suggests that the current implementation may not be correct for the Forward direction. This should be investigated and fixed. // Forward, i.e., when resize ops are propagated from // producers to consumers. For example, ResizeTest.SliceThenPadLeftHalf // would fail with this. Revisit for the Forward case if necessary. if (direction == Direction::Forward) { continue; }

[naoyam]

!test