Lunderberg commented on code in PR #12972: URL: https://github.com/apache/tvm/pull/12972#discussion_r993613214
########## src/arith/conjunctive_normal_form.cc: ########## @@ -0,0 +1,415 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ + +/*! + * \file tvm/arith/conjunctive_normal_form.cc + */ + +#include "conjunctive_normal_form.h" + +#include <tvm/arith/analyzer.h> +#include <tvm/tir/expr.h> + +#include <optional> +#include <unordered_map> +#include <unordered_set> +#include <utility> +#include <vector> + +#include "pattern_match.h" +#include "rewrite_simplify.h" + +namespace tvm { +namespace arith { + +namespace { +/* \brief A utility for simplifying expressions using conjunctive/disjuctive normal forms */ +class AndOfOrs { + public: + /*! \brief Construct the simplifier + * + * Convert a PrimExpr to the internal representation. + * + * \param expr The PrimExpr to be simplified. + */ + explicit AndOfOrs(const PrimExpr& expr); + + /*! \brief Convert internal representation to PrimExpr */ + PrimExpr AsPrimExpr() const; + + /*! \brief Simplify the internal representation */ + void Simplify(Analyzer* analyzer); + + private: + /*! \brief Internal utility, simplify within each group of expressions + * + * For each pair of values within a chunk, attempt to simplify them into + * a single expression. + * + * For example, + * before = (a == 5) && ((b < 10) || (b > 10)) + * after = (a == 5) && ((b != 10) || false) + */ + void SimplifyWithinChunks(Analyzer* analyzer); + + /*! \brief Internal utility, simplify across groups of expressions + * + * For each pair of chunks, if the two chunks differ by only a single + * term, attempt to simplify those differing terms. + * + * For example, + * before = ((a == 5) || (b <= 10)) && ((a == 5) || (b >= 10)) + * after = ((a == 5) || (b == 10)) && ((a == 5) || true) + */ + void SimplifyAcrossChunks(Analyzer* analyzer); + + /*! \brief Remove instances of true/false from internal representation + * + * To avoid invalidating iterators, `SimplifyWithinChunks` and + * `SimplifyAcrossChunks` may replace keys, but may not remove keys from + * the internal representation. For example, `(a < 5) && (a < 10)` + * would be simplified to `(a < 5) && true`. The `Cleanup` function + * removes these leftover instances of true/false. + */ + void Cleanup(); Review Comment: I like `RemoveTrueFalse`, and updated. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: commits-unsubscr...@tvm.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
