chore: import upstream snapshot with attribution

include/tvm/arith/pattern.h

@@ -0,0 +1,54 @@
+/*
+ * 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/pattern.h
+ * \brief Expression pattern detectors.
+ */
+#ifndef TVM_ARITH_PATTERN_H_
+#define TVM_ARITH_PATTERN_H_
+
+#include <tvm/ir/expr.h>
+#include <tvm/tirx/expr.h>
+
+namespace tvm {
+namespace arith {
+/*!
+ * \brief Detect if e can be rewritten as e = sum_{i=0}^{n-1} var[i] * coeff[i] + coeff[n]
+ *  Where coeff[i] and base are invariant of var[j] for all i and j.
+ *
+ * \param e The expression to be detected.
+ * \param vars List of variables to be used in detection.
+ * \return [coeff[i]] if it is possible, empty array if it is not.
+ */
+ffi::Array<PrimExpr> DetectLinearEquation(const PrimExpr& e, const ffi::Array<tirx::Var>& vars);
+
+/*!
+ * \brief Detect if expression corresponds to clip bound of the vars
+ *
+ * \param e The expression to be detected.
+ * \param vars List of variables to be used in detection.
+ * \return concat([min_value[i], max_value[i]]), None is returned if there is no min or max value
+ *          return empty if the e does not match the pattern.
+ */
+ffi::Array<PrimExpr> DetectClipBound(const PrimExpr& e, const ffi::Array<tirx::Var>& vars);
+
+}  // namespace arith
+}  // namespace tvm
+#endif  // TVM_ARITH_PATTERN_H_