[ARITH] Revamp IntSet (#3272)

include/tvm/arithmetic.h

@@ -328,71 +328,14 @@ class ConstraintContext {
   std::function<void()> exit_;
 };
 
-/*!
- * \brief Analyzer that contains bunch of sub-analyzers.
- *
- * Each sub-analyzer can make use of another sub-analyzer
- * by weak reference of this.
- *
- * NOTE for sub-analyzer developers:
- * If the analyzer uses memoization, we need to clear the internal
- * cache when information about a Var has been overrideen.
- */
-class Analyzer {
- public:
-  /*! \brief sub-analyzer: const integer bound */
-  ConstIntBoundAnalyzer const_int_bound;
-  /*! \brief sub-analyzer: modular set */
-  ModularSetAnalyzer modular_set;
-  /*! \brief sub-analyzer rewrite simplify */
-  RewriteSimplifier rewrite_simplify;
-  /*! \brief sub-analyzer canonical simplify */
-  CanonicalSimplifier canonical_simplify;
-  /*! \brief constructor */
-  Analyzer();
-  /*!
-   * \brief Notify all the sub-analyzers that var
-   *        is created and binded to expr.
-   *
-   *  Each var can only be binded once.
-   *
-   * \param var The variable.
-   * \param expr The expression we bind to.
-   */
-  void Bind(const VarExpr& var, const Expr& expr);
-  /*!
-   * \brief Notify all the sub-analyzers that var
-   *        is created and binded to a range.
-   *
-   *  Each var can only be binded once.
-   *
-   * \param var The variable.
-   * \param range The range we bind to.
-   */
-  void Bind(const VarExpr& var, const Range& range);
-  /*!
-   * \brief Whether can we proof expr >= val.
-
-   *  Non-negative proof is very useful in integer analysis
-   *  to lower divisions and mods given difference in trunc and ceil mode.
-   *
-   * \param expr The expression.
-   * \param lower_bound The lower bound.
-   * \return Whether we can proof it.
-   *
-   * \note Analyzer will call into sub-analyzers to get the result.
-   */
-  bool CanProveGreaterEqual(const Expr& expr, int64_t lower_bound);
-};
-
 //-----------------------------------------------
-// Integer set abstraction API.
+// Integer set data structure.
 //
 // This is a API build on top of the base
 // integer analysis API to provide set analysis.
 //------------------------------------------------
 /*!
- * \brief Sign of an expression or set.
+ * \brief Sign type of an integer expression.
  */
 enum SignType {
   kPositive,
@@ -401,8 +344,13 @@ enum SignType {
   kUnknown
 };
 
-// internal node container of int set.
-struct IntSetNode;
+/*!
+ * \brief Base class of all IntSet containers.
+ */
+struct IntSetNode : public Node {
+  static constexpr const char* _type_key = "IntSet";
+  TVM_DECLARE_BASE_NODE_INFO(IntSetNode, Node);
+};
 
 /*!
  * \brief Integer set class, represent a set of integers in one dimension.
@@ -424,11 +372,6 @@ class IntSet : public NodeRef {
    * \return The covering range.
    */
   Range cover_range(Range max_range) const;
-  /*!
-   * \brief find an interval that covers the set.
-   * \return The covering interval set.
-   */
-  IntSet cover_interval() const;
   /*! \return Lower bound of the set */
   Expr min() const;
   /*! \return upper bound of the set */
@@ -493,33 +436,91 @@ class IntSet : public NodeRef {
 };
 
 /*!
- * \brief Base class of all IntSet containers.
+ * \brief Integer set analyzer.
  */
-struct IntSetNode : public Node {
-  static constexpr const char* _type_key = "IntSet";
-  TVM_DECLARE_BASE_NODE_INFO(IntSetNode, Node);
+class IntSetAnalyzer {
+ public:
+  /*!
+   * \brief Find a symbolic integer set that contains all possible values of
+   *        expr given the domain of each variables.
+   *
+   * \param expr The expression of interest.
+   * \param dom_map The domain map to indicate which variable to relax.
+   * \return the result of the analysis.
+   */
+  IntSet operator()(const Expr& expr, const Map<Var, IntSet>& dom_map);
+
+ private:
+  friend class Analyzer;
+  explicit IntSetAnalyzer(Analyzer* parent);
+  ~IntSetAnalyzer();
+  class Impl;
+  /*! \brief Internal impl */
+  Impl* impl_;
 };
 
 /*!
- * \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.
+ * \brief Analyzer that contains bunch of sub-analyzers.
  *
- * \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.
- */
-Array<Expr> DetectLinearEquation(const Expr& e, const Array<Var>& vars);
-
-/*!
- * \brief Detect if expression corresponds to clip bound of the vars
+ * Each sub-analyzer can make use of another sub-analyzer
+ * by weak reference of this.
  *
- * \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.
+ * NOTE for sub-analyzer developers:
+ * If the analyzer uses memoization, we need to clear the internal
+ * cache when information about a Var has been overridden.
  */
-Array<Expr> DetectClipBound(const Expr& e, const Array<Var>& vars);
+class Analyzer {
+ public:
+  /*! \brief sub-analyzer: const integer bound */
+  ConstIntBoundAnalyzer const_int_bound;
+  /*! \brief sub-analyzer: modular set */
+  ModularSetAnalyzer modular_set;
+  /*! \brief sub-analyzer rewrite simplify */
+  RewriteSimplifier rewrite_simplify;
+  /*! \brief sub-analyzer canonical simplify */
+  CanonicalSimplifier canonical_simplify;
+  /*! \brief sub-analyzer: int set */
+  IntSetAnalyzer int_set;
+  /*! \brief constructor */
+  Analyzer();
+  /*!
+   * \brief Notify all the sub-analyzers that var
+   *        is created and binded to expr.
+   *
+   *  Each var can only be binded once.
+   *
+   * \param var The variable.
+   * \param expr The expression we bind to.
+   */
+  void Bind(const VarExpr& var, const Expr& expr);
+  /*!
+   * \brief Notify all the sub-analyzers that var
+   *        is created and binded to a range.
+   *
+   *  Each var can only be binded once.
+   *
+   * \param var The variable.
+   * \param range The range we bind to.
+   */
+  void Bind(const VarExpr& var, const Range& range);
+  /*!
+   * \brief Whether can we prove expr >= val.
+
+   *  Non-negative proof is very useful in integer analysis
+   *  to lower divisions and mods given difference in trunc and ceil mode.
+   *
+   * \param expr The expression.
+   * \param lower_bound The lower bound.
+   * \return Whether we can prove it.
+   *
+   * \note Analyzer will call into sub-analyzers to get the result.
+   */
+  bool CanProveGreaterEqual(const Expr& expr, int64_t lower_bound);
+};
 
+//-----------------------------------------------
+// Integer set legacy API.
+//------------------------------------------------
 /*!
  * \brief Find an symbolic integer set that contains all possible values of
  *  e given the domain of each iteration variables.
@@ -638,6 +639,29 @@ IntSet DeduceBound(Expr v, Expr cond,
  */
 Domain DomainTouched(Stmt body, const Tensor &tensor, bool consider_calls, bool consider_provides);
 
+// Expression pattern detector.
+/*!
+ * \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.
+ */
+Array<Expr> DetectLinearEquation(const Expr& e,
+                                 const Array<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.
+ */
+Array<Expr> DetectClipBound(const Expr& e,
+                            const Array<Var>& vars);
+
 // implementation
 inline const IntSetNode* IntSet::operator->() const {
   return static_cast<const IntSetNode*>(node_.get());

python/tvm/arith.py

@@ -32,21 +32,21 @@ class IntSet(NodeBase):
         return _api_internal._IntSetIsEverything(self)
 
 
-@register_node
+@register_node("arith.IntervalSet")
 class IntervalSet(IntSet):
-    """Represent set of continuous interval"""
-    def min(self):
-        """get the minimum value"""
-        return _api_internal._IntervalSetGetMin(self)
-
-    def max(self):
-        """get the maximum value"""
-        return _api_internal._IntervalSetGetMax(self)
+    """Represent set of continuous interval [min_value, max_value]
 
+    Parameters
+    ----------
+    min_value : Expr
+        The minimum value in the interval.
 
-@register_node
-class StrideSet(IntSet):
-    """Represent set of strided integers"""
+    max_value : Expr
+        The maximum value in the interval.
+    """
+    def __init__(self, min_value, max_value):
+        self.__init_handle_by_constructor__(
+            _make_IntervalSet, min_value, max_value)
 
 
 @register_node("arith.ModularSet")
@@ -114,6 +114,7 @@ class Analyzer:
         self._modular_set = _mod("modular_set")
         self._rewrite_simplify = _mod("rewrite_simplify")
         self._canonical_simplify = _mod("canonical_simplify")
+        self._int_set = _mod("int_set")
         self._enter_constraint_context = _mod("enter_constraint_context")
 
     def const_int_bound(self, expr):
@@ -176,6 +177,24 @@ class Analyzer:
         """
         return self._canonical_simplify(expr)
 
+    def int_set(self, expr, dom_map):
+        """Compute a symbolic IntSet that covers expr for all values in dom_map.
+
+        Parameters
+        ----------
+        expr : tvm.Expr
+            The expression.
+
+        dom_map : Dict[Var, tvm.arith.IntSet]
+            The domain for variables to be relaxed.
+
+        Returns
+        -------
+        result : IntSet
+            The result.
+        """
+        return self._int_set(expr, dom_map)
+
     def bind(self, var, expr):
         """Bind a variable to the expression.
 

src/api/api_arith.cc

@@ -39,6 +39,7 @@ TVM_REGISTER_API("arith.intset_vector")
 TVM_REGISTER_API("arith.intset_interval")
 .set_body_typed(IntSet::interval);
 
+
 TVM_REGISTER_API("arith.DetectLinearEquation")
 .set_body_typed(DetectLinearEquation);
 
@@ -110,6 +111,10 @@ TVM_REGISTER_API("arith._CreateAnalyzer")
         return PackedFunc([self](TVMArgs args, TVMRetValue *ret) {
             *ret = self->canonical_simplify(args[0]);
         });
+      } else if (name == "int_set") {
+        return PackedFunc([self](TVMArgs args, TVMRetValue *ret) {
+            *ret = self->int_set(args[0], args[1]);
+        });
       } else if (name == "bind") {
         return PackedFunc([self](TVMArgs args, TVMRetValue *ret) {
             auto& sptr = args[1].node_sptr();

src/arithmetic/analyzer.cc

@@ -31,7 +31,8 @@ Analyzer::Analyzer()
     : const_int_bound(this),
       modular_set(this),
       rewrite_simplify(this),
-      canonical_simplify(this) {
+      canonical_simplify(this),
+      int_set(this) {
 }
 
 void Analyzer::Bind(const VarExpr& v, const Expr& expr) {
@@ -74,7 +75,7 @@ void ConstraintContext::ExitWithScope() {
 
 bool Analyzer::CanProveGreaterEqual(const Expr& expr, int64_t lower_bound) {
   if (const auto* ptr = expr.as<ir::IntImm>()) {
-    return ptr->value > lower_bound;
+    return ptr->value >= lower_bound;
   }
   auto bd = this->const_int_bound(this->rewrite_simplify(expr));
   if (bd->min_value >= lower_bound) return true;

src/arithmetic/bound_deducer.cc

@@ -6,9 +6,9 @@
  * 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
@@ -30,12 +30,12 @@
 
 #include <unordered_set>
 #include <unordered_map>
+#include "int_set.h"
 
 namespace tvm {
 namespace arith {
 
 using namespace ir;
-using HalideIR::Internal::Interval;
 
 // a visitor to find the path to the target variable
 // from a expression.
@@ -293,7 +293,7 @@ IntSet DeduceBound(Expr v, Expr e,
   BoundDeducer d(v, e, hint_map, relax_map);
   d.Deduce();
   if (!d.success) return IntSet::nothing();
-  Expr min = Interval::neg_inf, max = Interval::pos_inf;
+  Expr min = neg_inf(), max = pos_inf();
   if (d.is_greater) {
     min = d.result;
   } else {

src/arithmetic/canonical_simplify.cc

@@ -18,7 +18,6 @@
  */
 
 /*!
- *  Copyright (c) 2019 by Contributors
  * \file canonical_simplify.cc
  * \brief Canonical form based simplification.
  */
@@ -763,7 +762,10 @@ Mutate_(const Mod* op, const Expr& self) {
           if (TryCompare(temp, cval) == kLT) {
             return temp;
           } else {
-            return SplitModConst(ToSplitExpr(temp), cval);
+            // contonue to use logic below.
+            a = extra;
+            psum = a.as<SumExprNode>();
+            CHECK(psum != nullptr);
           }
         }
       }

src/arithmetic/compute_expr.h

@@ -6,9 +6,9 @@
  * 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
@@ -27,8 +27,8 @@
 #define TVM_ARITHMETIC_COMPUTE_EXPR_H_
 
 #include <tvm/ir.h>
-#include <arithmetic/Interval.h>
 #include <limits>
+#include <algorithm>
 
 namespace tvm {
 namespace arith {
@@ -105,12 +105,12 @@ inline Expr ComputeExpr<ir::Mod>(Expr a, Expr b) {
 
 template<>
 inline Expr ComputeExpr<ir::Max>(Expr a, Expr b) {
-  return HalideIR::Internal::Interval::make_max(a, b);
+  return max(a, b);
 }
 
 template<>
 inline Expr ComputeExpr<ir::Min>(Expr a, Expr b) {
-  return HalideIR::Internal::Interval::make_min(a, b);
+  return min(a, b);
 }
 
 template<typename Op>

src/arithmetic/const_fold.h

@@ -6,9 +6,9 @@
  * 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
@@ -206,6 +206,7 @@ inline Expr TryConstFold<ir::Min>(Expr a, Expr b) {
       if (pa && pb) return IntImm::make(rtype, std::min(pa->value, pb->value));
       if (fa && fb) return FloatImm::make(rtype, std::min(fa->value, fb->value));
     });
+  if (a.same_as(b)) return a;
   return Expr();
 }
 
@@ -216,6 +217,7 @@ inline Expr TryConstFold<ir::Max>(Expr a, Expr b) {
       if (pa && pb) return IntImm::make(rtype, std::max(pa->value, pb->value));
       if (fa && fb) return FloatImm::make(rtype, std::max(fa->value, fb->value));
     });
+  if (a.same_as(b)) return a;
   return Expr();
 }
 
@@ -307,6 +309,58 @@ inline Expr TryConstFold<ir::Not>(Expr a) {
   return Expr();
 }
 
+/*! \brief Helper namespace for symbolic value limits */
+struct SymbolicLimits {
+  /*! \brief positive infinity */
+  static Expr pos_inf_;
+  /*! \brief negative infinity */
+  static Expr neg_inf_;
+};
+
+/*!
+ * \brief Opaque expression representing positive infinity.
+ *
+ *  It can can only be used as parameter of by min/max
+ *  for integer analysis and cannot be used in normal expressions.
+ *
+ * \return positive infinity.
+ */
+inline Expr pos_inf() {
+  return SymbolicLimits::pos_inf_;
+}
+
+/*!
+ * \brief Check if value is positive infinity.
+ * \param value The value to be checked.
+ *
+ * \return The check result.
+ */
+inline bool is_pos_inf(const Expr& value) {
+  return value.same_as(SymbolicLimits::pos_inf_);
+}
+
+/*!
+ * \brief Opaque expression representing negative infinity.
+ *
+ *  It can can only be used as parameter of by min/max
+ *  for integer analysis and cannot be used in normal expressions.
+ *
+ * \return negative infinity.
+ */
+inline Expr neg_inf() {
+  return SymbolicLimits::neg_inf_;
+}
+
+/*!
+ * \brief Check if value is negative infinity.
+ * \param value The value to be checked.
+ *
+ * \return The check result.
+ */
+inline bool is_neg_inf(const Expr& value) {
+  return value.same_as(SymbolicLimits::neg_inf_);
+}
+
 }  // namespace arith
 }  // namespace tvm
 #endif  // TVM_ARITHMETIC_CONST_FOLD_H_

src/arithmetic/detect_linear_equation.cc

@@ -6,9 +6,9 @@
  * 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
@@ -19,8 +19,8 @@
 
 /*!
  *  Copyright (c) 2017 by Contributors
- * \file bound_deducer.cc
- * \brief Utility to deduce bound of expression
+ * \file detect_linear_equation.cc
+ * \brief Utility to detect patterns in the expression.
  */
 #include <tvm/expr.h>
 #include <tvm/ir_pass.h>

src/arithmetic/int_op_overflow.h

@@ -6,9 +6,9 @@
  * 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

src/arithmetic/int_set.h

+/*
+ * 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 int_set.h
+ * \brief Internal data structure for integer set.
+ */
+#ifndef TVM_ARITHMETIC_INT_SET_H_
+#define TVM_ARITHMETIC_INT_SET_H_
+
+#include <tvm/arithmetic.h>
+#include <tvm/expr_operator.h>
+#include <limits>
+#include "const_fold.h"
+
+namespace tvm {
+namespace arith {
+
+/*!
+ * \brief Symbolic interval set.
+ *
+ * \note We intentionally keep the internal of IntSet private,
+         as we might change it later.
+ */
+class IntervalSetNode : public IntSetNode {
+ public:
+  /*! \brief Minimum value in the interval. */
+  Expr min_value;
+  /*! \brief Maximum value in the interval. */
+  Expr max_value;
+
+  // visitor overload.
+  void VisitAttrs(tvm::AttrVisitor* v) final {
+    v->Visit("min_value", &min_value);
+    v->Visit("max_value", &max_value);
+  }
+
+  /*! \return Whether the interval has upper bound. */
+  bool HasUpperBound() const {
+    return !is_pos_inf(max_value) && !IsEmpty();
+  }
+  /*! \return Whether the interval has lower bound. */
+  bool HasLowerBound() const {
+    return !is_neg_inf(min_value) && !IsEmpty();
+  }
+  /*! \return Whether the interval is a single point. */
+  bool IsSinglePoint() const {
+    return min_value.same_as(max_value);
+  }
+  /*! \return whether interval represent nothing */
+  bool IsEmpty() const {
+    // during computations, either extreme could occur.
+    return is_pos_inf(min_value) || is_neg_inf(max_value);
+  }
+  /*! \return whether interval represent everything */
+  bool IsEverything() const {
+    return is_neg_inf(min_value) && is_pos_inf(max_value);
+  }
+
+  static constexpr const char* _type_key = "arith.IntervalSet";
+  TVM_DECLARE_NODE_TYPE_INFO(IntervalSetNode, IntSetNode);
+};
+
+/*!
+ * \brief Interval set used for symbolic integer analysis.
+ * \sa IntervalSetNode
+ */
+class IntervalSet : public IntSet {
+ public:
+  /*!
+   * \brief Make a new instance of interval set.
+   * \param min_value The minimum value in the interval.
+   * \param max_value The maximum value in the interval.
+   * \return The created set.
+   */
+  TVM_DLL IntervalSet(Expr min_value, Expr max_value);
+
+  /*!
+   * \brief Create an IntervalSet that represents a single point.
+   * \param value The value to be represented.
+   * \return The result set.
+   */
+  static IntervalSet SinglePoint(Expr value) {
+    return IntervalSet(value, value);
+  }
+  /*!
+   * \brief Create an IntervalSet that represents everything.
+   * \param value The value to be represented.
+   * \return The result set.
+   */
+  static IntervalSet Everything() {
+    return IntervalSet(neg_inf(), pos_inf());
+  }
+  /*!
+   * \brief Create an empty eet.
+   * \return The result set.
+   */
+  static IntervalSet Empty() {
+    return IntervalSet(pos_inf(), neg_inf());
+  }
+
+  TVM_DEFINE_NODE_REF_COW(IntervalSetNode);
+  TVM_DEFINE_NODE_REF_METHODS(IntervalSet, IntSet, IntervalSetNode);
+};
+
+/*!
+ * \brief Create union of two IntervalSets.
+ * \param analyzer The analyzer for simplification analysis.
+ * \param a The first set.
+ * \param b The second set.
+ * \return The result set.
+ */
+TVM_DLL IntervalSet Union(Analyzer* analyzer, IntervalSet a, IntervalSet b);
+
+/*!
+ * \brief Create insersection of two IntervalSets.
+ * \param analzyer The analyzer for simplification analysis.
+ * \param a The first set.
+ * \param b The second set.
+ * \return The result set.
+ */
+TVM_DLL IntervalSet Intersect(Analyzer *analzyer, IntervalSet a, IntervalSet b);
+
+}  // namespace arith
+}  // namespace tvm
+
+#endif  // TVM_ARITHMETIC_INT_SET_H_

src/arithmetic/int_set_internal.h

-/*
- * 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.
- */
-
-/*!
- *  Copyright (c) 2017 by Contributors
- * \file int_set_internal.h
- * \brief Implementations of integer set
- */
-#ifndef TVM_ARITHMETIC_INT_SET_INTERNAL_H_
-#define TVM_ARITHMETIC_INT_SET_INTERNAL_H_
-
-#include <tvm/ir.h>
-#include <tvm/ir_pass.h>
-#include <tvm/arithmetic.h>
-
-namespace tvm {
-namespace arith {
-
-using HalideIR::Internal::Interval;
-
-/*! \brief Set of continuous interval */
-struct IntervalSet : public IntSetNode {
-  /*! \brief the internal interval*/
-  Interval i;
-
-  static IntSet make(Interval i) {
-    NodePtr<IntervalSet> n =
-        make_node<IntervalSet>();
-    n->i = i;
-    return IntSet(n);
-  }
-  static IntSet make(Expr min, Expr max) {
-    NodePtr<IntervalSet> n =
-        make_node<IntervalSet>();
-    n->i.min = min;
-    n->i.max = max;
-    return IntSet(n);
-  }
-
-  static constexpr const char* _type_key = "IntervalSet";
-  TVM_DECLARE_NODE_TYPE_INFO(IntervalSet, IntSetNode);
-};
-
-/*!
- * \brief set represented by strided integers
- *  Reserved for cases where strided access is supported.
- */
-struct StrideSet : public IntSetNode {
-  /*! \brief the base inetrval */
-  Interval base;
-  /*! \brief additional extents in positive number */
-  Array<Expr> extents;
-  /*! \brief additional strides in positive number */
-  Array<Expr> strides;
-
-  static constexpr const char* _type_key = "StrideSet";
-  TVM_DECLARE_NODE_TYPE_INFO(StrideSet, IntSetNode);
-};
-
-}  // namespace arith
-}  // namespace tvm
-
-#endif  // TVM_ARITHMETIC_INT_SET_INTERNAL_H_

src/lang/expr_operator.cc

@@ -6,9 +6,9 @@
  * 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
@@ -188,7 +188,15 @@ Expr operator%(Expr a, Expr b) {
   return ir::Mod::make(a, b);
 }
 
+
 Expr min(Expr a, Expr b) {
+  // inf-aware simplificaiton
+  using arith::is_pos_inf;
+  using arith::is_neg_inf;
+  if (is_pos_inf(a)) return b;
+  if (is_neg_inf(a)) return a;
+  if (is_pos_inf(b)) return a;
+  if (is_neg_inf(b)) return b;
   BinaryOpMatchTypes(a, b);
   Expr ret = arith::TryConstFold<ir::Min>(a, b);
   if (ret.defined()) return ret;
@@ -196,6 +204,13 @@ Expr min(Expr a, Expr b) {
 }
 
 Expr max(Expr a, Expr b) {
+  // inf-aware simplificaiton
+  using arith::is_pos_inf;
+  using arith::is_neg_inf;
+  if (is_pos_inf(a)) return a;
+  if (is_neg_inf(a)) return b;
+  if (is_pos_inf(b)) return b;
+  if (is_neg_inf(b)) return a;
   BinaryOpMatchTypes(a, b);
   Expr ret = arith::TryConstFold<ir::Max>(a, b);
   if (ret.defined()) return ret;

src/pass/loop_partition.cc

@@ -6,9 +6,9 @@
  * 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
@@ -28,7 +28,7 @@
 #include <tvm/arithmetic.h>
 #include <unordered_map>
 #include <unordered_set>
-#include "../arithmetic/int_set_internal.h"
+#include "../arithmetic/int_set.h"
 #include "../runtime/thread_storage_scope.h"
 
 namespace tvm {
@@ -366,7 +366,7 @@ class LoopPartitioner : public IRMutator {
 
   std::pair<IntSet, std::unordered_set<const Node*>>
   GetIntervalAndCondset(const Partition &partitions,
-                        const arith::Interval &for_interval,
+                        const arith::IntervalSet &for_interval,
                         bool cond_value);
 
   inline Stmt MakeFor(const Node* op, Expr extent, Stmt body);
@@ -374,6 +374,7 @@ class LoopPartitioner : public IRMutator {
   /* Candidate IRs that may be partitioned potentially */
   std::unordered_map<const Variable*, IntSet> hint_map_;
   std::unordered_map<const Variable*, IntSet> relax_map_;
+  arith::Analyzer analyzer_;
   CandidateSelector selector;
 };
 
@@ -381,16 +382,17 @@ class LoopPartitioner : public IRMutator {
 // given in the second component provably have value given by cond_value
 std::pair<IntSet, std::unordered_set<const Node*>>
 LoopPartitioner::GetIntervalAndCondset(const Partition &partitions,
-                                       const arith::Interval &for_interval,
+                                       const arith::IntervalSet &for_interval,
                                        bool cond_value) {
   Array<IntSet> sets;
   std::unordered_set<const Node*> cond_set;
 
   for (const auto &kv : partitions) {
     if (kv.first.second == cond_value) {
-      arith::Interval interval = kv.second.as<arith::IntervalSet>()->i;
-      arith::Interval intersection = arith::Interval::make_intersection(interval, for_interval);
-      if (!intersection.is_empty()) {
+      arith::IntervalSet interval = Downcast<arith::IntervalSet>(kv.second);
+      arith::IntervalSet intersection = arith::Intersect(
+          &analyzer_, interval, for_interval);
+      if (!intersection->IsEmpty()) {
         sets.push_back(kv.second);
         cond_set.insert(kv.first.first);
       }
@@ -463,11 +465,12 @@ Stmt LoopPartitioner::TryPartition(const Node* node,
                                    Expr max,
                                    Stmt body,
                                    bool partition_thread_scope) {
+  using namespace arith;
   PartitionFinder finder(var, hint_map_, relax_map_);
   finder.Visit(body);
   if (finder.partitions.empty()) return Stmt();
 
-  arith::Interval for_interval(min, max);
+  arith::IntervalSet for_interval(min, max);
   bool cond_value;
   IntSet middle_interval;
   std::unordered_set<const Node*> cond_set;
@@ -478,7 +481,7 @@ Stmt LoopPartitioner::TryPartition(const Node* node,
     // if such interval doesn't exist, find an interval in which all
     // conditions on var are false
     std::tie(middle_interval, cond_set) =
-            GetIntervalAndCondset(finder.partitions, for_interval, false);
+        GetIntervalAndCondset(finder.partitions, for_interval, false);
     if (middle_interval.is_nothing())
       // we couldn't find an interval in which the condintions are provably true or false
       // Therefore, we can't partition the loop based on those conds
@@ -488,7 +491,7 @@ Stmt LoopPartitioner::TryPartition(const Node* node,
     cond_value = true;
   }
 
-  arith::Interval middle_interval_i = middle_interval.as<arith::IntervalSet>()->i;
+  IntervalSet middle_interval_i = Downcast<IntervalSet>(middle_interval);
   // middle_interval is the subrange of the loop variable range for which a
   // set of conditions are true (or false resp.)
   // The part of the loop variable range that is before (after resp.) that
@@ -499,7 +502,7 @@ Stmt LoopPartitioner::TryPartition(const Node* node,
   Expr body_begin;
   Stmt pre_stmt;
   bool pre_stmt_recurse = true;
-  if (middle_interval_i.has_lower_bound()) {
+  if (middle_interval_i->HasLowerBound()) {
     body_begin = ir::Simplify(middle_interval.min());
     if (!can_prove(body_begin == min)) {
       Expr cond = (body_begin - min >= 0);
@@ -524,7 +527,7 @@ Stmt LoopPartitioner::TryPartition(const Node* node,
   Expr post_doubt_begin;
   Stmt post_stmt;
   bool post_stmt_recurse = true;
-  if (middle_interval_i.has_upper_bound()) {
+  if (middle_interval_i->HasUpperBound()) {
     post_doubt_begin = ir::Simplify(middle_interval.max() + 1);
     if (!can_prove(middle_interval.max() == max)) {
       // require the extent to be non-negative

tests/python/unittest/test_arith_deduce_bound.py

+# 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.
+import tvm
+
+def test_deduce():
+    a = tvm.var('a')
+    b = tvm.var('b')
+    c = tvm.var('c')
+    d = tvm.var('d')
+
+    b_s = tvm.arith.IntervalSet(2, 3)
+    c_s = tvm.arith.IntervalSet(10, 15)
+    d_s = tvm.arith.IntervalSet(-3, -1)
+    zero = tvm.const(0, "int32")
+
+    e0 = (-b)*a+c-d
+    res0 = tvm.arith.DeduceBound(a, e0>=0, {b: b_s, c: c_s, d: d_s}, {})
+    ans0 = ((d - c) /(b*-1))
+    assert str(tvm.ir_pass.Simplify(res0.max_value)) == str(ans0)
+
+    # expression containing variable a is on rhs
+    res0 = tvm.arith.DeduceBound(a, zero <= e0, {b: b_s, c: c_s, d: d_s}, {})
+    assert str(tvm.ir_pass.Simplify(res0.max_value)) == str(ans0)
+
+    e0 = d*a+c-d
+    res0 = tvm.arith.DeduceBound(a, e0>=0, {b: b_s, c: c_s, d: d_s}, {})
+    ans0 = ((0-c)/d + 1)
+    assert str(tvm.ir_pass.Simplify(res0.max_value)) == str(ans0)
+
+    # expression containing variable a is on rhs
+    res0 = tvm.arith.DeduceBound(a, zero <= e0, {b: b_s, c: c_s, d: d_s}, {})
+    assert str(tvm.ir_pass.Simplify(res0.max_value)) == str(ans0)
+
+    e1 = (a*4+b < c)
+    res1 = tvm.arith.DeduceBound(a, e1, {b: b_s, c: c_s, d: d_s}, {})
+    ans1 = (((c - b) + -1)/4)
+    assert str(tvm.ir_pass.Simplify(res1.max_value)) == str(ans1)
+
+    # expression containing variable a is on rhs
+    e1 = (c > a*4+b)
+    res1 = tvm.arith.DeduceBound(a, e1, {b: b_s, c: c_s, d: d_s}, {})
+    assert str(tvm.ir_pass.Simplify(res1.max_value)) == str(ans1)
+
+    e2 = (tvm.max(5, a * 4) < 0)
+    res2 = tvm.arith.DeduceBound(a, e2, {b: b_s, c: c_s, d: d_s}, {})
+    assert str(res2.max_value) == "neg_inf"
+    assert str(res2.min_value) == "pos_inf"
+
+    # expression containing variable a is on rhs
+    e2 = (zero < tvm.max(5, a * 4))
+    res2 = tvm.arith.DeduceBound(a, e2, {b: b_s, c: c_s, d: d_s}, {})
+    assert str(res2.max_value) == "neg_inf"
+    assert str(res2.min_value) == "pos_inf"
+
+
+    e3 = (-b)+a*c-d
+    res3 = tvm.arith.DeduceBound(a, e3>=0, {b: b_s, c: c_s, d: d_s}, {b: b_s, d: d_s})
+    ans3 = 2/c+1
+    assert str(tvm.ir_pass.Simplify(res3.min_value)) == str(ans3)
+
+    res3 = tvm.arith.DeduceBound(a, zero <= e3, {b: b_s, c: c_s, d: d_s}, {b: b_s, d: d_s})
+    assert str(tvm.ir_pass.Simplify(res3.min_value)) == str(ans3)
+
+def test_check():
+    a = tvm.var('a')
+    b = tvm.var('b')
+    c = tvm.var('c')
+    d = tvm.var('d')
+
+    b_s = tvm.arith.IntervalSet(2, 3)
+    c_s = tvm.arith.IntervalSet(5, 7)
+    d_s = tvm.arith.IntervalSet(-3, -1)
+
+    # no compare operator
+    res1 = tvm.arith.DeduceBound(a, a+b, {b: b_s}, {})
+    assert res1.is_nothing()
+
+    # multiple compare operators
+    res2 = tvm.arith.DeduceBound(a, (a+b>3).astype(c.dtype)>c , {b: b_s, c: c_s}, {})
+    assert res2.is_nothing()
+
+    # multiple target variable
+    res2 = tvm.arith.DeduceBound(a, a*2-a>b, {b: b_s}, {})
+    assert res2.is_nothing()
+
+def test_deduce_basic():
+    def test_basic(a1, a2, coff):
+        a = tvm.var('a')
+        b = tvm.var('b')
+        b_s = tvm.arith.IntervalSet(a1, a2)
+        e0 = b + a*coff + 3
+
+        res1 = tvm.arith.DeduceBound(a, e0<17, {b: b_s}, {b: b_s})
+        [x, y] = [res1.max_value, b_s.max_value] if coff > 0 else [res1.min_value, b_s.min_value]
+        assert (tvm.ir_pass.Simplify((x * coff + 3 + y) < 17)).value == 1
+
+        # expression containing variable a is on rhs
+        res1 = tvm.arith.DeduceBound(a, tvm.const(17, "int32") < e0, {b: b_s}, {b: b_s})
+        [x, y] = [res1.max_value, b_s.max_value] if coff < 0 else [res1.min_value, b_s.min_value]
+        assert (tvm.ir_pass.Simplify((x * coff + 3 + y) > 17)).value == 1
+
+        # expression containing variable a is on rhs
+        res1 = tvm.arith.DeduceBound(a, tvm.const(17, "int32")>= e0, {b: b_s}, {b: b_s})
+        [x, y] = [res1.max_value, b_s.max_value] if coff > 0 else [res1.min_value, b_s.min_value]
+        assert (tvm.ir_pass.Simplify((x * coff + 3 + y) <= 17)).value == 1
+
+        res1 = tvm.arith.DeduceBound(a, e0>=17, {b: b_s}, {b: b_s})
+        [x, y] = [res1.max_value, b_s.max_value] if coff < 0 else [res1.min_value, b_s.min_value]
+        assert (tvm.ir_pass.Simplify((x * coff + 3 + y) >= 17)).value == 1
+
+    test_basic(0, 4, 4)
+    test_basic(1, 5, 4)
+    test_basic(2, 6, 4)
+    test_basic(0, 4, -4)
+    test_basic(1, 5, -4)
+    test_basic(2, 6, -4)
+
+def test_deduce_complex():
+    def test_complex(a1, a2, coff):
+        a = tvm.var('a')
+        b = tvm.var('b')
+        b_s = tvm.arith.IntervalSet(a1, a2)
+        e0 = (b*3 + a* coff) * 4
+
+        res1 = tvm.arith.DeduceBound(a, e0<63, {b: b_s}, {b: b_s})
+        [t, x] = [res1.max_value, b_s.max_value] if coff > 0 else [res1.min_value, b_s.min_value]
+        assert (tvm.ir_pass.Simplify(((x*3 + t* coff) * 4) < 63)).value == 1
+
+        # expression containing variable a is on rhs
+        res1 = tvm.arith.DeduceBound(a, tvm.const(63, "int32")>= e0, {b: b_s}, {b: b_s})
+        [t, x] = [res1.max_value, b_s.max_value] if coff > 0 else [res1.min_value, b_s.min_value]
+        assert (tvm.ir_pass.Simplify(((x*3 + t* coff) * 4) <= 63)).value == 1
+
+        res1 = tvm.arith.DeduceBound(a, e0>63, {b: b_s}, {b: b_s})
+        [t, x] = [res1.max_value, b_s.max_value] if coff < 0 else [res1.min_value, b_s.min_value]
+        assert (tvm.ir_pass.Simplify(((x*3 + t* coff) * 4) > 63)).value == 1
+
+        # expression containing variable a is on rhs
+        res1 = tvm.arith.DeduceBound(a, tvm.const(63, "int32") <= e0, {b: b_s}, {b: b_s})
+        [t, x] = [res1.max_value, b_s.max_value] if coff < 0 else [res1.min_value, b_s.min_value]
+        assert (tvm.ir_pass.Simplify(((x*3 + t* coff) * 4) >= 63)).value == 1
+
+    test_complex(0, 4, 4)
+    test_complex(0, 4, -4)
+    test_complex(2, 6, 4)
+    test_complex(0, 4, -4)
+    test_complex(1, 5, -4)
+    test_complex(2, 6, -4)
+
+
+if __name__ == "__main__":
+    test_check()
+    test_deduce_basic()
+    test_deduce_complex()

tests/python/unittest/test_arith_intset.py

@@ -16,168 +16,87 @@
 # under the License.
 import tvm
 
+
+class IntSetChecker:
+    def __init__(self):
+        self.analyzer = tvm.arith.Analyzer()
+
+    def verify(self, data, dmap, expected):
+        res = self.analyzer.int_set(data, dmap)
+        def err_msg():
+            return "\ndata={}\ndmap={}\nres={}\nexpected={}".format(data, dmap, res, expected)
+        def equal(x, y):
+            res = self.analyzer.canonical_simplify(x - y)
+            return tvm.ir_pass.Equal(res, 0)
+        assert equal(res.min_value, expected[0]), err_msg()
+        assert equal(res.max_value, expected[1]), err_msg()
+
 def test_basic():
-    s = tvm.arith.intset_interval(2, 3)
-    assert s.min().value == 2
-    assert s.max().value == 3
+    s = tvm.arith.IntervalSet(2, 3)
+    assert s.min_value.value == 2
+    assert s.max_value.value == 3
+
 
 def test_vector():
     base = 10
     stride = 3
     lanes = 2
     s = tvm.arith.intset_vector(tvm.make.Ramp(base, stride, lanes))
-    assert s.min().value == base
-    assert s.max().value == base + stride * lanes - 1
-
-def test_deduce():
-    a = tvm.var('a')
-    b = tvm.var('b')
-    c = tvm.var('c')
-    d = tvm.var('d')
-
-    b_s = tvm.arith.intset_interval(2, 3)
-    c_s = tvm.arith.intset_interval(10, 15)
-    d_s = tvm.arith.intset_interval(-3, -1)
-    zero = tvm.const(0, "int32")
-
-    e0 = (-b)*a+c-d
-    res0 = tvm.arith.DeduceBound(a, e0>=0, {b: b_s, c: c_s, d: d_s}, {})
-    ans0 = ((d - c) /(b*-1))
-    assert str(tvm.ir_pass.Simplify(res0.max())) == str(ans0)
-
-    # expression containing variable a is on rhs
-    res0 = tvm.arith.DeduceBound(a, zero <= e0, {b: b_s, c: c_s, d: d_s}, {})
-    assert str(tvm.ir_pass.Simplify(res0.max())) == str(ans0)
-
-    e0 = d*a+c-d
-    res0 = tvm.arith.DeduceBound(a, e0>=0, {b: b_s, c: c_s, d: d_s}, {})
-    ans0 = ((0-c)/d + 1)
-    assert str(tvm.ir_pass.Simplify(res0.max())) == str(ans0)
-
-    # expression containing variable a is on rhs
-    res0 = tvm.arith.DeduceBound(a, zero <= e0, {b: b_s, c: c_s, d: d_s}, {})
-    assert str(tvm.ir_pass.Simplify(res0.max())) == str(ans0)
-
-    e1 = (a*4+b < c)
-    res1 = tvm.arith.DeduceBound(a, e1, {b: b_s, c: c_s, d: d_s}, {})
-    ans1 = (((c - b) + -1)/4)
-    assert str(tvm.ir_pass.Simplify(res1.max())) == str(ans1)
-
-    # expression containing variable a is on rhs
-    e1 = (c > a*4+b)
-    res1 = tvm.arith.DeduceBound(a, e1, {b: b_s, c: c_s, d: d_s}, {})
-    assert str(tvm.ir_pass.Simplify(res1.max())) == str(ans1)
-
-    e2 = (tvm.max(5, a * 4) < 0)
-    res2 = tvm.arith.DeduceBound(a, e2, {b: b_s, c: c_s, d: d_s}, {})
-    assert str(res2.max()) == "neg_inf"
-    assert str(res2.min()) == "pos_inf"
-
-    # expression containing variable a is on rhs
-    e2 = (zero < tvm.max(5, a * 4))
-    res2 = tvm.arith.DeduceBound(a, e2, {b: b_s, c: c_s, d: d_s}, {})
-    assert str(res2.max()) == "neg_inf"
-    assert str(res2.min()) == "pos_inf"
-
-
-    e3 = (-b)+a*c-d
-    res3 = tvm.arith.DeduceBound(a, e3>=0, {b: b_s, c: c_s, d: d_s}, {b: b_s, d: d_s})
-    ans3 = 2/c+1
-    assert str(tvm.ir_pass.Simplify(res3.min())) == str(ans3)
-
-    res3 = tvm.arith.DeduceBound(a, zero <= e3, {b: b_s, c: c_s, d: d_s}, {b: b_s, d: d_s})
-    assert str(tvm.ir_pass.Simplify(res3.min())) == str(ans3)
-
-def test_check():
-    a = tvm.var('a')
-    b = tvm.var('b')
-    c = tvm.var('c')
-    d = tvm.var('d')
-
-    b_s = tvm.arith.intset_interval(2, 3)
-    c_s = tvm.arith.intset_interval(5, 7)
-    d_s = tvm.arith.intset_interval(-3, -1)
-
-    # no compare operator
-    res1 = tvm.arith.DeduceBound(a, a+b, {b: b_s}, {})
-    assert res1.is_nothing()
-
-    # multiple compare operators
-    res2 = tvm.arith.DeduceBound(a, (a+b>3).astype(c.dtype)>c , {b: b_s, c: c_s}, {})
-    assert res2.is_nothing()
-
-    # multiple target variable
-    res2 = tvm.arith.DeduceBound(a, a*2-a>b, {b: b_s}, {})
-    assert res2.is_nothing()
-
-def test_deduce_basic():
-    def test_basic(a1, a2, coff):
-        a = tvm.var('a')
-        b = tvm.var('b')
-        b_s = tvm.arith.intset_interval(a1, a2)
-        e0 = b + a*coff + 3
-
-        res1 = tvm.arith.DeduceBound(a, e0<17, {b: b_s}, {b: b_s})
-        [x, y] = [res1.max(), b_s.max()] if coff > 0 else [res1.min(), b_s.min()]
-        assert (tvm.ir_pass.Simplify((x * coff + 3 + y) < 17)).value == 1
-
-        # expression containing variable a is on rhs
-        res1 = tvm.arith.DeduceBound(a, tvm.const(17, "int32") < e0, {b: b_s}, {b: b_s})
-        [x, y] = [res1.max(), b_s.max()] if coff < 0 else [res1.min(), b_s.min()]
-        assert (tvm.ir_pass.Simplify((x * coff + 3 + y) > 17)).value == 1
-
-        # expression containing variable a is on rhs
-        res1 = tvm.arith.DeduceBound(a, tvm.const(17, "int32")>= e0, {b: b_s}, {b: b_s})
-        [x, y] = [res1.max(), b_s.max()] if coff > 0 else [res1.min(), b_s.min()]
-        assert (tvm.ir_pass.Simplify((x * coff + 3 + y) <= 17)).value == 1
-
-        res1 = tvm.arith.DeduceBound(a, e0>=17, {b: b_s}, {b: b_s})
-        [x, y] = [res1.max(), b_s.max()] if coff < 0 else [res1.min(), b_s.min()]
-        assert (tvm.ir_pass.Simplify((x * coff + 3 + y) >= 17)).value == 1
-
-    test_basic(0, 4, 4)
-    test_basic(1, 5, 4)
-    test_basic(2, 6, 4)
-    test_basic(0, 4, -4)
-    test_basic(1, 5, -4)
-    test_basic(2, 6, -4)
-
-def test_deduce_complex():
-    def test_complex(a1, a2, coff):
-        a = tvm.var('a')
-        b = tvm.var('b')
-        b_s = tvm.arith.intset_interval(a1, a2)
-        e0 = (b*3 + a* coff) * 4
-
-        res1 = tvm.arith.DeduceBound(a, e0<63, {b: b_s}, {b: b_s})
-        [t, x] = [res1.max(), b_s.max()] if coff > 0 else [res1.min(), b_s.min()]
-        assert (tvm.ir_pass.Simplify(((x*3 + t* coff) * 4) < 63)).value == 1
-
-        # expression containing variable a is on rhs
-        res1 = tvm.arith.DeduceBound(a, tvm.const(63, "int32")>= e0, {b: b_s}, {b: b_s})
-        [t, x] = [res1.max(), b_s.max()] if coff > 0 else [res1.min(), b_s.min()]
-        assert (tvm.ir_pass.Simplify(((x*3 + t* coff) * 4) <= 63)).value == 1
-
-        res1 = tvm.arith.DeduceBound(a, e0>63, {b: b_s}, {b: b_s})
-        [t, x] = [res1.max(), b_s.max()] if coff < 0 else [res1.min(), b_s.min()]
-        assert (tvm.ir_pass.Simplify(((x*3 + t* coff) * 4) > 63)).value == 1
-
-        # expression containing variable a is on rhs
-        res1 = tvm.arith.DeduceBound(a, tvm.const(63, "int32") <= e0, {b: b_s}, {b: b_s})
-        [t, x] = [res1.max(), b_s.max()] if coff < 0 else [res1.min(), b_s.min()]
-        assert (tvm.ir_pass.Simplify(((x*3 + t* coff) * 4) >= 63)).value == 1
-
-    test_complex(0, 4, 4)
-    test_complex(0, 4, -4)
-    test_complex(2, 6, 4)
-    test_complex(0, 4, -4)
-    test_complex(1, 5, -4)
-    test_complex(2, 6, -4)
+    assert s.min_value.value == base
+    assert s.max_value.value == base + stride * lanes - 1
+
+
+def test_add_sub():
+    ck = IntSetChecker()
+    x, y = tvm.var("x"), tvm.var("y")
+    ck.verify(x + y, {x : tvm.arith.IntervalSet(0, 10)}, (y, 10 + y))
+    ck.verify(x + y,
+              {x : tvm.arith.IntervalSet(0, 10), y : tvm.arith.IntervalSet(1, 11)},
+              (1, 21))
+    ck.verify(x - y,
+              {x : tvm.arith.IntervalSet(0, 10), y : tvm.arith.IntervalSet(1, 11)},
+              (-11, 9))
+
+def test_mul_div():
+    ck = IntSetChecker()
+    x, y = tvm.var("x"), tvm.var("y")
+    ck.analyzer.update(y, tvm.arith.ConstIntBound(1, 100), override=True)
+    ck.verify(x * y, {x : tvm.arith.IntervalSet(0, 10)}, (0, 10 * y))
+    ck.verify(x * 2, {x : tvm.arith.IntervalSet(1, 10)}, (2, 20))
+    ck.verify(x * -2, {x : tvm.arith.IntervalSet(1, 10)}, (-20, -2))
+    ck.verify(x / y, {x : tvm.arith.IntervalSet(0, 10)}, (0, 10 / y))
+    ck.verify(x / 2, {x : tvm.arith.IntervalSet(1, 10)}, (0, 5))
+
+
+def test_mod():
+    ck = IntSetChecker()
+    x, y = tvm.var("x"), tvm.var("y")
+    ck.analyzer.update(y, tvm.arith.ConstIntBound(1, 100), override=True)
+    ck.verify(x % y, {x : tvm.arith.IntervalSet(0, 10)}, (0, y - 1))
+    ck.verify(x % 10, {x : tvm.arith.IntervalSet(1, 10)}, (0, 9))
+
+def test_max_min():
+    ck = IntSetChecker()
+    x, y = tvm.var("x"), tvm.var("y")
+    ck.verify(tvm.max(x, x + 1), {x : tvm.arith.IntervalSet(0, 10)}, (1, 11))
+    ck.verify(tvm.min(x - 1, x + 1), {x : tvm.arith.IntervalSet(0, 10)}, (-1, 9))
+    ck.verify(tvm.min(x, y), {}, (tvm.min(x, y), tvm.min(x, y)))
+    ck.verify(tvm.max(x, y), {}, (tvm.max(x, y), tvm.max(x, y)))
+
+
+def test_select():
+    ck = IntSetChecker()
+    x, y = tvm.var("x"), tvm.var("y")
+    ck.verify(tvm.expr.Select(x > 0, x - 1, x + 1),
+              {x : tvm.arith.IntervalSet(0, 10)}, (-1, 11))
+
 
 if __name__ == "__main__":
     test_basic()
     test_vector()
-    test_deduce()
-    test_check()
-    test_deduce_basic()
-    test_deduce_complex()
+    test_add_sub()
+    test_mul_div()
+    test_max_min()
+    test_select()
+    test_mod()
+