onnxruntime-tvm/include/tvm/arithmetic.h

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/*!
* Copyright (c) 2016 by Contributors
* \file tvm/arithmetic.h
* \brief Algebra and set operations and simplifications.
*/
#ifndef TVM_ARITHMETIC_H_
#define TVM_ARITHMETIC_H_
#include <vector>
#include <unordered_map>
#include <memory>
#include "expr.h"
namespace tvm {
class Tensor;
/*! \brief namespace of arithmetic */
namespace arith {
/*!
* \brief Sign of an expression or set.
*/
enum SignType {
kPositive,
kNegative,
kZero,
kUnknown
};
// internal node container of int set.
struct IntSetNode;
/*!
* \brief Integer set class, represent a set of integers in one dimension.
*/
class IntSet : public NodeRef {
public:
/*! \brief constructor */
IntSet() {}
// constructor from not container.
explicit IntSet(NodePtr<Node> n) : NodeRef(n) {}
/*!
* \brief access the internal node container
* \return the pointer to the internal node container
*/
inline const IntSetNode* operator->() const;
/*!
* \brief Find a range that covers the region.
* \param max_range The range to be covered.
* \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 */
Expr max() const;
/*! \return Whether the set represent nothing */
bool is_nothing() const;
/*! \return Whether the set represent everything */
bool is_everything() const;
/*! \return Whether the set is a single point */
bool is_single_point() const;
/*! \return Whether the set is proved to be bigger than 0 */
bool can_prove_positive() const;
/*! \return Whether the set is proved to be smaller than 0 */
bool can_prove_negative() const;
/*! \return The sign of the elements in the integer set */
SignType sign_type() const;
/*!
* \brief The single point value, call only if is_single_point is true
* \return The point value.
*/
Expr point_value() const;
/*!
* \brief Try to match IntSet with range r.
*
* \note It is guanrateed that IntSet::range(r).match_range(r) == true
* \return true if we can prove they are the same.
*/
bool match_range(const Range& r) const;
/*! \return The set contains nothing */
static IntSet nothing();
/*! \return The set contains everything */
static IntSet everything();
/*!
* \brief construct a point set.
* \param point The point in the set.
* \return construct a single point set
*/
static IntSet single_point(Expr point);
/*!
* \brief construct a integer set from vector expression.
* \param vec The vector expression, can also be single point.
* \return The result set containing the indices in the vector.
*/
static IntSet vector(Expr vec);
/*!
* \brief Construct a set representing a range.
* \param r The range
* \return constructed set.
*/
static IntSet range(Range r);
/*!
* \brief Construct a set representing a interval.
* \param min The minimum value of the interval.
* \param max The maximum value of the interval.
* \return constructed set.
*/
static IntSet interval(Expr min, Expr max);
};
/*!
* \brief Range of a linear integer function.
* Use to do specify the possible index values.
*
* set = { coeff * x + base | x in Z }
*
* When coeff != 0, it can also be written as
* set = { n | n % coeff == base }
*
* This is useful to decide if the index is dividable by certain value.
* For example, if index = 0 + 4 x, then we know it can be divided by 4.
*/
struct ModularEntry {
/*! \brief linear co-efficient */
int coeff{1};
/*! \brief The base */
int base{0};
/*! \return entry represent everything */
static ModularEntry everything() {
// always safe to set 0 + x, so it can be everything.
ModularEntry e;
e.coeff = 1;
e.base = 0;
return e;
}
/*!
* \brief Add two modular entries together to get a new modular entry.
* \param a The left operand.
* \param b The right operand.
* \return The combined modular entry.
*/
static ModularEntry Add(const ModularEntry& a,
const ModularEntry& b);
};
/*!
* \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 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);
/*!
* \brief Find an symbolic integer set that contains all possible values of
* e given the domain of each iteration variables.
*
* \param e The expression to be evaluated.
* \param dom_map The domain of each variable.
* \return An integer set that can cover all the possible values of e.
*/
IntSet EvalSet(Expr e,
const Map<IterVar, IntSet>& dom_map);
/*!
* \brief Same as EvalSet, but takes unordered_map
*
* \param e The expression to be evaluated.
* \param dom_map The domain of each variable.
* \return An integer set that can cover all the possible values of e.
*/
IntSet EvalSet(Expr e,
const std::unordered_map<const Variable*, IntSet>& dom_map);
/*!
* \brief Find an symbolic integer set that contains is union over
* all the possible conditional values in dom_map.
*
* \param r The initial range.
* \param dom_map The domain of each variable.
* \return An integer set that can cover all the possible values.
*/
IntSet EvalSet(Range r,
const Map<IterVar, IntSet>& dom_map);
/*!
* \brief Find an symbolic integer set that contains is union over
* all the possible conditional values in dom_map.
*
* \param s The initial set.
* \param dom_map The domain of each variable.
* \return An integer set that can cover all the possible values.
*/
IntSet EvalSet(IntSet s,
const std::unordered_map<const Variable*, IntSet>& dom_map);
/*!
* \brief Same as EvalSet, but takes unordered_map
*
* \param r The range to be evaluated.
* \param dom_map The domain of each variable.
* \return An integer set that can cover all the possible values of e.
*/
IntSet EvalSet(Range r,
const std::unordered_map<const Variable*, IntSet>& dom_map);
/*! \brief Map from Expr to IntSet */
using ExprIntSetMap = std::unordered_map<Expr, IntSet, ExprHash, ExprEqual>;
/*!
* \brief Find the integer set of every sub-expression, given the
* domain of each iteration variables.
*
* \param e The expression to be evaluated.
* \param dom_map The domain of each variable.
* \return the map from the expression to its possible value.
*/
ExprIntSetMap EvalSetForEachSubExpr(
Expr e,
const std::unordered_map<const Variable*, IntSet>& dom_map);
/*!
* \brief Create an union set of all sets
* \param sets The sets to be unioned
* \return the set after union
*/
IntSet Union(const Array<IntSet>& sets);
/*!
* \brief Create an union set of all sets
* \param sets The sets to be intersected
* \return the set after intersected
*/
IntSet Intersect(const Array<IntSet>& sets);
/*!
* \brief Deduce the bound of the target variable in a expression,
* give the domain of each variables. Return undefined IntSet to
* represent failure.
*
* \param v The target variable to be deduced.
* \param cond The conditional expression.
* \param hint_map The domain of variable, used to help deduce.
* \param relax_map The domain of each variable, used to relax the domain,
* The deduce bound mush implies e for all value in relax_map
* \return An integer set that can cover all the possible values.
*/
IntSet DeduceBound(Expr v, Expr cond,
const Map<Var, IntSet>& hint_map,
const Map<Var, IntSet>& relax_map);
/*!
* \brief Same as DeduceBound with unordered_map signature.
*
* \param v The target variable to be deduced.
* \param cond The conditional expression.
* \param hint_map The domain of variable, used to help deduce.
* \param relax_map The domain of each variable, used to relax the domain,
* The deduce bound mush implies e for all value in relax_map
* \return An integer set that can cover all the possible values.
*/
IntSet DeduceBound(Expr v, Expr cond,
const std::unordered_map<const Variable*, IntSet>& hint_map,
const std::unordered_map<const Variable*, IntSet>& relax_map);
/*!
* \brief Infer a regular domain that covers all the calls or provides within the given statement.
* \param body The given statement.
* \param tensor The name of the calls or provides.
* \param consider_calls If calls (read) are considered.
* \param consider_provides If provides (write) are considered.
* \return The domain that covers all the calls or provides within the given statement.
*/
Domain DomainTouched(Stmt body, const Tensor &tensor, bool consider_calls, bool consider_provides);
/*!
* \brief Evaluate the expression with modular analysis
* \param e The expression to be evaluated.
* \param mod_map Map of modular statistics of known variables.
* \return The ModularEntry covering all possible value of e.
*/
ModularEntry EvalModular(
const Expr& e,
const std::unordered_map<const Variable*, ModularEntry>& mod_map);
/*!
* \brief Same as EvalModular, used by front-end.
* \param e The expression to be evaluated.
* \param mod_map Map of modular statistics of known variables.
* \return A ModularSet covering all possible value of e.
*/
IntSet EvalModular(const Expr& e,
const Map<Var, IntSet>& mod_map);
// implementation
inline const IntSetNode* IntSet::operator->() const {
return static_cast<const IntSetNode*>(node_.get());
}
} // namespace arith
} // namespace tvm
#endif // TVM_ARITHMETIC_H_