tvm::arith::RewriteSimplifier Class Reference

Rewrite-rule based simplifier. More...

#include <analyzer.h>

Collaboration diagram for tvm::arith::RewriteSimplifier:

Public Types
enum	Extension {   kNone = 0 , kTransitivelyProveInequalities = (1 << 0) , kConvertBooleanToAndOfOrs = (1 << 1) , kApplyConstraintsToBooleanBranches = (1 << 2) ,   kComparisonOfProductAndSum = (1 << 3) }
	Flags to enable more computationally-intensive simplifications. More...

Public Member Functions
PrimExpr	operator() (const PrimExpr &expr)
	analyze the expr More...
void	Update (const Var &var, const PrimExpr &new_expr, bool allow_override=false)
	Update binding of var to a new expression. More...
std::function< void()>	EnterConstraint (const PrimExpr &constraint)
	Update the internal state to enter constraint. More...
void	SetEnabledExtensions (Extension flags)
	Enable an optional extension or extensions. More...
Extension	GetEnabledExtensions () const
	Return the currently enabled extensions. More...
ObjectRef	GetStatsCounters () const
	Return the statistics counters. More...
void	ResetStatsCounters ()
	Reset the statistics counters. More...
void	SetMaximumRewriteSteps (int64_t maximum)
	Set the maximum allowed number of rewrite steps. More...

Friends
class	Analyzer
class	ConstraintContext
class	CanonicalSimplifier

Detailed Description

Rewrite-rule based simplifier.

Member Enumeration Documentation

Extension

enum tvm::arith::RewriteSimplifier::Extension

Flags to enable more computationally-intensive simplifications.

These simplifications may be required for specific schedules, but would impose too high a compile-time cost to enable by default. They can be enabled on an as-needed basis by calling RewriteSimplifier::SetEnabledExtensions prior to using RewriteSimplifier::operator().

Flags are defined as powers of two to allow future expansion. To enable multiple extensions, a user should pass a bitwise OR of the flags for each desired extension.

Enumerator
kNone
kTransitivelyProveInequalities
kConvertBooleanToAndOfOrs
kApplyConstraintsToBooleanBranches
kComparisonOfProductAndSum

Member Function Documentation

EnterConstraint()

std::function<void()> tvm::arith::RewriteSimplifier::EnterConstraint

(

const PrimExpr &

constraint

)

Update the internal state to enter constraint.

Parameters

constraint

A constraint expression.

Returns

an exit function that must be called to cleanup the constraint can be nullptr.

GetEnabledExtensions()

Extension tvm::arith::RewriteSimplifier::GetEnabledExtensions

(

)

const

Return the currently enabled extensions.

GetStatsCounters()

ObjectRef tvm::arith::RewriteSimplifier::GetStatsCounters

(

)

const

Return the statistics counters.

operator()()

PrimExpr tvm::arith::RewriteSimplifier::operator()

(

const PrimExpr &

expr

)

analyze the expr

Parameters

expr	The expression of interest.

Returns

the result of the analysis.

ResetStatsCounters()

void tvm::arith::RewriteSimplifier::ResetStatsCounters

(

)

Reset the statistics counters.

SetEnabledExtensions()

void tvm::arith::RewriteSimplifier::SetEnabledExtensions

(

Extension

flags

)

Enable an optional extension or extensions.

Parameters

flags

A bitwise OR of all optional extensions that should be enabled.

SetMaximumRewriteSteps()

void tvm::arith::RewriteSimplifier::SetMaximumRewriteSteps

(

int64_t

maximum

)

Set the maximum allowed number of rewrite steps.

By default, the simplifier may perform as many steps as are required. If a positive limit is set, then the simplifier will throw an exception when exceeding that number of rewrite steps. This allows tests to guard against performance regressions.

Note: To maintain accurate usage counters, Analyzer instances should be re-used wherever possible. For example, TIR transformations should declare a single Analyzer that is used throughout the pass, and utility functions should receive an Analyzer* from their calling scope.

Update()

void tvm::arith::RewriteSimplifier::Update	(	const Var &	var,
		const PrimExpr &	new_expr,
		bool	allow_override = false
	)

Update binding of var to a new expression.

Parameters

var	The variable of interest.
new_expr
allow_override	Whether we allow override of existing information.

Friends And Related Function Documentation

Analyzer

friend class Analyzer

friend

CanonicalSimplifier

friend class CanonicalSimplifier

friend

ConstraintContext

friend class ConstraintContext

friend

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The documentation for this class was generated from the following file:

• include/tvm/arith/analyzer.h