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...
ffi::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()

ffi::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