mlir::SDBMExpr Class Reference

#include <SDBMExpr.h>

Inheritance diagram for mlir::SDBMExpr:

Collaboration diagram for mlir::SDBMExpr:

Public Types
using	ImplType = detail::SDBMExprStorage

Public Member Functions
	SDBMExpr ()
	SDBMExpr (ImplType *expr)
	SDBMExpr (const SDBMExpr &)=default
SDBMExpr &	operator= (const SDBMExpr &)=default
bool	operator== (const SDBMExpr &other) const
	SDBM expressions can be compared straight-forwardly. More...
bool	operator!= (const SDBMExpr &other) const
	operator bool () const
bool	operator! () const
SDBMExpr	operator- ()
	Negate the given SDBM expression. More...
void	print (raw_ostream &os) const
	Prints the SDBM expression. More...
void	dump () const
template<typename U >
bool	isa () const
	LLVM-style casts. More...
template<typename U >
U	dyn_cast () const
template<typename U >
U	cast () const
::llvm::hash_code	hash_value () const
	Support for LLVM hashing. More...
SDBMExprKind	getKind () const
	Returns the kind of the SDBM expression. More...
MLIRContext *	getContext () const
	Returns the MLIR context in which this expression lives. More...
SDBMDialect *	getDialect () const
	Returns the SDBM dialect instance. More...
AffineExpr	getAsAffineExpr () const

Static Public Member Functions
static Optional< SDBMExpr >	tryConvertAffineExpr (AffineExpr affine)

Protected Attributes
ImplType *	impl

Detailed Description

Striped Difference-Bounded Matrix (SDBM) expression is a base left-hand side expression for the SDBM framework. SDBM expressions are a subset of affine expressions supporting low-complexity algorithms for the operations used in loop transformations. In particular, are supported:

• constant expressions;
• single variables (dimensions and symbols) with +1 or -1 coefficient;
• stripe expressions: "x # C", where "x" is a single variable or another stripe expression, "#" is the stripe operator, and "C" is a constant expression; "#" is defined as x - x mod C.
• sum expressions between single variable/stripe expressions and constant expressions;
• difference expressions between single variable/stripe expressions. SDBMExpr class hierarchy provides a type-safe interface to constructing and operating on SDBM expressions. For example, it requires the LHS of a sum expression to be a single variable or a stripe expression. These restrictions are intended to force the caller to perform the necessary simplifications to stay within the SDBM domain, because SDBM expressions do not combine in more cases than they do. This choice may be reconsidered in the future.

SDBM expressions are grouped into the following structure

• expression
  • varying
    • direct
      • sum <- (term, constant)
      • term
        • symbol
        • dimension
        • stripe <- (direct, constant)
    • negation <- (direct)
    • difference <- (direct, term)
  • constant The notation <- (...) denotes the types of subexpressions a compound expression can combine. The tree of subexpressions essentially imposes the following canonicalization rules:
  • constants are always folded;
  • constants can only appear on the RHS of an expression;
  • double negation must be elided;
  • an additive constant term is only allowed in a sum expression, and should be sunk into the nearest such expression in the tree;
  • zero constant expression can only appear at the top level.

SDBMExpr and derived classes are thin wrappers around a pointer owned by an MLIRContext, and should be used by-value. They are uniqued in the MLIRContext and immortal.

Member Typedef Documentation

ImplType

using mlir::SDBMExpr::ImplType = detail::SDBMExprStorage

Constructor & Destructor Documentation

SDBMExpr() [1/3]

mlir::SDBMExpr::SDBMExpr ( )

inline

SDBMExpr() [2/3]

mlir::SDBMExpr::SDBMExpr ( ImplType *  expr )

inline

SDBMExpr() [3/3]

mlir::SDBMExpr::SDBMExpr ( const SDBMExpr &  )

default

SDBM expressions are thin wrappers around a unique'ed immutable pointer, which makes them trivially assignable and trivially copyable.

Member Function Documentation

cast()

template<typename U >

U mlir::SDBMExpr::cast ( ) const

inline

dump()

void SDBMExpr::dump

(

)

const

dyn_cast()

template<typename U >

U mlir::SDBMExpr::dyn_cast ( ) const

inline

getAsAffineExpr()

AffineExpr SDBMExpr::getAsAffineExpr

(

)

const

Convert the SDBM expression into an Affine expression. This always succeeds because SDBM are a subset of affine.

getContext()

MLIRContext * SDBMExpr::getContext

(

)

const

Returns the MLIR context in which this expression lives.

getDialect()

SDBMDialect * SDBMExpr::getDialect

(

)

const

Returns the SDBM dialect instance.

getKind()

SDBMExprKind SDBMExpr::getKind

(

)

const

Returns the kind of the SDBM expression.

hash_value()

::llvm::hash_code mlir::SDBMExpr::hash_value ( ) const

inline

Support for LLVM hashing.

isa()

template<typename U >

bool mlir::SDBMExpr::isa ( ) const

inline

LLVM-style casts.

operator bool()

mlir::SDBMExpr::operator bool ( ) const

inlineexplicit

SDBM expressions are convertible to bool: null expressions are converted to false, non-null expressions are converted to true.

operator!()

bool mlir::SDBMExpr::operator! ( ) const

inline

operator!=()

bool mlir::SDBMExpr::operator!= ( const SDBMExpr &  other ) const

inline

operator-()

SDBMExpr SDBMExpr::operator-

(

)

Negate the given SDBM expression.

operator=()

SDBMExpr& mlir::SDBMExpr::operator= ( const SDBMExpr &  )

default

operator==()

bool mlir::SDBMExpr::operator== ( const SDBMExpr &  other ) const

inline

SDBM expressions can be compared straight-forwardly.

print()

void SDBMExpr::print

(

raw_ostream &

os

)

const

Prints the SDBM expression.

tryConvertAffineExpr()

Optional< SDBMExpr > SDBMExpr::tryConvertAffineExpr ( AffineExpr  affine )

static

Try constructing an SDBM expression from the given affine expression. This may fail if the affine expression is not representable as SDBM, in which case llvm::None is returned. The conversion procedure recognizes (nested) multiplicative ((x floordiv B) * B) and additive (x - x mod B) patterns for the stripe expression.

Member Data Documentation

impl

ImplType* mlir::SDBMExpr::impl

protected

---

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

• include/mlir/Dialect/SDBM/SDBMExpr.h
• lib/Dialect/SDBM/SDBMExpr.cpp