The fixed point semantics work similarly to fltSemantics. More...

#include "llvm/ADT/APFixedPoint.h"

Classes
struct	Lsb
	Used to differentiate between constructors with Width and Lsb from the default Width and scale. More...

Public Member Functions
	FixedPointSemantics (unsigned Width, unsigned Scale, bool IsSigned, bool IsSaturated, bool HasUnsignedPadding)
	FixedPointSemantics (unsigned Width, Lsb Weight, bool IsSigned, bool IsSaturated, bool HasUnsignedPadding)
bool	isValidLegacySema () const
	Check if the Semantic follow the requirements of an older more limited version of this class.
unsigned	getWidth () const
unsigned	getScale () const
int	getLsbWeight () const
int	getMsbWeight () const
bool	isSigned () const
bool	isSaturated () const
bool	hasUnsignedPadding () const
void	setSaturated (bool Saturated)
bool	hasSignOrPaddingBit () const
	return true if the first bit doesn't have a strictly positive weight
unsigned	getIntegralBits () const
	Return the number of integral bits represented by these semantics.
LLVM_ABI FixedPointSemantics	getCommonSemantics (const FixedPointSemantics &Other) const
	Return the FixedPointSemantics that allows for calculating the full precision semantic that can precisely represent the precision and ranges of both input values.
LLVM_ABI void	print (llvm::raw_ostream &OS) const
	Print semantics for debug purposes.
LLVM_ABI bool	fitsInFloatSemantics (const fltSemantics &FloatSema) const
	Returns true if this fixed-point semantic with its value bits interpreted as an integer can fit in the given floating point semantic without overflowing to infinity.
bool	operator== (FixedPointSemantics Other) const
bool	operator!= (FixedPointSemantics Other) const
LLVM_ABI uint32_t	toOpaqueInt () const
	Convert the semantics to a 32-bit unsigned integer.

Static Public Member Functions
static FixedPointSemantics	GetIntegerSemantics (unsigned Width, bool IsSigned)
	Return the FixedPointSemantics for an integer type.
static LLVM_ABI FixedPointSemantics	getFromOpaqueInt (uint32_t)
	Create a FixedPointSemantics object from an integer created via toOpaqueInt().

Static Public Attributes
static constexpr unsigned	WidthBitWidth = 16
static constexpr unsigned	LsbWeightBitWidth = 13

Detailed Description

The fixed point semantics work similarly to fltSemantics.

The width specifies the whole bit width of the underlying scaled integer (with padding if any). The scale represents the number of fractional bits in this type. When HasUnsignedPadding is true and this type is unsigned, the first bit in the value this represents is treated as padding.

Definition at line 35 of file APFixedPoint.h.

Constructor & Destructor Documentation

◆ FixedPointSemantics() [1/2]

llvm::FixedPointSemantics::FixedPointSemantics	(	unsigned	Width,
		unsigned	Scale,
		bool	IsSigned,
		bool	IsSaturated,
		bool	HasUnsignedPadding )

inline

Definition at line 44 of file APFixedPoint.h.

References FixedPointSemantics().

Referenced by FixedPointSemantics(), getCommonSemantics(), getFromOpaqueInt(), GetIntegerSemantics(), operator!=(), and operator==().

◆ FixedPointSemantics() [2/2]

llvm::FixedPointSemantics::FixedPointSemantics	(	unsigned	Width,
		Lsb	Weight,
		bool	IsSigned,
		bool	IsSaturated,
		bool	HasUnsignedPadding )

inline

Definition at line 48 of file APFixedPoint.h.

References assert(), llvm::isInt(), llvm::isUInt(), and llvm::FixedPointSemantics::Lsb::LsbWeight.

Member Function Documentation

◆ fitsInFloatSemantics()

bool llvm::FixedPointSemantics::fitsInFloatSemantics ( const fltSemantics & FloatSema ) const

Returns true if this fixed-point semantic with its value bits interpreted as an integer can fit in the given floating point semantic without overflowing to infinity.

For example, a signed 8-bit fixed-point semantic has a maximum and minimum integer representation of 127 and -128, respectively. If both of these values can be represented (possibly inexactly) in the floating point semantic without overflowing, this returns true.

Definition at line 148 of file APFixedPoint.cpp.

References F, llvm::APFixedPoint::getMax(), llvm::APFixedPoint::getMin(), llvm::APFixedPoint::getValue(), llvm::APSInt::isSigned(), isSigned(), llvm::APFloatBase::opOverflow, and llvm::APFloatBase::rmNearestTiesToAway.

Referenced by llvm::APFixedPoint::getFromFloatValue().

◆ getCommonSemantics()

FixedPointSemantics llvm::FixedPointSemantics::getCommonSemantics ( const FixedPointSemantics & Other ) const

Return the FixedPointSemantics that allows for calculating the full precision semantic that can precisely represent the precision and ranges of both input values.

This does not compute the resulting semantics for a given binary operation.

Definition at line 171 of file APFixedPoint.cpp.

References FixedPointSemantics(), getLsbWeight(), getMsbWeight(), hasSignOrPaddingBit(), hasUnsignedPadding(), isSaturated(), isSigned(), and llvm::Other.

Referenced by llvm::FixedPointBuilder< IRBuilderTy >::CreateAdd(), llvm::FixedPointBuilder< IRBuilderTy >::CreateDiv(), llvm::FixedPointBuilder< IRBuilderTy >::CreateMul(), and llvm::FixedPointBuilder< IRBuilderTy >::CreateSub().

◆ getFromOpaqueInt()

FixedPointSemantics llvm::FixedPointSemantics::getFromOpaqueInt ( uint32_t I )

static

Create a FixedPointSemantics object from an integer created via toOpaqueInt().

Definition at line 36 of file APFixedPoint.cpp.

References F, FixedPointSemantics(), and I.

◆ GetIntegerSemantics()

FixedPointSemantics llvm::FixedPointSemantics::GetIntegerSemantics	(	unsigned	Width,
		bool	IsSigned )

inlinestatic

Return the FixedPointSemantics for an integer type.

Definition at line 104 of file APFixedPoint.h.

References FixedPointSemantics().

Referenced by llvm::FixedPointBuilder< IRBuilderTy >::CreateFixedToInteger(), llvm::FixedPointBuilder< IRBuilderTy >::CreateIntegerToFixed(), and llvm::APFixedPoint::getFromIntValue().

◆ getIntegralBits()

unsigned llvm::FixedPointSemantics::getIntegralBits ( ) const

inline

Return the number of integral bits represented by these semantics.

These are separate from the fractional bits and do not include the sign or padding bit.

Definition at line 80 of file APFixedPoint.h.

References getMsbWeight(), and hasSignOrPaddingBit().

Referenced by llvm::APFixedPoint::convert().

◆ getLsbWeight()

int llvm::FixedPointSemantics::getLsbWeight ( ) const

inline

Definition at line 64 of file APFixedPoint.h.

Referenced by llvm::APFixedPoint::convert(), getCommonSemantics(), llvm::APFixedPoint::getFromFloatValue(), and print().

◆ getMsbWeight()

int llvm::FixedPointSemantics::getMsbWeight ( ) const

inline

Definition at line 65 of file APFixedPoint.h.

Referenced by getCommonSemantics(), getIntegralBits(), and print().

◆ getScale()

unsigned llvm::FixedPointSemantics::getScale ( ) const

inline

Definition at line 63 of file APFixedPoint.h.

References assert(), and isValidLegacySema().

Referenced by llvm::FixedPointBuilder< IRBuilderTy >::CreateFixedToFloating(), llvm::FixedPointBuilder< IRBuilderTy >::CreateFloatingToFixed(), and print().

◆ getWidth()

unsigned llvm::FixedPointSemantics::getWidth ( ) const

inline

Definition at line 62 of file APFixedPoint.h.

Referenced by llvm::APFixedPoint::convert(), llvm::FixedPointBuilder< IRBuilderTy >::CreateFloatingToFixed(), llvm::APFixedPoint::getFromFloatValue(), and print().

◆ hasSignOrPaddingBit()

bool llvm::FixedPointSemantics::hasSignOrPaddingBit ( ) const

inline

return true if the first bit doesn't have a strictly positive weight

Definition at line 75 of file APFixedPoint.h.

Referenced by getCommonSemantics(), and getIntegralBits().

◆ hasUnsignedPadding()

bool llvm::FixedPointSemantics::hasUnsignedPadding ( ) const

inline

Definition at line 70 of file APFixedPoint.h.

Referenced by llvm::FixedPointBuilder< IRBuilderTy >::CreateFloatingToFixed(), llvm::FixedPointBuilder< IRBuilderTy >::CreateShl(), and getCommonSemantics().

◆ isSaturated()

bool llvm::FixedPointSemantics::isSaturated ( ) const

inline

Definition at line 69 of file APFixedPoint.h.

Referenced by llvm::APFixedPoint::convert(), llvm::FixedPointBuilder< IRBuilderTy >::CreateFloatingToFixed(), llvm::FixedPointBuilder< IRBuilderTy >::CreateShl(), getCommonSemantics(), and llvm::APFixedPoint::getFromFloatValue().

◆ isSigned()

bool llvm::FixedPointSemantics::isSigned ( ) const

inline

Definition at line 68 of file APFixedPoint.h.

Referenced by llvm::APFixedPoint::convert(), llvm::FixedPointBuilder< IRBuilderTy >::CreateFixedToFloating(), llvm::FixedPointBuilder< IRBuilderTy >::CreateFloatingToFixed(), llvm::FixedPointBuilder< IRBuilderTy >::CreateShl(), llvm::FixedPointBuilder< IRBuilderTy >::CreateShr(), fitsInFloatSemantics(), getCommonSemantics(), and llvm::APFixedPoint::getFromFloatValue().

◆ isValidLegacySema()

bool llvm::FixedPointSemantics::isValidLegacySema ( ) const

inline

Check if the Semantic follow the requirements of an older more limited version of this class.

Definition at line 59 of file APFixedPoint.h.

Referenced by getScale(), and print().

◆ operator!=()

bool llvm::FixedPointSemantics::operator!= ( FixedPointSemantics Other ) const

inline

Definition at line 116 of file APFixedPoint.h.

References FixedPointSemantics(), and llvm::Other.

◆ operator==()

bool llvm::FixedPointSemantics::operator== ( FixedPointSemantics Other ) const

inline

Definition at line 111 of file APFixedPoint.h.

References FixedPointSemantics(), and llvm::Other.

◆ print()

void llvm::FixedPointSemantics::print ( llvm::raw_ostream & OS ) const

Print semantics for debug purposes.

Definition at line 21 of file APFixedPoint.cpp.

References getLsbWeight(), getMsbWeight(), getScale(), getWidth(), and isValidLegacySema().

◆ setSaturated()

void llvm::FixedPointSemantics::setSaturated ( bool Saturated )

inline

Definition at line 72 of file APFixedPoint.h.

◆ toOpaqueInt()

uint32_t llvm::FixedPointSemantics::toOpaqueInt ( ) const

Convert the semantics to a 32-bit unsigned integer.

The result is dependent on the host endianness and not stable across LLVM versions. See getFromOpaqueInt() to convert it back to a FixedPointSemantics object.

Definition at line 32 of file APFixedPoint.cpp.

References llvm::bit_cast().

Member Data Documentation

◆ LsbWeightBitWidth

unsigned llvm::FixedPointSemantics::LsbWeightBitWidth = 13

staticconstexpr

Definition at line 38 of file APFixedPoint.h.

◆ WidthBitWidth

unsigned llvm::FixedPointSemantics::WidthBitWidth = 16

staticconstexpr

Definition at line 37 of file APFixedPoint.h.

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

include/llvm/ADT/APFixedPoint.h
lib/Support/APFixedPoint.cpp

Classes

Public Member Functions

Static Public Member Functions

Static Public Attributes

Detailed Description

Constructor & Destructor Documentation

◆ FixedPointSemantics() [1/2]

◆ FixedPointSemantics() [2/2]

Member Function Documentation

◆ fitsInFloatSemantics()

◆ getCommonSemantics()

◆ getFromOpaqueInt()

◆ GetIntegerSemantics()

◆ getIntegralBits()

◆ getLsbWeight()

◆ getMsbWeight()

◆ getScale()

◆ getWidth()

◆ hasSignOrPaddingBit()

◆ hasUnsignedPadding()

◆ isSaturated()

◆ isSigned()

◆ isValidLegacySema()

◆ operator!=()

◆ operator==()

◆ print()

◆ setSaturated()

◆ toOpaqueInt()

Member Data Documentation

◆ LsbWeightBitWidth

◆ WidthBitWidth