LLVM  17.0.0git
Classes | Public Member Functions | Static Public Member Functions | Static Public Attributes | List of all members
llvm::FixedPointSemantics Class Reference

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

#include "llvm/ADT/APFixedPoint.h"

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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. More...
 
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 More...
 
unsigned getIntegralBits () const
 Return the number of integral bits represented by these semantics. More...
 
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. More...
 
void print (llvm::raw_ostream &OS) const
 Print semantics for debug purposes. More...
 
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. More...
 
bool operator== (FixedPointSemantics Other) const
 
bool operator!= (FixedPointSemantics Other) const
 

Static Public Member Functions

static FixedPointSemantics GetIntegerSemantics (unsigned Width, bool IsSigned)
 Return the FixedPointSemantics for an integer type. More...
 

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.

Referenced by getCommonSemantics(), and GetIntegerSemantics().

◆ 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(), 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 132 of file APFixedPoint.cpp.

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

Referenced by llvm::APFixedPoint::convertToFloat(), and llvm::APFixedPoint::getFromFloatValue().

◆ getCommonSemantics()

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

◆ GetIntegerSemantics()

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

◆ 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(), hasSignOrPaddingBit(), and llvm::max().

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

◆ getLsbWeight()

int llvm::FixedPointSemantics::getLsbWeight ( ) const
inline

◆ getMsbWeight()

int llvm::FixedPointSemantics::getMsbWeight ( ) const
inline

◆ getScale()

unsigned llvm::FixedPointSemantics::getScale ( ) const
inline

◆ getWidth()

unsigned llvm::FixedPointSemantics::getWidth ( ) const
inline

◆ 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

◆ isSaturated()

bool llvm::FixedPointSemantics::isSaturated ( ) const
inline

◆ isSigned()

bool llvm::FixedPointSemantics::isSigned ( ) const
inline

◆ 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 Other.

◆ operator==()

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

Definition at line 111 of file APFixedPoint.h.

References 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().

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

◆ setSaturated()

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

Definition at line 72 of file APFixedPoint.h.

Member Data Documentation

◆ LsbWeightBitWidth

constexpr unsigned llvm::FixedPointSemantics::LsbWeightBitWidth = 13
staticconstexpr

Definition at line 38 of file APFixedPoint.h.

◆ WidthBitWidth

constexpr 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: