FixedPoint< FractionalBits, Rounded, FastApproximation > Class Template Reference

Fixed point number with a configurable number of fractional bits. More...

#include <fixedpoint.h>

Public Member Functions
constexpr	FixedPoint ()=default
	Default constructor.
template<std::size_t OtherFractionalBits>
constexpr	FixedPoint (FixedPoint< OtherFractionalBits > other) noexcept
	Construct a fixed point number from another fixed point number.
template<std::integral T>
constexpr	FixedPoint (T value) noexcept
	Convert an integer to a fixed point number.
constexpr	FixedPoint (float value) noexcept
	Convert from a float to a fixed point number.
constexpr	operator float () const noexcept
	Explicit conversion to float.
constexpr	FixedPoint (double value) noexcept
	Convert from a double to a fixed point number.
	operator double () const noexcept
	Explicit conversion to double.
template<std::size_t OutputFractionalBits>
constexpr FixedPoint< OutputFractionalBits >	as () const
	Convert to a fixed point number with a different number of fractional bits.
template<std::integral T>
	operator T () const noexcept
	Explicit conversion to integer.
	operator bool () const noexcept
constexpr FixedPoint	operator- () const
	Negation operator.
constexpr BaseType	raw () const noexcept
	Get the internal value.
constexpr FixedPoint	operator+ (const FixedPoint &rhs) const
	Addition operator Add two fixed point numbers with the same number of fractional bits.
constexpr FixedPoint	operator+= (const FixedPoint &rhs)
	Addition operator Add two fixed point numbers with the same number of fractional bits.
constexpr FixedPoint	operator- (const FixedPoint &rhs) const
	Subtraction operator Subtract two fixed point numbers with the same number of fractional bits.
constexpr FixedPoint	operator-= (const FixedPoint &rhs)
	Subtraction operator Subtract two fixed point numbers with the same number of fractional bits.
constexpr FixedPoint	operator* (const FixedPoint &rhs) const
	Multiplication operator Multiply two fixed point numbers with the same number of fractional bits.
constexpr FixedPoint	operator*= (const FixedPoint &rhs)
	Multiplication operator Multiply two fixed point numbers with the same number of fractional bits.
template<std::size_t OutputFractionalBits = FractionalBits, std::size_t OtherFractionalBits, bool OtherRounded, bool OtherApproximating>
constexpr FixedPoint< OutputFractionalBits, Rounded, FastApproximation >	operator* (const FixedPoint< OtherFractionalBits, OtherRounded, OtherApproximating > &rhs) const
	Multiplication operator Multiply two fixed point numbers with different number of fractional bits.
template<std::size_t OtherFractionalBits>
constexpr FixedPoint	operator*= (const FixedPoint< OtherFractionalBits > &rhs)
	Multiplication operator Multiply two fixed point numbers with different number of fractional bits.
constexpr FixedPoint	operator/ (const FixedPoint &rhs) const
	Division operator Divide two fixed point numbers with the same number of fractional bits.
constexpr FixedPoint	operator/= (const FixedPoint &rhs)
	Division operator Divide two fixed point numbers with the same number of fractional bits.
template<std::size_t OtherFractionalBitsA, std::size_t OtherFractionalBitsB>
constexpr FixedPoint	MultiplyAdd (const FixedPoint< OtherFractionalBitsA > &a, const FixedPoint< OtherFractionalBitsB > &b) const
	Fused multiply-add operation for fixed point numbers with a different number of fractional bits.
constexpr FixedPoint	MultiplyAdd (const FixedPoint &a, const FixedPoint &b) const
	Fused multiply-add operation for fixed point numbers with the same number of fractional bits.
constexpr bool	operator== (const FixedPoint &rhs) const noexcept
	Equality operator.
constexpr std::strong_ordering	operator<=> (const FixedPoint &rhs) const noexcept
	Three-way comparison operator.
template<std::size_t OtherFractionalBits>
constexpr bool	operator== (const FixedPoint< OtherFractionalBits > &rhs) const noexcept
	Equality operator for fixed point numbers with different number of fractional bits.
template<std::size_t OtherFractionalBits>
constexpr std::strong_ordering	operator<=> (const FixedPoint< OtherFractionalBits > &rhs) const noexcept
	Three-way comparison operator for fixed point numbers with different number of fractional bits.
template<typename T>
constexpr bool	operator== (const T &rhs) const noexcept
	Equality operator for integers and floating point numbers.

Static Public Member Functions
static constexpr FixedPoint	from_raw (BaseType raw) noexcept
	Construct from a raw value.

Static Public Attributes
static constexpr std::size_t	fractional_bits = FractionalBits
static constexpr std::size_t	integral_bits = 32 - FractionalBits
static constexpr bool	rounded = Rounded
static constexpr bool	fast_approximation = FastApproximation

Private Types
using	BaseType = int32_t
using	IntermediateType = int64_t

Static Private Member Functions
static int32_t	signed_most_significant_word_multiply_add (int32_t a, int32_t b, int32_t c)
	a + b * c
static int32_t	signed_most_significant_word_multiply (int32_t a, int32_t b)
static constexpr BaseType	one () noexcept

Private Attributes
BaseType	value_ {0}

Detailed Description

template<std::size_t FractionalBits, bool Rounded = false, bool FastApproximation = true>
class FixedPoint< FractionalBits, Rounded, FastApproximation >

Fixed point number with a configurable number of fractional bits.

Note

This class only supports 32-bit signed fixed point numbers

Template Parameters

FractionalBits	The number of fractional bits
Rounded	Whether to round the result when performing operations
FastApproximation	Whether to use a fast approximation for operations

Constructor & Destructor Documentation

FixedPoint() [1/4]

template<std::size_t FractionalBits, bool Rounded = false, bool FastApproximation = true>

template<std::size_t OtherFractionalBits>

FixedPoint< FractionalBits, Rounded, FastApproximation >::FixedPoint ( FixedPoint< OtherFractionalBits > other )

inlineexplicitconstexprnoexcept

Construct a fixed point number from another fixed point number.

Note

This will saturate or truncate (and/or round) the value if the number of fractional bits is different

FixedPoint() [2/4]

template<std::size_t FractionalBits, bool Rounded = false, bool FastApproximation = true>

template<std::integral T>

FixedPoint< FractionalBits, Rounded, FastApproximation >::FixedPoint ( T value )

inlineexplicitconstexprnoexcept

Convert an integer to a fixed point number.

Note

This truncates the integer if it is too large

FixedPoint() [3/4]

template<std::size_t FractionalBits, bool Rounded = false, bool FastApproximation = true>

FixedPoint< FractionalBits, Rounded, FastApproximation >::FixedPoint ( float value )

inlineexplicitconstexprnoexcept

Convert from a float to a fixed point number.

Note

VFP instruction - 1 cycle for issue, 4 cycles result latency

FixedPoint() [4/4]

template<std::size_t FractionalBits, bool Rounded = false, bool FastApproximation = true>

FixedPoint< FractionalBits, Rounded, FastApproximation >::FixedPoint ( double value )

inlineexplicitconstexprnoexcept

Convert from a double to a fixed point number.

Note

VFP instruction - 1 cycle for issue, 4 cycles result latency

Member Function Documentation

operator double()

template<std::size_t FractionalBits, bool Rounded = false, bool FastApproximation = true>

FixedPoint< FractionalBits, Rounded, FastApproximation >::operator double ( ) const

inlineexplicitnoexcept

Explicit conversion to double.

Note

VFP instruction - 1 cycle for issue, 4 cycles result latency

operator float()

template<std::size_t FractionalBits, bool Rounded = false, bool FastApproximation = true>

FixedPoint< FractionalBits, Rounded, FastApproximation >::operator float ( ) const

inlineexplicitconstexprnoexcept

Explicit conversion to float.

Note

VFP instruction - 1 cycle for issue, 4 cycles result latency

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

• src/deluge/util/fixedpoint.h