FloatFormat Class Reference

Encoding information for a single floating-point format. More...

#include <float.hh>

Public Types
enum	floatclass {   normalized = 0, infinity = 1, zero = 2, nan = 3,   denormalized = 4 }
	The various classes of floating-point encodings. More...

Public Member Functions
	FloatFormat (int4 sz)
	Construct default IEEE 754 standard settings. More...
double	getHostFloat (uintb encoding, floatclass *type) const
	Convert an encoding into host's double. More...
uintb	getEncoding (double host) const
	Convert host's double into this encoding. More...
uintb	convertEncoding (uintb encoding, const FloatFormat *formin) const
	Convert between two different formats. More...
uintb	extractFractionalCode (uintb x) const
	Extract the fractional part of the encoding. More...
bool	extractSign (uintb x) const
	Extract the sign bit from the encoding. More...
int4	extractExponentCode (uintb x) const
	Extract the exponent from the encoding. More...
uintb	opEqual (uintb a, uintb b) const
	Equality comparison (==) More...
uintb	opNotEqual (uintb a, uintb b) const
	Inequality comparison (!=) More...
uintb	opLess (uintb a, uintb b) const
	Less-than comparison (<) More...
uintb	opLessEqual (uintb a, uintb b) const
	Less-than-or-equal comparison (<=) More...
uintb	opNan (uintb a) const
	Test if Not-a-Number (NaN) More...
uintb	opAdd (uintb a, uintb b) const
	Addition (+) More...
uintb	opDiv (uintb a, uintb b) const
	Division (/) More...
uintb	opMult (uintb a, uintb b) const
	Multiplication (*) More...
uintb	opSub (uintb a, uintb b) const
	Subtraction (-) More...
uintb	opNeg (uintb a) const
	Unary negate. More...
uintb	opAbs (uintb a) const
	Absolute value (abs) More...
uintb	opSqrt (uintb a) const
	Square root (sqrt) More...
uintb	opTrunc (uintb a, int4 sizeout) const
	Convert floating-point to integer. More...
uintb	opCeil (uintb a) const
	Ceiling (ceil) More...
uintb	opFloor (uintb a) const
	Floor (floor) More...
uintb	opRound (uintb a) const
	Round. More...
uintb	opInt2Float (uintb a, int4 sizein) const
	Convert integer to floating-point. More...
uintb	opFloat2Float (uintb a, const FloatFormat &outformat) const
	Convert between floating-point precisions. More...
void	saveXml (ostream &s) const
	Save the format to an XML stream. More...
void	restoreXml (const Element *el)
	Restore the format from XML. More...

Detailed Description

Encoding information for a single floating-point format.

This class supports manipulation of a single floating-point encoding. An encoding can be converted to and from the host format and convenience methods allow p-code floating-point operations to be performed on natively encoded operands. This follows the IEEE754 standards.

Member Enumeration Documentation

floatclass

enum FloatFormat::floatclass

The various classes of floating-point encodings.

Enumerator
normalized	A normal floating-point number.
infinity	An encoding representing an infinite value.
zero	An encoding of the value zero.
nan	An invalid encoding, Not-a-Number.
denormalized	A denormalized encoding (for very small values)

Constructor & Destructor Documentation

FloatFormat()

FloatFormat::FloatFormat

(

int4

sz

)

Construct default IEEE 754 standard settings.

Set format for a given encoding size according to IEEE 754 standards

Parameters

sz	is the size of the encoding in bytes

Member Function Documentation

convertEncoding()

uintb FloatFormat::convertEncoding	(	uintb	encoding,
		const FloatFormat *	formin
	)		const

Convert between two different formats.

Parameters

encoding	is the value in the other FloatFormat
formin	is the other FloatFormat

Returns

the equivalent value in this FloatFormat

extractExponentCode()

int4 FloatFormat::extractExponentCode

(

uintb

x

)

const

Extract the exponent from the encoding.

Parameters

x	is an encoded floating-point value

Returns

the (signed) exponent

extractFractionalCode()

uintb FloatFormat::extractFractionalCode

(

uintb

x

)

const

Extract the fractional part of the encoding.

Parameters

x	is an encoded floating-point value

Returns

the fraction part of the value aligned to the top of the word

extractSign()

bool FloatFormat::extractSign

(

uintb

x

)

const

Extract the sign bit from the encoding.

Parameters

x	is an encoded floating-point value

Returns

the sign bit

getEncoding()

uintb FloatFormat::getEncoding

(

double

host

)

const

Convert host's double into this encoding.

Parameters

host	is the double value to convert

Returns

the equivalent encoded value

getHostFloat()

double FloatFormat::getHostFloat	(	uintb	encoding,
		floatclass *	type
	)		const

Convert an encoding into host's double.

Parameters

encoding	is the encoding value
type	points to the floating-point class, which is passed back

Returns

the equivalent double value

opAbs()

uintb FloatFormat::opAbs

(

uintb

a

)

const

Absolute value (abs)

Parameters

a	is an encoded floating-point value

Returns

abs(a)

opAdd()

uintb FloatFormat::opAdd	(	uintb	a,
		uintb	b
	)		const

Addition (+)

Parameters

a	is the first floating-point value
b	is the second floating-point value

Returns

a + b

opCeil()

uintb FloatFormat::opCeil

(

uintb

a

)

const

Ceiling (ceil)

Parameters

a	is an encoded floating-point value

Returns

ceil(a)

opDiv()

uintb FloatFormat::opDiv	(	uintb	a,
		uintb	b
	)		const

Division (/)

Parameters

a	is the first floating-point value
b	is the second floating-point value

Returns

a / b

opEqual()

uintb FloatFormat::opEqual	(	uintb	a,
		uintb	b
	)		const

Equality comparison (==)

Parameters

a	is the first floating-point value
b	is the second floating-point value

Returns

true if (a == b)

opFloat2Float()

uintb FloatFormat::opFloat2Float	(	uintb	a,
		const FloatFormat &	outformat
	)		const

Convert between floating-point precisions.

Parameters

a	is an encoded floating-point value
outformat	is the desired output FloatFormat

Returns

a converted to the output FloatFormat

opFloor()

uintb FloatFormat::opFloor

(

uintb

a

)

const

Floor (floor)

Parameters

a	is an encoded floating-point value

Returns

floor(a)

opInt2Float()

uintb FloatFormat::opInt2Float	(	uintb	a,
		int4	sizein
	)		const

Convert integer to floating-point.

Parameters

a	is a signed integer value
sizein	is the number of bytes in the integer encoding

Returns

a converted to an encoded floating-point value

opLess()

uintb FloatFormat::opLess	(	uintb	a,
		uintb	b
	)		const

Less-than comparison (<)

Parameters

a	is the first floating-point value
b	is the second floating-point value

Returns

true if (a < b)

opLessEqual()

uintb FloatFormat::opLessEqual	(	uintb	a,
		uintb	b
	)		const

Less-than-or-equal comparison (<=)

Parameters

a	is the first floating-point value
b	is the second floating-point value

Returns

true if (a <= b)

opMult()

uintb FloatFormat::opMult	(	uintb	a,
		uintb	b
	)		const

Multiplication (*)

Parameters

a	is the first floating-point value
b	is the second floating-point value

Returns

a * b

opNan()

uintb FloatFormat::opNan

(

uintb

a

)

const

Test if Not-a-Number (NaN)

Parameters

a	is an encoded floating-point value

Returns

true if a is Not-a-Number

opNeg()

uintb FloatFormat::opNeg

(

uintb

a

)

const

Unary negate.

Parameters

a	is an encoded floating-point value

Returns

-a

opNotEqual()

uintb FloatFormat::opNotEqual	(	uintb	a,
		uintb	b
	)		const

Inequality comparison (!=)

Parameters

a	is the first floating-point value
b	is the second floating-point value

Returns

true if (a != b)

opRound()

uintb FloatFormat::opRound

(

uintb

a

)

const

Round.

Parameters

a	is an encoded floating-point value

Returns

round(a)

opSqrt()

uintb FloatFormat::opSqrt

(

uintb

a

)

const

Square root (sqrt)

Parameters

a	is an encoded floating-point value

Returns

sqrt(a)

opSub()

uintb FloatFormat::opSub	(	uintb	a,
		uintb	b
	)		const

Subtraction (-)

Parameters

a	is the first floating-point value
b	is the second floating-point value

Returns

a - b

opTrunc()

uintb FloatFormat::opTrunc	(	uintb	a,
		int4	sizeout
	)		const

Convert floating-point to integer.

Parameters

a	is an encoded floating-point value
sizeout	is the desired encoding size of the output

Returns

an integer encoding of a

restoreXml()

void FloatFormat::restoreXml

(

const Element *

el

)

Restore the format from XML.

Restore object from a <floatformat> XML tag

Parameters

el	is the element

saveXml()

void FloatFormat::saveXml

(

ostream &

s

)

const

Save the format to an XML stream.

Write the format out to a <floatformat> XML tag.

Parameters

s	is the output stream

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

• float.hh
• float.cc