L1GctTwosComplement< nBits > Class Template Reference

Definition of signed integer types with overflow. More...

#include <L1GctTwosComplement.h>

Public Member Functions
	L1GctTwosComplement ()
	Construct a signed integer with initial value zero. More...
	L1GctTwosComplement (uint32_t raw)
	Construct a signed integer from raw data, checking for overFlow. More...
	L1GctTwosComplement (int value)
	Construct a signed integer, checking for overflow. More...
template<int mBits>
	L1GctTwosComplement (const L1GctTwosComplement< mBits > &rhs)
	Copy contructor to move data between representations with different numbers of bits. More...
L1GctTwosComplement	operator+ (const L1GctTwosComplement &rhs) const
	add two numbers of the same size More...
L1GctTwosComplement	operator- () const
	overload unary - (negation) operator More...
L1GctTwosComplement &	operator= (int value)
	overload = operator More...
bool	overFlow () const
	access overflow More...
uint32_t	raw () const
	access raw data More...
void	reset ()
	reset value and overflow to zero More...
void	setOverFlow (bool oflow)
	set the overflow bit More...
void	setRaw (uint32_t raw)
	set the raw data More...
void	setValue (int value)
	set value from signed int More...
int	size () const
	return number of bits More...
int	value () const
	access value as signed int More...
	~L1GctTwosComplement ()
	Destructor. More...

Private Member Functions
void	checkOverFlow (uint32_t rawValue, uint32_t &maskValue, bool &overFlow)

Private Attributes
uint32_t	m_data
int	m_nBits
bool	m_overFlow

Static Private Attributes
static const int	MAX_NBITS = 24
static const int	MAX_VALUE = 1 << (MAX_NBITS - 1)

Detailed Description

template<int nBits>
class L1GctTwosComplement< nBits >

Definition of signed integer types with overflow.

This file defines the template class L1GctTwosComplement. It is used to store energy values that are represented in a given number of bits in hardware. The type has a built-in overFlow that is set if the value to be represented is outside the allowed range for that number of bits. This type represents signed integers; unsigned integers are represented by L1GctUnsignedInt. Functions are defined to add two values, and to copy data into a different number of bits.

this header file contains method definitions because these are template classes see http://www.parashift.com/c++-faq-lite/templates.html#faq-35.12

Author

Jim Brooke & Greg Heath

Date

May 2006

Definition at line 28 of file L1GctTwosComplement.h.

Constructor & Destructor Documentation

L1GctTwosComplement() [1/4]

template<int nBits>

L1GctTwosComplement< nBits >::L1GctTwosComplement

(

)

Construct a signed integer with initial value zero.

Definition at line 99 of file L1GctTwosComplement.h.

                                                {
  m_nBits = nBits > 0 && nBits < MAX_NBITS ? nBits : 16;
  this->reset();
}

L1GctTwosComplement() [2/4]

template<int nBits>

L1GctTwosComplement< nBits >::L1GctTwosComplement

(

uint32_t

raw

)

Construct a signed integer from raw data, checking for overFlow.

Definition at line 106 of file L1GctTwosComplement.h.

                                                            {
  m_nBits = nBits > 0 && nBits < MAX_NBITS ? nBits : 16;
  m_overFlow = false;
  this->setRaw(raw);
}

L1GctTwosComplement() [3/4]

template<int nBits>

L1GctTwosComplement< nBits >::L1GctTwosComplement

(

int

value

)

Construct a signed integer, checking for overflow.

Definition at line 114 of file L1GctTwosComplement.h.

                                                         {
  m_nBits = nBits > 0 && nBits < MAX_NBITS ? nBits : 16;
  m_overFlow = false;
  this->setValue(value);
}

~L1GctTwosComplement()

template<int nBits>

L1GctTwosComplement< nBits >::~L1GctTwosComplement ( )

inline

Destructor.

Definition at line 37 of file L1GctTwosComplement.h.

{}

L1GctTwosComplement() [4/4]

template<int nBits>

template<int mBits>

L1GctTwosComplement< nBits >::L1GctTwosComplement

(

const L1GctTwosComplement< mBits > &

rhs

)

Copy contructor to move data between representations with different numbers of bits.

Definition at line 124 of file L1GctTwosComplement.h.

                                                                                     {
  m_nBits = nBits > 0 && nBits < MAX_NBITS ? nBits : 16;
  this->setRaw(rhs.raw());
  this->setOverFlow(this->overFlow() || rhs.overFlow());
}

Member Function Documentation

checkOverFlow()

template<int nBits>

void L1GctTwosComplement< nBits >::checkOverFlow ( uint32_t  rawValue, uint32_t &  maskValue, bool &  overFlow  )

private

Definition at line 217 of file L1GctTwosComplement.h.

                                                                                                     {
  uint32_t signBit = 1 << (m_nBits - 1);
  uint32_t signExtendBits = (static_cast<uint32_t>(MAX_VALUE) - signBit) << 1;
  // Consider and return only MAX_NBITS least significant bits
  uint32_t mskRawValue = rawValue & ((1 << MAX_NBITS) - 1);
  uint32_t value;
  bool ofl;

  if ((mskRawValue & signBit) == 0) {
    value = mskRawValue & ~signExtendBits;
  } else {
    value = mskRawValue | signExtendBits;
  }
  ofl = value != mskRawValue;

  maskValue = value;
  overFlow = ofl;
}

operator+()

template<int nBits>

L1GctTwosComplement< nBits > L1GctTwosComplement< nBits >::operator+

(

const L1GctTwosComplement< nBits > &

rhs

)

const

add two numbers of the same size

Definition at line 181 of file L1GctTwosComplement.h.

                                                                                                            {
  // temporary variable for storing the result (need to set its size)
  L1GctTwosComplement<nBits> temp;
  uint32_t sum;
  bool ofl;

  // do the addition here
  sum = this->raw() + rhs.raw();
  ofl = this->overFlow() || rhs.overFlow();

  //fill the temporary argument
  temp.setRaw(sum);
  temp.setOverFlow(temp.overFlow() || ofl);

  // return the temporary
  return temp;
}

operator-()

template<int nBits>

L1GctTwosComplement< nBits > L1GctTwosComplement< nBits >::operator-

(

)

const

overload unary - (negation) operator

Definition at line 201 of file L1GctTwosComplement.h.

                                                                       {
  L1GctTwosComplement<nBits> temp;
  temp.setValue(-this->value());
  temp.setOverFlow(temp.overFlow() || this->overFlow());
  return temp;
}

operator=()

template<int nBits>

L1GctTwosComplement< nBits > & L1GctTwosComplement< nBits >::operator=

(

int

value

)

overload = operator

Definition at line 210 of file L1GctTwosComplement.h.

                                                                           {
  this->setValue(value);
  return *this;
}

overFlow()

template<int nBits>

bool L1GctTwosComplement< nBits >::overFlow ( ) const

inline

access overflow

Definition at line 62 of file L1GctTwosComplement.h.

Referenced by L1GctJetFinderBase::doHtSums(), L1GctMet::inputOverFlow(), L1GctTwosComplement< L1GctInternEtSum::kMissExOrEyNBits >::L1GctTwosComplement(), L1GctMet::metVector(), and L1GctTwosComplement< L1GctInternEtSum::kMissExOrEyNBits >::operator+().

{ return m_overFlow; }

raw()

template<int nBits>

uint32_t L1GctTwosComplement< nBits >::raw ( ) const

inline

access raw data

Definition at line 56 of file L1GctTwosComplement.h.

Referenced by L1GctTwosComplement< L1GctInternEtSum::kMissExOrEyNBits >::L1GctTwosComplement(), and L1GctTwosComplement< L1GctInternEtSum::kMissExOrEyNBits >::operator+().

{ return m_data; }

reset()

template<int nBits>

void L1GctTwosComplement< nBits >::reset

(

void

)

reset value and overflow to zero

Definition at line 132 of file L1GctTwosComplement.h.

Referenced by L1GctWheelEnergyFpga::resetProcessor(), L1GctWheelJetFpga::resetProcessor(), L1GctJetLeafCard::resetProcessor(), and L1GctGlobalEnergyAlgos::resetProcessor().

                                       {
  m_data = static_cast<uint32_t>(0);
  m_overFlow = false;
}

setOverFlow()

template<int nBits>

void L1GctTwosComplement< nBits >::setOverFlow ( bool  oflow )

inline

set the overflow bit

Definition at line 53 of file L1GctTwosComplement.h.

Referenced by L1GctJetFinderBase::doHtSums(), L1GctTwosComplement< L1GctInternEtSum::kMissExOrEyNBits >::operator-(), L1GctGlobalEnergyAlgos::setInputWheelEx(), L1GctGlobalEnergyAlgos::setInputWheelEy(), L1GctGlobalEnergyAlgos::setInputWheelHx(), and L1GctGlobalEnergyAlgos::setInputWheelHy().

{ m_overFlow = oflow; }

setRaw()

template<int nBits>

void L1GctTwosComplement< nBits >::setRaw

(

uint32_t

raw

)

set the raw data

Definition at line 139 of file L1GctTwosComplement.h.

                                                    {
  checkOverFlow(raw, m_data, m_overFlow);
}

setValue()

template<int nBits>

void L1GctTwosComplement< nBits >::setValue

(

int

value

)

set value from signed int

Definition at line 145 of file L1GctTwosComplement.h.

Referenced by L1GctGlobalEnergyAlgos::setInputWheelEx(), L1GctGlobalEnergyAlgos::setInputWheelEy(), L1GctGlobalEnergyAlgos::setInputWheelHx(), and L1GctGlobalEnergyAlgos::setInputWheelHy().

                                                   {
  int chkValue, posValue;
  uint32_t raw;

  // Make sure we have an integer in the range MAX_NBITS
  chkValue = value;
  if (chkValue < -MAX_VALUE) {
    chkValue = -MAX_VALUE;
    m_overFlow = true;
  }
  if (chkValue >= MAX_VALUE) {
    chkValue = MAX_VALUE - 1;
    m_overFlow = true;
  }

  // Transform negative values to large positive values
  posValue = chkValue < 0 ? chkValue + (1 << MAX_NBITS) : chkValue;
  raw = static_cast<uint32_t>(posValue);

  // Use the setRaw method to check overflow for our given size nBits
  this->setRaw(raw);
}

size()

template<int nBits>

int L1GctTwosComplement< nBits >::size ( void  ) const

inline

return number of bits

Definition at line 65 of file L1GctTwosComplement.h.

Referenced by ntupleDataFormat._Collection::__iter__(), and ntupleDataFormat._Collection::__len__().

{ return m_nBits; }

value()

template<int nBits>

int L1GctTwosComplement< nBits >::value

(

void

)

const

access value as signed int

Definition at line 170 of file L1GctTwosComplement.h.

Referenced by average.Average::average(), L1GctMet::inputOverFlow(), and L1GctMet::metVector().

                                            {
  int value, result;
  int maxValueInNbits;
  maxValueInNbits = 1 << (m_nBits - 1);
  value = static_cast<int>(m_data);
  result = value < maxValueInNbits ? value : value - (1 << MAX_NBITS);
  return result;
}

Member Data Documentation

m_data

template<int nBits>

uint32_t L1GctTwosComplement< nBits >::m_data

private

Definition at line 81 of file L1GctTwosComplement.h.

Referenced by L1GctTwosComplement< L1GctInternEtSum::kMissExOrEyNBits >::raw().

m_nBits

template<int nBits>

int L1GctTwosComplement< nBits >::m_nBits

private

Definition at line 78 of file L1GctTwosComplement.h.

Referenced by L1GctTwosComplement< L1GctInternEtSum::kMissExOrEyNBits >::size().

m_overFlow

template<int nBits>

bool L1GctTwosComplement< nBits >::m_overFlow

private

Definition at line 84 of file L1GctTwosComplement.h.

Referenced by L1GctTwosComplement< L1GctInternEtSum::kMissExOrEyNBits >::overFlow(), and L1GctTwosComplement< L1GctInternEtSum::kMissExOrEyNBits >::setOverFlow().

MAX_NBITS

template<int nBits>

const int L1GctTwosComplement< nBits >::MAX_NBITS = 24

staticprivate

Definition at line 86 of file L1GctTwosComplement.h.

MAX_VALUE

template<int nBits>

const int L1GctTwosComplement< nBits >::MAX_VALUE = 1 << (MAX_NBITS - 1)

staticprivate

Definition at line 87 of file L1GctTwosComplement.h.