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

#include <L1GctTwosComplement.h>

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

Constructor & Destructor Documentation

template<int nBits>

L1GctTwosComplement< nBits >::L1GctTwosComplement ( )

Construct a signed integer with initial value zero.

Definition at line 101 of file L1GctTwosComplement.h.

References reset().

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

template<int nBits>

L1GctTwosComplement< nBits >::L1GctTwosComplement ( uint32_t raw )

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

Definition at line 108 of file L1GctTwosComplement.h.

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

template<int nBits>

L1GctTwosComplement< nBits >::L1GctTwosComplement ( int value )

Construct a signed integer, checking for overflow.

Definition at line 116 of file L1GctTwosComplement.h.

References reco::JetExtendedAssociation::setValue().

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

template<int nBits>

L1GctTwosComplement< nBits >::~L1GctTwosComplement ( ) [inline]

Destructor.

Definition at line 38 of file L1GctTwosComplement.h.

{ }

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 126 of file L1GctTwosComplement.h.

References L1GctTwosComplement< nBits >::overFlow(), and L1GctTwosComplement< nBits >::raw().

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

Member Function Documentation

template<int nBits>

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

Definition at line 219 of file L1GctTwosComplement.h.

References relativeConstraints::value.

                                                                                                     {
  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;

}

template<int nBits>

L1GctTwosComplement< nBits > L1GctTwosComplement< nBits >::operator+ ( const L1GctTwosComplement< nBits > & rhs ) const

add two numbers of the same size

Definition at line 178 of file L1GctTwosComplement.h.

References L1GctTwosComplement< nBits >::overFlow(), L1GctTwosComplement< nBits >::raw(), L1GctTwosComplement< nBits >::setOverFlow(), L1GctTwosComplement< nBits >::setRaw(), and groupFilesInBlocks::temp.

                                                                                  {

  // 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;

}

template<int nBits>

L1GctTwosComplement< nBits > L1GctTwosComplement< nBits >::operator- ( ) const

overload unary - (negation) operator

Definition at line 200 of file L1GctTwosComplement.h.

References L1GctTwosComplement< nBits >::overFlow(), L1GctTwosComplement< nBits >::setOverFlow(), L1GctTwosComplement< nBits >::setValue(), groupFilesInBlocks::temp, and relativeConstraints::value.

                                                                        {

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

template<int nBits>

L1GctTwosComplement< nBits > & L1GctTwosComplement< nBits >::operator= ( int value )

overload = operator

Definition at line 210 of file L1GctTwosComplement.h.

References reco::JetExtendedAssociation::setValue().

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

}

template<int nBits>

bool L1GctTwosComplement< nBits >::overFlow ( ) const [inline]

access overflow

Definition at line 63 of file L1GctTwosComplement.h.

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

{ return m_overFlow; }

template<int nBits>

uint32_t L1GctTwosComplement< nBits >::raw ( ) const [inline]

access raw data

Definition at line 57 of file L1GctTwosComplement.h.

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

{ return m_data; }

template<int nBits>

void L1GctTwosComplement< nBits >::reset ( void )

reset value and overflow to zero

Definition at line 134 of file L1GctTwosComplement.h.

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

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

template<int nBits>

void L1GctTwosComplement< nBits >::setOverFlow ( bool oflow ) [inline]

set the overflow bit

Definition at line 54 of file L1GctTwosComplement.h.

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

{ m_overFlow = oflow; }

template<int nBits>

void L1GctTwosComplement< nBits >::setRaw ( uint32_t raw )

set the raw data

Definition at line 141 of file L1GctTwosComplement.h.

Referenced by L1GctTwosComplement< nBits >::operator+().

                                                    {
  checkOverFlow(raw, m_data, m_overFlow);
}

template<int nBits>

void L1GctTwosComplement< nBits >::setValue ( int value )

set value from signed int

Definition at line 147 of file L1GctTwosComplement.h.

References relativeConstraints::value.

Referenced by L1GctTwosComplement< nBits >::operator-(), 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);
}

template<int nBits>

int L1GctTwosComplement< nBits >::size ( void ) const [inline]

return number of bits

Definition at line 66 of file L1GctTwosComplement.h.

{ return m_nBits; }

template<int nBits>

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

access value as signed int

Definition at line 166 of file L1GctTwosComplement.h.

References query::result, and relativeConstraints::value.

Referenced by 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;
}