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GLAST/LAT > DAQ and FSW > FSW > Doxygen Index > PBS / V2-10-10

Constituent: pbs     Tag: sun-gcc

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FFS.ih.xx-xxx-xxx File Reference

Implements the generic version of the FFS routines. More...

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Functions
FFS__LCL_FNC int	FFSL (unsigned int w)
	Find first leading set bit in a 32-bit word, MSb = 0.
FFS__LCL_FNC int	FFSl (unsigned int w)
	Find first leading set bit in a 32-bit word, LSb = 0.
FFS__LCL_FNC int	FFST (unsigned int w)
	Find first trailing set bit in a 32-bit word, MSb = 0.
FFS__LCL_FNC int	FFSt (unsigned int w)
	Find first trailing set bit in a 32-bit word, LSb = 0.
FFS__LCL_FNC int	CNTLZ (unsigned int w)
	Counts the number of leading 0's in a 32 bit word.
FFS__LCL_FNC int	CNTTZ (unsigned int w)
	Counts the number of trailing 0's in a 32 bit word.

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Detailed Description

Implements the generic version of the FFS routines.

Author:

JJRussell - russell@slac.stanford.edu

    CVS $Id: FFS.ih.xx-xxx-xxx,v 1.4 2004/12/07 16:13:06 russell Exp $

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Function Documentation

int CNTLZ (  unsigned int  w  )

Counts the number of leading 0's in a 32 bit word. Parameters: w  The 32 bit word to be examined. Returns: The number of leading 0's in a 32 bit word. This routine examines a 32 bit longword, returning the count of leading 0s (left (MSb) to right (LSb)) If it finds a bit it returns a value in the range 0-31. This routine is almost a synomyn for FFSL, but it is protected against 0, returning 32 if the word is 0.

int CNTTZ (  unsigned int  w  )

Counts the number of trailing 0's in a 32 bit word. Parameters: w  The 32 bit word to be examined. Returns: The number of trailing 0's in a 32 bit word. This routine examines a 32 bit longword, returning the count of trailing 0s (left (MSb) to right (LSb)) If it finds a bit it returns a value in the range 0-31. This routine is almost a synomyn for FFSt, but it is protected against 0, returning 32 if the word is 0.

int FFSl (  unsigned int  w  )

Find first leading set bit in a 32-bit word, LSb = 0. Parameters: w  The 32 bit word to examined from the MSb to LSb for the first set bit. Returns: The number of the first set bit in w, where LSb = 0 This routine examines a 32 bit longword from left (MSb) to right (LSb) looking for the first bit set. If it finds a bit it returns a value in the range 0-31. The routine is not protected against 0 as an input and the result is undefined.

int FFSL (  unsigned int  w  )

Find first leading set bit in a 32-bit word, MSb = 0. Parameters: w  The 32 bit word to examined from the MSb to LSb for the first set bit. Returns: The number of the first set bit in w, where MSb = 0 This routine examines a 32 bit longword from left (MSb) to right (LSb) looking for the first bit set. If it finds a bit it returns a value in the range 0-31. The routine is not protected against 0 as an input and the result is undefined.

int FFSt (  unsigned int  w  )

Find first trailing set bit in a 32-bit word, LSb = 0. Parameters: w  The 32 bit word to examined from the LSb to MSb for the first set bit. Returns: The number of the first set bit in w, where LSb = 0 This routine examines a 32 bit longword from right (MSb) to left (LSb) looking for the first bit set. If it finds a bit it returns a value in the range 0-31. The routine is not protected against 0 as an input and the result is undefined.

int FFST (  unsigned int  w  )

Find first trailing set bit in a 32-bit word, MSb = 0. Parameters: w  The 32 bit word to examined from the LSb to MSb for the first set bit. Returns: The number of the first set bit in w, where MSb = 0 This routine examines a 32 bit longword from right (MSb) to left (LSb) looking for the first bit set. If it finds a bit it returns a value in the range 0-31. The routine is not protected against 0 as an input and the result is undefined.

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