\hypertarget{BFU_8h}{ \section{BFU.h File Reference} \label{BFU_8h}\index{BFU.h@{BFU.h}} } Bit Field Unpack Routines. {\tt \#include \char`\"{}PBS/FFS.ih\char`\"{}}\par Include dependency graph for BFU.h:\begin{figure}[H] \begin{center} \leavevmode \includegraphics[width=97pt]{BFU_8h__incl} \end{center} \end{figure} This graph shows which files directly or indirectly include this file:\begin{figure}[H] \begin{center} \leavevmode \includegraphics[width=89pt]{BFU_8h__dep__incl} \end{center} \end{figure} \subsection*{Data Structures} \begin{CompactItemize} \item struct \hyperlink{struct__BFU}{\_\-BFU} \begin{CompactList}\small\item\em The return value of the BFU routines, capturing the current 32-bit word that is being used as a source and the extracted value. \item\end{CompactList}\end{CompactItemize} \subsection*{Defines} \begin{CompactItemize} \item \#define \hyperlink{BFU_8h_a0}{\_\-bfu\_\-get\_\-pos}(\_\-bfu)~\_\-bfu.val \begin{CompactList}\small\item\em Gets the current buffer bit position. \item\end{CompactList}\item \#define \hyperlink{BFU_8h_a1}{\_\-bfu\_\-get\_\-tmp}(\_\-bfu)~\_\-bfu.cur \begin{CompactList}\small\item\em Gets the current temporary buffer. \item\end{CompactList}\item \#define {\bf \_\-bfu\_\-get}(\_\-bfu, \_\-tmp, \_\-pos) \item \#define \hyperlink{BFU_8h_a3}{\_\-bfu\_\-put\_\-tmp}(\_\-bfu, \_\-tmp)~\_\-bfu.cur = \_\-tmp; \begin{CompactList}\small\item\em Updates the current temporary buffer. \item\end{CompactList}\item \#define \hyperlink{BFU_8h_a4}{\_\-bfu\_\-put\_\-pos}(\_\-bfu, \_\-pos)~\_\-bfu.val = \_\-pos; \begin{CompactList}\small\item\em Gets the current buffer bit position. \item\end{CompactList}\item \#define \hyperlink{BFU_8h_a5}{\_\-bfu\_\-put}(\_\-bfu, \_\-tmp, \_\-pos) \begin{CompactList}\small\item\em Updates the current temporary buffer and buffer bit position. \item\end{CompactList}\item \#define \hyperlink{BFU_8h_a6}{\_\-bfu\_\-construct}(\_\-bfu, \_\-s, \_\-alignment, \_\-src, \_\-boff) \begin{CompactList}\small\item\em Constructs a BFU from an arbitrarily aligned source buffer pointer, and a bit offset {\em \_\-boff\/}. Also returns a 32-bit aligned pointer to be used with \_\-bfu\_\-extract. \item\end{CompactList}\item \#define \hyperlink{BFU_8h_a7}{\_\-bfu\_\-construct\-W}(\_\-bfu, \_\-src, \_\-boff) \begin{CompactList}\small\item\em Constructs a BFU from an 32-bit (word) aligned source buffer pointer and a bit offset {\em \_\-boff\/}. \item\end{CompactList}\item \#define \hyperlink{BFU_8h_a8}{\_\-bfu\_\-extract\-Boolean}(\_\-bfu, \_\-wrds, \_\-position) \begin{CompactList}\small\item\em Extracts the next bit, returning it as a boolean value. The justification is unspecfied. The implementation is the most efficient of \_\-bfu\_\-extract\-BL or \_\-bfu\_\-extract\-BR. Use one of those routine if the justification needs to be specified. \item\end{CompactList}\item \#define \hyperlink{BFU_8h_a9}{\_\-bfu\_\-extract\-BR}(\_\-bfu, \_\-wrds, \_\-position) \begin{CompactList}\small\item\em Extracts the right justified bit from the current position. \item\end{CompactList}\item \#define \hyperlink{BFU_8h_a10}{\_\-bfu\_\-extract\-BL}(\_\-bfu, \_\-wrds, \_\-position) \begin{CompactList}\small\item\em Extracts the left justified bit from the current position. \item\end{CompactList}\item \#define \hyperlink{BFU_8h_a11}{\_\-bfu\_\-extract\-L}(\_\-bfu, \_\-wrds, \_\-position, \_\-width) \begin{CompactList}\small\item\em Extracts a left justified value from the current position. \item\end{CompactList}\item \#define \hyperlink{BFU_8h_a12}{\_\-bfu\_\-extract\-R}(\_\-bfu, \_\-wrds, \_\-position, \_\-width) \begin{CompactList}\small\item\em Extracts a right justified value from the current position. \item\end{CompactList}\item \#define \hyperlink{BFU_8h_a13}{\_\-bfu\_\-extract32}(\_\-bfu, \_\-wrds, \_\-position) \begin{CompactList}\small\item\em Extracts 32 bits from the current position. \item\end{CompactList}\item \#define \hyperlink{BFU_8h_a14}{\_\-bfu\_\-count1s}(\_\-bfu, \_\-wrds, \_\-position) \begin{CompactList}\small\item\em Counts the number of 1s till the first clear bit. \item\end{CompactList}\item \#define \hyperlink{BFU_8h_a15}{\_\-bfu\_\-revert}(\_\-bfu, \_\-wrds, \_\-position, \_\-nwidth, \_\-nexp) \begin{CompactList}\small\item\em Counts the number of 1s till the first clear bit. \item\end{CompactList}\end{CompactItemize} \subsection*{Typedefs} \begin{CompactItemize} \item \hypertarget{BFU_8h_a16}{ typedef \hyperlink{struct__BFU}{\_\-BFU} \hyperlink{BFU_8h_a16}{BFU}} \label{BFU_8h_a16} \begin{CompactList}\small\item\em Typedef for struct \hyperlink{struct__BFU}{\_\-BFU}. \item\end{CompactList}\end{CompactItemize} \subsection*{Functions} \begin{CompactItemize} \item static \_\-\_\-inline \hyperlink{struct__BFU}{BFU} \hyperlink{BFU_8h_a17}{BFU\_\-\_\-bit\-L} (const unsigned int $\ast$wrds, unsigned int cur, unsigned int position) \begin{CompactList}\small\item\em Unpacks the left justified bit from the current position. \item\end{CompactList}\item static \_\-\_\-inline \hyperlink{struct__BFU}{BFU} \hyperlink{BFU_8h_a18}{BFU\_\-\_\-bit\-R} (const unsigned int $\ast$wrds, unsigned int cur, unsigned int position) \begin{CompactList}\small\item\em Unpacks the right justified bit from the current position. \item\end{CompactList}\item static \_\-\_\-inline \hyperlink{struct__BFU}{BFU} \hyperlink{BFU_8h_a19}{BFU\_\-\_\-boolean} (const unsigned int $\ast$wrds, unsigned int cur, unsigned int position) \begin{CompactList}\small\item\em Unpacks the next bit. This is equivalent to a bit extract, but the justification (left or right) is unspecified. Rather the must efficient extraction is used, returning only 0 or non-zero. Use BFU\_\-\_\-bit\-L or BFU\_\-\_\-bit\-R if a specific justification is needed. \item\end{CompactList}\item static \_\-\_\-inline \hyperlink{struct__BFU}{BFU} \hyperlink{BFU_8h_a20}{BFU\_\-\_\-word\-R} (const unsigned int $\ast$wrds, unsigned int cur, unsigned int position, unsigned int width) \begin{CompactList}\small\item\em Unpacks a right justified bit field from the current position. The width of the bit field must be less than 32 bits. \item\end{CompactList}\item static \_\-\_\-inline \hyperlink{struct__BFU}{BFU} \hyperlink{BFU_8h_a21}{BFU\_\-\_\-word\-L} (const unsigned int $\ast$wrds, unsigned int cur, unsigned int position, unsigned int width) \begin{CompactList}\small\item\em Unpacks a left justified bit field from the current position. The width of the bit field must be less than 32 bits. \item\end{CompactList}\item static \_\-\_\-inline \hyperlink{struct__BFU}{BFU} \hyperlink{BFU_8h_a22}{BFU\_\-\_\-word} (const unsigned int $\ast$wrds, unsigned int cur, unsigned int position) \begin{CompactList}\small\item\em Unpacks exactly 32 bits from the current position. \item\end{CompactList}\item static \_\-\_\-inline \hyperlink{struct__BFU}{BFU} \hyperlink{BFU_8h_a23}{BFU\_\-\_\-ffc} (const unsigned int $\ast$wrds, unsigned int cur, unsigned int position) \begin{CompactList}\small\item\em Scans the input bit stream for the first clear bit, this effectively counts the number of set bits. \item\end{CompactList}\end{CompactItemize} \subsection{Detailed Description} Bit Field Unpack Routines. \begin{Desc} \item[Author:]JJRussell - \href{mailto:russell@slac.stanford.edu}{\tt russell@slac.stanford.edu}\end{Desc} Inline functions to (left justified) unpack bit fields. \subsection{Define Documentation} \hypertarget{BFU_8h_a6}{ \index{BFU.h@{BFU.h}!_bfu_construct@{\_\-bfu\_\-construct}} \index{_bfu_construct@{\_\-bfu\_\-construct}!BFU.h@{BFU.h}} \subsubsection[\_\-bfu\_\-construct]{\setlength{\rightskip}{0pt plus 5cm}\#define \_\-bfu\_\-construct(\_\-bfu, \_\-s, \_\-alignment, \_\-src, \_\-boff)}} \label{BFU_8h_a6} {\bf Value:} \footnotesize\begin{verbatim}do \ { \ /* Move to the nearest 32-bit boundary */ \ \ /* Convert to a 32-bit pointer */ \ _s = (const unsigned int *)_src; \ \ /* Calculate the number of bits that are not a multiple of 32 */ \ alignment = ((int)_s & 0x3) << 3; \ \ /* Add this to the bit offset */ \ _boff += _alignment; \ \ /* Reset the pointer back to the nearest 32-bit boundary */ \ _s = (const unsigned int *)((int)_s & ~0x3); \ \ /* Extract the first word */ \ _bfu.cur = _s[_boff >> 5]; \ _bfu.val = boff; \ \ } while (0) \end{verbatim}\normalsize Constructs a BFU from an arbitrarily aligned source buffer pointer, and a bit offset {\em \_\-boff\/}. Also returns a 32-bit aligned pointer to be used with \_\-bfu\_\-extract. \begin{Desc} \item[Parameters:] \begin{description} \item[{\em \_\-bfu}]The BFU structure to populate \item[{\em \_\-s}]Returned as a 32-bit aligned version of {\em \_\-src\/} \item[{\em \_\-alignment}]Returned as the alignment adjustment. This value should be subtracted off when resetting the bit offset back to a value that corresponds to the alignment associated with {\em \_\-src\/}. \item[{\em \_\-src}]The source buffer pointer \item[{\em \_\-boff}]The original bit offset, returned as the adjusted offset to compensate for any possible alignment to {\em \_\-s\/} \end{description} \end{Desc} \hypertarget{BFU_8h_a7}{ \index{BFU.h@{BFU.h}!_bfu_constructW@{\_\-bfu\_\-constructW}} \index{_bfu_constructW@{\_\-bfu\_\-constructW}!BFU.h@{BFU.h}} \subsubsection[\_\-bfu\_\-constructW]{\setlength{\rightskip}{0pt plus 5cm}\#define \_\-bfu\_\-construct\-W(\_\-bfu, \_\-src, \_\-boff)}} \label{BFU_8h_a7} {\bf Value:} \footnotesize\begin{verbatim}_bfu.cur = _src[_boff >> 5]; \ _bfu.val = _boff \ \end{verbatim}\normalsize Constructs a BFU from an 32-bit (word) aligned source buffer pointer and a bit offset {\em \_\-boff\/}. \begin{Desc} \item[Parameters:] \begin{description} \item[{\em \_\-bfu}]The BFU structure to populate \item[{\em \_\-src}]The source buffer pointer \item[{\em \_\-boff}]The original bit offset, returned as the adjusted offset to compensate for any possible alignment to {\em \_\-s\/} \end{description} \end{Desc} \hypertarget{BFU_8h_a14}{ \index{BFU.h@{BFU.h}!_bfu_count1s@{\_\-bfu\_\-count1s}} \index{_bfu_count1s@{\_\-bfu\_\-count1s}!BFU.h@{BFU.h}} \subsubsection[\_\-bfu\_\-count1s]{\setlength{\rightskip}{0pt plus 5cm}\#define \_\-bfu\_\-count1s(\_\-bfu, \_\-wrds, \_\-position)}} \label{BFU_8h_a14} {\bf Value:} \footnotesize\begin{verbatim}(_bfu = BFU__ffc (_wrds, _bfu_get_tmp(bfu), _position), \ _position += (_bfu.val -= _position), \ _bfu.val - 1) \end{verbatim}\normalsize Counts the number of 1s till the first clear bit. \begin{Desc} \item[Returns:]The number of bits to the first clear bit\end{Desc} \begin{Desc} \item[Parameters:] \begin{description} \item[{\em \_\-bfu}]The bit field unpacking context \item[{\em \_\-wrds}]The source word array \item[{\em \_\-position}]The bit position of the left most bit of the field to be extracted in the source array\end{description} \end{Desc} \hypertarget{BFU_8h_a13}{ \index{BFU.h@{BFU.h}!_bfu_extract32@{\_\-bfu\_\-extract32}} \index{_bfu_extract32@{\_\-bfu\_\-extract32}!BFU.h@{BFU.h}} \subsubsection[\_\-bfu\_\-extract32]{\setlength{\rightskip}{0pt plus 5cm}\#define \_\-bfu\_\-extract32(\_\-bfu, \_\-wrds, \_\-position)}} \label{BFU_8h_a13} {\bf Value:} \footnotesize\begin{verbatim}(_bfu = BFU__word (_wrds, _bfu.cur, _position), \ _position += 32, \ _bfu.val) \end{verbatim}\normalsize Extracts 32 bits from the current position. \begin{Desc} \item[Returns:]The extract value\end{Desc} \begin{Desc} \item[Parameters:] \begin{description} \item[{\em \_\-bfu}]The bit field unpacking context \item[{\em \_\-wrds}]The source word array \item[{\em \_\-position}]The bit position of the left most bit of the field to be extracted in the source array\end{description} \end{Desc} \hypertarget{BFU_8h_a10}{ \index{BFU.h@{BFU.h}!_bfu_extractBL@{\_\-bfu\_\-extractBL}} \index{_bfu_extractBL@{\_\-bfu\_\-extractBL}!BFU.h@{BFU.h}} \subsubsection[\_\-bfu\_\-extractBL]{\setlength{\rightskip}{0pt plus 5cm}\#define \_\-bfu\_\-extract\-BL(\_\-bfu, \_\-wrds, \_\-position)}} \label{BFU_8h_a10} {\bf Value:} \footnotesize\begin{verbatim}(_bfu = BFU__bitL (_wrds, _bfu.cur, _position), \ _position += 1, \ _bfu.val) \end{verbatim}\normalsize Extracts the left justified bit from the current position. \begin{Desc} \item[Returns:]The left justified bit\end{Desc} \begin{Desc} \item[Parameters:] \begin{description} \item[{\em \_\-bfu}]The bit field unpacking context \item[{\em \_\-wrds}]The source word array \item[{\em \_\-position}]The bit position of the bit to be extracted from the source array\end{description} \end{Desc} \hypertarget{BFU_8h_a8}{ \index{BFU.h@{BFU.h}!_bfu_extractBoolean@{\_\-bfu\_\-extractBoolean}} \index{_bfu_extractBoolean@{\_\-bfu\_\-extractBoolean}!BFU.h@{BFU.h}} \subsubsection[\_\-bfu\_\-extractBoolean]{\setlength{\rightskip}{0pt plus 5cm}\#define \_\-bfu\_\-extract\-Boolean(\_\-bfu, \_\-wrds, \_\-position)}} \label{BFU_8h_a8} {\bf Value:} \footnotesize\begin{verbatim}(_bfu = BFU__boolean (_wrds, _bfu.cur, _position), \ _position += 1, \ _bfu.val) \end{verbatim}\normalsize Extracts the next bit, returning it as a boolean value. The justification is unspecfied. The implementation is the most efficient of \_\-bfu\_\-extract\-BL or \_\-bfu\_\-extract\-BR. Use one of those routine if the justification needs to be specified. \begin{Desc} \item[Return values:] \begin{description} \item[{\em 0,if}]the bit was 0 \item[{\em !=0,if}]the bit was 1\end{description} \end{Desc} \begin{Desc} \item[Parameters:] \begin{description} \item[{\em \_\-bfu}]The bit field unpacking context \item[{\em \_\-wrds}]The source word array \item[{\em \_\-position}]The bit position of the bit to be extracted from the source array\end{description} \end{Desc} \hypertarget{BFU_8h_a9}{ \index{BFU.h@{BFU.h}!_bfu_extractBR@{\_\-bfu\_\-extractBR}} \index{_bfu_extractBR@{\_\-bfu\_\-extractBR}!BFU.h@{BFU.h}} \subsubsection[\_\-bfu\_\-extractBR]{\setlength{\rightskip}{0pt plus 5cm}\#define \_\-bfu\_\-extract\-BR(\_\-bfu, \_\-wrds, \_\-position)}} \label{BFU_8h_a9} {\bf Value:} \footnotesize\begin{verbatim}(_bfu = BFU__bitR (_wrds, _bfu.cur, _position), \ _position += 1, \ _bfu.val) \end{verbatim}\normalsize Extracts the right justified bit from the current position. \begin{Desc} \item[Returns:]The right justified bit\end{Desc} \begin{Desc} \item[Parameters:] \begin{description} \item[{\em \_\-bfu}]The bit field unpacking context \item[{\em \_\-wrds}]The source word array \item[{\em \_\-position}]The bit position of the bit to be extracted from the source array\end{description} \end{Desc} \hypertarget{BFU_8h_a11}{ \index{BFU.h@{BFU.h}!_bfu_extractL@{\_\-bfu\_\-extractL}} \index{_bfu_extractL@{\_\-bfu\_\-extractL}!BFU.h@{BFU.h}} \subsubsection[\_\-bfu\_\-extractL]{\setlength{\rightskip}{0pt plus 5cm}\#define \_\-bfu\_\-extract\-L(\_\-bfu, \_\-wrds, \_\-position, \_\-width)}} \label{BFU_8h_a11} {\bf Value:} \footnotesize\begin{verbatim}(_bfu = BFU__wordL (_wrds, _bfu.cur, _position, _width), \ _position += _width, \ _bfu.val) \end{verbatim}\normalsize Extracts a left justified value from the current position. \begin{Desc} \item[Returns:]The left justified value\end{Desc} \begin{Desc} \item[Parameters:] \begin{description} \item[{\em \_\-bfu}]The bit field unpacking context \item[{\em \_\-wrds}]The source word array \item[{\em \_\-position}]The bit position of the left most bit of the field to be extracted in the source array \item[{\em \_\-width}]The width of the field to be extracted; must be $<$ 32\end{description} \end{Desc} \hypertarget{BFU_8h_a12}{ \index{BFU.h@{BFU.h}!_bfu_extractR@{\_\-bfu\_\-extractR}} \index{_bfu_extractR@{\_\-bfu\_\-extractR}!BFU.h@{BFU.h}} \subsubsection[\_\-bfu\_\-extractR]{\setlength{\rightskip}{0pt plus 5cm}\#define \_\-bfu\_\-extract\-R(\_\-bfu, \_\-wrds, \_\-position, \_\-width)}} \label{BFU_8h_a12} {\bf Value:} \footnotesize\begin{verbatim}(_bfu = BFU__wordR (_wrds, _bfu.cur, _position, _width), \ _position += _width, \ _bfu.val) \end{verbatim}\normalsize Extracts a right justified value from the current position. \begin{Desc} \item[Returns:]The right justified value\end{Desc} \begin{Desc} \item[Parameters:] \begin{description} \item[{\em \_\-bfu}]The bit field unpacking context \item[{\em \_\-wrds}]The source word array \item[{\em \_\-position}]The bit position of the left most bit of the field to be extracted in the source array \item[{\em \_\-width}]The width of the field to be extracted; must be $<$ 32\end{description} \end{Desc} \hypertarget{BFU_8h_a2}{ \index{BFU.h@{BFU.h}!_bfu_get@{\_\-bfu\_\-get}} \index{_bfu_get@{\_\-bfu\_\-get}!BFU.h@{BFU.h}} \subsubsection[\_\-bfu\_\-get]{\setlength{\rightskip}{0pt plus 5cm}\#define \_\-bfu\_\-get(\_\-bfu, \_\-tmp, \_\-pos)}} \label{BFU_8h_a2} {\bf Value:} \footnotesize\begin{verbatim}_tmp = _bfu.cur; \ _pos = _bfu.val; \end{verbatim}\normalsize \hypertarget{BFU_8h_a0}{ \index{BFU.h@{BFU.h}!_bfu_get_pos@{\_\-bfu\_\-get\_\-pos}} \index{_bfu_get_pos@{\_\-bfu\_\-get\_\-pos}!BFU.h@{BFU.h}} \subsubsection[\_\-bfu\_\-get\_\-pos]{\setlength{\rightskip}{0pt plus 5cm}\#define \_\-bfu\_\-get\_\-pos(\_\-bfu)~\_\-bfu.val}} \label{BFU_8h_a0} Gets the current buffer bit position. \begin{Desc} \item[Return values:] \begin{description} \item[{\em The}]value of the current buffer bit position \end{description} \end{Desc} \begin{Desc} \item[Parameters:] \begin{description} \item[{\em \_\-bfu}]The context to fetch the buffer bit position from\end{description} \end{Desc} \hypertarget{BFU_8h_a1}{ \index{BFU.h@{BFU.h}!_bfu_get_tmp@{\_\-bfu\_\-get\_\-tmp}} \index{_bfu_get_tmp@{\_\-bfu\_\-get\_\-tmp}!BFU.h@{BFU.h}} \subsubsection[\_\-bfu\_\-get\_\-tmp]{\setlength{\rightskip}{0pt plus 5cm}\#define \_\-bfu\_\-get\_\-tmp(\_\-bfu)~\_\-bfu.cur}} \label{BFU_8h_a1} Gets the current temporary buffer. \begin{Desc} \item[Return values:] \begin{description} \item[{\em The}]value of the temporary buffer \end{description} \end{Desc} \begin{Desc} \item[Parameters:] \begin{description} \item[{\em \_\-bfu}]The context to fetch the temporary buffer from\end{description} \end{Desc} \hypertarget{BFU_8h_a5}{ \index{BFU.h@{BFU.h}!_bfu_put@{\_\-bfu\_\-put}} \index{_bfu_put@{\_\-bfu\_\-put}!BFU.h@{BFU.h}} \subsubsection[\_\-bfu\_\-put]{\setlength{\rightskip}{0pt plus 5cm}\#define \_\-bfu\_\-put(\_\-bfu, \_\-tmp, \_\-pos)}} \label{BFU_8h_a5} {\bf Value:} \footnotesize\begin{verbatim}_bfu.cur = _tmp; \ _bfu.val = _pos; \end{verbatim}\normalsize Updates the current temporary buffer and buffer bit position. \begin{Desc} \item[Parameters:] \begin{description} \item[{\em \_\-bfu}]The context to update \item[{\em \_\-tmp}]The updated value of the temporary holding buffer \item[{\em \_\-pos}]The updated value of the buffer bit position\end{description} \end{Desc} \hypertarget{BFU_8h_a4}{ \index{BFU.h@{BFU.h}!_bfu_put_pos@{\_\-bfu\_\-put\_\-pos}} \index{_bfu_put_pos@{\_\-bfu\_\-put\_\-pos}!BFU.h@{BFU.h}} \subsubsection[\_\-bfu\_\-put\_\-pos]{\setlength{\rightskip}{0pt plus 5cm}\#define \_\-bfu\_\-put\_\-pos(\_\-bfu, \_\-pos)~\_\-bfu.val = \_\-pos;}} \label{BFU_8h_a4} Gets the current buffer bit position. \begin{Desc} \item[Parameters:] \begin{description} \item[{\em \_\-bfu}]The context to fetch the buffer bit position from \item[{\em \_\-pos}]The updated value of the buffer bit position\end{description} \end{Desc} \hypertarget{BFU_8h_a3}{ \index{BFU.h@{BFU.h}!_bfu_put_tmp@{\_\-bfu\_\-put\_\-tmp}} \index{_bfu_put_tmp@{\_\-bfu\_\-put\_\-tmp}!BFU.h@{BFU.h}} \subsubsection[\_\-bfu\_\-put\_\-tmp]{\setlength{\rightskip}{0pt plus 5cm}\#define \_\-bfu\_\-put\_\-tmp(\_\-bfu, \_\-tmp)~\_\-bfu.cur = \_\-tmp;}} \label{BFU_8h_a3} Updates the current temporary buffer. \begin{Desc} \item[Parameters:] \begin{description} \item[{\em \_\-bfu}]The context to fetch the temporary buffer from \item[{\em \_\-tmp}]Returned as the updated value of the temporary holding buffer\end{description} \end{Desc} \hypertarget{BFU_8h_a15}{ \index{BFU.h@{BFU.h}!_bfu_revert@{\_\-bfu\_\-revert}} \index{_bfu_revert@{\_\-bfu\_\-revert}!BFU.h@{BFU.h}} \subsubsection[\_\-bfu\_\-revert]{\setlength{\rightskip}{0pt plus 5cm}\#define \_\-bfu\_\-revert(\_\-bfu, \_\-wrds, \_\-position, \_\-nwidth, \_\-nexp)}} \label{BFU_8h_a15} {\bf Value:} \footnotesize\begin{verbatim}({ \ int val; \ int exp = _bfu_extractR (_bfu, _wrds, _position, _nexp) - 1; \ int nleading = (1 << _nexp) - 1; \ int ntrailing = (_nwidth - nleading > 0) ? _nwidth - nleading : 0; \ int nbits = (exp >= 0) \ ? (exp += ntrailing, val = (1 << exp), exp) \ : (val = 0, exp = ntrailing); \ \ /* printf ("Exp = %2u, Nbits = %2u\n", exp, nbits); */ \ \ /* If any more bits, get them */ \ if (nbits > 0) \ { \ /* printf ("Val = %8.8x -> ", val); */ \ val |= _bfu_extractR (_bfu, _wrds, _position, nbits); \ /* printf ("%8.8x\n", val); */ \ } \ val; \ }) \end{verbatim}\normalsize Counts the number of 1s till the first clear bit. \begin{Desc} \item[Returns:]The number of bits to the first clear bit\end{Desc} \begin{Desc} \item[Parameters:] \begin{description} \item[{\em \_\-bfu}]The bit field unpacking context \item[{\em \_\-wrds}]The source word array \item[{\em \_\-position}]The bit position of the left most bit of the field to be extracted in the source array \item[{\em \_\-nwidth}]The bit width of the word to be reverted \item[{\em \_\-nexp}]The number bits used to store the exponent\end{description} \end{Desc} \begin{Desc} \item[Warning:]This macro uses a GCC enhancement to the preprocessor and is likely not portable.\end{Desc} \subsection{Function Documentation} \hypertarget{BFU_8h_a17}{ \index{BFU.h@{BFU.h}!BFU__bitL@{BFU\_\-\_\-bitL}} \index{BFU__bitL@{BFU\_\-\_\-bitL}!BFU.h@{BFU.h}} \subsubsection[BFU\_\-\_\-bitL]{\setlength{\rightskip}{0pt plus 5cm}static \_\-\_\-inline \hyperlink{struct__BFU}{BFU} BFU\_\-\_\-bit\-L (const unsigned int $\ast$ {\em wrds}, unsigned int {\em cur}, unsigned int {\em position})\hspace{0.3cm}{\tt \mbox{[}static\mbox{]}}}} \label{BFU_8h_a17} Unpacks the left justified bit from the current position. \begin{Desc} \item[Returns:]The extracted bit, right justified\end{Desc} \begin{Desc} \item[Parameters:] \begin{description} \item[{\em wrds}]The input word array \item[{\em cur}]The current set of bits one is working on \item[{\em position}]The current bit position in the output bit field\end{description} \end{Desc} \hypertarget{BFU_8h_a18}{ \index{BFU.h@{BFU.h}!BFU__bitR@{BFU\_\-\_\-bitR}} \index{BFU__bitR@{BFU\_\-\_\-bitR}!BFU.h@{BFU.h}} \subsubsection[BFU\_\-\_\-bitR]{\setlength{\rightskip}{0pt plus 5cm}static \_\-\_\-inline \hyperlink{struct__BFU}{BFU} BFU\_\-\_\-bit\-R (const unsigned int $\ast$ {\em wrds}, unsigned int {\em cur}, unsigned int {\em position})\hspace{0.3cm}{\tt \mbox{[}static\mbox{]}}}} \label{BFU_8h_a18} Unpacks the right justified bit from the current position. \begin{Desc} \item[Returns:]The extracted bit, right justified\end{Desc} \begin{Desc} \item[Parameters:] \begin{description} \item[{\em wrds}]The input word array \item[{\em cur}]The current set of bits one is working on \item[{\em position}]The current bit position in the output bit field\end{description} \end{Desc} \hypertarget{BFU_8h_a19}{ \index{BFU.h@{BFU.h}!BFU__boolean@{BFU\_\-\_\-boolean}} \index{BFU__boolean@{BFU\_\-\_\-boolean}!BFU.h@{BFU.h}} \subsubsection[BFU\_\-\_\-boolean]{\setlength{\rightskip}{0pt plus 5cm}static \_\-\_\-inline \hyperlink{struct__BFU}{BFU} BFU\_\-\_\-boolean (const unsigned int $\ast$ {\em wrds}, unsigned int {\em cur}, unsigned int {\em position})\hspace{0.3cm}{\tt \mbox{[}static\mbox{]}}}} \label{BFU_8h_a19} Unpacks the next bit. This is equivalent to a bit extract, but the justification (left or right) is unspecified. Rather the must efficient extraction is used, returning only 0 or non-zero. Use BFU\_\-\_\-bit\-L or BFU\_\-\_\-bit\-R if a specific justification is needed. \begin{Desc} \item[Return values:] \begin{description} \item[{\em 0,if}]bit was 0 \item[{\em !=0,if}]bit was 1 (i.e. non-zero\end{description} \end{Desc} \begin{Desc} \item[Parameters:] \begin{description} \item[{\em wrds}]The input word array \item[{\em cur}]The current set of bits one is working on \item[{\em position}]The current bit position in the output bit field\end{description} \end{Desc} \hypertarget{BFU_8h_a23}{ \index{BFU.h@{BFU.h}!BFU__ffc@{BFU\_\-\_\-ffc}} \index{BFU__ffc@{BFU\_\-\_\-ffc}!BFU.h@{BFU.h}} \subsubsection[BFU\_\-\_\-ffc]{\setlength{\rightskip}{0pt plus 5cm}static \_\-\_\-inline \hyperlink{struct__BFU}{BFU} BFU\_\-\_\-ffc (const unsigned int $\ast$ {\em wrds}, unsigned int {\em cur}, unsigned int {\em position})\hspace{0.3cm}{\tt \mbox{[}static\mbox{]}}}} \label{BFU_8h_a23} Scans the input bit stream for the first clear bit, this effectively counts the number of set bits. \begin{Desc} \item[Returns:]The updated BFU past the first clear bit.\end{Desc} \begin{Desc} \item[Parameters:] \begin{description} \item[{\em wrds}]The input word array \item[{\em cur}]The current 32-bit word \item[{\em position}]The current bit position in the output bit field\end{description} \end{Desc} \hypertarget{BFU_8h_a22}{ \index{BFU.h@{BFU.h}!BFU__word@{BFU\_\-\_\-word}} \index{BFU__word@{BFU\_\-\_\-word}!BFU.h@{BFU.h}} \subsubsection[BFU\_\-\_\-word]{\setlength{\rightskip}{0pt plus 5cm}static \_\-\_\-inline \hyperlink{struct__BFU}{BFU} BFU\_\-\_\-word (const unsigned int $\ast$ {\em wrds}, unsigned int {\em cur}, unsigned int {\em position})\hspace{0.3cm}{\tt \mbox{[}static\mbox{]}}}} \label{BFU_8h_a22} Unpacks exactly 32 bits from the current position. \begin{Desc} \item[Returns:]The extracted field, right justified\end{Desc} \begin{Desc} \item[Parameters:] \begin{description} \item[{\em wrds}]The input word array \item[{\em cur}]The current set of bits one is working on \item[{\em position}]The current bit position in the output bit field\end{description} \end{Desc} \hypertarget{BFU_8h_a21}{ \index{BFU.h@{BFU.h}!BFU__wordL@{BFU\_\-\_\-wordL}} \index{BFU__wordL@{BFU\_\-\_\-wordL}!BFU.h@{BFU.h}} \subsubsection[BFU\_\-\_\-wordL]{\setlength{\rightskip}{0pt plus 5cm}static \_\-\_\-inline \hyperlink{struct__BFU}{BFU} BFU\_\-\_\-word\-L (const unsigned int $\ast$ {\em wrds}, unsigned int {\em cur}, unsigned int {\em position}, unsigned int {\em width})\hspace{0.3cm}{\tt \mbox{[}static\mbox{]}}}} \label{BFU_8h_a21} Unpacks a left justified bit field from the current position. The width of the bit field must be less than 32 bits. \begin{Desc} \item[Returns:]The extracted field, left justified + the current buffered word\end{Desc} \begin{Desc} \item[Parameters:] \begin{description} \item[{\em wrds}]The input word array \item[{\em cur}]The current set of bits one is working on \item[{\em position}]The current bit position in the output bit field \item[{\em width}]The width of the field to be extracted\end{description} \end{Desc} \hypertarget{BFU_8h_a20}{ \index{BFU.h@{BFU.h}!BFU__wordR@{BFU\_\-\_\-wordR}} \index{BFU__wordR@{BFU\_\-\_\-wordR}!BFU.h@{BFU.h}} \subsubsection[BFU\_\-\_\-wordR]{\setlength{\rightskip}{0pt plus 5cm}static \_\-\_\-inline \hyperlink{struct__BFU}{BFU} BFU\_\-\_\-word\-R (const unsigned int $\ast$ {\em wrds}, unsigned int {\em cur}, unsigned int {\em position}, unsigned int {\em width})\hspace{0.3cm}{\tt \mbox{[}static\mbox{]}}}} \label{BFU_8h_a20} Unpacks a right justified bit field from the current position. The width of the bit field must be less than 32 bits. \begin{Desc} \item[Returns:]The extracted field, right justified\end{Desc} \begin{Desc} \item[Parameters:] \begin{description} \item[{\em wrds}]The input word array \item[{\em cur}]The current set of bits one is working on \item[{\em position}]The current bit position in the output bit field \item[{\em width}]The width of the field to be extracted\end{description} \end{Desc}