From: Shriya Sharma <shriya@redsemiconductor.com>
Date: Tue, 9 Jan 2024 13:32:09 +0000 (+0000)
Subject: Bug 1244: Added description for pospopcount
X-Git-Url: https://git.libre-soc.org/?p=libreriscv.git;a=commitdiff_plain;h=3c5a80bf4d322582f18d99536ed61a70643725e7

Bug 1244: Added description for pospopcount
---

diff --git a/conferences/fosdem2024/fosdem2024_ddffirst/fosdem2024_ddffirst.tex b/conferences/fosdem2024/fosdem2024_ddffirst/fosdem2024_ddffirst.tex
index ea65ac8eb..0f42add4b 100644
--- a/conferences/fosdem2024/fosdem2024_ddffirst/fosdem2024_ddffirst.tex
+++ b/conferences/fosdem2024/fosdem2024_ddffirst/fosdem2024_ddffirst.tex
@@ -170,7 +170,7 @@ for (i = 0; i < VL; i++)
 		identical to general-purpose Simple-V DD-FFirst...
 	\end{itemize}
 	
-}
+}Po
 
 \frame{\frametitle{maxloc}
   \begin{itemize}
@@ -183,6 +183,7 @@ for (i = 0; i < VL; i++)
   \begin{itemize}
 	\item 	Positional popcount adds up the totals of each bit set to 1 in each bit-position, of an array of input values.
 	\item   Notoriously difficult to do in SIMD assembler: typically 550 lines
+
    \end{itemize}
 	
 	\lstinputlisting[language={}]{pospopcount.c}
@@ -192,7 +193,7 @@ for (i = 0; i < VL; i++)
 \frame{\frametitle{Pospopcount}
 	
 	\begin{center}
-		\includegraphics[width=0.6\textwidth]{pospopcount.png}
+		\includegraphics[width=0.5\textwidth]{pospopcount.png}
 	\end{center}
 	
 }
@@ -200,8 +201,17 @@ for (i = 0; i < VL; i++)
 \frame{\frametitle{Pospopcount}
 	
 	\begin{center}
-		\includegraphics[width=0.6\textwidth]{array_popcnt.png}
+		\includegraphics[width=0.5\textwidth]{array_popcnt.png}
 	\end{center}
+
+  \begin{itemize}
+  		\item	Part of the challenge is therefore to perform an appropriate transpose of the data,
+  				in blocks that suit the processor and the ISA capacity.
+		\item 	The gbbd instruction is used for implementing the transpose function, 
+				preparing the data for using the standard popcount instruction.
+
+	
+	\end{itemize}
 	
 }