X-Git-Url: https://bilbo.iut-bm.univ-fcomte.fr/and/gitweb/kahina_paper1.git/blobdiff_plain/f34b6d5ff83430d63ac32d2253feb4646b988940..7f2978c0d220516decb65faf2b8ba2da34df8db2:/paper.tex?ds=inline diff --git a/paper.tex b/paper.tex index d0913cc..e3dde6e 100644 --- a/paper.tex +++ b/paper.tex @@ -582,8 +582,7 @@ Algorithm~\ref{alg2-cuda} shows a sketch of the Ehrlich-Aberth algorithm using C \caption{CUDA Algorithm to find roots with the Ehrlich-Aberth method} \KwIn{$Z^{0}$ (Initial root's vector), $\varepsilon$ (error tolerance - threshold), P(Polynomial to solve), Pu (the derivative of P), $n$ - (Polynomial's degrees), $\Delta z_{max}$ (maximum value of stop condition)} + threshold), P(Polynomial to solve), Pu (the derivative of P), $n$ (Polynomial's degrees),$\Delta z_{max}$ (maximum value of stop condition)} \KwOut {$Z$ (The solution root's vector), $ZPrec$ (the previous solution root's vector)} @@ -606,7 +605,7 @@ Copy results from GPU memory to CPU memory\; \end{algorithm} ~\\ -After the initialization step, all data of the root finding problem to be solved must be copied from the CPU memory to the GPU global memory, because the GPUs only access data already present in their memories. Next, all the data-parallel arithmetic operations inside the main loop \verb=(while(...))= are executed as kernels by the GPU. The first kernel named \textit{save} in line 6 of Algorithm~\ref{alg2-cuda} consists in saving the vector of polynomial's root found at the previous time-step in GPU memory, in order to check the convergence of the roots after each iteration (line 8, Algorithm~\ref{alg2-cuda}). +After the initialization step, all data of the root finding problem to be solved must be copied from the CPU memory to the GPU global memory, because the GPUs only access data already present in their memories. Next, all the data-parallel arithmetic operations inside the main loop \verb=(do ... while(...))= are executed as kernels by the GPU. The first kernel named \textit{save} in line 6 of Algorithm~\ref{alg2-cuda} consists in saving the vector of polynomial's root found at the previous time-step in GPU memory, in order to check the convergence of the roots after each iteration (line 8, Algorithm~\ref{alg2-cuda}). The second kernel executes the iterative function $H$ and updates $d\_Z$, according to Algorithm~\ref{alg3-update}. We notice that the @@ -617,16 +616,16 @@ exponential logarithm algorithm. \begin{algorithm}[H] \label{alg3-update} %\LinesNumbered -\caption{Kernel\_update} +\caption{Kernel update} \eIf{$(\left|d\_Z\right|<= R)$}{ -$kernel\_update((d\_Z,d\_Pcoef,d\_Pdegres,d\_Pucoef,d\_Pudegres)$\;} +$kernel\_update((d\_Z,d\_P,d\_Pu)$\;} { -$kernel\_update\_ExpoLog((d\_Z,d\_Pcoef,d\_Pdegres,d\_Pucoef,d\_Pudegres))$\; +$kernel\_update\_ExpoLog((d\_Z,d\_P,\_Pu))$\; } \end{algorithm} -The first form executes formula \ref{eq:SimplePolynome} if the modulus +The first form executes formula the EA function Eq.~\ref{Eq:Hi} if the modulus of the current complex is less than the a certain value called the radius i.e. ($ |z^{k}_{i}|<= R$), else the kernel executes the EA.EL function Eq.~\ref{Log_H2}