New GPU example

docs/src/gettingstarted.tex

@@ -422,24 +422,21 @@ call P%build(A,desc_A,info)
 The code discussed here  shows how to set  up a
 program exploiting the combined GPU capabilities of PSBLAS and
 AMG4PSBLAS. The code example is available in the source distribution
-directory \verb|amg4psblas/tests/gpu|. 
+directory \verb|amg4psblas/examples/gpu|. 
 
 First of all, we need to include the appropriate modules and
 declare some auxiliary variables:
 \begin{listing}[h!]
 \ifpdf
 \begin{minted}[breaklines=true,bgcolor=bg,fontsize=\small]{fortran}
-program amg_d_pde3d
+program amg_dexample_gpu
   use psb_base_mod
   use amg_prec_mod
   use psb_krylov_mod
   use psb_util_mod
   use psb_gpu_mod
   use data_input
-  use amg_d_pde3d_base_mod
-  use amg_d_pde3d_exp_mod
-  use amg_d_pde3d_gauss_mod
-  use amg_d_genpde_mod
+  use amg_d_pde_mod
   implicit none
   .......
   ! GPU variables
@@ -452,17 +449,14 @@ program amg_d_pde3d
 \begin{minipage}{.90\textwidth}
 {\small
 \begin{verbatim}
-program amg_d_pde3d
+program amg_dexample_gpu
   use psb_base_mod
   use amg_prec_mod
   use psb_krylov_mod
   use psb_util_mod
   use psb_gpu_mod
   use data_input
-  use amg_d_pde3d_base_mod
-  use amg_d_pde3d_exp_mod
-  use amg_d_pde3d_gauss_mod
-  use amg_d_genpde_mod
+  use amg_d_pde_mod
   implicit none
   .......
   ! GPU variables
@@ -477,6 +471,9 @@ program amg_d_pde3d
 \fi
 \caption{setup of a GPU-enabled test program part one.\label{fig:gpu-ex1}}
 \end{listing}
+In this particular example we are choosing to employ a \verb|HLG| data
+structure for sparse matrices on GPUs; for more information please
+refer to the PSBLAS-EXT users' guide.
 
 We then have to initialize the GPU environment, and pass the
 appropriate MOLD variables to the build methods (see also the PSBLAS