Add note on how to overwrite compiler flags set by ExaHyPE Makefile.

e0_performance-studies.tex

@@ -229,7 +229,7 @@ MODE            = RELEASE
 DISTRIBUTEDMEM  = NONE
 SHAREDMEM       = TBB
 USE_IPO         = on
-COMPILER_CFLAGS = "" 
+PROJECT_CFLAGS  = "" 
 
 [parameters]
 ; a job is created for each configuration
@@ -266,7 +266,7 @@ lowPrioJobProcessing   = run_if_no_high_priority_job_left
 
 The matching specification file template is given below.
 It has to be in the novel \exahype\ JSON specification file format.
-You can generate the new format with the \texttt{-s} switch from
+You can generate the new format with the \texttt{-j} switch from
 the original \exahype\ specification file format.
 
 \begin{code}
@@ -427,16 +427,29 @@ export I_MPI_FABRICS="tmi"
 {{body}}
 \end{code}
 
+\section{Overwriting default compiler flags}
+
+To overwrite default compiler flags such as \texttt{-O3}, \texttt{-xHost}, or \texttt{-xCore-AVX}
+which will be added by \exahype\'s Makefile,
+create an environment variable \texttt{PROJECT\_CFLAGS} in the \texttt{[environment]}
+section in your \texttt{ini} file and add all flags to the right hand side, e.g.:
+\begin{code}
+PROJECT_CFLAGS="-g -no-vec -no-simd"
+\end{code}
+The flags specified here will be appended to the default compiler flags.
+Therefore, they overwrite the preceding compiler flags.
+
 \section{Supercomputer build environments and job script templates}
 You find build environments for a range of supercomputers in the 
-\texttt{ExaHyPE-Engine/Benchmarks/environment} subfolder.
+\texttt{ExaHyPE-Engine}\texttt{/Benchmarks/environment} subfolder.
 You find job templates for a range of supercomputers in the 
-\texttt{ExaHyPE-Engine/Benchmarks/job-templates} subfolder.
+\texttt{ExaHyPE-Engine}\texttt{/Benchmarks/job-templates} subfolder.
 
 \section{Further post-processing of CSV tables}
 
 You can find further useful tools in the \texttt{ExaHyPE-Engine/Benchmarks/python}
 for post-processing the CSV tables generated by \texttt{sweep.py}.
+It is often convenient to symlink them directly into your project folder.
 
 The \texttt{tableslicer.py} tool provides the following options:
 \begin{code}