Update Gray Scott performances

Performances/G++9.3.0/grayscott_seqIntrinsics.gnuplot

+set terminal png notransparent crop enhanced size 800,600 font "arial,14"
+set grid xtics ytics mytics
+set key out vert center top
+set logscale y
+set xlabel "nb elements"
+set ylabel "elapsed time per element [ns/el]"
+set output "grayscott_seqIntrinsicsElapsedTimeCyEl.png"
+plot "perf_grayscott_seq_vectorize_O1.txt" using 1:2:($2-$4):($2+$4) title "perf grayscott seq vectorize O1" with yerrorlines lw 2,"perf_grayscott_seq_vectorize_Ofast.txt" using 1:2:($2-$4):($2+$4) title "perf grayscott seq vectorize Ofast" with yerrorlines lw 2,"perf_grayscott_seq_intrinsics_O1.txt" using 1:2:($2-$4):($2+$4) title "perf grayscott seq intrinsics O1" with yerrorlines lw 2,"perf_grayscott_seq_intrinsics_O2.txt" using 1:2:($2-$4):($2+$4) title "perf grayscott seq intrinsics O2" with yerrorlines lw 2,"perf_grayscott_seq_intrinsics_O3.txt" using 1:2:($2-$4):($2+$4) title "perf grayscott seq intrinsics O3" with yerrorlines lw 2,"perf_grayscott_seq_intrinsics_Ofast.txt" using 1:2:($2-$4):($2+$4) title "perf grayscott seq intrinsics Ofast" with yerrorlines lw 2,
+set xlabel "nb elements"
+set ylabel "elapsed time [ns]"
+set output "grayscott_seqIntrinsicsElapsedTime.png"
+plot "perf_grayscott_seq_vectorize_O1.txt" using 1:3:($3-$5):($3+$5) title "perf grayscott seq vectorize O1" with yerrorlines lw 2,"perf_grayscott_seq_vectorize_Ofast.txt" using 1:3:($3-$5):($3+$5) title "perf grayscott seq vectorize Ofast" with yerrorlines lw 2,"perf_grayscott_seq_intrinsics_O1.txt" using 1:3:($3-$5):($3+$5) title "perf grayscott seq intrinsics O1" with yerrorlines lw 2,"perf_grayscott_seq_intrinsics_O2.txt" using 1:3:($3-$5):($3+$5) title "perf grayscott seq intrinsics O2" with yerrorlines lw 2,"perf_grayscott_seq_intrinsics_O3.txt" using 1:3:($3-$5):($3+$5) title "perf grayscott seq intrinsics O3" with yerrorlines lw 2,"perf_grayscott_seq_intrinsics_Ofast.txt" using 1:3:($3-$5):($3+$5) title "perf grayscott seq intrinsics Ofast" with yerrorlines lw 2,