Add script to plot gather data

Signed-off-by: Rafael Ravedutti <rafaelravedutti@gmail.com>

util/plot_gather_data.py

@@ -0,0 +1,74 @@
+import matplotlib.pyplot as plt
+import sys
+
+filename = sys.argv[1]
+output_file = filename.replace(".txt", ".pdf")
+fig = plt.figure()
+ax = plt.axes()
+plot_data = {}
+
+status = 0 # No header found
+md_case = False
+stride = None
+dims = None
+freq = None
+cl_size = None
+vector_width = None
+cache_lines_per_gather = None
+
+with open(filename, 'r') as fp:
+    for line in fp.readlines():
+        line = line.strip()
+
+        if len(line) <= 0:
+            continue
+
+        if line.startswith("Stride,"):
+            status = 1
+            md_case = True if "Dims" in line else False
+            continue
+
+        if line.startswith("N,"):
+            status = 2
+            continue
+
+        assert status == 1 or status == 2, "Invalid input!"
+
+        if status == 1:
+            if md_case:
+                stride, dims, freq, cl_size, vector_width, cache_lines_per_gather = line.split(',')
+            else:
+                stride, freq, cl_size, vector_width, cache_lines_per_gather = line.split(',')
+
+            stride = int(stride)
+            continue
+
+        if md_case:
+            N, size, total_time, time_per_it, cy_per_iter, cy_per_gather, cy_per_elem  = line.split(',')
+        else:
+            N, size, total_time, time_per_it, cy_per_gather, cy_per_elem  = line.split(',')
+
+        size = float(size)
+        cycles = float(cy_per_iter) if md_case else float(cy_per_gather)
+
+        if stride not in plot_data:
+            plot_data[stride] = {}
+
+        plot_data[stride][size] = cycles if size not in plot_data[stride] \
+                                  else min(cycles, plot_data[stride][size])
+
+for stride in plot_data:
+    sizes = list(plot_data[stride].keys())
+    sizes.sort()
+    cycles = [plot_data[stride][size] for size in sizes]
+    ax.plot(sizes, cycles, marker='.', label=str(stride))
+
+cy_label = "Cycles per iteration" if md_case else "Cycles per gather"
+ax.vlines([32, 1000], 0, 1, transform=ax.get_xaxis_transform(), linestyles='dashed', color=['#444444', '#777777'])
+#ax.vlines([32, 1000, 28000], 0, 1, transform=ax.get_xaxis_transform(), linestyles='dashed', color=['#444444', '#777777', '#aaaaaa'])
+ax.set(xlabel='Array size (kB)', ylabel=cy_label)
+ax.set_xscale('log')
+#ax.set_xticks([32, 1000, 28000])
+#ax.set_xlim(0, 200000)
+plt.legend(title="Stride")
+fig.savefig(output_file, bbox_inches = 'tight', pad_inches = 0)