Test the overhead of just calling a GL function. The Python script is
a helper to do multiple runs and compare the results.
diff --git a/progs/tests/api_speed.py b/progs/tests/api_speed.py
new file mode 100755
index 0000000..d2096762
--- /dev/null
+++ b/progs/tests/api_speed.py
@@ -0,0 +1,143 @@
+#!/usr/bin/env python2
+
+# (C) Copyright IBM Corporation 2004
+# All Rights Reserved.
+#
+# Permission is hereby granted, free of charge, to any person obtaining a
+# copy of this software and associated documentation files (the "Software"),
+# to deal in the Software without restriction, including without limitation
+# on the rights to use, copy, modify, merge, publish, distribute, sub
+# license, and/or sell copies of the Software, and to permit persons to whom
+# the Software is furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice (including the next
+# paragraph) shall be included in all copies or substantial portions of the
+# Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+# IBM AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+# IN THE SOFTWARE.
+#
+# Authors:
+# Ian Romanick <idr@us.ibm.com>
+
+
+# This script is used to run api_speed against several different libGL
+# libraries and compare the results. See the show_usage function for more
+# details on how to use it.
+
+
+import re, os, sys, getopt
+
+class results:
+ def process_file(self, f):
+ self.cycles = {}
+ self.iterations = -1
+
+ for line in f.readlines():
+ m = re.match("(\d+) calls to (.{20}) required (\d+) cycles.", line)
+
+ if self.iterations != -1 and int(m.group(1)) != self.iterations:
+ raise
+
+ # This could be done with lstrip, but the version of
+ # the Python library on my system doesn't have it.
+ # The installed version of Python is quite old. :(
+
+ temp = m.group(2)
+ function_name = None
+ for i in range(len(temp)):
+ if temp[i] != ' ':
+ function_name = temp[i:]
+ break
+
+ if function_name == None:
+ raise
+
+ self.cycles[ function_name ] = int(m.group(3))
+ self.iterations = int(m.group(1))
+
+
+ def show_results(self):
+ for name in self.cycles:
+ print "%s -> %f" % (name, float(self.cycles[name]) / self.iterations)
+
+
+ def compare_results(self, other):
+ for name in self.cycles:
+ if other.cycles.has_key(name):
+ a = float(self.cycles[name]) / self.iterations
+ b = float(other.cycles[name]) / other.iterations
+ p = (100.0 * b / a) - 100.0
+ print "%- 20s %7.2f - %7.2f = % -6.2f (%+.1f%%)" % (name, a, b, a - b, p)
+ return
+
+
+def make_execution_string(lib, iterations):
+ if lib == None:
+ return "./api_speed %u" % (iterations)
+ else:
+ return "LD_PRELOAD=%s ./api_speed %u" % (lib, iterations)
+
+
+def show_usage():
+ print """Usage: %s [-i iterations] {library ...}
+
+The full path to one or more libGL libraries (including the full name of the
+library) can be included on the command-line. Each library will be tested,
+and the results compared. The first library listed will be used as the
+"base line" for all comparisons.""" % (sys.argv[0])
+ sys.exit(1)
+
+
+if __name__ == '__main__':
+ try:
+ (args, trail) = getopt.getopt(sys.argv[1:], "i:")
+ except Exception,e:
+ show_usage()
+
+ iterations = 1000000
+ try:
+ for (arg,val) in args:
+ if arg == "-i":
+ iterations = int(val)
+ except Exception,e:
+ show_usage()
+
+
+ result_array = []
+ names = []
+
+
+ # If no libraries were specifically named, just run the test against
+ # the default system libGL.
+
+ if len(trail) == 0:
+ s = make_execution_string( None, iterations )
+ r = results()
+ r.process_file( os.popen(s) )
+ result_array.append(r)
+ else:
+ for lib in trail:
+ s = make_execution_string( lib, iterations )
+ r = results()
+ r.process_file( os.popen(s) )
+ names.append(lib)
+ result_array.append(r)
+
+
+ # If the test was only run against one library, just show the results
+ # of the test run. Otherwise, compare each successive run against
+ # the first run.
+
+ if len( result_array ) == 1:
+ result_array[0].show_results()
+ else:
+ for i in range(1, len( result_array )):
+ print "%s vs. %s" % (names[0], names[i])
+ result_array[0].compare_results( result_array[i] )
+ print ""