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## create_ladder_graph.py @b3834e5 — raw · history · blame

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43``` ```#!/usr/bin/env python """A ladder graph creation program. This is a python program that creates c source code that will generate CFGs that are ladder graphs. Ladder graphs are generally the worst case for a lot of dominance related algorithms (Dominance frontiers, etc), and often generate N^2 or worse behavior. One good use of this program is to test whether your linear time algorithm is really behaving linearly. """ import argparse def main(): parser = argparse.ArgumentParser(description=__doc__) parser.add_argument('rungs', type=int, help="Number of ladder rungs. Must be a multiple of 2") args = parser.parse_args() if (args.rungs % 2) != 0: print "Rungs must be a multiple of 2" return print "int ladder(int *foo, int *bar, int x) {" rung1 = xrange(0, args.rungs, 2) rung2 = xrange(1, args.rungs, 2) for i in rung1: print "rung1%d:" % i print "*foo = x++;" if i != rung1[-1]: print "if (*bar) goto rung1%d;" % (i+2) print "else goto rung2%d;" % (i+1) else: print "goto rung2%d;" % (i+1) for i in rung2: print "rung2%d:" % i print "*foo = x++;" if i != rung2[-1]: print "goto rung2%d;" % (i+2) else: print "return *foo;" print "}" if __name__ == '__main__': main() ```