50 lines · python
1#!/usr/bin/env python2"""A ladder graph creation program.3 4This is a python program that creates c source code that will generate5CFGs that are ladder graphs. Ladder graphs are generally the worst case6for a lot of dominance related algorithms (Dominance frontiers, etc),7and often generate N^2 or worse behavior.8 9One good use of this program is to test whether your linear time algorithm is10really behaving linearly.11"""12 13from __future__ import print_function14 15import argparse16 17 18def main():19 parser = argparse.ArgumentParser(description=__doc__)20 parser.add_argument(21 "rungs", type=int, help="Number of ladder rungs. Must be a multiple of 2"22 )23 args = parser.parse_args()24 if (args.rungs % 2) != 0:25 print("Rungs must be a multiple of 2")26 return27 print("int ladder(int *foo, int *bar, int x) {")28 rung1 = range(0, args.rungs, 2)29 rung2 = range(1, args.rungs, 2)30 for i in rung1:31 print("rung1%d:" % i)32 print("*foo = x++;")33 if i != rung1[-1]:34 print("if (*bar) goto rung1%d;" % (i + 2))35 print("else goto rung2%d;" % (i + 1))36 else:37 print("goto rung2%d;" % (i + 1))38 for i in rung2:39 print("rung2%d:" % i)40 print("*foo = x++;")41 if i != rung2[-1]:42 print("goto rung2%d;" % (i + 2))43 else:44 print("return *foo;")45 print("}")46 47 48if __name__ == "__main__":49 main()50