karatsuba.py

#! /usr/bin/python3 -B
#
# Copyright (c) 2018-2019 Gavin D. Howard and contributors.
#
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice, this
#   list of conditions and the following disclaimer.
#
# * Redistributions in binary form must reproduce the above copyright notice,
#   this list of conditions and the following disclaimer in the documentation
#   and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
#

import os
import sys
import subprocess
import time

def usage():
	print("usage: {} [test_num exe]".format(script))
	print("\n    test_num is the last Karatsuba number to run through tests")
	sys.exit(1)

script = sys.argv[0]
testdir = os.path.dirname(script)

print("\nWARNING: This script is for distro and package maintainers.")
print("It is for finding the optimal Karatsuba number.")
print("It takes forever to run.")
print("You have been warned.\n")

if __name__ != "__main__":
	usage()

mx = 520
mx2 = mx // 2
mn = 16

num = "9" * mx

if len(sys.argv) >= 2:
	test_num = int(sys.argv[1])
else:
	test_num = 0

if len(sys.argv) >= 3:
	exe = sys.argv[2]
else:
	exe = testdir + "/bin/bc"

exedir = os.path.dirname(exe)

indata = "for (i = 0; i < 100; ++i) {} * {}\n1.23456789^10000\nhalt".format(num, num)

times = []
nums = []
runs = []
nruns = 5

for i in range(0, nruns):
	runs.append(0)

tests = [ "multiply", "modulus", "power", "sqrt" ]

for i in range(mn, mx2 + 1):

	print("\nCompiling...\n")

	makecmd = [ "./configure.sh", "-O3", "-k{}".format(i) ]
	p = subprocess.run(makecmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)

	if p.returncode != 0:
		print("configure.sh returned an error ({}); exiting...".format(p.returncode))
		sys.exit(p.returncode)

	makecmd = [ "make" ]
	p = subprocess.run(makecmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)

	if p.returncode != 0:
		print("make returned an error ({}); exiting...".format(p.returncode))
		sys.exit(p.returncode)

	if (test_num >= i):

		print("Running tests...\n")

		for test in tests:

			cmd = [ "{}/tests/test.sh".format(testdir), "bc", test, "0", exe ]

			p = subprocess.run(cmd + sys.argv[3:], stderr=subprocess.PIPE)

			if p.returncode != 0:
				print("{} test failed:\n".format(test, p.returncode))
				print(p.stderr.decode())
				print("\nexiting...")
				sys.exit(p.returncode)

		print("")

	elif test_num == 0:

		print("Timing Karatsuba Num: {}".format(i), end='', flush=True)

		for j in range(0, nruns):

			cmd = [ exe, "{}/tests/bc/power.txt".format(testdir) ]

			start = time.perf_counter()
			p = subprocess.run(cmd, input=indata.encode(), stdout=subprocess.PIPE, stderr=subprocess.PIPE)
			end = time.perf_counter()

			if p.returncode != 0:
				print("bc returned an error; exiting...")
				sys.exit(p.returncode)

			runs[j] = end - start

		run_times = runs[1:]
		avg = sum(run_times) / len(run_times)

		times.append(avg)
		nums.append(i)
		print(", Time: {}".format(times[i - mn]))

opt = nums[times.index(min(times))]

print("\nOptimal Karatsuba Num (for this machine): {}".format(opt))
print("Run the following:\n")
print("./configure.sh -O3 -k {}".format(opt))
print("make")