1#!/usr/bin/env python
2# Copyright 2019 The Chromium Authors. All rights reserved.
3# Use of this source code is governed by a BSD-style license that can be
4# found in the LICENSE file.
5
6from __future__ import division
7from __future__ import print_function
8
9from array import array
10import os
11import random
12import shutil
13import sys
14
15MAX_INPUT_SIZE = 5000  # < 1 MB so we don't blow up fuzzer build sizes.
16MAX_FLOAT32 = 3.4028235e+38
17
18
19def IsValidSize(n):
20  if n == 0:
21    return False
22  # PFFFT only supports transforms for inputs of length N of the form
23  # N = (2^a)*(3^b)*(5^c) where a >= 5, b >=0, c >= 0.
24  FACTORS = [2, 3, 5]
25  factorization = [0, 0, 0]
26  for i, factor in enumerate(FACTORS):
27    while n % factor == 0:
28      n = n // factor
29      factorization[i] += 1
30  return factorization[0] >= 5 and n == 1
31
32
33def WriteFloat32ArrayToFile(file_path, size, generator):
34  """Generate an array of float32 values and writes to file."""
35  with open(file_path, 'wb') as f:
36    float_array = array('f', [generator() for _ in range(size)])
37    float_array.tofile(f)
38
39
40def main():
41  if len(sys.argv) < 2:
42    print('Usage: %s <path to output directory>' % sys.argv[0])
43    sys.exit(1)
44
45  output_path = sys.argv[1]
46  # Start with a clean output directory.
47  if os.path.exists(output_path):
48    shutil.rmtree(output_path)
49  os.makedirs(output_path)
50
51  # List of valid input sizes.
52  N = [n for n in range(MAX_INPUT_SIZE) if IsValidSize(n)]
53
54  # Set the seed to always generate the same random data.
55  random.seed(0)
56
57  # Generate different types of input arrays for each target length.
58  for n in N:
59    # Zeros.
60    WriteFloat32ArrayToFile(
61        os.path.join(output_path, 'zeros_%d' % n), n, lambda: 0)
62    # Max float 32.
63    WriteFloat32ArrayToFile(
64        os.path.join(output_path, 'max_%d' % n), n, lambda: MAX_FLOAT32)
65    # Random values in the s16 range.
66    rnd_s16 = lambda: 32768.0 * 2.0 * (random.random() - 0.5)
67    WriteFloat32ArrayToFile(
68        os.path.join(output_path, 'rnd_s16_%d' % n), n, rnd_s16)
69
70  sys.exit(0)
71
72
73if __name__ == '__main__':
74  main()
75