diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index 11132fe7319..820b029a783 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,3 +1,15 @@ +2013-12-22 Hans-Peter Nilsson + + * testsuite/20_util/hash/chi2_quality.h: Break out from + chi2_quality.cc. + * testsuite/20_util/hash/chi2_q_bit_flip_set.cc: Ditto. + * testsuite/20_util/hash/chi2_q_document_words.cc: Ditto. + * testsuite/20_util/hash/chi2_q_bit_string_set.cc: Ditto. Increase + SAMPLES to 35000 for simulator targets. + * testsuite/20_util/hash/chi2_q_numeric_pattern_set.cc: Ditto. + * testsuite/20_util/hash/chi2_q_uniform_random.cc: Ditto. + * testsuite/20_util/hash/chi2_quality.cc: Remove. + 2013-12-10 Paolo Carlini * testsuite/20_util/is_base_of/value.cc: Add test. diff --git a/libstdc++-v3/testsuite/20_util/hash/chi2_q_bit_flip_set.cc b/libstdc++-v3/testsuite/20_util/hash/chi2_q_bit_flip_set.cc new file mode 100644 index 00000000000..4d4f183bb17 --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/hash/chi2_q_bit_flip_set.cc @@ -0,0 +1,61 @@ +// { dg-options "-std=gnu++0x" } +// Use smaller statistics when running on simulators, so it takes less time. +// { dg-options "-std=gnu++0x -DSAMPLES=30000" { target simulator } } + +// Copyright (C) 2010-2013 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. +// +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. +// +// You should have received a copy of the GNU General Public License +// along with this library; see the file COPYING3. If not see +// . + +#include "chi2_quality.h" + +// Tests chi^2 for a distribution of strings that differ from each +// other by only a few bits. We start with an arbitrary base string, and +// flip three random bits for each member of the set. +void +test_bit_flip_set() +{ + bool test __attribute__((unused)) = true; + const unsigned long N = SAMPLES; + const unsigned long k = N/100; + const unsigned int len = 67; + const unsigned int bitlen = len * 8; + const unsigned int bits_to_flip = 3; + const char base[len+1] = "abcdefghijklmnopqrstuvwxyz" + "ABCDEFGHIJKLMNOPQRSTUVWXYZ" + "0123456789!@#$%"; + + std::unordered_set set; + while (set.size() < N) + { + std::string s(base, base+len); + for (unsigned int i = 0; i < bits_to_flip; ++i) + { + int bit = rand() % bitlen; + s[bit/8] ^= (1 << (bit%8)); + } + set.insert(s); + } + + double chi2 = chi2_hash(set, k); + VERIFY( chi2 < k*1.1 ); +} + +int +main() +{ + test_bit_flip_set(); + return 0; +} diff --git a/libstdc++-v3/testsuite/20_util/hash/chi2_q_bit_string_set.cc b/libstdc++-v3/testsuite/20_util/hash/chi2_q_bit_string_set.cc new file mode 100644 index 00000000000..6fb90120ac3 --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/hash/chi2_q_bit_string_set.cc @@ -0,0 +1,55 @@ +// { dg-options "-std=gnu++0x" } +// Use smaller statistics when running on simulators, so it takes less time. +// For e.g. cris-elf, mipsisa32r2el-elf, powerpc-eabi and i386-linux-gnu, +// this test fails for SAMPLES=30000. +// { dg-options "-std=gnu++0x -DSAMPLES=35000" { target simulator } } + +// Copyright (C) 2010-2013 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. +// +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. +// +// You should have received a copy of the GNU General Public License +// along with this library; see the file COPYING3. If not see +// . + +#include "chi2_quality.h" + +// Tests chi^2 for a set of strings that all consist of '1' and '0'. +void +test_bit_string_set() +{ + bool test __attribute__((unused)) = true; + const unsigned long N = SAMPLES; + const unsigned long k = N/100; + std::vector set; + std::string s; + for (unsigned long i = 0; i < N; ++i) + { + s.clear(); + for (unsigned int j = 0; j < sizeof(unsigned long) * 8; ++j) + { + const bool bit = (1UL << j) & i; + s.push_back(bit ? '1' : '0'); + } + set.push_back(s); + } + + double chi2 = chi2_hash(set, k); + VERIFY( chi2 < k*1.1 ); +} + +int +main() +{ + test_bit_string_set(); + return 0; +} diff --git a/libstdc++-v3/testsuite/20_util/hash/chi2_q_document_words.cc b/libstdc++-v3/testsuite/20_util/hash/chi2_q_document_words.cc new file mode 100644 index 00000000000..befd3c83ccc --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/hash/chi2_q_document_words.cc @@ -0,0 +1,52 @@ +// On some simulators, the workload is simply too large with values big +// enough for the test to pass the quality test, so just skip it altogether. +// { dg-do run { target { ! simulator } } } +// { dg-options "-std=gnu++0x" } + +// Copyright (C) 2010-2013 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. +// +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. +// +// You should have received a copy of the GNU General Public License +// along with this library; see the file COPYING3. If not see +// . + +#include "chi2_quality.h" + +// Tests chi^2 for a set of words taken from a document written in English. +void +test_document_words() +{ + bool test __attribute__((unused)) = true; + const std::string f_name = "thirty_years_among_the_dead_preproc.txt"; + std::ifstream in(f_name); + VERIFY( in.is_open() ); + std::vector words; + words.assign(std::istream_iterator(in), + std::istream_iterator()); + VERIFY( words.size() > 100000 ); + std::sort(words.begin(), words.end()); + auto it = std::unique(words.begin(), words.end()); + words.erase(it, words.end()); + VERIFY( words.size() > 5000 ); + + const unsigned long k = words.size() / 20; + double chi2 = chi2_hash(words, k); + VERIFY( chi2 < k*1.1 ); +} + +int +main() +{ + test_document_words(); + return 0; +} diff --git a/libstdc++-v3/testsuite/20_util/hash/chi2_q_numeric_pattern_set.cc b/libstdc++-v3/testsuite/20_util/hash/chi2_q_numeric_pattern_set.cc new file mode 100644 index 00000000000..2819ec24727 --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/hash/chi2_q_numeric_pattern_set.cc @@ -0,0 +1,52 @@ +// { dg-options "-std=gnu++0x" } +// Use smaller statistics when running on simulators, so it takes less time. +// For x86_64-linux-gnu SAMPLES=30000 fails, so increase slightly. +// { dg-options "-std=gnu++0x -DSAMPLES=35000" { target simulator } } + +// Copyright (C) 2010-2013 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. +// +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. +// +// You should have received a copy of the GNU General Public License +// along with this library; see the file COPYING3. If not see +// . + +#include "chi2_quality.h" + +// Tests chi^2 of a set of strings that all have a similar pattern, +// intended to mimic some sort of ID string. +void +test_numeric_pattern_set() +{ + bool test __attribute__((unused)) = true; + const unsigned long N = SAMPLES; + const unsigned long k = N/100; + std::vector set; + for (unsigned long i = 0; i < N; ++i) + { + long i1 = i % 100000; + long i2 = i / 100000; + char buf[16]; + std::sprintf(buf, "XX-%05lu-%05lu", i1, i2); + set.push_back(buf); + } + + double chi2 = chi2_hash(set, k); + VERIFY( chi2 < k*1.1 ); +} + +int +main() +{ + test_numeric_pattern_set(); + return 0; +} diff --git a/libstdc++-v3/testsuite/20_util/hash/chi2_q_uniform_random.cc b/libstdc++-v3/testsuite/20_util/hash/chi2_q_uniform_random.cc new file mode 100644 index 00000000000..5440fe3f2ef --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/hash/chi2_q_uniform_random.cc @@ -0,0 +1,53 @@ +// { dg-options "-std=gnu++0x" } +// Use smaller statistics when running on simulators, so it takes less time. +// For powerpc-eabi, SAMPLES=30000 fails. +// { dg-options "-std=gnu++0x -DSAMPLES=35000" { target simulator } } + +// Copyright (C) 2010-2013 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. +// +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. +// +// You should have received a copy of the GNU General Public License +// along with this library; see the file COPYING3. If not see +// . + +#include "chi2_quality.h" + +// Tests chi^2 for a distribution of uniformly generated random strings. +void +test_uniform_random() +{ + bool test __attribute__((unused)) = true; + std::srand(137); + std::unordered_set set; + std::string s; + const unsigned long N = SAMPLES; + const unsigned long k = N/100; + const unsigned int len = 25; + while (set.size() < N) + { + s.clear(); + for (unsigned int i = 0; i < len; ++i) + s.push_back(rand() % 128); + set.insert(s); + } + + double chi2 = chi2_hash(set, k); + VERIFY( chi2 < k*1.1 ); +} + +int +main() +{ + test_uniform_random(); + return 0; +} diff --git a/libstdc++-v3/testsuite/20_util/hash/chi2_quality.cc b/libstdc++-v3/testsuite/20_util/hash/chi2_quality.cc deleted file mode 100644 index 4e50da0ff3f..00000000000 --- a/libstdc++-v3/testsuite/20_util/hash/chi2_quality.cc +++ /dev/null @@ -1,218 +0,0 @@ -// { dg-options "-std=gnu++0x" } - -// Use smaller statistics when running on simulators, so it takes less time. -// { dg-options "-std=gnu++0x -DSAMPLES=30000" { target simulator } } - -// Copyright (C) 2010-2013 Free Software Foundation, Inc. -// -// This file is part of the GNU ISO C++ Library. This library is free -// software; you can redistribute it and/or modify it under the -// terms of the GNU General Public License as published by the -// Free Software Foundation; either version 3, or (at your option) -// any later version. -// -// This library is distributed in the hope that it will be useful, -// but WITHOUT ANY WARRANTY; without even the implied warranty of -// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -// GNU General Public License for more details. -// -// You should have received a copy of the GNU General Public License -// along with this library; see the file COPYING3. If not see -// . - -// This file uses the chi^2 test to measure the quality of a hash -// function, by computing the uniformity with which it distributes a set -// of N strings into k buckets (where k is significantly greater than N). -// -// Each bucket has B[i] strings in it. The expected value of each bucket -// for a uniform distribution is z = N/k, so -// chi^2 = Sum_i (B[i] - z)^2 / z. -// -// We check whether chi^2 is small enough to be consistent with the -// hypothesis of a uniform distribution. If F(chi^2, k-1) is close to -// 0 (where F is the cumulative probability distribution), we can -// reject that hypothesis. So we don't want F to be too small, which -// for large k, means we want chi^2 to be not too much larger than k. -// -// We use the chi^2 test for several sets of strings. Any non-horrible -// hash function should do well with purely random strings. A really -// good hash function will also do well with more structured sets, -// including ones where the strings differ by only a few bits. - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#ifndef SAMPLES -#define SAMPLES 300000 -#endif - -template - double - chi2_hash(const Container& c, long buckets) - { - std::vector counts(buckets); - std::hash hasher; - double elements = 0; - for (auto i = c.begin(); i != c.end(); ++i) - { - ++counts[hasher(*i) % buckets]; - ++elements; - } - - const double z = elements / buckets; - double sum = 0; - for (long i = 0; i < buckets; ++i) - { - double delta = counts[i] - z; - sum += delta*delta; - } - return sum/z; - } - -// Tests chi^2 for a distribution of uniformly generated random strings. -void -test_uniform_random() -{ - bool test __attribute__((unused)) = true; - std::srand(137); - std::unordered_set set; - std::string s; - const unsigned long N = SAMPLES; - const unsigned long k = N/100; - const unsigned int len = 25; - while (set.size() < N) - { - s.clear(); - for (unsigned int i = 0; i < len; ++i) - s.push_back(rand() % 128); - set.insert(s); - } - - double chi2 = chi2_hash(set, k); - VERIFY( chi2 < k*1.1 ); -} - -// Tests chi^2 for a distribution of strings that differ from each -// other by only a few bits. We start with an arbitrary base string, and -// flip three random bits for each member of the set. -void -test_bit_flip_set() -{ - bool test __attribute__((unused)) = true; - const unsigned long N = SAMPLES; - const unsigned long k = N/100; - const unsigned int len = 67; - const unsigned int bitlen = len * 8; - const unsigned int bits_to_flip = 3; - const char base[len+1] = "abcdefghijklmnopqrstuvwxyz" - "ABCDEFGHIJKLMNOPQRSTUVWXYZ" - "0123456789!@#$%"; - - std::unordered_set set; - while (set.size() < N) - { - std::string s(base, base+len); - for (unsigned int i = 0; i < bits_to_flip; ++i) - { - int bit = rand() % bitlen; - s[bit/8] ^= (1 << (bit%8)); - } - set.insert(s); - } - - double chi2 = chi2_hash(set, k); - VERIFY( chi2 < k*1.1 ); -} - -// Tests chi^2 of a set of strings that all have a similar pattern, -// intended to mimic some sort of ID string. -void -test_numeric_pattern_set() -{ - bool test __attribute__((unused)) = true; - const unsigned long N = SAMPLES; - const unsigned long k = N/100; - std::vector set; - for (unsigned long i = 0; i < N; ++i) - { - long i1 = i % 100000; - long i2 = i / 100000; - char buf[16]; - std::sprintf(buf, "XX-%05lu-%05lu", i1, i2); - set.push_back(buf); - } - - double chi2 = chi2_hash(set, k); - VERIFY( chi2 < k*1.1 ); -} - -// Tests chi^2 for a set of strings that all consist of '1' and '0'. -void -test_bit_string_set() -{ - bool test __attribute__((unused)) = true; - const unsigned long N = SAMPLES; - const unsigned long k = N/100; - std::vector set; - std::string s; - for (unsigned long i = 0; i < N; ++i) - { - s.clear(); - for (unsigned int j = 0; j < sizeof(unsigned long) * 8; ++j) - { - const bool bit = (1UL << j) & i; - s.push_back(bit ? '1' : '0'); - } - set.push_back(s); - } - - double chi2 = chi2_hash(set, k); - VERIFY( chi2 < k*1.1 ); -} - -// Tests chi^2 for a set of words taken from a document written in English. -void -test_document_words() -{ - // That file is 187587 single-word lines. To avoid a timeout, just skip - // this part, which would take up to 95% of the program runtime (with - // SAMPLES == 10000), if we're not supposed to run anywhere that long. -#if SAMPLES >= 100000 - bool test __attribute__((unused)) = true; - const std::string f_name = "thirty_years_among_the_dead_preproc.txt"; - std::ifstream in(f_name); - VERIFY( in.is_open() ); - std::vector words; - words.assign(std::istream_iterator(in), - std::istream_iterator()); - VERIFY( words.size() > 100000 ); - std::sort(words.begin(), words.end()); - auto it = std::unique(words.begin(), words.end()); - words.erase(it, words.end()); - VERIFY( words.size() > 5000 ); - - const unsigned long k = words.size() / 20; - double chi2 = chi2_hash(words, k); - VERIFY( chi2 < k*1.1 ); -#endif -} - -int -main() -{ - test_uniform_random(); - test_bit_flip_set(); - test_numeric_pattern_set(); - test_bit_string_set(); - test_document_words(); - return 0; -} diff --git a/libstdc++-v3/testsuite/20_util/hash/chi2_quality.h b/libstdc++-v3/testsuite/20_util/hash/chi2_quality.h new file mode 100644 index 00000000000..09da79926ac --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/hash/chi2_quality.h @@ -0,0 +1,74 @@ +// Copyright (C) 2010-2013 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. +// +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. +// +// You should have received a copy of the GNU General Public License +// along with this library; see the file COPYING3. If not see +// . + +// This file uses the chi^2 test to measure the quality of a hash +// function, by computing the uniformity with which it distributes a set +// of N strings into k buckets (where k is significantly greater than N). +// +// Each bucket has B[i] strings in it. The expected value of each bucket +// for a uniform distribution is z = N/k, so +// chi^2 = Sum_i (B[i] - z)^2 / z. +// +// We check whether chi^2 is small enough to be consistent with the +// hypothesis of a uniform distribution. If F(chi^2, k-1) is close to +// 0 (where F is the cumulative probability distribution), we can +// reject that hypothesis. So we don't want F to be too small, which +// for large k, means we want chi^2 to be not too much larger than k. +// +// We use the chi^2 test for several sets of strings. Any non-horrible +// hash function should do well with purely random strings. A really +// good hash function will also do well with more structured sets, +// including ones where the strings differ by only a few bits. + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#ifndef SAMPLES +#define SAMPLES 300000 +#endif + +template + double + chi2_hash(const Container& c, long buckets) + { + std::vector counts(buckets); + std::hash hasher; + double elements = 0; + for (auto i = c.begin(); i != c.end(); ++i) + { + ++counts[hasher(*i) % buckets]; + ++elements; + } + + const double z = elements / buckets; + double sum = 0; + for (long i = 0; i < buckets; ++i) + { + double delta = counts[i] - z; + sum += delta*delta; + } + return sum/z; + }